SEALED COMPRESSOR AND REFRIGERATION CYCLE DEVICE

Abstract

According to one embodiment, a sealed compressor is configured to suction a working fluid to a rotary compression mechanism section through a suction pipe extending into an accumulator. The sealed compressor has a relation of Aac/Acy≦4, Vac/Vcy≧20, and As/Acy≧0.12 when an inner diameter cross-sectional area of the accumulator is denoted by Aac (mm2), an inner diameter cross-sectional area of a cylinder chamber is denoted by Acy (mm2), an liquid retaining capacity to an upper end of the suction pipe inside the accumulator is denoted by Vac (cc), a total displacement volume of the rotary compression mechanism section is denoted by Vcy (cc), and a total inner diameter cross-sectional area of an extension portion inside the accumulator of the suction pipe is denoted by As (mm2).

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of PCT Application No. PCT/JP2012/062997, filed May 22, 2012 and based upon and claiming the benefit of priority from Japanese Patent Application No. 2011-128363, filed Jun. 8, 2011, the entire contents of all of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to sealed compressors and refrigeration cycle devices.

BACKGROUND

In a refrigeration cycle device such as an air conditioner, a technique is known in which refrigerant compressed by a sealed compressor passes through an outdoor heat exchanger, an expansion device, and an indoor heat exchanger connected to the sealed compressor via a four-way valve as a cycle. The sealed compressor used in the refrigeration cycle device includes a rotary compression mechanism section therein and an accumulator on the suction side thereof. The accumulator prevents a liquid back. Further, the sealed compressor is configured to change its rotation speed by an inverter.

In the related art, the sealed compressor was designed to improve its characteristics during the operation at a rated rotation speed, for example, a rotation speed of 60 rps. Then, since the suction loss did not cause any problem during the operation at the rated rotation speed, the suction loss was not sufficiently considered. However, it is proved that there is a case in which the suction loss increases and the performance is largely degraded when the sealed compressor is operated at the rotation speed other than the rated rotation speed, for example, at a high rotation speed.

BRIEF DESCRIPTION OF THE DRAWINGS

A general architecture that implements the various features of the embodiments will now be described with reference to the drawings. The drawings and the associated descriptions are provided to illustrate the embodiments and not to limit the scope of the invention.

FIG. 1 is an explanatory diagram schematically illustrating a configuration of a refrigeration cycle device of an embodiment.

FIG. 2 is a cross-sectional view illustrating a configuration of a sealed compressor used in the refrigeration cycle device.

FIG. 3 is an explanatory diagram illustrating a relation between a suction loss and an area ratio of a total inner diameter cross-sectional area and a cylinder inner diameter cross-sectional area of the sealed compressor.

FIG. 4 is an explanatory diagram illustrating a relation between an in-pipe flow velocity and the area ratio of the total inner diameter cross-sectional area and the cylinder inner diameter cross-sectional area of the sealed compressor.

FIG. 5 is an explanatory diagram illustrating a relation between the suction loss and the area ratio of the total inner diameter cross-sectional area and the cylinder inner diameter cross-sectional area of the sealed compressor.

DETAILED DESCRIPTION

Various embodiments will be described hereinafter with reference to the accompanying drawings.

In general, according to one embodiment, a sealed compressor comprises a rotary compression mechanism section accommodated in a sealed casing and an accumulator provided outside the sealed casing, the compressor configured to suction a working fluid to the rotary compression mechanism section through at least one suction pipe extending into the accumulator and connected thereto, wherein the rotary compression mechanism section comprises at least one cylinder each forming a cylinder chamber, and when an inner diameter cross-sectional area of the accumulator is denoted by Aac (mm²), an inner diameter cross-sectional area of one cylinder chamber is denoted by Acy (mm²), a liquid retaining capacity to an upper end of the suction pipe inside the accumulator is denoted by Vac (cc), a total displacement volume of the rotary compression mechanism section is denoted by Vcy (cc), and a total inner diameter cross-sectional area of an extension portion inside the accumulator of the suction pipe is denoted by As (mm²), a relation of Aac/Acy≦4, Vac/Vcy≧20, and As/Acy≧0.12 is satisfied.

