Scroll fluid machine

Abstract

In the scroll fluid machine in which an orbiting scroll 10 is pivot-driven by a rotary shaft 102 rotatably supported by the casing 100 and a pivot shaft 104 eccentrically and rotatably supported by the rotary shaft 102, as a method, a self-rotation prevention board 109 is attached to one end of the pivot shaft 104 and a self-rotation prevention pin 110 is attached to the self-rotation prevention board 109. The self-rotation prevention pin 110 is configured to perform an orbiting motion while keeping in contact with the inner surface of the self-rotation prevention bearing (guide body) 111. Further, as another method, the outer periphery of one end 104b of the pivot shaft is configure to perform an orbiting motion while keeping in contact with the inner surface of the balance bearing (guide body) 51. Based on these methods, an eccentrically pivot driven orbiting scroll performs an orbiting motion without whirling, and thus a high-speed operation of the scroll fluid machine is enabled.

Description

PRIORITY

This application claims priority to International application No. PCT/JP2008/073096 filed Dec. 18, 2008.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an eccentrically-orbiting-driving scroll fluid machine.

2. Description of the Related Art

A scroll fluid machine has a work part configured with combination of a fixed scroll having a spiral wrap on a paneling and a similar orbiting scroll. The aforementioned orbiting scroll is fixed to the shaft of a drive device and is driven to perform an orbiting motion without self-rotation, thereby the working fluid entering through an inlet tube is compressed and discharged through an outlet tube, and thus the scroll fluid machine functions as a compressor or a blower. If the high-pressure working fluid entering through the entrance of the fixed scroll is expanded and discharged through an exit, then the scroll fluid machine functions as an expander taking power from the shaft of the drive device.

An eccentrically-orbiting drive device, which has a pivot shaft, is proposed as a drive device used for a scroll fluid machine. For example, the scroll fluid machine as described in Japanese patent No. JP,3761503,B (20.1.2006) includes an eccentrically-orbiting drive device and a fluid machine body that is driven by the eccentrically-orbiting drive device. The pivot shaft of the aforementioned eccentrically-orbiting drive device is passing through the orbiting scroll of the fluid machine body and attached thereto. A first and a second eccentrically-orbiting support means are provided at both sides of the aforementioned orbiting scroll, supporting the pivot shaft such that the pivot shaft can perform an eccentrically-orbiting motion with respect to the fixed scroll of the aforementioned fluid machine body.

DISCLOSURE OF THE INVENTION

1. Problems to be Solved by the Invention

In this scroll fluid machine, a pivot shaft bearing supporting a pivot shaft is provided at both sides of an orbiting scroll. A rotary shaft bearing is provided at the outside of both pivot shaft bearings via a rotational body having the same axis line as the rotary shaft of eccentrically-orbiting drive device. As such, when the rotary shaft bearing is driven by the pivot shaft during operation, rotational resistance caused by the rotary shaft bearing and the pivot shaft bearing is applied in the moving direction of the pivot shaft without a mechanism of synchronizing the rotation of both pivot shafts. Thereby, a smooth drive of the pivot shaft is prevented, and thus corresponding wraps have contact with each other, possibly making noise or causing wear or welding of wraps. An object of the present invention is to prevent whirling while keeping a smooth drive of the pivot shaft and provide a configuration of preventing contact between corresponding wraps, occurrence of noise, and wear or welding of wraps.

2. Means for Solving the Problems

The present invention is to solve the aforementioned problems. One of the most important aspects of the present invention is to provide a reliable scroll fluid machine that prevents corresponding wraps from having contact with each other, which causes occurrence of vibration noise, wear or welding of wraps, with a configuration having little resistance in the moving direction. Thus, provided is a means for preventing the pivot shaft from being radially displaced even if the rotation speeds up and a centrifugal force of the orbiting scroll is increased or the differential pressure between the outlet pressure and the inlet pressure is increased and the load radially applied to the pivot shaft is increased.

