COMPRESSOR

Abstract

A compressor includes two rotors opposed to each other in an axial direction, and a vane contacting the rotors. While the vane is moved in the axial direction with rotation of the rotors, the vane is restricted from rotating by a vane groove. The compressor includes compression chambers in which suction and compression of fluid are performed with rotation of the rotors, and a communication mechanism switched between a communicating state in which the compression chambers communicate with each other, and a non-communicating state in which the compression chambers do not communicate with each other.

Description

BACKGROUND

The present disclosure relates to a compressor.

Japanese Laid-Open Patent Publication No. 51-97006 describes a compressor including a rotary shaft, rotors rotated with rotation of the rotary shaft, a vane moving in the axial direction of the rotary shaft with rotation of the rotors, and compression chambers. In this compressor, by rotating the rotors, fluid is drawn into the compression chambers, and the fluid is compressed in the compression chambers. This document mentions that suction and compression of the fluid are independently performed in two compression chambers that are provided to correspond to the two rotors.

There is still room for improvement for the above-described compressor in which suction and compression of the fluid are performed in the two compression chambers while the vane moves in the axial direction of the rotary shaft with the rotation of the rotors.

SUMMARY

An object of the present disclosure is to provide a compressor that efficiently compresses fluid by using two compression chambers.

In accordance with a first aspect of the present disclosure, a compressor is provided that includes: a rotary shaft; a first rotor including a ring-shaped first rotor surface, and rotated with rotation of the rotary shaft; a second rotor opposed to the first rotor in an axial direction of the rotary shaft, rotated with the rotation of the rotary shaft, and including a ring-shaped second rotor surface; a first cylindrical portion including a first inner circumferential surface opposed to an outer circumferential surface of the first rotor in a radial direction of the rotary shaft, and housing the first rotor; a second cylindrical portion including a second inner circumferential surface opposed to an outer circumferential surface of the second rotor in the radial direction, and housing the second rotor; a wall portion arranged between the rotors, and including a first wall surface opposed to the first rotor surface in the axial direction, and a second wall surface opposed to the second rotor surface in the axial direction; a vane contacting the rotor surfaces in a state where the vane is inserted into a vane groove formed in the wall portion, and moving in the axial direction with rotation of the rotors; a first compression chamber formed by the first rotor surface, the first wall surface, and the first inner circumferential surface, a volume change of the first compression chamber being caused by the vane with rotation of the first rotor, such that suction and compression of fluid are performed; a second compression chamber formed by the second rotor surface, the second wall surface, and the second inner circumferential surface, a volume change of the second compression chamber being caused by the vane with rotation of the second rotor, such that suction and compression of the fluid are performed; and a communication mechanism switched between a communicating state in which the first compression chamber and the second compression chamber communicate with each other, and a non-communicating state in which the first compression chamber and the second compression chamber do not communicate with each other.

Other aspects and advantages of the present disclosure will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating exemplary embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure may be understood by reference to the following description together with the accompanying drawings:

FIG. 1 is a cross-sectional view showing an outline of a compressor;

FIG. 2 is an exploded perspective view of a main configuration;

FIG. 3 is an exploded perspective view of the main configuration seen from the opposite side from FIG. 2;

FIG. 4 is a partial enlarged view of FIG. 1;

FIG. 5 is a cross-sectional view of the rotors, a vane, and a rear cylinder;

FIG. 6 is cross-sectional view taken along line 6-6 in FIG. 5;

FIG. 7 is a bottom view, with a part cut away, of the main configuration in a state where a part of the cylinders;

FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 4 in a non-communicating state;

FIG. 9 is a cross-sectional view taken along line 8-8 in FIG. 4 in a communicating state;

FIG. 10A is a cross-sectional view showing the rotors and their surroundings;

FIG. 10B is a development view showing the situation of the rotors and the vane in the state of FIG. 10A;

FIG. 11A is a cross-sectional view showing the rotors and their surroundings;

FIG. 11B is a development view showing the situation of the rotors and the vane in the state of FIG. 11A;

FIG. 12 is graph showing the volume change of a first embodiment;

FIG. 13 is a cross-sectional view schematically showing the outline of a compressor of a second embodiment;

FIG. 14 is a cross-sectional view for describing the communication mechanism of the second embodiment;

FIG. 15 is a development view showing a situation of the rotors and the vane;

FIG. 16 is a development view showing a situation of the rotors and the vane;

FIG. 17A is a graph showing the volume change of the second embodiment, and the like;

FIG. 17B is a time chart showing a state of an open/close portion;

FIG. 17C is a time chart showing a state of the communication mechanism;

FIG. 18 is a schematic diagram showing a modification of the communication mechanism; and

FIG. 19 is a schematic diagram showing a modification of the communication mechanism.

DETAILED DESCRIPTION

First Embodiment

A compressor according to a first embodiment will now be described with reference to FIGS. 1 to 12. The compressor of the first embodiment is mounted on and used in a vehicle. The compressor is used for a vehicle air-conditioner. The fluid to be compressed by the compressor is refrigerant including oil. FIGS. 1 and 4 show side views of a rotary shaft 12 and the rotors 60 and 80.

As shown in FIG. 1, a compressor 10 includes a housing 11, a rotary shaft 12, an electric motor 13, an inverter 14, a front cylinder 40, a rear cylinder 50, a front rotor 60 as a first rotor, and rear rotor 80 as a second rotor. The housing 11 has a generally tubular shape, and includes a suction port 11a through which a suction fluid is drawn in from the outside, and a discharge port 11b from which the fluid is discharged. The rotary shaft 12, the electric motor 13, the inverter 14, the cylinders 40 and 50, and the rotors 60 and 80 are housed in the housing 11.

The housing 11 includes a front housing member 21, a rear housing member 22, and an inverter cover 23. The front housing member 21 has a tubular shape with a closed end, and is opened toward the rear housing member 22. The suction port 11a is provided at a position between an open end and the bottom in a side wall portion of the front housing member 21. However, the position of the suction port 11a is arbitrary. The rear housing member 22 has a tubular shape with a closed end, and is opened toward the front housing member 21. The discharge port lib is provided in a side surface of the bottom of the rear housing member 22. The position of the discharge port 11b is arbitrary.

The front housing member 21 and the rear housing member 22 are unitized with their openings opposed to each other. The inverter cover 23 is arranged in the bottom of the front housing member 21, which is the opposite side from the rear housing member 22. The inverter cover 23 is fixed to the front housing member 21 with being butted to the bottom of the front housing member 21.

The inverter 14 is housed in the inverter cover 23. The inverter 14 drives the electric motor 13. The rotary shaft 12 is supported by the housing 11 in a rotatable state. A ring-shaped first bearing holding part 31 protruding from the bottom is provided in the bottom of the front housing member 21. A first radial bearing 32, which rotationally supports a first end of the rotary shaft 12, is provided inside in the radial direction of the first bearing holding part 31. A ring-shaped second bearing holding part 33 protruding from the bottom is provided in the bottom of the rear housing member 22. A second radial bearing 34 is also provided inside the radial direction of the second bearing holding part 33. The second radial bearing 34 rotationally supports the second end of the rotary shaft 12, which is on the opposite side from the first end. The axial direction Z of the rotary shaft 12 matches the axial direction of the housing 11.

As shown in FIGS. 1 to 4, the front cylinder 40 houses the front rotor 60. The front cylinder 40 has a tubular shape with a closed end formed to be somewhat smaller than the rear housing member 22. The front cylinder 40 is opened toward the bottom of the rear housing member 22. The front cylinder 40 includes a front cylinder bottom 41, and a front cylinder side wall portion 42 extending from the front cylinder bottom 41 toward the rear housing member 22. The front cylinder side wall portion 42 is a first cylindrical portion, and enters inside the rear housing member 22.

As shown in FIGS. 3 and 4, the front cylinder 40 includes a front cylinder inner circumferential surface 43 as a first inner circumferential surface. The front cylinder inner circumferential surface 43 is a cylindrical surface extending in an axial direction Z. The front cylinder 40 further includes a front large diameter surface 44 whose diameter is larger than the front cylinder inner circumferential surface 43. The front large diameter surface 44 is provided in a tip part (open end) of the front cylinder side wall portion 42. A front stepped surface 45 is formed between the front cylinder inner circumferential surface 43 and the front large diameter surface 44.

A bulged part 46 projecting to the radially outside of the rotary shaft 12 is provided in the front cylinder side wall portion 42. The bulged part 46 is provided in the base end of the front cylinder side wall portion 42, i.e., near the front cylinder bottom 41. The front housing member 21 and the rear housing member 22 are unitized with the bulged part 46 being inserted therebetween. The housings 21 and 22 regulate the position gap in the axial direction Z of the front cylinder 40.

As shown in FIG. 4, the front cylinder bottom 41 has a stepped shape in the axial direction Z. The front cylinder bottom 41 includes a first bottom 41a arranged on the central side, and a second bottom 41b arranged radially outside of the first bottom 41a, and closer to the rear housing member 22 than the first bottom 41a. A front insertion hole 41c, to which the rotary shaft 12 can be inserted, is formed in the first bottom 41a. The rotary shaft 12 is inserted into the front insertion hole 41c.

As shown in FIG. 1, the front housing member 21 and the front cylinder bottom 41 form a motor chamber A1, and house the electric motor 13 in the motor chamber A1. The electric motor 13 rotates the rotary shaft 12 in the direction indicated by an arrow M when driving power is supplied from the inverter 14. The suction port 11a is provided in the front housing member 21 that forms the motor chamber A1. Therefore, the suction fluid drawn in from the suction port 11a is introduced into the motor chamber A1. That is, the suction fluid exists in the motor chamber A1.

Within the compressor 10, the inverter 14, the electric motor 13, and the rotors 60 and 80 are arranged in order in the axial direction Z. The position of each of these parts is arbitrary, and the inverter 14 may be arranged radially outside of the electric motor 13.

As shown in FIGS. 2 to 4, the rear cylinder 50 has a tubular shape with a closed end. The rear cylinder 50 is opened toward the bottom of the rear housing member 22. The rear cylinder 50 is formed to be somewhat smaller than the front cylinder 40, and is housed in the rear housing member 22. The rear cylinder 50 is fitted to the front cylinder 40 with the open end of the rear cylinder 50 being butted to the bottom of the rear housing member 22.

The rear cylinder 50 includes an intermediate wall portion 51 forming the bottom of the rear cylinder 50, and a rear cylinder side wall portion 55 extending in the axial direction Z toward the rear housing member 22 from the intermediate wall portion 51. The rear cylinder side wall portion 55 and the intermediate wall portion 51 correspond to a second cylindrical portion and a wall portion, respectively.

As shown in FIG. 4, the intermediate wall portion 51 is arranged so that its wall thickness direction matches the axial direction Z. Therefore, the intermediate wall portion 51 includes a first wall surface 52 and a second wall surface 53 that are perpendicular to the axial direction Z. The intermediate wall portion 51 has a ring shape, and is fitted to the front cylinder 40. A wall through-hole 54 extending through the axial direction Z is formed in the intermediate wall portion 51. The wall through-hole 54 is a through-hole having a larger diameter than the rotary shaft 12. The rotary shaft 12 is inserted into the wall through-hole 54.