A refrigeration cycle device 100 that uses a sealed compressor 1 according to one embodiment will be described by referring to FIGS. 1 to 5.

FIG. 1 is an explanatory diagram schematically illustrating a configuration of the refrigeration cycle device 100 according to the embodiment, FIG. 2 is a cross-sectional view illustrating a configuration of the sealed compressor 1 and an accumulator 2 used in the refrigeration cycle device 100, FIG. 3 is an explanatory diagram illustrating a relation between an area ratio As/Acy of a total inner diameter cross-sectional area As of an extension portion inside the accumulator of a suction pipe and an inner diameter cross-sectional area Acy of one cylinder chamber in the sealed compressor 1 and a suction loss ratio Ws/Wth of suction loss Ws of the extension portion inside the accumulator of the suction pipe and theoretical work Wth of the compressor, FIG. 4 is an explanatory diagram illustrating a relation between the area ratio As/Acy of the total inner diameter cross-sectional area As of the extension portion inside the accumulator of the suction pipe and the inner diameter cross-sectional area Acy of one cylinder chamber and in-pipe flow velocity Vs of the extension portion inside the accumulator of the suction pipe in the sealed compressor 1, and FIG. 5 is an explanatory diagram illustrating a relation between the area ratio As/Acy and the suction loss ratio Ws/Wth of the sealed compressor 1 during a rated operation and a high-speed operation.

The refrigeration cycle device 100 is used in an air conditioner. Hereinafter, the refrigeration cycle device 100 will be described as an air conditioner 100.

As illustrated in FIG. 1, the air conditioner 100 comprises: a sealed compressor 1 comprising an accumulator 2 on a suction side thereof; a four-way valve 101; an outdoor heat exchanger 102 as a heat-source-side heat exchanger; an expansion device 103; and an indoor heat exchanger 104 as a use-side heat exchanger. The air conditioner 100 has a configuration in which the sealed compressor 1, the four-way valve 101, the outdoor heat exchanger 102, the expansion device 103, and the indoor heat exchanger 104 communicate with each other as a cycle.

In the air conditioner 100, the four-way valve 101 is connected to a suction side of the accumulator 2 of the sealed compressor 1. Further, in the air conditioner 100, the four-way valve 101 is connected to a discharge side of the sealed compressor 1. In the air conditioner 100, the outdoor heat exchanger 102, the expansion device 103, and the indoor heat exchanger 104 are sequentially connected to the four-way valve 101, and the flow direction of refrigerant discharged from the sealed compressor 1 is switched when the passageway of the four-way valve 101 is switched.

The sealed compressor 1 includes a sealed container 10, a rotary compression mechanism section 11 provided in the lower portion inside the sealed container 10, a motor unit 12 provided in the upper portion of the sealed container 10, a refrigerant suction pipe 13 provided in the sealed container 10, and a refrigerant discharge pipe 14 provided in the sealed container 10. Further, the sealed compressor 1 includes the accumulator 2 connected to the suction pipe 13.

The upper portion of the sealed container 10 is provided with an upper cover 10a which seals the inside of the sealed container 10, and the upper cover 10a is fixed by welding or the like so as to seal the inside of the sealed container 10 after the rotary compression mechanism section 11 and the motor unit 12 are accommodated in the sealed container 10.

The rotary compression mechanism section 11 includes a first cylinder 21, a second cylinder 22, a rotary shaft 23, a pair of rollers 24, a bearing 25, a partition plate 26, and blades.

The first cylinder 21 forms a first cylinder chamber 21a having a columnar shape. Further, the first cylinder 21 includes a blade accommodation groove communicating with the first cylinder chamber 21a and a suction port connected to the suction pipe 13 so as to communicate with the first cylinder chamber 21a. The blade is accommodated in the blade accommodation groove so as to protrude and retract with respect to the first cylinder chamber 21a.

The outer dimension of the first cylinder 21 is slightly smaller than the inner diameter of the sealed container 10. The first cylinder 21 is inserted into the sealed container 10, and is positioned and fixed to the inner peripheral surface of the sealed container 10 by welding from the outside of the sealed container 10. Furthermore, the first cylinder 21 includes a communication hole 21b which causes a lower space of the first cylinder 21 to communicate with an upper space of the first cylinder 21 when the first cylinder is fixed to the sealed container 10.