In the present invention, a fluid machine comprises: a pivot shaft eccentrically and rotatably supported by a rotary shaft; a self-rotation prevention means for preventing the self-rotation of the pivot shaft; and a work part configured with combination of an orbiting scroll, fitted in a pivot drive part of the pivot shaft, having spiral wraps on both surfaces, and a pair of fixed scrolls fixed to one end of the casing; wherein the pivot shaft passes through the work part, a fixed scroll located at the most outer part has a guide body, and one end of the pivot shaft performs an orbiting motion guided by the guide body, and thus a load is generated so as to cancel the load radially applied to the pivot shaft. As such, the orbiting scroll is prevented from being displaced or inclined more than the given orbit radius. The guide body is a self-rotation prevention guide or a balance bearing attached to the fixed scroll at the most outer side. The self-rotation prevention guide guides the self-rotation prevention pins attached to more than two locations of the self-rotation prevention board that is attached to the tip of the pivot shaft. The balance bearing guides the tip of the pivot shaft.

3. Effect of the Invention

According to the scroll fluid machine of the present invention, one end of said pivot shaft performs an orbiting motion guided by said guide body, thereby a load is radially applied to the pivot shaft. The guide body generates a load, which can cancel the load radially applied to the pivot shaft. Thereby, the orbiting scroll is prevented from being displaced or inclined more than the given orbit radius. Further, even if the centrifugal force of the orbiting scroll is increased when the scroll fluid machine is driven at high-speed rotation, the wraps of the orbiting scroll and the fixed scroll are prevented from having contact with each other, thereby vibration noise, wear or welding of the wraps are prevented. Therefore, high-reliability scroll fluid machine can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an axis-direction cross-sectional view illustrating a first embodiment.

FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1.

FIG. 3 is a partial cross-sectional view illustrating a modified example of the first embodiment.

FIG. 4 is an axis-direction cross-sectional view illustrating another modified example of the first embodiment.

FIG. 5 is an axis-direction cross-sectional view illustrating a second embodiment.

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

FIG. 7 is a partial cross-sectional view illustrating a modified example of the second embodiment.

FIG. 8 is an axis-direction cross-sectional view illustrating a third embodiment.

FIG. 9 is an axis-direction cross-sectional view illustrating a fourth embodiment.

FIG. 10 is an axis-direction cross-sectional view illustrating a fifth embodiment.

FIG. 11 is an axis-direction cross-sectional view illustrating a sixth embodiment.

FIG. 12 is an axis-direction cross-sectional view illustrating a seventh embodiment.

FIG. 13 is an axis-direction cross-sectional view illustrating a modified example of the seventh embodiment.

FIG. 14 is a view illustrating a state in which scroll wraps are combined in FIG. 13.

FIG. 15 is an axis-direction cross-sectional view illustrating an eighth embodiment.

FIG. 16 is an axis-direction cross-sectional view illustrating a modified example of the eighth embodiment.

FIG. 17 is an axis-direction cross-sectional view illustrating a ninth embodiment.

FIG. 18 is an axis-direction cross-sectional view illustrating a tenth embodiment.

FIG. 19 is an axis-direction cross-sectional view illustrating a modified example of the tenth embodiment.

FIG. 20 is an axis-direction cross-sectional view illustrating a modified example of the ninth embodiment or the tenth embodiment.

FIG. 21 is an axis-direction cross-sectional view illustrating an eleventh embodiment.

FIG. 22 is a partial cross-sectional view illustrating a first example of a joint part between an orbiting scroll and orbiting drive shaft.

FIG. 23 is a partial cross-sectional view illustrating a second example of a joint part between an orbiting scroll and orbiting drive shaft.

FIG. 24 is a partial cross-sectional view illustrating a third example of a joint part between an orbiting scroll and orbiting drive shaft.

FIG. 25 is a partial cross-sectional view illustrating a part of self-rotation prevention bearing in a twelfth embodiment.

FIG. 26 is a partial cross-sectional view illustrating a part of balance bearing in a twelfth embodiment.

FIG. 27 is an axis-direction cross-sectional view illustrating a thirteenth embodiment.