The rear cylinder side wall portion 55 has a cylindrical shape extending in the axial direction Z, and includes a rear cylinder inner circumferential surface 56 as a second inner circumferential surface, and a rear cylinder outer circumferential surface 57. The rear cylinder inner circumferential surface 56 is a cylindrical surface having a smaller diameter than the front cylinder inner circumferential surface 43. Therefore, the rear cylinder inner circumferential surface 56 is arranged inside in the radial direction of the front cylinder inner circumferential surface 43. The rear cylinder outer circumferential surface 57 includes a several cylindrical surfaces having different diameters, and thus has a stepped shape. The rear cylinder outer circumferential surface 57 includes a first part surface 57a, a second part surface 57b whose diameter is larger than the first part surface 57a, and a third part surface 57c whose diameter is larger than the second part surface 57b.

The first part surface 57a contacts the front cylinder inner circumferential surface 43. The second part surface 57b contacts the front large diameter surface 44. The third part surface 57c is flush with the outer circumferential surface of the front cylinder side wall portion 42. A first rear stepped surface 58 formed between the part surfaces 57a and 57b contacts a front stepped surface 45, and a second rear stepped surface 59 formed between the part surfaces 57b and 57c contacts the open end of the front cylinder 40.

As shown in FIG. 4, the front cylinder bottom 41, the front cylinder inner circumferential surface 43, and the first wall surface 52 form a front housing chamber A2 that houses the front rotor 60. The front housing chamber A2 has a generally cylindrical shape. The inside bottom surface of the rear housing member 22, the rear cylinder inner circumferential surface 56, and the second wall surface 53 form a rear housing chamber A3 that houses the rear rotor 80. The rear housing chamber A3 has a generally cylindrical shape.

Since the diameter of the rear cylinder inner circumferential surface 56 is smaller than the diameter of the front cylinder inner circumferential surface 43, the rear housing chamber A3 is smaller than the front housing chamber A2, and the volume of the rear housing chamber A3 is smaller than the volume of the front housing chamber A2. The housing chambers A2 and A3 are divided by the intermediate wall portion 51. The rotors 60 and 80 are arranged to be opposed to each other in the axial direction Z, with the intermediate wall portion 51 being arranged therebetween.

The rotary shaft 12 and the rotors 60 and 80 have the same axis. That is, the compressor 10 has the structure for axial center movement, instead of eccentric movement. The circumferential directions of the rotors 60 and 80 match the circumferential direction of the rotary shaft 12, the radial directions of the rotors 60 and 80 match the radial direction R of the rotary shaft 12, and the axial directions of the rotors 60 and 80 match the axial direction Z of the rotary shaft 12. Therefore, the circumferential direction, the radial direction R, and the axial direction Z of the rotary shaft 12 may be properly read as the circumferential direction, the radial direction, and the axial direction of the rotors 60 and 80.

As shown in FIGS. 2 to 5, the front rotor 60 has a ring shape, and includes a front through-hole 61 into which the rotary shaft 12 can be inserted. The front through-hole 61 has the same diameter as the rotary shaft 12. The front rotor 60 is attached to the rotary shaft 12 with the rotary shaft 12 being inserted into the front through-hole 61.

The front rotor 60 rotates with the rotation of the rotary shaft 12. That is, the front rotor 60 integrally rotates with the rotary shaft 12. The configuration for the front rotor 60 to integrally rotate with the rotary shaft 12 is arbitrary, and there are, for example, a configuration in which the front rotor 60 is fixed to the rotary shaft 12, and a configuration in which the front rotor 60 is engaged with the outer circumference of the rotary shaft 12.

A front rotor outer circumferential surface 62, which is an outer circumferential surface of the front rotor 60, is a cylindrical surface having the same axis as the rotary shaft 12. The diameter of the front rotor outer circumferential surface 62 is the same as that of the front cylinder inner circumferential surface 43. There may be a slight gap between the front rotor outer circumferential surface 62 and the front cylinder inner circumferential surface 43.

The front rotor 60 includes a front rotor surface 70 as a first rotor surface opposed to first wall surface 52. The front rotor surface 70 has a ring shape. The front rotor surface 70 includes a first front flat surface 71 and a second front flat surface 72 that are perpendicular to the axial direction Z, and a pair of front curving surfaces 73 connecting the front flat surfaces 71 and 72. The first and second front flat surfaces 71 and 72 correspond to first and second flat surfaces, respectively.

As shown in FIG. 5, the front flat surfaces 71 and 72 are shifted to the axial direction Z. The second front flat surface 72 is arranged closer to the first wall surface 52 than the first front flat surface 71. The second front flat surface 72 contacts the first wall surface 52. Additionally, the front flat surfaces 71 and 72 are separated in the circumferential direction of the front rotor 60, and are shifted 180 degrees. The front flat surfaces 71 and 72 have sectoral shapes. In the following description, the circumferential direction positions of the rotors 60 and 80 are called the angular positions.

Each of the pair of front curving surfaces 73 has a sectoral shape. As shown in FIG. 3, the pair of front curving surfaces 73 oppose to the direction perpendicular to the axial direction Z and the direction along which the front flat surfaces 71 and 72 are arranged. Both of the front curving surfaces 73 have an identical shape. Each of the pair of front curving surfaces 73 connects the front flat surfaces 71 and 72. One of the pair of front curving surfaces 73 connects one ends in the circumferential directions of the front flat surfaces 71 and 72, and the other connects the other ends of in the circumferential directions of the front flat surfaces 71 and 72.

As shown in FIG. 3, let the angular position of the boundary part between the front curving surface 73 and the first front flat surface 71 be a first angular position θ1, and let the angular position of the boundary part between the front curving surface 73 and the second front flat surface 72 be a second angular position θ2. In FIG. 3, each of the angular positions 01 and 82 are indicated by broken lines. However, actually, the boundary parts are continued smoothly.

The front curving surface 73 is a curving surface displaced in the axial direction Z in accordance with the angular position of the front rotor 60. The front curving surface 73 is curved in the axial direction Z so as to be gradually closer to the first wall surface 52 from the first angular position θ1 to the second angular position θ2. Therefore, as shown in FIG. 6, when the front curving surface 73 is cut at a middle position, the front curving surface 73 is located at a position that is between the front flat surfaces 71 and 72 in the axial direction Z, and that is separated from the first wall surface 52. The front curving surface 73 is curved in the axial direction Z so as to be gradually closer to or distant from the first wall surface 52 between two arbitrary angular positions that are mutually separated in the circumferential direction, which are not limited to the first angular position θ1 and the second angular position θ2.

As shown in FIG. 7, the front curving surface 73 includes a front concave surface 73a that is curved in the axial direction Z so as to be concave toward the first wall surface 52, and a front convex surface 73b that is curved in the axial direction Z so as to be convex toward the first wall surface 52. The front concave surface 73a is arranged closer to the first front flat surface 71 than the second front flat surface 72, and the front convex surface 73b is arranged closer to the second front flat surface 72 than the first front flat surface 71. The front concave surface 73a is connected to the front convex surface 73b. The front curving surface 73 is a curving surface with an inflection point. The angle range occupied by the front convex surface 73b may be the same as or different from the angle range occupied by the front concave surface 73a. The position of the inflection point is arbitrary.

As shown in FIGS. 2 to 5, the rear rotor 80 has a ring shape, and includes a rear through-hole 81 into which the rotary shaft 12 can be inserted. The rear through-hole 81 has the same diameter as the rotary shaft 12. The rotary shaft 12 is inserted into the rear through-hole 81, and the rear rotor 80 is engaged with the front rotor 60. The engagement of the front rotor 60 and the rear rotor 80 will be described later. The rear rotor 80 rotates with the rotation of the rotary shaft 12. That is, the rear rotor 80 integrally rotates with the rotary shaft 12. The configuration for the rear rotor 80 to integrally rotate with the rotary shaft 12 is arbitrary, and there are, for example, a configuration in which the rear rotor 80 is fixed to the rotary shaft 12, and a configuration in which the rear rotor 80 is engaged with the outer circumference of the rotary shaft 12.

As shown in FIGS. 4 to 6, the rear rotor 80 is formed to be smaller than the front rotor 60. The diameter of the rear rotor 80 is smaller than the diameter of the front rotor 60. A rear rotor outer circumferential surface 82, which is an outer circumferential surface of the rear rotor 80, is a cylindrical surface having a smaller diameter than the front rotor outer circumferential surface 62. The diameter of the rear rotor outer circumferential surface 82 is the same as that of the rear cylinder inner circumferential surface 56. There may be a slight gap between the rear rotor outer circumferential surface 82 and the rear cylinder inner circumferential surface 56.

As shown in FIGS. 2 and 4, the rear rotor 80 includes a rear rotor surface 90 as a second rotor surface opposed to the second wall surface 53. The rear rotor surface 90 has a ring shape. The rear rotor surface 90 includes a first rear flat surface 91 and a second rear flat surface 92 that are perpendicular to the axial direction Z, and a pair of rear curving surfaces 93 that connect the rear flat surfaces 91 and 92.

As shown in FIG. 5, the rear flat surfaces 91 and 92 are shifted in the axial direction Z. The second rear flat surface 92 is arranged closer to the second wall surface 53 than the first rear flat surface 91. The second rear flat surface 92 contacts the second wall surface 53. The rear flat surfaces 91 and 92 are separated in the circumferential direction of the rear rotor 80, and are shifted 180 degrees. The rear flat surfaces 91 and 92 have sectoral shapes.

Each of the pair of rear curving surfaces 93 has a sectoral shape. The pair of rear curving surfaces 93 oppose to the direction perpendicular to the axial direction Z and the direction along which the rear flat surfaces 91 and 92 are arranged. One of the pair of the rear curving surfaces 93 connects one ends in the circumferential direction of the rear flat surfaces 91 and 92, and the other connects the other ends in the circumferential direction of the rear flat surfaces 91 and 92.

The rotor surfaces 70 and 90 are arranged to be opposed to each other in the axial direction Z with the intermediate wall portion 51 therebetween. The distance between the rotor surfaces 70 and 90 is constant irrespective of the angular positions and the circumferential direction positions of the rotor surfaces 70 and 90. As shown in FIG. 5, the first front flat surface 71 and the second rear flat surface 92 are opposed to each other in the axial direction Z, and the second front flat surface 72 and the first rear flat surface 91 are opposed to each other in the axial direction Z, respectively. The shift amount in the axial direction Z between the front flat surfaces 71 and 72 is the same as the shift amount between the rear flat surfaces 91 and 92. The shift amount in the axial direction Z between the front flat surfaces 71 and 72, and the shift amount between the rear flat surfaces 91 and 92 are called the shift amount L1.