The second cylinder 22 forms a second cylinder chamber 22a having a columnar shape. Further, the second cylinder 22 includes a blade accommodation groove communicating with the second cylinder chamber 22a and a suction port connected to the suction pipe 13 so as to communicate with the second cylinder chamber 22a. The blade is accommodated in the blade accommodation groove so as to protrude and retract with respect to the second cylinder chamber 22a.

The first cylinder 21 and the second cylinder 22 have different outer shapes and dimensions. Furthermore, the first cylinder chamber 21a and the second cylinder chamber 22a are set to have the same inner diameter and the same height.

The rotary shaft 23 is inserted through the first cylinder chamber 21a and the second cylinder chamber 22a and is pivoted by the bearing 25. The rotary shaft 23 includes crank eccentric portions 28 which are positioned inside the first cylinder chamber 21a and the second cylinder chamber 22a so as to have, for example, a phase difference of about 180°.

The two crank eccentric portions 28 have the same eccentric amount, and the heights thereof are slightly smaller than those of the first cylinder chamber 21a and the second cylinder chamber 22a.

Rollers 24 respectively engage with the crank eccentric portions 28 so as to be slidable inside the first cylinder chamber 21a and the second cylinder chamber 22a and to be slidable on the end of the blade. The heights of the rollers 24 are substantially equal to the heights of the first cylinder chamber 21a and the second cylinder chamber 22a.

Since the pair of rollers 24 are provided at the crank eccentric portions 28 disposed with a phase difference therebetween, the rollers have a phase difference of about 180°. The rollers 24 eccentrically rotate inside the first and second cylinder chambers 21a and 22a. Since the first and second cylinder chambers 21a and 22a have the same inner diameter and the same height and the two crank eccentric portions 28 and 28 have the same eccentric amount, the first and second cylinders 21 and 22 have the same displacement volume.

The bearing 25 includes a primary bearing 31 provided in an upper surface portion of the first cylinder 21 covering the upper side of the first cylinder chamber 21a and a secondary bearing 32 provided in a lower surface portion of the second cylinder 22 covering the lower side of the second cylinder chamber 22a. The bearing 25 is formed so that the rotary shaft 23 is pivoted by the primary bearing 31 and the secondary bearing 32.

The primary bearing 31 forms the upper surface of the first cylinder chamber 21a, and the roller 24 slides on the upper surface. The primary bearing 31 is equipped with a first valve cover 33 which covers the upper side of the primary bearing 31. Further, the primary bearing 31 includes a first discharge hole 34 which guides the refrigerant from the first cylinder chamber 21a to the first valve cover 33 and a first open/close valve 35 which opens and closes the first discharge hole 34.

The secondary bearing 32 forms the lower surface of the second cylinder chamber 22a, and the roller 24 slides on the lower surface. The secondary bearing 32 is equipped with a second valve cover 36 which covers the lower side of the secondary bearing 32. Further, the secondary bearing 32 includes a second discharge hole 37 which guides the refrigerant from the second cylinder chamber 22a to the second valve cover 36 and a second open/close valve 38 which opens and closes the second discharge hole 37.

Furthermore, the first cylinder 21, the second cylinder 22, the partition plate 26, the primary bearing 31, the secondary bearing 32, the first valve cover 33, and the second valve cover 36 are integrally coupled to one another by a bolt B and the like, and the coupled components are fixed to the sealed container 10 via the first cylinder 21.

The partition plate 26 has an outer diameter larger than the inner diameters of the first cylinder chamber 21a and the second cylinder chamber 22a and smaller than the outer dimensions of the first cylinder 21 and the second cylinder 22. The partition plate 26 is disposed so as to cover the first cylinder chamber 21a and the second cylinder chamber 22a.