DESCRIPTION OF SYMBOLS

• 1 first fixed scroll
• 2 second fixed scroll
• 3 third fixed scroll
• 3g heat insulating plate
• 4 fourth fixed scroll
• 5 fifth fixed scroll
• 6 sixth fixed scroll
• 10 orbiting scroll
• 11 first orbiting scroll
• 12 second orbiting scroll
• 13 third orbiting scroll
• 14 fourth orbiting scroll
• 36 vent hole
• 50 bearing block
• 51 balance bearing (guide body)
• 51a first balance bearing (guide body)
• 51b second balance bearing (guide body)
• 52 balance bearing inner race
• 52a first balance bearing inner race
• 52b second balance bearing inner race
• 53 cylinder member
• 60 self-rotation prevention board
• 61 self-rotation prevention pin
• 62 self-rotation prevention bearing (self-rotation prevention guide)
• 63 self-rotation prevention bearing inner race
• 64 self-rotation prevention slide member (self-rotation prevention guide)
• 71 outlet
• 84 inlet
• 85 exhaust outlet
• 100 casing
• 101 rotary shaft bearing
• 102 rotary shaft
• 103 pivot shaft bearing
• 104 pivot shaft
• 104a pivot drive part
• 104b one end of pivot shaft
• 104c another end of pivot shaft
• 104d second pivot drive part
• 107 inlet
• 108 outlet
• 109 self-rotation prevention board
• 110 self-rotation prevention pin
• 111 self-rotation prevention bearing (guide body)
• 112 self-rotation prevention bearing inner race
• 113 outlet cover
• 114 outlet chamber
• 115 self-rotation prevention slide member (guide body)
• 116 cylinder member
• 117 cover
• 207a compressor inlet
• 207b expander entrance
• 208a compressor outlet
• 208b expander exit
• 307 blower inlet
• 308 blower outlet

DESCRIPTION OF THE PREFERRED EMBODIMENTS

First Embodiment

FIG. 1 shows a first embodiment. FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1. The opposite face of wraps of a first fixed scroll 1 in which a paneling has spiral wraps are fixed to a casing 100. An orbiting scroll 10 in which a paneling has spiral wraps is provided on the first fixed scroll 1, and a second fixed scroll 2 in which a paneling has spiral wraps is provided on the orbiting scroll 10 and fixed to the first fixed scroll 1. The first fixed scroll 1, the orbiting scroll 10 and the second fixed scroll 2 constitute a work part. First fixed scroll wraps 1a and orbiting scroll wraps 10a provided on the orbiting scroll 10 are combined to constitute a set of first work chambers 21. Orbiting scroll wraps 10b provided on the orbiting scroll 10 and second fixed scroll wraps 2a are combined to constitute a set of second work chambers 22.

An outer race of the rotary shaft bearing 101 is provided at two positions of the casing 100. The rotary shaft 102 is fitted in an inner race of the rotary shaft bearing 101. A stator 105 of a motor is fixed to the casing 100 and a rotor 106 of the motor is fixed to the rotary shaft 102. A balancer 47 for balancing the whole centrifugal forces is provided on the rotary shaft 102. Bearing housing is provided at both ends of the rotary shaft 102, eccentrically located from the center of rotation. The outer race of the pivot bearing 103 is provided in the bearing housing. The pivot shaft 104 is fitted in the inner race of the pivot bearing 103. The pivot shaft 104 passes through a first fixed scroll through-hole 1c. A hole is provided in the center of the orbiting scroll 10. The hole is fitted to a pivot drive part 102a without relative rotation therebetween. One end of the pivot shaft 104b passes through a second fixed scroll through-hole 2c, extending outside. A self-rotation prevention board 109 is fixed to one end of the pivot shaft 104b. As shown in FIG. 2, a self-rotation prevention pin 110 is embedded at three locations on the inner side of the self-rotation prevention board 109. A self-rotation prevention bearing (guide body) 111 is provided on the front side of the second fixed scroll 2 as a self-rotation prevention guide. The self-rotation prevention board 109, self-rotation prevention pin 110 and the self-rotation prevention bearing (guide body) 111 constitute a self-rotation prevention means. The self-rotation prevention pin 110 is incorporated keeping in contact with the inner race 112 of the self-rotation prevention bearing. If the outer diameter of the self-rotation prevention pin 110 is defined as d1, the inner diameter of the inner race 112 of the self-rotation prevention bearing is defined as D1 and the orbit radius of the pivot shaft 104 when this fluid machine is driven, is defined as ε and the inner gap of the bearing is defined as δ, then d1, D1, ε and δ are determined so as to satisfy the following equation:

2ε−δ≦D1−d1≦2ε+δ  (Formula 1)

If the value of D1−d1 is determined as described above, the self-rotation prevention pin 110 can keep substantially in contact with the inner race 112 of the self-rotation prevention bearing, and thereby self-rotation of the pivot shaft 104 can be securely prevented. Further, one end 104b of the pivot shaft cannot be bent inward by a strong force. As such, noise does not occur and machine loss is reduced. One end 104b of the pivot shaft, even if a centrifugal force of the orbiting scroll 10 is applied to the pivot drive part 104a, does not bend further once the bearing inner gap of self-rotation prevention bearing (guide body) 111 becomes zero. Thereby, contact of scroll wraps can be prevented. As such, the scroll fluid machine, having even a large orbiting scroll, can rotate at high speed faster than conventional machines.

An outlet cover 113 is fixed to the outer face of second fixed scroll 2, sealing an outlet chamber 114. The outlet cover 113 encloses a self-rotation prevention board 109 and the self-rotation prevention bearing (guide body) 111. An outlet 108 is provided on the outlet cover 113. An inlet 107 is provided on the outer periphery of the second fixed scroll 2.

Next, operation of this scroll fluid machine is described. When windings of the stator 105 are energized, the rotor 106 rotates, thereby the rotary shaft 102 rotates such that the pivot shaft 104 is driven eccentrically, self-rotation being prevented as described below. The pivot drive part 104a, being a part of the pivot shaft 104 pivot drives the orbiting scroll 10. The first work chamber 21 including the first fixed scroll wrap 1a and the orbiting scroll wrap 10a and the second work chamber 22 including the second fixed scroll wrap 2a and the orbiting scroll wrap 10b move from the outer periphery side to the inner periphery side, and thus the volume is decreased, causing the inside fluid to be compressed. An orbiting paneling communication hole 10c is provided at the center part of the paneling of the orbiting scroll 10. As such, the work chamber 21 and the work chamber 22 are communicated at the center part. As a result, fluid is taken in through the inlet 107, compressed through an intake chamber 130, jointly flown into the work chamber 22, flown into the outlet chamber 114 through a second fixed scroll through-hole 2c, and discharged to the outside from the outlet 108.

Based on Formula 1 showing the relationships among the outer diameter d1 of the self-rotation prevention pin 110, the inner diameter D1 of the inner race 112 of the self-rotation prevention bearing and the orbit radius ε, the self-rotation prevention pin 110 performs an orbiting motion while applying a certain contact force constantly to the inner race 112 of the self-rotation prevention bearing. The self-rotation prevention board 109 performs an orbiting motion, however cannot rotate due to the self-rotation prevention pin 110 provided at two or more locations of the self-rotation prevention board 109. The self-rotation prevention board 109 is fixed to one end 104b of the pivot shaft 104, thereby the pivot shaft 104, being prevented from self-rotating, performs an orbiting motion. Further, the orbiting scroll 10, fitted in the pivot drive part 104a without relative rotation, is prevented from self-rotating and performs an orbiting motion.

Further, since the orbiting scroll 10 has mass, a centrifugal force occurs in an orthogonal direction to the shaft when the orbiting scroll 10 performs an orbiting motion. The whole centrifugal force is canceled by the balancer 47. However, the centrifugal force applies a load to the shaft such that the orbiting scroll is radially displaced. This load works to bend the pivot drive part 104a. The pivot drive part 104a is bent in the direction of a synthetic load around the pivot bearing 103 as a fulcrum point. As a result, the orbiting scroll 10 is also bent toward the synthetic load while being displaced. Thereby, orbiting scroll wraps 10a and 10b come close to the first fixed scroll wrap 1a and the second fixed scroll wrap 2a. When wraps come close to each other, gaps between the wraps, which are initially set to be small to minimize a leak, becomes zero, and triggering a slide. Thereby, slide loss occurs in wraps. Further, vibration noise occurs in the scroll fluid machine. Additionally, wear of wraps is increased, welding occurs between wraps, and so on. That is, both performance and reliability of the scroll fluid machine are lost.