As shown in FIGS. 4, 6 and 7, the degree of curvature of the front curving surface 73 is the same as the degree of curvature of the rear curving surface 93. That is, the front curving surface 73 and the rear curving surface 93 are curved in the same direction, so that the separation distance are not changed in accordance with the angular positions of the curving surfaces. Accordingly, the separation distance between the rotor surfaces 70 and 90 is constant irrespective of the angular positions. The rotor surfaces 70 and 90 have an identical shape except that they have different diameters. Since the shapes of the first rear flat surface 91, the second rear flat surface 92, and the rear curving surface 93 are the same as those of the first front flat surface 71, the second front flat surface 72, and the front curving surface 73, a detailed description is omitted.

As shown in FIGS. 2 to 5, the compressor 10 includes a vane 100, and a vane groove 110 into which the vane 100 is inserted. The vane 100 contacts the rotors 60 and 80, and thus moves in the axial direction Z with the rotation of the rotors 60 and 80. The vane 100 is arranged between the rotors 60 and 80, i.e., between the rotor surfaces 70 and 90, with the surface of the vane 100 being perpendicular to the circumferential direction of the rotary shaft 12. The vane 100 has a tabular shape having the thickness in the direction perpendicular to the axial direction Z.

The vane 100 has a first vane end 101 and a second vane end 102 as the opposite ends in the axial direction Z. The first vane end 101 contacts the front rotor surface 70, and the second vane end 102 contacts the rear rotor surface 90. Although the shapes of the vane ends 101 and 102 are arbitrary, may be curved so as to be convex toward the rotor surfaces 70 and 90.

As shown in FIGS. 2 to 4, the vane groove 110 is formed in the rear cylinder 50. The vane groove 110 is formed over both of the intermediate wall portion 51 and the rear cylinder side wall portion 55. The vane groove 110 is a slit extending through the rear cylinder 50 in a radial direction R. The opposite ends of the vane groove 110 in the radial direction R are opened. The vane groove 110 extends through the intermediate wall portion 51. The end on the front rotor 60 side of the opposite ends of the vane groove 110 in the axial direction Z is opened. The opposite side surfaces of the vane groove 110 are opposed to corresponding surfaces of the opposite surfaces of the vane 100. The width of the vane groove 110, i.e., the distance between the side surfaces of the vane groove 110, is the same as or slightly larger than the thickness of the vane 100.

As shown in FIG. 4 and FIG. 7, the vane groove 110 extends in the axial direction Z from the intermediate wall portion 51 to the middle of the rear cylinder side wall portion 55. The vane groove 110 also exists radially outside of the rear rotor 80. The length in the axial direction Z of the vane groove 110 is the same as or longer than the length in the axial direction Z of the vane 100. By inserting the vane 100 into the vane groove 110, the movement of the vane 100 in the circumferential direction is restricted. In contrast, it is permitted for the vane 100 to move in the axial direction Z along the vane groove 110.

According to this configuration, when the rotors 60 and 80 rotate, the vane 100 moves in the axial direction Z while sliding on the rotor surfaces 70 and 90. Accordingly, the first vane end 101 of the vane 100 enters into the front housing chamber A2, or the second vane end 102 enters into the rear housing chamber A3. In contrast, the vane 100 contacts both side surfaces of the vane groove 110, and thus the movement in the circumferential direction is restricted. Therefore, even if the rotors 60 and 80 are rotated, the vane 100 is not rotated.

The vane groove 110 allows the arrangement of the vane 100 over the housing chambers A2 and A3 and restricts the rotation of the vane 100, even if the rotors 60 and 80 are rotated.

The movement distance of the vane 100 is the displacement amount (the shift amount L1) in the axial direction Z between the front flat surfaces 71 and 72 (or between the rear flat surfaces 91 and 92). Additionally, during the rotation of the rotors 60 and 80, the vane 100 continues to contact the rotor surfaces 70 and 90. That is, the vane 100 does not contact intermittently, and does not periodically repeat separation and contact.

As shown in FIG. 6, the curving surfaces 73 and 93 may be slightly recessed from the outside toward the inside of the radial direction R as long as they contact the vane ends 101 and 102. In this case, the vane ends 101 and 102 contact from the radially inner end toward the radially outer end of the curving surfaces 73 and 93, while slightly shifting the contact position with the curving surfaces 73 and 93 in the circumferential direction. This is not a limitation, and the curving surfaces 73 and 93 may extend straight in the direction perpendicular to the axial direction Z, so that a displacement along the radial direction R at an identical angle position may not occur. That is, as long as the separation distance between the curving surfaces 73 and 93 is constant at the angular position of the same radius, the separation distance may be slightly changed along the radial direction R, or may be constant.

As shown in FIG. 4, a front compression chamber A4 is formed in the front housing chamber A2 by the front rotor 60 (the front rotor surface 70), the front cylinder inner circumferential surface 43, and the first wall surface 52.

A rear compression chamber A5 is formed in the rear housing chamber A3 by the rear rotor 80 (the rear rotor surface 90), the rear cylinder inner circumferential surface 56, and the second wall surface 53. In the compression chambers A4 and A5, with the rotation of the rotary shaft 12, their volumes are periodically changed, and suction/compression of fluid are performed by the vane 100. That is, the vane 100 produces a volume change in the compression chambers A4 and A5. This point will be described later.

Since the front rotor 60 is formed to be larger than the rear rotor 80, the front compression chamber A4 is larger than the rear compression chamber A5. That is, the maximum volume of the front compression chamber A4 is larger than the maximum volume of the rear compression chamber A5.

As shown in FIGS. 2 and 3, an introduction port 111 for introducing the suction fluid in the motor chamber A1 into the front compression chamber A4 is formed in the front rotor 60. The introduction port 111 has an oval shape that is long in the radial direction R. The shape of the introduction port 111 is not limited to this, and is arbitrary.

The introduction port 111 extends through the front rotor 60 in the axial direction Z. The introduction port 111 is arranged near the radially outer end of the front rotor 60. The introduction port 111 is arranged at a position where the introduction port 111 communicates with the front compression chamber A4 at the phase at which the volume of the front compression chamber A4 becomes large, and does not communicate with the front compression chamber A4 at the phase at which the volume of the front compression chamber A4 becomes small.

The introduction port 111 is provided near the boundary between the second front flat surface 72 and the front curving surface 73, specifically, near the end in the circumferential direction of the front curving surface 73 close to the second front flat surface 72. Further, the introduction port 111 is formed in the front curving surface 73 on the opposite side in the rotation direction with respect to the second front flat surface 72.

As shown in FIGS. 2 and 3, communication holes 112 communicating with the introduction port 111 are formed in the front cylinder 40. The communication holes 112 are provided at the positions corresponding to the introduction port 111. When seen from the axial direction Z, the communication holes 112 are formed at the positions that overlap with the trajectory of the introduction port 111 when the front rotor 60 is rotated. The communication holes 112 extend in the circumferential direction of the rotary shaft 12, and four communication holes 112 are separated from each other in the circumferential direction. Accordingly, even if the position of the introduction port 111 changes with the rotation of the front rotor 60, the communication between the introduction port 111 and the communication holes 112 is easily maintained.

A discharge port 113 that discharges the compression fluid compressed in the rear compression chamber A5 is formed in the rear rotor 80. The discharge port 113 extends through the rear rotor 80 in the axial direction Z. The discharge port 113 is formed to be smaller than the introduction port 111. The discharge port 113 is circular. The shape of the discharge port 113 is not limited to this, and is arbitrary.

The discharge port 113 is arranged at a position where the discharge port 113 communicates with the rear compression chamber A5 at the phase at which the volume of the rear compression chamber A5 becomes small, and does not communicate with the rear compression chamber A5 at the phase at which the volume of the rear compression chamber A5 becomes large. The discharge port 113 is provided near the boundary between the second rear flat surface 92 and the rear curving surface 93, specifically, at the end in the circumferential direction of the rear curving surface 93 close to the second rear flat surface 92. Further, the discharge port 113 is formed in the rear curving surface 93 that is on the rotation direction side with respect to the second rear flat surface 92.

When seen from the axial direction Z, the introduction port 111 is arranged on the same side as the discharge port 113, instead of the opposite side from the discharge port 113, on the basis of the center line passing through the centers of the rotors 60 and 80, and extending in the direction along which the flat surfaces 71 and 72 are arranged. However, the positions of the introduction port 111 and the discharge port 113 are arbitrary. A discharge valve that closes the discharge port 113 and makes the discharge port 113 open based on application of a specified pressure may be provided. The discharge valve is not essential.

As shown in FIG. 1, the compressor 10 includes a discharge chamber A6 into which the compression fluid discharged from the discharge port 113 flows, and a discharge passage 114 that connects the discharge chamber A6 and the discharge port 11b. The discharge chamber A6 is formed by the rear cylinder 50 and the rear housing member 22. The discharge chamber A6 is arranged between the discharge port 113 and the rear housing member 22. When seen from the axial direction Z, the discharge chamber A6 is formed in a ring shape so as to overlap with the trajectory of the discharge port 113 accompanying the rotation of the rear rotor 80. Accordingly, it is possible to limit the situation in which the discharge port 113 and the discharge chamber A6 do not communicate with each other, depending on the angular position of the rear rotor 80. According to this configuration, the fluid discharged from the discharge port 113 is discharged from the discharge port 11b via the discharge chamber A6 and the discharge passage 114.

The compressor 10 includes a communication mechanism 120 that switches between a communicating state in which the compression chambers A4 and A5 communicate with each other, and a non-communicating state in which the compression chambers A4 and A5 are not communicating with each other. A detailed configuration of the communication mechanism 120 is described below.

As shown in FIGS. 2 to 4, the communication mechanism 120 includes a front boss portion 121 as a first boss portion provided in the front rotor 60, a front rotary valve 122 as a first engagement portion, a rear boss portion 123 as a second boss portion provided in the rear rotor 80, and a rear rotary valve 124 as a second engagement portion. When the rotary shaft 12 is rotated, the boss portions 121 and 123 are also rotated.

The front boss portion 121 protrudes toward the rear rotor 80 from the front rotor surface 70. The front boss portion 121 protrudes further toward the rear rotor surface 90 than the second front flat surface 72. The front boss portion 121 consists of a cylinder provided in the radially inner end of the front rotor surface 70. The rotary shaft 12 is inserted into the front boss portion 121. The outer diameter of the front boss portion 121 is substantially the same as the diameter of the wall through-hole 54. The front boss portion 121 is fitted to be slidable from the first wall surface 52 to the wall through-hole 54. The front boss portion 121 includes an annular front boss tip surface 121a.

As shown in FIG. 3, the front rotary valve 122 protrudes toward the rear rotor 80 from the front boss tip surface 121a. Two front rotary valves 122 are provided at the positions separated in the circumferential direction. The front rotary valves 122 have sectoral shapes. The inner circumferential surfaces of the front rotary valves 122 are flush with the inner circumferential surface of the front boss portion 121, and contact the outer circumferential surface of the rotary shaft 12. The outer circumferential surfaces of the front rotary valves 122 are flush with the outer circumferential surface of the front boss portion 121.