The blade is formed so that its height is substantially equal to each of the heights of the first and second cylinder chambers 21a and 22a. The blade is formed so that its front end has, for example, a semi-cylindrical shape. For example, when a back pressure is applied to the back surface of the blade, the blade is pressed toward the roller 24 by the back pressure, and the front end of the blade comes into line-contact with the outer peripheral surface of the roller 24 regardless of the rotation angle of the roller 24.

The blade accommodation grooves are respectively formed in the first and second cylinders 21 and 22 so that the blades partition between the suction ports and the first and second discharge ports 34 and 37. When the blades comes into contact with the rollers 24, the first and second cylinder chambers 21a and 22a are defined as the suction chambers and the compression chambers.

The motor unit 12 includes a stator 51 fixed to the inner surface of the sealed container 10 and a rotor 52 disposed inside the stator 51 with a predetermined gap therebetween. The rotor 52 is fixed to the rotary shaft 23. The motor unit 12 is connected to, for example, an inverter that changes the operation frequency. Furthermore, the inverter is electrically connected to a control unit that controls the inverter, and changes the rotation speed of the rotary shaft 23 to an arbitrary rotation speed if necessary.

Two suction pipes 13 are respectively connected to the suction ports of the first cylinder 21 and the second cylinder 22. Further, each suction pipe 13 is bent upward by about 90° at the halfway portion protruding from the sealed container 10 so as to extend into the accumulator 2, and its end is disposed at a predetermined height of the accumulator 2. Furthermore, the height of the end of the suction pipe 13 extending into the accumulator 2 is appropriately set if necessary since the capacity for the liquid refrigerant and lubricating oil storable inside the accumulator 2 changes by the height.

Further, the suction pipe 13 includes an oil return hole 13a provided at a predetermined position in the height direction from the bottom surface of the accumulator 2 in the portion extending into the accumulator 2. Furthermore, the oil return hole 13a may be formed so as to supply the lubricating oil accumulated at the lower side inside the accumulator 2 to the first cylinder chamber 21a and the second cylinder chamber 22a along with the gas refrigerant, and the height of the oil return hole 13a is appropriately set depending on the dimension or the capacity of the accumulator 2.

The discharge pipe 14 is connected to the upper end of the sealed container 10, that is, the upper cover 10a. The discharge pipe 14 is connected to the four-way valve 101.

The accumulator 2 includes a cylindrical container 61 of which both ends are blocked and a gas/liquid separation unit 62 provided inside the container 61. In the accumulator 2, the suction pipe 13 is inserted into the container 61 from the lower end of the container 61, the suction pipe 13 extends to the position right below the gas/liquid separation unit 62, and the upper end of the container 61 is connected with a return pipe 63 through which the refrigerant returns. Furthermore, the return pipe 63 is connected to the four-way valve 101.

The gas/liquid separation unit 62 is a refrigerant guide unit that prevents the refrigerant returned from the return pipe 63 from directly entering the suction pipes 13 and 13 right below the gas/liquid separation unit 62. That is, the gas/liquid separation unit 62 is formed so that the refrigerant as the gas/liquid mixture returned from the return pipe 63 may collide with the gas/liquid separation unit 62 and the colliding refrigerant as the gas/liquid mixture may be guided toward the inner peripheral surface of the container 61.

The accumulator 2 is a so-called a gas/liquid separator capable of storing the liquid refrigerant and the lubricating oil at the lower side of the container 61 by the gas/liquid separation unit 62 and supplying the gas refrigerant from the suction pipe 13.

Further, in the sealed compressor 1, as illustrated in FIG. 2, when the inner diameter cross-sectional area of the container 61 of the accumulator 2 is denoted by Aac (mm²), the inner diameter cross-sectional area of each of the first and second cylinder chambers 21a and 22a (the inner diameter cross-sectional area of one cylinder chamber) is denoted by Acy (mm²), the total inner diameter cross-sectional area of extension portions inside the accumulator of the suction pipes 13 and 13 (the sum of the inner diameter cross-sectional areas of two suction pipes) is denoted by As (mm²), the total displacement volume of the rotary compression mechanism section 11 of the sealed compressor 1 (the sum of the displacement volumes of the first and second cylinders 21 and 22) is denoted by Vcy (cc), the liquid retaining capacity from the bottom surface of the container 61 to the upper end of the suction pipe 13 of the accumulator 2 is denoted by Vac (cc), the inner diameter of each of the first and second cylinder chambers 21a and 22a (the inner diameter of one cylinder chamber) is denoted by φDcy (mm), the axial distance between the upper surface of the first cylinder 21 and the lower surface of the second cylinder 22 is denoted by L (mm), the distance between the axial center of the first cylinder 21 and the axial center of the second cylinder 22 is denoted by Lc (mm), and the distance between the axial centers of the connecting portions of two suction pipes 13 and 13 with respect to the first cylinder 21 and the second cylinder 22 is denoted by Lp (mm), the respective dimensions of the sealed compressor 1 are set so as to satisfy the relation of