As shown in FIGS. 2 and 4, the rear boss portion 123 protrudes toward the front rotor 60 from the rear rotor surface 90. The rear boss portion 123 protrudes further toward the front rotor surface 70 than the second rear flat surface 92. The rear boss portion 123 consists of a cylinder provided in the radially inner end of the rear rotor surface 90. The rotary shaft 12 is inserted into the rear boss portion 123. The outer diameter of the rear boss portion 123 is substantially the same as the diameter of the wall through-hole 54. The rear boss portion 123 is fitted to be slidable from the second wall surface 53 side to the wall through-hole 54. The rear boss portion 123 includes an annular rear boss tip surface 123a.

The rear rotary valve 124 protrudes toward the front rotor 60 from the rear boss tip surface 123a. The rear rotary valve 124 consists of a columnar body including a curved inner circumferential surface and an outer circumferential surface. The inner circumferential surface of the rear rotary valve 124 is flush with the inner circumferential surface of the rear boss portion 123, and contacts the outer circumferential surface of the rotary shaft 12. The outer circumferential surface of the rear rotary valve 124 is flush with the outer circumferential surface of the front rotary valves 122. The length of the circumferential direction of rear rotary valve 124 is the same as that of the interval distance of the circumferential direction of the front rotary valves 122.

As shown in FIGS. 8 and 9, the rear rotary valve 124 is engaged with the two front rotary valves 122 in the circumferential direction. The rear rotary valve 124 is fitted between the rotary valves 122 by being sandwiched by the two front rotary valves 122 from the circumferential direction. The relative positions in the circumferential direction of the rotors 60 and 80 are specified by fitting the rotary valves 122 and 124.

One sectoral connecting valve 125 is formed by the front rotary valves 122 and the rear rotary valve 124. The connecting valve 125 is arranged in the wall through-hole 54. The rotary valves 122 and 124 are engaged with each other within the wall through-hole 54. The connecting valve 125 does not have a closed ring shape, and has a sectoral shape. Therefore, an open space 126 where fluid can move is formed in the wall through-hole 54. The pen space 126 is formed between the rotary shaft 12 and a wall inner circumferential surface 54a, which is the inner circumferential surfaces of the wall through-hole 54. The open space 126 is formed by the end surfaces in the circumferential direction of the connecting valve 125, the outer circumferential surface of the rotary shaft 12, and the wall inner circumferential surface 54a.

The connecting valve 125 includes a valve outer circumferential surface 125a having the same diameter as the diameter of the wall through-hole 54. The valve outer circumferential surface 125a is configured by the outer circumferential surfaces of the rotary valves 122 and 124. Since the outer circumferential surfaces of the rotary valves 122 and 124 are flush with each other, the valve outer circumferential surface 125a forms one continuous circumferential surface. The valve outer circumferential surface 125a contacts the wall inner circumferential surface 54a of the wall through-hole 54. Wall inner circumferential surface 54a is also an inner circumferential surface of the intermediate wall portion 51 formed in ring shape.

The height of the front rotary valve 122 is the same as the height of the rear rotary valve 124. The heights of the rotary valve 122 and 124 are the protrusion dimensions of the rotary valves 122 and 124, and are the lengths in the axial direction Z from the boss tip surfaces 121a and 123a. As shown in FIGS. 4 and 5, the tip surface 122a of the front rotary valve 122 contacts the rear boss tip surface 123a, and the tip surface 124a of the rear rotary valve 124 contacts the front boss tip surface 121a, respectively. These define the relative positions in the axial direction Z of the rotors 60 and 80.

A protrusion 127 is provided in the rear boss tip surface 123a separately from the rear rotary valve 124. The protrusion 127 is provided at a position symmetrical with respect to the rear rotary valve 124 about the rotary shaft 12. The inner circumferential surface of the protrusion 127 contacts the rotary shaft 12. Accordingly, the protrusion 127 sandwiches the rotary shaft 12 with the rear rotary valve 124. Therefore, the position shift of the rear rotor 80 to the direction perpendicular to the axial direction Z is restricted.

The outer diameter of the protrusion 127 is smaller than the diameter of the wall through-hole 54. Therefore, a gap exists between the protrusion 127 and the wall inner circumferential surface 54a. The communication mechanism 120 includes a communication passage 130 communicates between the compression chambers A4 and A5. The communication passage 130 includes a front-side opening 131, a rear side opening 132, and a communication groove 133.

As shown in FIG. 8, the front-side opening 131 and the rear side opening 132 are formed in the intermediate wall portion 51. The openings 131 and 132 are separated in the circumferential directions of the rotors 60 and 80. The front-side opening 131 and the rear side opening 132 are arranged at either side of the vane 100. The front-side opening 131 is formed on one surface of the vane 100 located on the other side of the rotation directions of the rotors 60 and 80, and the rear side opening 132 is formed on the other surface of the vane 100 located on the rotation direction side of the rotors 60 and 80, respectively. The openings 131 and 132 communicate with the vane groove 110.

As shown in FIG. 2, the front-side opening 131 is opened toward the front compression chamber A4 and the wall through-hole 54. The front-side opening 131 is formed in the both of the first wall surface 52 and the wall inner circumferential surface 54a in the intermediate wall portion 51. The front-side opening 131 is configured so that the fluid in the front compression chamber A4 can be made to flow into the wall through-hole 54.

As shown in FIG. 3, the front-side opening 131 is not formed in the second wall surface 53. That is, the front-side opening 131 does not extend through the intermediate wall portion 51 in the axial direction Z, and does not directly communicate with the front compression chamber A4 and the rear compression chamber A5 to each other.

The rear side opening 132 is opened toward the rear compression chamber A5 and the wall through-hole 54. The rear side opening 132 is formed in both of the second wall surface 53 and the wall inner circumferential surface 54a in the intermediate wall portion 51. The rear side opening 132 is configured so that the fluid in the rear compression chamber A5 can be made to flow into the wall through-hole 54. In contrast, the rear side opening 132 is not formed in the first wall surface 52. That is, the rear side opening 132 does not extend through the intermediate wall portion 51 in the axial direction Z, and does not directly communicate with the front compression chamber A4 and the rear compression chamber A5 to each other.

As shown in FIG. 8, the front-side opening 131 has a half-U shape, and extends in the radial direction R. The rear side opening 132 has a half-U shape that is symmetrical to the front-side opening 131. The shapes of the openings 131 and 132 are not limited to these, and are arbitrary. The vane 100 divides the front-side opening 131 and the rear side opening 132. The vane 100 restricts the fluid from directly flowing into the rear side opening 132 from the front-side opening 131.

The communication groove 133 is a part that is recessed outward in the radial direction of the wall inner circumferential surface 54a. The communication groove 133 is arranged between the front-side opening 131 and the rear side opening 132 in the wall inner circumferential surface 54a so as to bypass the vane 100. The communication groove 133 extends in the circumferential direction of the wall inner circumferential surface 54a. The communication groove 133 communicates with the rear side opening 132, and communicates with the open space 126. The circumferential direction of the wall inner circumferential surface 54a matches the circumferential directions of the rotors 60 and 80. Therefore, the circumferential direction of the wall inner circumferential surface 54a can also be said to be the circumferential directions of the rotors 60 and 80.

In contrast, the communication groove 133 does not directly communicate with the front-side opening 131. The communication groove 133 and the front-side opening 131 are separated in the circumferential direction of the wall inner circumferential surface 54a. Therefore, the fluid does not directly flow into the communication groove 133 from the front-side opening 131. The communication groove 133 is not formed, and a groove-less surface 54a a exists between the communication groove 133 and the front-side opening 131 in the wall inner circumferential surface 54a.

According to this configuration, the fluid does not directly flow into the communication groove 133 from the front-side opening 131. Therefore, the fluid flows from the front-side opening 131 into the wall through-hole 54 that is radially inside, flows into the communication groove 133 via the wall through-hole 54 (radially inside of the groove-less surface 54a a), thereafter flows into the rear side opening 132.

FIG. 8 shows a case where the connecting valve 125 is arranged radially inside of the front-side opening 131. In this case, the connecting valve 125 closes the opening part that is radially inside of the front-side opening 131. Accordingly, the inflow of the fluid that goes to the communication groove 133 from the front-side opening 131 is restricted. Accordingly, the compression chambers A4 and A5 are in the non-communicating state in which they are not communicating with each other. The position where the connecting valve 125 closes the front-side opening 131, i.e., the radially inside position in the front-side opening 131, corresponds to a closed position.

Especially, when the connecting valve 125 is arranged radially inside with respect to the groove-less surface 54a a, the valve outer circumferential surface 125a of the connecting valve 125 contacts the groove-less surface 54a a. Accordingly, the connecting valve 125 is arranged between the front-side opening 131 and the communication groove 133. Thus, the leakage of the fluid that goes to the communication groove 133 from the front-side opening 131 is restricted.

FIG. 9 shows a case where the connecting valve 125 is moved in the circumferential direction of the rotors 60 and 80 with respect to the front-side opening 131. In this case, the connecting valve 125 does not close the opening part that is radially inside of the front-side opening 131. Additionally, since the connecting valve 125 is not arranged radially inside of the groove-less surface 54a a, it is difficult for the connecting valve 125 to inhibit the liquid from flowing into the wall through-hole 54 from the front-side opening 131, and flows into the communication groove 133. Accordingly, the inflow of the fluid that goes to the communication groove 133 from the front-side opening 131 via the open space 126 is permitted. Accordingly, the fluid in the front compression chamber A4 passes through the front-side opening 131→the open space 126→the communication groove 133→the rear side opening 132, and moves to the rear compression chamber A5. Accordingly, the compression chambers A4 and A5 are in the communicating state, in which they are communicating with each other.

The position where the connecting valve 125 is shifted with respect to the opening part radially inside of the front-side opening 131, i.e., the position where the connecting valve 125 does not close the front-side opening 131, corresponds to an open position. The connecting valve 125 is provided on the communication passage 130, and moves to the open position for opening the communication passage 130, and the closed position for closing the communication passage 130, in accordance with the angular positions of the rotors 60 and 80. The communication mechanism 120 switches between the communicating state in which the communication passage 130 is connected via the open space 126, and the non-communicating state in which the communication passage 130 is cut off by the connecting valve 125, in accordance with the rotation positions of the rotors 60 and 80.

Even if the valve outer circumferential surface 125a and the groove-less surface 54a a contact each other, as long as the open space 126 is arranged in radially inside areas of the openings 131 and 132 so as to extend to the radially inside areas of the vane 100, the movement of the fluid between the front-side opening 131 and the rear side opening 132 is permitted via the inside area of the vane 100.

In this configuration, the communication period of the front compression chamber A4 and the rear compression chamber A5 in one cycle of rotation of the rotors 60 and 80 is defined by the length in the circumferential direction of the valve outer circumferential surface 125a (the angle range occupied by the connecting valve 125). Additionally, the timing at which the compression chambers A4 and A5 communicate with each other in one cycle of rotation of the rotors 60 and 80 is defined by the angular position of the connecting valve 125. Accordingly, when the angular position of the connecting valve 125, or the length in the circumferential direction of the valve outer circumferential surface 125a is adjusted, the timing at which the compression chambers A4 and A5 communicate with each other and the communication period are adjusted.

As shown in FIGS. 8 and 9, the inner end surface 103, which is an end face radially inside of the vane 100, contacts the outer circumferential surfaces of the boss portions 121 and 123, and the valve outer circumferential surface 125a. The outer circumferential surfaces of the boss portions 121 and 123 are flush with each other, the outer circumferential surfaces of the boss portions 121 and 123 are flush with the valve outer circumferential surface 125a, and the outer circumferential surfaces of the rotary valves 122 and 124 are flush with each other. The inner end surface 103 of the vane 100 is a concave surface that is curved with the same curvature as the outer circumferential surfaces of the boss portions 121 and 123, and the valve outer circumferential surface 125a. Therefore, the inner end surface 103 of the vane 100 comes into surface contact with the outer circumferential surfaces of the boss portions 121 and 123, and the valve outer circumferential surface 125a.

An outer end surface 104, which is an end face radially outside of the vane 100, is flush with the first part surface 57a of the rear cylinder 50. The outer end surface 104 of the vane 100 contacts the front cylinder inner circumferential surface 43 of the front cylinder 40. The vane 100 is sandwiched by the outer circumferential surfaces of the boss portions 121 and 123 and the valve outer circumferential surface 125a, and the front cylinder inner circumferential surface 43 from the radial direction R. Accordingly, it is possible to limit the position shift in the radial direction R of the vane 100. Additionally, it is possible to limit the fluid from leaking from the boundary part between the vane 100 (the inner end surface 103) and the outer circumferential surfaces of the boss portions 121 and 123 and the valve outer circumferential surface 125a, or from the boundary part between the vane 100 (the outer end surface 104) and the front cylinder inner circumferential surface 43.

Next, using FIGS. 10 and 11, a detailed description is given of the positional relationship among the introduction port 111, the discharge port 113, and the openings 131 and 132, and the compression chambers A4 and A5.

FIG. 10A is a development view showing the rotors 60 and 80 and the vane 100 in the state shown in FIG. 10B, and FIG. 118 is a development view showing the rotors 60 and 80 and the vane 100 in the state shown in FIG. 11A. FIGS. 10B and 11B schematically show the openings 131 and 132 and the open space 126 provided in the intermediate wall portion 51. The state in which the openings 131 and 132 are connected via the open space 126 corresponds to the state in which the compression chambers A4 and A5 are communicating with each other.

As shown in FIGS. 10A and 10B, the vane 100 does not enter into the front housing chamber A2 in the circumstance in which the vane 100 contacts the second front flat surface 72 and the first rear flat surface 91. In this case, the number of the front compression chamber A4 is one, the front compression chamber A4 is filled with the suction fluid, and the front compression chamber A4 reaches the maximum volume.

In contrast, since a part of the vane 100 enters into the rear housing chamber A3, in the rear housing chamber A3, two rear compression chambers A5 (a first rear compression chamber A5a and a second rear compression chamber A5b) are formed at either side of the vane 100. The first rear compression chamber A5a and the second rear compression chamber A5b are divided by the contacting part between the second rear flat surface 92 and the second wall surface 53 and the vane 100, and adjacent to each other in the circumferential direction.

The first rear compression chamber A5a communicates with the rear side opening 132, and does not communicate with the discharge port 113. The second rear compression chamber A5b communicates with the discharge port 113, and does not communicate with the rear side opening 132. The vane 100 divides the first rear compression chamber A5a communicating with the rear side opening 132 and the second rear compression chamber A5b communicating with the discharge port 113, so that the rear side opening 132 does not directly communicate with the discharge port 113.

Thereafter, when the rotary shaft 12 is rotated by the electric motor 13, the rotors 60 and 80 are rotated. Then, the vane 100 is moved in the axial direction Z (the left and right directions in FIG. 10B), and a part of the vane 100 enters into the front housing chamber A2. Accordingly, as shown in FIG. 11B, two front compression chambers A4 (a first front compression chamber A4a and second front compression chamber A4b) are formed in either side of the vane 100. The first front compression chamber A4a and the second front compression chamber A4b are divided by the contacting part of the second front flat surface 72 and the first wall surface 52 and vane 100, and adjacent to each other in the circumferential direction.

The first front compression chamber A4a communicates with the introduction port 111, and does not communicate with the front-side opening 131. The second front compression chamber A4b communicates with the front-side opening 131, and does not communicates with the introduction port 111. The vane 100 divides the first front compression chamber A4a communicating with the introduction port 111, and the second front compression chamber A4b communicating with the front-side opening 131, so that the introduction port 111 and the front-side opening 131 do not directly communicate with each other.

When the rotors 60 and 80 are rotated in this state, the volumes of the compression chambers A4 and A5 are changed. In the first front compression chamber A4a, the volume is increased and the suction fluid is drawn in from the introduction port 111, and, in the second front compression chamber A4b, the volume is decreased and the compression of the suction fluid is performed. Similarly, in the second rear compression chamber A5b, the volume is decreased and the fluid is compressed. In contrast, in the first rear compression chamber A5a, the space itself becomes large. However, since the communication mechanism 120 is in the non-communicating state, the fluid does not flow into the first rear compression chamber A5a.

Thereafter, as shown in FIGS. 11A and 11B, after the vane 100 passes the first front flat surface 71 and the second rear flat surface 92, the compression chambers A4 and A5 (the second front compression chamber A4b and the first rear compression chamber A5a) communicate with each other. Accordingly, an intermediate pressure fluid having a higher pressure than the suction fluid compressed in the second front compression chamber A4b is introduced into the first rear compression chamber A5a. That is, the communication passage 130 communicates between the second front compression chamber A4b and the first rear compression chamber A5a.

Thereafter, when the rotors 60 and 80 are rotated to the position at which the vane 100 contacts the second front flat surface 72 and the first rear flat surface 91, all the intermediate pressure fluid in the second front compression chamber A4b is introduced into the first rear compression chamber A5a, and the compression chambers A4 and A5 do not communicate with each other. In contrast, the introduced intermediate pressure fluid is compressed as the fluid of the second rear compression chamber A5b at the time of next rotations of the rotors 60 and 80, and is discharged from the discharge port 113. In this case, since the intermediate pressure fluid is further compressed in the second rear compression chamber A5b, the compressed fluid whose pressure is made higher than the intermediate pressure fluid is discharged from the discharge port 113.

By rotating the rotors 60 and 80, in the compression chambers A4 and A5, the cycle movement of suction and compression having 720 degrees as one cycle (two rotations of the rotors 60 and 80) is repeated. A two stage compression is performed in which the intermediate pressure fluid compressed in the front compression chamber A4 is compressed again in the rear compression chamber A5.

Although the description has been given by distinguishing between the front compression chambers A4a and A4b, when the fact that the cycle movement having 720 degrees as one cycle is performed in the front compression chamber A4, the first front compression chamber A4a is the front compression chamber A4 whose phase is 0 degrees to 360 degrees, the second front compression chamber A4b is the front compression chamber A4 whose phase is 360 degrees to 720 degrees. That is, the space formed by the front rotor surface 70, the first wall surface 52, and the front cylinder inner circumferential surface 43 is divided into the front compression chamber A4 whose phase is 0 degrees to 360 degrees, and the front compression chamber A4 whose phase is 360 degrees to 720 degrees by the vane 100. In other words, the vane 100 generates volume changes of the first chamber and the second chamber (the volume of the first chamber is increased, and the volume of the second chamber is decreased) with the rotations of the rotors 60 and 80, in the state where the above-described space is divided into the first chamber into which the fluid is drawn in, and the second chamber from which the fluid is discharged. The same also applies to the first rear compression chamber A5a and the second rear compression chamber A5b.

The communication passage 130 is a passage that communicates between the front compression chamber A4 having a phase of 360 degrees to 720 degrees (a compression stage) and the compression chamber A5 having a phase of 0 degrees to 360 degrees (a suction stage). The communication mechanism 120 makes the front compression chamber A4 having a phase of 360 degrees to 720 degrees, and the rear compression chamber A5 having a phase of 0 degrees to 360 degrees communicate with each other and not to communicate with each other.

Next, the volume changes of the compression chambers A4 and A5 is described by using FIG. 12. In FIG. 12, the broken line indicates the volume change of the front compression chamber A4, the long dashed short dashed line indicates the volume change of the rear compression chamber A5, and the continuous line indicates the substantial volume change for the combination of the compression chambers A4 and A5, i.e., the volume change of the entire compressor 10, respectively. The volume changes of the compression chambers A4 and A5 are accompanied by a phase difference. As for the phase difference, the rotor surfaces 70 and 90 are curved in the axial direction Z so as to make the separation distance between them constant, and the volume changes of the compression chambers A4 and A5 are realized by one vane 100. Additionally, a phase difference is realized since the compression spaces A4 and A5 communicate with each other in the second half of the compression stage of the compression spaces A4.

As shown in FIG. 12, the phase of the volume change of the rear compression chamber A5 is advanced compared with the volume change of the front compression chamber A4. The compressor 10 is configured such that, in the second half stage of the compression operation of the suction fluid in the front compression chamber A4, the compression chambers A4 and A5 communicate with each other, the suction of the intermediate pressure fluid into the rear compression chamber A5 is started, and the volume of the rear compression chamber A5 is increased. Therefore, as indicated by the continuous line in FIG. 12, the volume change of the entire compressor 10 forms a graph connecting the volume change of the front compression chamber A4 and the volume change of the rear compression chamber A5 to each other.

The first embodiment has the following advantages.

(1-1) The compressor 10 includes the rotors 60 and 80 rotated with the rotation of the rotary shaft 12, and the cylinder side wall portions 42 and 55 that house the rotors 60 and 80. The cylinder side wall portions 42 and 55 have cylinder inner circumferential surfaces 43 and 56 opposed to the rotor outer circumferential surfaces 62 and 82 in the radial direction R of the rotors 60 and 80, respectively. The rotors 60 and 80 have ring-shaped rotor surfaces 70 and 90. The compressor 10 includes the intermediate wall portion 51 arranged between the rotors 60 and 80, and including wall surfaces 52 and 53 opposed to the rotor surfaces 70 and 90 in the axial direction Z. Additionally, the compressor 10 includes the vane 100 that contacts the rotor surfaces 70 and 90 in the state where the vane 100 is inserted into the vane groove 110 formed in the intermediate wall portion 51. The vane 100 is moved in the axial direction Z with the rotation of the rotors 60 and 80.

In this configuration, the compressor 10 includes compression chambers A4 and A5. In the compression chambers A4 and A5, the volume change is caused by the vane 100 with the rotations of the rotors 60 and 80, and the suction and compression of the fluid are performed. The front compression chamber A4 is formed by the front rotor surface 70, the first wall surface 52, and the front cylinder inner circumferential surface 43. The rear compression chamber A5 is formed by the rear rotor surface 90, the second wall surface 53, and the rear cylinder inner circumferential surface 56. The compressor 10 includes the communication mechanism 120 that switches between the communicating state in which the compression chambers A4 and A5 communicate with each other, and the non-communicating state in which the compression chambers A4 and A5 are not communicating with each other.