Aac/Acy≦4,

0.12 As/Acy≦0.25,

Vac/Vcy≧20,

0.9≦L/Dcy≦1.1, and

Lp>Lc.

Furthermore, the inner diameter cross-sectional area Aac of the accumulator 2 indicates the opening area of the body of the container 61 of the accumulator 2. The total inner diameter cross-sectional area As of extension portions inside the accumulator of the suction pipes 13 and 13 indicates the sum of the opening areas of two suction pipes 13 extending into the accumulator 2. Further, the total displacement volume Vcy of the first and second cylinders 21 and 22 indicates the sum of the displacement volume of the first cylinder 21 as the volume between the inner peripheral surface of the first cylinder chamber 21a and the outer peripheral surface of the roller 24 and the displacement volume of the second cylinder 22 as the volume between the inner peripheral surface of the second cylinder chamber 22a and the outer peripheral surface of the roller 24.

The liquid retaining capacity Vac of the accumulator 2 indicates the capacity in which the liquid refrigerant and the lubricating oil may be stored inside the accumulator 2 when the accumulator performs the gas/liquid separation and specifically, the volume reaching the water level at which the liquid refrigerant and the lubricating oil do not enter the suction pipes 13 and 13 inside the accumulator 2 becomes the liquid retaining capacity.

In the air conditioner 100 that uses the sealed compressor 1 with such a configuration, when power is first supplied to the motor unit 12 of the sealed compressor 1 from a driving device such as an inverter, the rotor 52 rotates, and hence the rotary shaft 23 fixed to the rotor 52 rotates. Due to the rotation of the rotary shaft 23, the crank eccentric portions 28 and 28 and the rollers 24 and 24 eccentrically rotate. By the rotational sliding actions of the rollers 24 and 24, the refrigerant suctioned into the first cylinder chamber 21a and the second cylinder chamber 22a is compressed.

When the rollers 24 and 24 move to a predetermined position, the first and second open/close valves 35 and 38 are opened, and the compressed refrigerant is discharged from the first discharge hole 34 and the second discharge hole 37 into the sealed container 10 through the first valve cover 33 and the second valve cover 36. The refrigerant which flow into the sealed container 10 moves to the four-way valve 101 through the discharge pipe 14.

Here, the four-way valve 101 connects the secondary side of the sealed compressor 1 to the outdoor heat exchanger 102 during the cooling operation of the air conditioner 100. As indicated by the solid arrow C of FIG. 1, the refrigerant compressed by the sealed compressor 1 passes through the outdoor heat exchanger 102, and exchanges heat with the outdoor air so as to be condensed. Subsequently, the condensed refrigerant passes through the indoor heat exchanger 104 through the expansion device 103, exchanges heat with the indoor air, evaporates, and cools the indoor air.

The refrigerant which passes through the indoor heat exchanger 104 passes through the four-way valve 101 and moves to the accumulator 2. In the refrigerant which moves into the accumulator 2, the liquid refrigerant and the lubricating oil are stored in the accumulator 2 by the gas/liquid separation unit 62, and the gas refrigerant are suctioned from the suction pipes 13 into the sealed compressor 1. Further, at this time, the stored lubricating oil is suctioned from the oil return hole 13a and is suctioned into the first cylinder chamber 21a and the second cylinder chamber 22a along with the gas refrigerant. By repeating these operations, the air conditioner 100 performs a heat exchange operation as a cooling operation.

Furthermore, in the heating operation of the air conditioner 100, the four-way valve 101 connects the secondary side of the sealed compressor 1 to the indoor heat exchanger 104. As indicated by the dashed arrow H of FIG. 1, the refrigerant compressed by the sealed compressor 1 passes through the indoor heat exchanger 104 and exchanges heat with the indoor air to be condensed. The condensed refrigerant passes through the outdoor heat exchanger 102 through the expansion device 103, and exchanges heat with the outdoor air in the outdoor heat exchanger 102 to evaporate. The evaporating refrigerant is separated into gas and liquid through the four-way valve 101 and the accumulator 2, and is suctioned by the sealed compressor 1. By repeating these operations, the air conditioner 100 performs a heat exchange operation as a heating operation.

Next, the basis of the setting of the respective dimensions of the sealed compressor 1 according to the embodiment will be described in detail by referring to FIGS. 3 to 5.

In the sealed compressor 1 using the rollers 24, when the ratio Aac/Acy between the inner diameter cross-sectional area Aac (mm²) of the container 61 of the accumulator 2 and the inner diameter cross-sectional area Acy (mm²) of each of the first and second cylinder chambers 21a and 22a (the inner diameter cross-sectional area of one cylinder chamber) becomes larger than 4, the inner diameter of the accumulator 2 increases, the entire sealed compressor 1 increases in size, the weight balance becomes poor, and the installation property is degraded. On the contrary, in the sealed compressor 1 of the embodiment, since the ratio Aac/Acy is set to 4 or less, the accumulator and the entire sealed compressor 1 decrease in size and the weight balance and the installation property may be improved.

Further, when the ratio Aac/Acy is simply set to 4 or less, the inner diameter of the accumulator 2 decreases, and hence there is a concern that the gas/liquid separation function may be degraded. For this reason, as a result of various experiments, when the ratio Vac/Vcy between the liquid retaining capacity Vac from the lower surface of the container 61 to the upper end of the suction pipe 13 of the accumulator 2 and the total displacement volume Vcy of the rotary compression mechanism section 11 (the sum of the displacement volumes of the first and second cylinders 21 and 22) is set to 20 or more, a sufficient liquid retaining capacity may be ensured, and the liquid back may be prevented.

Further, FIG. 3 illustrates the relation between the ratio As/Acy between the total inner diameter cross-sectional area As of extension portions inside the accumulator of the suction pipes 13 and 13 (the sum of the inner diameter cross-sectional areas of two suction pipes) and the inner diameter cross-sectional area Acy (mm²) of each of the first and second cylinder chambers 21a and 22a (the inner diameter cross-sectional area of one cylinder chamber) and the ratio Ws/Wth between the suction loss Ws of extension portions inside the accumulator of the suction pipes 13 and 13 and the theoretical work Wth of the compressor. That is, in FIG. 3, the horizontal axis indicates the ratio As/Acy, and the vertical axis indicates the ratio Ws/Wth. From FIG. 3, it is understood that the ratio Ws/Wth increases as the ratio As/Acy decreases and the ratio Ws/Wth, that is, the ratio of the suction loss with respect to the theoretical work abruptly increases particularly when the ratio As/Acy becomes smaller than 0.12.

As described above, when the ratio As/Acy is set to 0.12 or more, the suction loss Ws of the suction pipes 13 and 13 inside the accumulator 2 with respect to the theoretical work Wth of the compressor may be set to substantially 2% or less as illustrated in FIG. 3. Here, the theoretical work Wth of the compressor indicates the theoretical work which is derived by the design calculation of the sealed compressor 1.

Furthermore, FIG. 3 illustrates the measurement characteristics of four types of sealed compressors by preparing the sealed compressor in which the heights of the first cylinder 21 and the second cylinder 22 are respectively set to 18 mm using the configuration of two cylinders of the first cylinder 21 and the second cylinder 22 of the embodiment, the sealed compressor in which the heights of the first cylinder 21 and the second cylinder 22 are respectively set to 22 mm using the above-described configuration, the single cylinder type sealed compressor with one cylinder in which the height of the cylinder is set to 20 mm, and the single cylinder type sealed compressor in which the height of the cylinder is set to 25 mm. As illustrated in FIG. 3, the characteristics of four types of the sealed compressors substantially overlap one another along the same curve. In the four types of the sealed compressors, the inner diameters of the respective cylinder chambers are set to 43 mm and the characteristics are measured by adjusting the operation rotation speed so that the cooling ability becomes 15 kw using the refrigerant of R410A.