According to this configuration, by rotating the rotors 60 and 80, the suction and compression of the fluid in the compression chambers A4 and A5 are performed while the vane 100 is moved in the axial direction Z. Additionally, it is possible to make the compression chambers A4 and A5 communicate with each other, or not communicate with each other by the communication mechanism 120. Accordingly, the fluid compressed in the front compression chamber A4 can be made to flow into the rear compression chamber A5, and can be compressed again.

(1-2) The vane 100 is inserted into the vane groove 110, thereby regulating the movement in the circumferential direction of the rotors 60 and 80. Accordingly, it is regulated that the vane 100 is rotated with the rotation of the rotors 60 and 80. Thus, it is possible to limit the inconvenience such as application of a centrifugal force to the vane 100 by rotating the vane 100. Therefore, the application of an excessive force to the vane 100 can be limited.

(1-3) The wall through-hole 54 having a larger diameter than the rotary shaft 12 is formed in the intermediate wall portion 51. The communication mechanism 120 includes the communication passage 130 that communicates between the compression chambers A4 and A5 via a gap between the rotary shaft 12 and the wall inner circumferential surfaces 54a of the wall through-hole 54, and the connecting valve 125 that is moved between the open position and the closed position in accordance with the angular positions of the rotors 60 and 80 to open and close the communication passage 130.

According to this configuration, it is possible to place the communication passage 130 in the communicating state, or the non-communicating state in accordance with the angular positions of the rotors 60 and 80, by moving the connecting valve 125 between the open position and the closed position with the rotations of the rotors 60 and 80.

The communication passage 130 communicates between the compression chambers A4 and A5 via a gap between the rotary shaft 12 and the wall inner circumferential surfaces 54a. Therefore, as compared with the configuration that provides a communication passage radially outside of the rotors 60 and 80 so as to bypass the intermediate wall portion 51, it is possible to limit an increase in the size of the compressor 10 in the radial direction R.

(1-4) The communication passage 130 includes the communication groove 133 that is recessed outward in the radial direction of the wall inner circumferential surface 54a, the front-side opening 131, and the rear side opening 132. The front-side opening 131 is formed in the intermediate wall portion 51, and is opened to the front compression chamber A4 and the wall through-hole 54. The rear side opening 132 is formed at a position in the circumferential direction different from the front-side opening 131 in the intermediate wall portion 51, and is opened to the rear compression chamber A5 and the wall through-hole 54.

The connecting valve 125 is arranged in the wall through-hole 54, and has a sectoral shape. Therefore, the open space 126 communicating with the communication groove 133 is formed in the wall through-hole 54. Additionally, the valve outer circumferential surface 125a of the connecting valve 125 contacts the wall inner circumferential surface 54a. The communication groove 133 communicates with one of the openings 131 and 132 (the rear side opening 132), and is separated from the other opening (the front-side opening 131).

In this configuration, when the connecting valve 125 is arranged at the closed position, the connecting valve 125 is arranged radially inside of the opening part that is opened to the wall through-hole 54 of the front-side opening 131. Thus, the opening part is closed with the valve outer circumferential surface 125a. In contrast, when the connecting valve 125 is arranged at the open position, the connecting valve 125 is arranged at a position that is shifted in the circumferential direction of the rotors 60 and 80 with respect to the above-described opening part of the front-side opening 131. Thus, the movement of the fluid between the compression chambers A4 and A5 through the open space 126 is permitted.

According to this configuration, by rotating the rotors 60 and 80, the compression chambers A4 and A5 are automatically switched between the communicating state and the non-communicating state. Accordingly, it is possible to make the compression chambers A4 and A5 communicate with each other, or not communicate with each other during one rotation of the rotors 60 and 80.

According to this configuration, it is possible to adjust the time period during which the compression chambers A4 and A5 are made to communicate with each other, by adjusting the length in the circumferential direction of the valve outer circumferential surface 125a. Additionally, it is possible to adjust the timing at which the compression chambers A4 and A5 communicate with each other, by adjusting the angular position of connecting valve 125. Accordingly, it is possible to easily and freely adjust the communication/non-communication of the compression chambers A4 and A5.

(1-5) The communication mechanism 120 includes the cylindrical boss portions 121 and 123 protruding in the direction to be close to each other from the radially inner ends of the rotors 60 and 80, and the rotary valves 122 and 124 as engagement portions protruding in the direction to be close to each other from boss tip surfaces 121a and 123a, which are the tip surfaces of the boss portions 121 and 123. The rotary valves 122 and 124 are mutually engaged in the circumferential direction (the rotation direction of the rotors 60 and 80) of the rotors 60 and 80. The connecting valve 125 is configured by the rotary valves 122 and 124, and the valve outer circumferential surface 125a is configured by the outer circumferential surfaces of the rotary valves 122 and 124.

According to this configuration, the rotors 60 and 80 are mutually engaged with the rotary valves 122 and 124 that configure the connecting valve 125 switched between the communicating state and the non-communicating state. Accordingly, the relative positions in the circumferential direction of the rotors 60 and 80 are specified. Therefore, the position shift in the circumferential direction of the rotors 60 and 80 can be limited.

Since the rotary valves 122 and 124 are engaged with each other in the circumferential direction, when the rotors 60 and 80 are rotating, the relative positions in the circumferential direction of the rotors 60 and 80 are not easily changed due to the engagement between the rotary valves 122 and 124. Additionally, since the rotatory power of one of the rotors 60 and 80 is transmitted to the other via the engagement portion between the rotary valves 122 and 124, the synchronicity of rotation of the rotors 60 and 80 is improved.

(1-6) The vane 100 includes the first vane end 101 and the second vane end 102 as the opposite ends in the axial direction Z. The vane ends 101 and 102 contact the rotor surfaces 70 and 90. The front rotor surface 70 includes the front curving surface 73 that is displaced in the axial direction Z in accordance with its angular position. The rear rotor surface 90 includes the rear curving surface 93 that is displaced in the axial direction Z in accordance with its angular position. The front curving surface 73 and the rear curving surface 93 are opposed to each other in the axial direction Z via the intermediate wall portion 51. Each of the front curving surface 73 and the rear curving surface 93 is curved in the axial direction Z so that the separation distance is constant, irrespective of their angular positions.

According to this configuration, when the rotors 60 and 80 are rotated, the vane 100 is moved in the axial direction Z, while moving on the rotor surfaces 70 and 90. Accordingly, it is unnecessary to separately provide the configuration for moving the vane 100, and the configuration is simplified. The state that the separation distance between the curving surfaces 73 and 93 is constant irrespective of the angular positions of the rotors 60 and 80 includes some errors when the rotors 60 and 80 can be rotated in a state where the vane ends 101 and 102 contact the curving surfaces 73 and 93.

(1-7) the vane ends 101 and 102 are not intermittent, and continuously contact the rotor surfaces 70 and 90. That is, the vane ends 101 and 102 slide with respect to the rotor surfaces 70 and 90. According to this configuration, the sound is hardly generated when the vane ends 101 and 102 hit the rotor surfaces 70 and 90. Therefore, the quietness is improved.

(1-8) The front rotor surface 70 includes the front flat surfaces 71 and 72 arranged at positions mutually shifted in the axial direction Z. The second front flat surface 72 contacts the first wall surface 52. The front curving surface 73 connects the front flat surfaces 71 and 72. The rear rotor surface 90 includes the rear flat surfaces 91 and 92 arranged at positions mutually shifted in the axial direction Z. The second rear flat surface 92 contacts the second wall surface 53. The rear curving surface 93 connects the rear flat surfaces 91 and 92. The first front flat surface 71 and the second rear flat surface 92 are opposed to each other, and the second front flat surface 72 and the first rear flat surface 91 are opposed to each other.

According to this configuration, the communication between the front compression chamber A4 (the first front compression chamber A4a) on the side on which suction is performed, and the front compression chamber A4 (the second front compression chamber A4b) on the side on which compression is performed is restricted by the contact between the second front flat surface 72 and the first wall surface 52. Accordingly, the leakage of the fluid can be limited, and the efficiency is improved. Additionally, the first rear flat surface 91 is arranged at a position opposed to the second front flat surface 72, so as to correspond to the second front flat surface 72. Therefore, the separation distance between the first rear flat surface 91 and the second front flat surface 72 becomes constant, a trouble hardly occurs in the movement of the vane 100, and a gap between the vane 100 and the rotor surfaces 70 and 90 is hardly generated. The same also applies to the rear compression chamber A5.

(1-9) The compressor 10 includes the housing 11 in which the rotary shaft 12 is housed, and two radial bearings 32 and 34 that support the opposite ends of the rotary shaft 12 in the housing 11 in a rotatable state.

According to this configuration, both ends of the rotary shaft 12 are rotationally supported by the radial bearings 32 and 34. Therefore, compared with a scroll compressor in which only one end of the rotary shaft 12 is supported by a radial bearing, it is possible to stably support the rotary shaft 12. Accordingly, this configuration can respond to high speed rotation.

(1-10) The compressor 10 includes the first front compression chamber A4a and the second front compression chamber A4b that are divided by the vane 100 as the front compression chamber A4, and the first rear compression chamber A5a and the second rear compression chamber A5b that are divided by the vane 100 as rear compression chamber A5.

The first front compression chamber A4a is configured such that the suction fluid is drawn in when the volume is increased with the rotation of the front rotor 60. The second front compression chamber A4b is configured such that the volume is decreased with the rotation of the front rotor 60. The first rear compression chamber A5a is configured such that the volume is increased with the rotation of the rear rotor 80. The second rear compression chamber A5b is configured such that the volume is decreased with the rotation of the rear rotor 80, and the fluid is discharged.

In this configuration, the communication mechanism 120 is switched between the communicating state in which the second front compression chamber A4b and the first rear compression chamber A5a communicate with each other, and the non-communicating state in which the compression chambers A4b and A5a do not communicate with each other. Accordingly, it is possible to supply the intermediate pressure fluid compressed in the second front compression chamber A4b to the first rear compression chamber A5a in a suction stage, and to further compress the intermediate pressure fluid in the second rear compression chamber A5b.

Second Embodiment

A second embodiment is different from the first embodiment in the cycle movement of suction and compression. The differences are described in detail below.

As shown in FIG. 13, the compressor 10 is configured such that the suction fluid is drawn into not only the front compression chamber A4 but also the rear compression chamber A5. The compressor 10 includes a rear side suction passage 141 that introduces the suction fluid into the rear compression chamber A5, and an open/close portion 142 that opens and closes the rear side suction passage 141. The rear side suction passage 141 communicates the motor chamber A1 with the rear compression chamber A5. The rear side suction passage 141 is formed in the housing 11, and extends through the front cylinder 40 and the rear cylinder 50. The rear side suction passage 141 communicates with the first rear compression chamber A5a that communicates with the rear side opening 132 of the rear compression chamber A5.

The open/close portion 142 is provided on the rear side suction passage 141, and is switched between a closed state in which the rear side suction passage 141 is closed, and an open state in which the rear side suction passage 141 is opened. The closed state is the state where it is restricted that the suction fluid in the motor chamber A1 flows into the rear compression chamber A5 via the rear side suction passage 141. The open state is the state where it is permitted that the suction fluid in the motor chamber A1 flows into the rear compression chamber A5 via the rear side suction passage 141. The suction of the fluid into the rear compression chamber A5 is started and stopped by the open/close portion 142. Although the configuration of the open/close portion 142 is arbitrary, there are, for example, a configuration using a rotary valve as in the first embodiment, and a configuration using an electromagnetic valve.