As apparent from FIG. 3, since the relation of As/Acy≦0.12 is set, the suction loss ratio Ws/Wth (%) may be reduced regardless of the number of the cylinders or the volume thereof, and an abrupt increase in the suction loss may be prevented.

FIG. 4 is an explanatory diagram illustrating a relation between the area ratio As/Acy of the total inner diameter cross-sectional area As of the extension portion inside the accumulator of the suction pipe of the sealed compressor 1 and the inner diameter cross-sectional area Acy of one cylinder chamber and the in-pipe flow velocity Vs(m/s) of the extension portion inside the accumulator of the suction pipe, where the horizontal axis indicates the area ratio As/Acy and the vertical axis indicates the in-pipe flow velocity Vs(m/s).

In a case where the ratio As/Acy is set to 0.12 or more, as illustrated in FIG. 4, there is a tendency that the in-pipe flow velocity Vs (m/s) of the suction pipe 13 inside the accumulator 2 decreases as the ratio As/Acy increases even when one cylinder or two cylinders are used.

The suction pipe 13 inside the accumulator 2 is provided with the oil return hole 13a that returns the lubricating oil accumulated in the accumulator 2, and the lubricating oil is returned from the oil return hole 13a to the first cylinder chamber 21a and the second cylinder chamber 22a. Here, when the in-pipe flow velocity Vs decreases, there is a concern that the oil may not be sufficiently returned from the oil return hole 13a.

However, as illustrated in FIG. 4, when the relation of As/Acy≦0.25 is satisfied, the in-pipe flow velocity Vs may be maintained at 1 (m/s) or more, and the oil may be reliably returned by the oil return hole 13a.

FIG. 5 is an explanatory diagram illustrating a relation between the area ratio As/Acy and the ratio Ws/Wth of the suction loss Ws and the theoretical work Wth of the compressor in the sealed compressor 1 at the rated rotation speed (60 rps) and the high rotation speed (125 rps).

As apparent from FIG. 5, when the relation of 0.12≦As/Acy≦0.25 and Vac/Vcy≧20 is satisfied, the suction loss ratio Ws/Wth (%) may be reduced at not only the rated rotation speed (60 rps) but also the high rotation speed (125 rps), and an increase in the suction loss may be prevented.

Further, when the ratio L/Dcy of the axial distance L (mm) between the upper surface of the first cylinder 21 and the lower surface of the second cylinder 22 and the inner diameter φDcy (mm) of each of the first and second cylinders 21 and 22 (the inner diameter of one cylinder chamber) is set to be smaller than 0.9, the heights (thicknesses) of the first and second cylinders 21 and 22 decrease, and the suction ports connecting the suction pipes 13 and 13 also decrease in size, so that the suction loss increases. Meanwhile, when the ratio L/Dcy becomes larger than 1.1, the distance between the bearings increases, and the rotary shaft is bent by the compression load, so that the performance is degraded.

On the contrary, when the relation of 0.9≦L/Dcy≦1.1 is satisfied, the large suction ports of the first cylinder 21 and the second cylinder 22 may be ensured, and an increase in the distance between the bearings may be suppressed, so that degradation in performance may be prevented.

Further, when the relation of the distance Lc (mm) between the axial center of the first cylinder 21 and the axial center of the second cylinder 22 and the distance Lp (mm) between the axial centers of the connecting portions of two suction pipes 13 and 13 with respect to the first cylinder 21 and the second cylinder 22 is set as Lp>Lc, the distance Lp between the axial centers of the suction pipes 13 and 13 may be increased. That is, when the suction pipes 13 and 13 are connected to the sealed container 10, the member connecting the suction pipes 13 and 13 is connected to the sealed container 10 by welding. For this reason, when the distance Lp between the axial centers of the suction pipes 13 and 13 is set to a large value as possible, degradation in strength caused by welding may be prevented.

As described above, according to the air conditioner 100 that uses the sealed compressor 1 of the embodiment, since the above-described configuration is employed, even when the sealed compressor 1 is operated in a high-speed rotation state, an abrupt increase in the suction loss may be prevented, and degradation in suction loss may be reduced. Further, according to the air conditioner 100 that uses the sealed compressor 1, the oil is reliably returned, and hence the reliability may be improved.

Furthermore, the invention is not limited to the refrigeration cycle device 100 that uses the sealed compressor 1 of the embodiment. In the sealed compressor 1 of the above-described embodiment, a configuration has been described in which two cylinders, that is, the first cylinder 21 and the second cylinder 22 are used as the cylinders, but the invention is not limited thereto. In the relation of Aac/Acy≦4, 0.12≦As/Acy≦0.25, and Vac/Vcy≧20, the number of cylinders may be one or three or more.

With such a configuration, as illustrated in FIGS. 3 and 4, even in one cylinder, the suction loss may be reduced and the in-pipe flow velocity Vs of the suction pipe 13 for returning the oil may be obtained as in the sealed compressor 1 of the embodiment using two cylinders. Further, the same effect may be obtained even in three cylinders.

Further, in the above-described example, the refrigeration cycle device 100 has been described as the air conditioner 100 with a configuration having the four-way valve 101, but the invention is not limited thereto. For example, the refrigeration cycle device 100 may also be a refrigeration cycle device that performs only a heating operation or a cooling operation without the four-way valve 101 or a refrigeration cycle device other than the air conditioner.

Moreover, in the above-described example, the sealed compressor 1 has been described using a configuration in which the roller 24 and the blade are separately provided, but the invention is not limited thereto. For example, even in a swing type sealed compressor in which a roller and a blade are integrally provided, the same effect may be obtained.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.

Claims

1. A sealed compressor comprising a rotary compression mechanism section accommodated in a sealed casing and an accumulator provided outside the sealed casing, the compressor configured to suction a working fluid to the rotary compression mechanism section through at least one suction pipe extending into the accumulator and connected thereto,

wherein the rotary compression mechanism section comprises at least one cylinder each forming a cylinder chamber, and

when an inner diameter cross-sectional area of the accumulator is denoted by Aac (mm2), an inner diameter cross-sectional area of one cylinder chamber is denoted by Acy (mm2), a liquid retaining capacity to an upper end of the suction pipe inside the accumulator is denoted by Vac (cc), a total displacement volume of the rotary compression mechanism section is denoted by Vcy (cc), and a total inner diameter cross-sectional area of an extension portion inside the accumulator of the suction pipe is denoted by As (mm2), a relation of

Aac/Acy ≦4,

Vac/Vcy≧20, and

As/Acy≧0.12 is satisfied.

2. The sealed compressor of claim 1,

wherein the inner diameter cross-sectional area Acy (mm2) of one cylinder chamber and the total inner diameter cross-sectional area As (mm2) of the extension portion inside the accumulator of the suction pipe have a relation of

As/Acy 0.25.

3. The sealed compressor of claim 1,

wherein the rotary compression mechanism section comprises two cylinders provided with a partition plate interposed therebetween, and

when an inner diameter of one cylinder chamber is denoted by Dcy (mm) and a distance between end surfaces of said two cylinders opposite to the partition plate is denoted by L (mm),

a relation of 0.9≦L/Dcy≦1.1 is satisfied.

4. The sealed compressor of claim 1,

wherein the rotary compression mechanism section comprises two cylinders provided with a partition plate interposed therebetween and two suction pipes connecting the respective cylinders to the accumulator, and

when a distance between axial centers of the respective cylinders is denoted by Lc (mm) and a distance between axial centers of connecting portions of the two suction pipes with the respective cylinders is denoted by Lp (mm),

a relation of Lp>Lc is satisfied.

5. A refrigeration cycle device comprising:

the sealed compressor of claim 1;

a condenser connected to the sealed compressor;

an expansion device connected to the condenser; and

an evaporator connected to the expansion device.