Next, the communication mechanism 150 of the second embodiment is described.

As shown in FIG. 14, the communication mechanism 150 of the second embodiment includes two front rotary valves 151 and two rear rotary valves 152. The two front rotary valves 151 are arranged at positions that are separated and opposed to each other in the circumferential direction.

The two rear rotary valves 152 are also arranged at positions that are separated in the circumferential direction, and are opposed in the direction perpendicular to the opposing direction of the front rotary valves 151. The rear rotary valves 152 have pillar-shape including curved inner circumferential surface and outer circumferential surface. The rear rotary valves 152 are arranged between the two front rotary valves 151.

The rear rotary valve 152 is engaged with the two front rotary valves 151 in the circumferential direction. The rotary valves 151 and 152 pinch each other from the circumferential direction. The mutual relative positions in the circumferential direction of the rotors 60 and 80 are defined by the engagement between the rotary valves 151 and 152.

The front rotary valve 151 and the rear rotary valve 152 form one closed ring-shaped connecting valve 153. The connecting valve 153 is arranged within the wall through-hole 54. The rotary valves 151 and 152 are engaged with each other within the wall through-hole 54. The connecting valve 153 includes a valve outer circumferential surface 153a contacting the wall inner circumferential surface 54a. The communication mechanism 150 includes a communication passage 160 that communicates the compression chamber A4 with the compression chamber A5. The communication passage 160 includes a front-side opening 161, a rear side opening 162, and a communication groove 163.

The front-side opening 161 and the rear side opening 162 are formed in the intermediate wall portion 51. The openings 161 and 162 are separated in the circumferential direction of the rotors 60 and 80. The front-side opening 161 is arranged next to the vane 100. The front-side opening 161 is formed on one of the surfaces in the circumferential direction of the vane 100, i.e., on a surface of the vane 100 located on the other side of the rotation direction of the rotors 60 and 80. The front-side opening 161 communicates with the vane groove 110. The rear side openings 162 is shifted 180 degrees with respect to the front-side opening 161. Each of the positions of the openings 161 and 162 is point symmetric with respect to the central axis of the rotary shaft 12.

Similar to the first embodiment, the front-side opening 161 is formed in the first wall surface 52 in the intermediate wall portion 51, but is not formed in the second wall surface 53. The rear side opening 162 is formed in the second wall surface 53 in the intermediate wall portion 51, but is not formed in the first wall surface 52. That is, the openings 161 and 162 do not extend through the intermediate wall portion 51 in the axial direction Z, and do not directly communicate the compression chamber A4 with the rear compression chamber A5.

The communication groove 163 extends in the circumferential direction of the wall inner circumferential surface 54a, and communicates with the openings 161 and 162. The communication groove 163 is formed over a half circumference of the wall inner circumferential surface 54a, so as to connect the openings 161 and 162 to each other while bypassing the vane 100. According to this configuration, the fluid in the front compression chamber A4 flows into the rear compression chamber A5 via the front-side opening 161→the communication groove 163→the rear side opening 162.

Next, using FIGS. 15 and 16, the relationship between the positions of the openings 161 and 162 and the compression chambers A4 and A5 will be described in detail.

As described above, the position of the rear side opening 162 is 180 degrees different from the position of the front-side opening 161. In the state shown in FIG. 15, the rear side opening 162 is closed with the second rear flat surface 92. Therefore, the compression chambers A4 and A5 are not communicating with each other. Thereafter, when the rotors 60 and 80 are rotated, the second front compression chamber A4b and the first rear compression chamber A5a communicate with each other via the communication passage 160. Thereafter, as shown in FIG. 16, when the second rear flat surface 92 passes the vane 100, the second front compression chamber A4b and the second rear compression chamber A5b communicate with each other via the communication passage 160. Then, when the rear side opening 162 is closed again by the second rear flat surface 92, the compression chambers A4 and A5 do not communicate with each other.

The communication mechanism 150 (the communication passage 160) is a passage that makes the front compression chamber A4 whose phase is 360 degrees to 720 degrees, and the rear compression chamber A5 whose phase is 180 degrees to 540 degrees communicate with each other. The communication mechanism 150 makes the front compression chamber A4 in the stage where the volume is decreased, and the rear compression chamber A5 in the stage where the volume is switched from being increased to being decreased communicate with each other.

Thereafter, when the rotors 60 and 80 are rotated to a position at which the vane 100 contacts the second front flat surface 72 and the first rear flat surface 91, all of the compression fluid in the second front compression chamber A4b is discharged from the discharge port 113 via the rear compression chamber A5. Additionally, the suction fluid drawn into the first front compression chamber A4a is pumped or compressed as the fluid for the second front compression chamber A4b at the time of the next rotation of the rotors 60 and 80.

As described above, in the compression chambers A4 and A5, the cycle movement having two turns (720 degrees) of the rotors 60 and 80 as one cycle is repeated. Accordingly, the suction of the fluid, and the pumping or compression of the fluid are performed. The rear side suction passage 141 communicates with the first rear compression chamber A5a. Then, the open/close portion 142 is in the open state for the time period in which the phase of the rear compression chamber A5 is 0 degrees to a specific phase. Accordingly, the suction fluid is drawn into the rear compression chamber A5. The specific phase is 360 degrees or less, for example. The specific phase will be described later.

Using FIG. 17, a description will be given of a series of cycle movement of suction/compression performed by the compression chambers A4 and A5 of the second embodiment.

As shown in FIG. 17A, the compressor 10 is configured so that the phase difference is generated by the volume change of the front compression chamber A4 and the volume change of the rear housing chamber A3. Additionally, the compressor 10 is configured so that the volume change of the rear compression chamber A5 has a phase lag to the volume change of the front compression chamber A4. As for the phase difference, the rotor surfaces 70 and 90 are curved in the axial direction Z so as to make the separation distance between them constant, and the volume changes of the compression chambers A4 and A5 are realized by one vane 100. Additionally, the phase difference is realized because the suction fluid is drawn in when the phase of the rear compression chamber A5 is 0 degrees to the specific phase.

As shown in FIGS. 17A and 17B, in the compressor 10, after the suction of the fluid into the front compression chamber A4 (hereinafter referred to as the suction operation of the front compression chamber A4) is started, the open/close portion 142 is in the open state, and the suction of the fluid into the rear compression chamber A5 (hereinafter referred to as the suction operation of the rear compression chamber A5) is started. Accordingly, the suction of the fluid is performed in the compression chambers A4 and A5. Thereafter, when the suction of the fluid is completed by the front compression chamber A4, in which the suction of the fluid was started first, the volume decrease of the front compression chamber A4 is started.

As shown in FIGS. 17A and 17C, the communication mechanism 120 is configured to be in the open state at the timing (360 degrees) when the suction by the front compression chamber A4 ends. Accordingly, the compression chambers A4 and A5 communicate with each other. Therefore, with the volume decrease of the front compression chamber A4, the suction fluid in the front compression chamber A4 is pumped to the rear compression chamber A5 via the communication mechanism 120 (hereinafter referred to as the pumping operation of the front compression chamber A4). In this stage, the suction operation of the rear compression chamber A5 is continued.

That is, the pumping operation of the front compression chamber A4 and the suction operation of the rear compression chamber A5 are performed in the state where the compression chambers A4 and A5 communicate with each other. In this state, the suction fluid is drawn into the rear compression chamber A5 from both the front compression chamber A4 and the rear side suction passage 141. Accordingly, even after the suction operation of the front compression chamber A4 is completed, the substantial total volume of the compression chambers A4 and A5, i.e., the volume of the entire compressor 10 continues to be increased.

Thereafter, as shown in FIGS. 17A and 17B, the open/close portion 142 is in the closed state with the specific phase corresponding to the timing at which the volume of the entire compressor 10 reaches its maximum. Accordingly, the suction operation of the rear compression chamber A5 is completed, and the compression of the fluid housed in the rear compression chamber A5 in the rear compression chamber A5 (hereinafter referred to as the compression operations of the rear compression chamber A5) is started. Similarly, the compression of the fluid in the front compression chamber A4 (hereinafter referred to as the compression operation of the front compression chamber A4) is also performed. In this case, the compression chambers A4 and A5 communicate with each other.

That is, the compressor 10 is configured such that the compression operations are performed in the compression chambers A4 and A5 in the state where the compression chambers A4 and A5 communicate with each other. In the following description, the compression operations in the compression chambers A4 and A5 in the state where the compression chambers A4 and A5 communicate with each other is referred to as the parallel compression operation. Thereafter, the compression operation of the front compression chamber A4 is completed during the compression operation of the rear compression chamber A5. Then, as shown in FIGS. 17A and 17C, in synchronization with the completion of the compression operation of the front compression chamber A4, the communication mechanism 120 becomes the non-communicating state. After the compression operation of the front compression chamber A4 is completed, only the compression operation of the rear compression chamber A5 is continued, and when the compression operation is completed, one cycle of suction/compression in the compressor 10 is completed.

That is, the cycle movement performed by the compressor 10 of the second embodiment is performed in the following order:

(A) the front suction operation in which, in the state where the compression chambers A4 and A5 do not communicate with each other, while the suction operation of the front compression chamber A4 is performed, the suction operation of the rear compression chamber A5 is not performed;

(B) the parallel suction operation in which the suction operation of the fluid into the compression chambers A4 and A5 is performed;

(C) the communication intermediate operation in which the pumping operation of the front compression chamber A4 and the suction operation of the rear compression chamber A5 are performed in the state where the compression chambers A4 and A5 communicate with each other;

(D) the parallel compression operation; and

(E) the rear compression operation in which, in the state where the compression chambers A4 and A5 do not communicate with each other, while the compression operation of the rear compression chamber A5 is performed, the compression operation of the front compression chamber A4 is not performed.

The operation of the second embodiment will now be described.

As indicated by the continuous line in FIG. 17A, the suction fluid is drawn into the compression chambers A4 and A5 having mutually different phases for the volume change. Therefore, the substantial combined volume of the compression chambers A4 and A5 (the displacement of the compressor 10) is larger than the case where the front compression chamber A4 draws in independently. Particularly, even after the volume of the front compression chamber A4 reaches its maximum, since the volume is increased for the rear compression chamber A5, the volume of the entire compressor 10 is increased.

Thereafter, the communication intermediate operation→the parallel compression-operations→the rear compression operation are performed. Accordingly, the substantial volume of the compression chambers A4 and A5 is smoothly decreased. Accordingly, the substantial volume change for one cycle forms a smooth waveform with only one peak, instead of a waveform in which two peaks are generated as in the two-step compression method shown in FIG. 12. That is, during one cycle, locally, the volume hardly becomes small. Additionally, as indicated by the long dashed double-short dashed line in FIG. 17A, the pressure of the suction fluid drawn into the compression chambers A4 and A5 is smoothly increased.

The second embodiment has the following advantages.

(2-1) The compressor 10 is configured such that the suction fluid is drawn into both compression chambers A4 and A5 having shifted phases for the volume change. The compressor 10 performs the cycle movement including the parallel suction operations and the parallel compression operation. Particularly, the compressor 10 is configured such that the front suction operation→the parallel suction operations→the communication intermediate operation→the parallel compression operation→the rear compression operation are performed in this order. The parallel compression operation is the compression operation in the compression chambers A4 and A5 in the state where the compression chambers A4 and A5 are made to communicate with each other by the communication mechanism 150.

According to this configuration, as indicated by the continuous line in FIG. 17A, the volume change of the entire compressor 10 in one cycle movement can be smoothed. Accordingly, it is possible to limit the situation where the volume locally becomes small, thereby limiting the generation of over compression.

The above-described embodiments may be modified as follows. The above-described embodiments and the following modifications can be combined as long as the combined modifications remain technically consistent with each other.

The rear rotor 80 may have a larger diameter than the front rotor 60.

Although the rotors 60 and 80 have different diameters, this is not a limitation, and may have the same diameter. That is, the volumes of the compression chambers A4 and A5 may be the same.

The front flat surfaces 71 and 72 and the rear flat surfaces 91 and 92 may be omitted. That is, the entire rotor surfaces 70 and 90 may be curving surfaces.

The first vane end 101 and the front rotor surface 70 are not limited to the configuration in which they contact each other over the entire part from the radially inner end to the radially outer end, and may be configured to contact each other over a partial range in the radial direction. Additionally, the first vane end 101 and the front rotor surface 70 are not limited to the configuration in which they contact each other over the entire circumference, and may be configured to contact each other over a partial angular range. The same applies to the second vane end 102 and the rear rotor surface 90.

The number of the vane 100 is arbitrary, and may be plural, for example. Additionally, the circumferential direction position of the vane 100 is arbitrary.

The shapes of the vane 100 and the vane groove 110 are not limited to those in each of the embodiments, as long as the shapes allow the movement of the vane 100 in the axial direction Z, while the movement in the circumferential direction is restricted. For example, the vane may have a sectoral shape.

Additionally, the vane may be configured to move in the axial direction Z like a pendulum that moves about a predetermined place. That is, the vane may be configured to move in the axial direction Z in accordance with rotational movement, and not limited to linear movement.

The specific shapes of the cylinders 40 and 50 are arbitrary. For example, the bulged part 46 may be omitted. Additionally, though the cylinders 40 and 50 are different bodies, they may be integrally formed.

Similarly, the specific shapes of the housings 21 and 22 are also arbitrary.

The cylinders 40 and 50 may be omitted. In this case, the inner circumferential surface of the housing 11 may form the compression chambers A4 and A5. In this configuration, the housing 11 corresponds to the first cylindrical portion and the second cylindrical portion.

The electric motor 13 and the inverter 14 may be omitted. That is, the electric motor 13 and the inverter 14 are not essential in the compressor 10.

The rotors 60 and 80 may be each fixed to the rotary shaft 12 so as to be integrally rotated with the rotary shaft 12, or only one of the rotors 60 and 80 may be attached to the rotary shaft 12 to be integrally rotated with the rotary shaft 12, and the other may be attached to the rotary shaft 12 to be rotatable with respect to the rotary shaft 12. Even in this case, since the rotary valves 122 and 124 are engaged with each other in the circumferential direction, with the rotation of one of the rotors 60 and 80, the other is also rotated.

The outer circumferential surfaces of the boss portions 121 and 123 are not flush, and have stepped shapes. In this case, the inner end surface 103 of the vane 100 may similarly have a stepped shape, so that a gap is not formed.

As shown in FIGS. 18 and 19, the communication mechanism 200 may be formed so as to bypass the intermediate wall portion 51. For example, the communication mechanism 200 may communicate the compression chamber A4 with the compression chamber A5 via the communication passage 201 formed in the cylinder side wall portions 42 and 55. The communication passage 201 includes a front-side opening formed in the part that forms the second front compression chamber A4b of the front cylinder inner circumferential surfaces 43, and a rear side opening in the part that forms the first rear compression chamber A5a of the rear cylinder inner circumferential surfaces 56, and connects these openings to each other. In this case, the communication mechanism 200 is switched to the non-communicating state when the phase of the front compression chamber A4 is 0 degrees to 360 degrees, and to the communicating state when the phase of the front compression chamber A4 is 360 degrees to 720 degrees.

In this case, the boss portions 121 and 123 and the rotary valves 122 and 124 may be omitted. That is, it is not essential that the rotors 60 and 80 contact or engage with each other.

In this configuration, the diameter of the wall through-hole 54 may be reduced, so that the wall inner circumferential surface 54a and the rotary shaft 12 contact or be close to each other. Additionally, the inner end surface 103 of the vane 100 may directly contact the rotary shaft 12.

In the second embodiment, instead of the communication intermediate operation, under the circumstance where the compression chambers A4 and A5 do not communicate with each other, a non-communicating intermediate operation may be performed in which the compression operation of the front compression chamber A4 and the suction operation of the rear compression chamber A5 are performed.

As long as the rotary valves 122 and 124 are engaged with each other in the circumferential direction, the specific engagement manner is arbitrary. For example, two rear rotary valves 124 may be provided, and the front rotary valve 122 may be arranged between the rear rotary valves 124.

As long as the openings 131 and 132 are mutually separated in the circumferential direction, their specific positions are arbitrary.

The communication groove 133 may communicate with the front-side opening 131, and may be separated with respect to the rear side opening 132. In this case, switching is made between the communicating state and the non-communicating state by opening and closing the opening part to the wall through-hole 54 of the rear side opening 132 by the valve outer circumferential surface 125a.

In the second embodiment, the compression chambers A4 and A5 may communicate with each other during the parallel suction operations.

The open/close portion 142 may be omitted.

In the second embodiment, the suction operation of the front compression chamber A4 may be started after the suction operation of the rear compression chamber A5 is started. In this case, the compression operation of the front compression chamber A4 may be completed after the compression operation of the rear compression chamber A5 is completed.

In the second embodiment, the parallel suction operation may be omitted. In this case, the period may be adjusted in which the suction operations of the compression chambers A4 and A5 are performed, so that the parallel compression operation may be performed.

The compressor 10 may be used for devices other than an air-conditioner. For example, the compressor 10 may be used to supply compressed air to a fuel cell mounted in a fuel cell vehicle.

The compressor 10 may be mounted on any structure other than a vehicle.

The fluid to be compressed by the compressor 10 is not limited to refrigerant including oil, and is arbitrary.

Claims

1. A compressor comprising:

a rotary shaft;

a first rotor including a ring-shaped first rotor surface, and rotated with rotation of the rotary shaft;

a second rotor opposed to the first rotor in an axial direction of the rotary shaft, rotated with the rotation of the rotary shaft, and including a ring-shaped second rotor surface;

a first cylindrical portion including a first inner circumferential surface opposed to an outer circumferential surface of the first rotor in a radial direction of the rotary shaft, and housing the first rotor;

a second cylindrical portion including a second inner circumferential surface opposed to an outer circumferential surface of the second rotor in the radial direction, and housing the second rotor;

a wall portion arranged between the rotors, and including a first wall surface opposed to the first rotor surface in the axial direction, and a second wall surface opposed to the second rotor surface in the axial direction;

a vane contacting the rotor surfaces in a state where the vane is inserted into a vane groove formed in the wall portion, and moving in the axial direction with rotation of the rotors;

a first compression chamber formed by the first rotor surface, the first wall surface, and the first inner circumferential surface, a volume change of the first compression chamber being caused by the vane with rotation of the first rotor, such that suction and compression of fluid are performed;

a second compression chamber formed by the second rotor surface, the second wall surface, and the second inner circumferential surface, a volume change of the second compression chamber being caused by the vane with rotation of the second rotor, such that suction and compression of the fluid are performed; and

a communication mechanism switched between a communicating state in which the first compression chamber and the second compression chamber communicate with each other, and a non-communicating state in which the first compression chamber and the second compression chamber do not communicate with each other.

2. The compressor according to claim 1, wherein

a wall through-hole extending in the axial direction is formed in the wall portion,

a size in a radial direction of the wall through-hole is larger than a size in a radial direction of the rotary shaft, and

the communication mechanism includes a communication passage for communicating between the first compression chamber and the second compression chamber via a gap between the rotary shaft and an inner circumferential surface of the wall through-hole, and a valve that moves between an open position for opening the communication passage and a closed position for closing the communication passage in accordance with angular positions of the rotors.

3. The compressor according to claim 2, wherein

the communication passage includes a communication groove recessed outward in the radial direction of the rotary shaft from the inner circumferential surface of the wall through-hole, a first opening formed in the wall portion, and opened toward the first compression chamber and the wall through-hole, a second opening formed at a position different from the first opening in the wall portion in a circumferential direction, and opened toward the second compression chamber and the wall through-hole,

the valve has a sectoral shape, and is arranged in the wall through-hole,

the valve includes a valve outer circumferential surface contacting the inner circumferential surface of the wall through-hole,

the communication groove communicates with one opening of the openings, and is separated from the other opening,

when the valve is arranged at the closed position, since the valve is arranged radially inside of the opening part opened to the wall through-hole of the other opening, the valve outer circumferential surface closes the opening part, and

when the valve is arranged at the open position, since the valve is arranged at a position shifted in the circumferential direction with respect to the opening part, movement of fluid is permitted from the first compression chamber to the second compression chamber via an open space that is formed in the wall through-hole and communicates with the communication groove.

4. The compressor according to claim 3, wherein

the communication mechanism includes a cylindrical first boss portion projecting toward the second rotor from a radially inner end of the first rotor surface, and a second cylindrical boss portion projecting toward the first rotor from a radially inner end of the second rotor surface,

the valve is configured by a first engagement portion projecting toward the second rotor from a tip surface of the first boss portion, and a second engagement portion projecting toward the first rotor from a tip surface of the second boss portion, and engaging with the first engagement portion in the circumferential direction, and

the valve outer circumferential surface is configured by outer circumferential surfaces of the engagement portions.

5. The compressor according to claim 1, wherein

the vane includes a first vane end and a second vane end as opposite ends in the axial direction,

the first rotor surface that the first vane end contacts includes a first curving surface displaced in the axial direction in accordance with angular positions of the rotors,

the second rotor surface that the second vane end contacts includes a second curving surface displaced in the axial direction in accordance with the angular positions of the rotors, and

the first curving surface and the second curving surface are opposed to each other in the axial direction, and are curved in the axial direction such that a separation distance is constant irrespective of the angular positions of the rotors.

6. The compressor according to claim 5, wherein

the first rotor surface includes a first flat surface provided at a position separated in the axial direction with respect to the first wall surface and perpendicular to the axial direction, and a second flat surface provided at a position separated in the circumferential direction with respect to the first flat surface, perpendicular to the axial direction, and contacting the first wall surface, and

the first curving surface connects the first flat surface with the second flat surface, and is curved to be gradually close to the first wall surface from the first flat surface to the second flat surface.