However, according to the present invention, the self-rotation prevention pin 110 having contact with the self-rotation prevention bearing inner race 112, one end of the pivot shaft 104b cannot be displaced more than the orbit radius determined by the self-rotation prevention pin 110 and the self-rotation prevention bearing inner race 112.

Accordingly, even if the orbiting scroll 10 rotates at high speed, a centrifugal force is increased and thus a load bending the pivot drive part 104a becomes large, deflection of the pivot drive part 104a is prevented. As such, wraps do not contact each other. Therefore, the scroll fluid machine according to the present invention, can realize high-speed rotation compared to the conventional machines even if the scroll fluid machine has a large orbiting scroll.

FIG. 3 is a partial cross-sectional view illustrating a modified example of the first embodiment. As shown in FIG. 3, a self-rotation prevention slide member (guide body) 115 is used as a self-rotation prevention guide instead of the self-rotation prevention bearing (guide body) 111. The self-rotation prevention board 109, the self-rotation prevention pin 110 and the self-rotation prevention slide member (guide body) 115 constitute a self-rotation means. The self-rotation prevention slide member (guide body) 115 is made of self-lubricating material such as resin. The self-rotation prevention pin 110, which is in contact with and guided by the inner surface of the self-rotation prevention slide member (guide body) 115, performs an orbiting motion, thereby the self-rotation of the pivot shaft 104 and the orbiting scroll 10 is prevented while one end of pivot shaft 104b cannot be displaced more than the orbit radius determined by the self-rotation prevention pin 110 and the self-rotation prevention slide member (guide body) 115.

In this way, the self-rotation prevention pin 110 and the self-rotation prevention slide member (guide body) 115 are in contact with each other, and thus the self-rotation of the orbiting scroll can be securely prevented. Further, even if the centrifugal force of the orbiting scroll 10 is applied to the pivot drive part 104a, one end of pivot shaft 104b does not bend further after the self-rotation prevention pin 110 and the self-rotation prevention slide member (guide body) 115 come into contact. As such, contact between wraps can be prevented. Accordingly, the scroll fluid machine according to the present invention can perform an orbiting motion faster and more accurate than conventional machines, even with a large orbiting scroll.

FIG. 4 shows another modified example of the first embodiment. FIG. 4 shows an example of cooling with a fan 31 provided at the back end 102a of the rotary shaft when the first embodiment is used as a vacuum pump. A bearing board 35 is provided with a through-hole as a vent hole. An exhaust outlet 34 is provided on the lateral face of the casing 100 closer to the first fixed scroll 1 than the stator 105. The pivot shaft 104 is provided with a through-hole as a pivot shaft vent hole 32. A bottom plate 100a of the casing 100 has an opening to which a filter 30 is attached. When the fan 31 rotates together with the rotary shaft 102, air is taken in from the outside via the filter 30. The air entering through the filter 30 flows through a motor part space 33 in the casing 100 through the vent hole 36 and is exhausted to the outside through the exhaust outlet 34. In the mean time, the rotary shaft bearing 101 and the stator 105 are cooled down and are prevented from raising temperature excessively.

Further, air entering through the filter 30 flows out of the fan 31 and flows in an outlet chamber 114 through a pivot shaft vent hole 32, and is exhausted to the outside through the outlet 108 along with the air exhausted from a first work chamber 21 and a second work chamber 22. In the meantime the center part of the pivot bearing 101 and the orbiting scroll 10 is cooled down, thereby excessive temperature rise is prevented.

Further, FIG. 4 shows an example of a seal member provided to seal space between the work chamber side and the casing side when the first embodiment according to the present invention is used as a vacuum pump. A ring-shaped inner face seal 42 is attached so as to surround a firs fixed scroll through-hole 1c. A seal board 40 is in contact with the inner face seal 42 and attached to the pivot shaft 104. A seal cover 41 is attached to the casing side facing the seal board 40. A ring-shaped outer face seal 43 is attached to a seal cover 41, and is in contact with the seal board 40. Based on this configuration, space on the side of the work chamber and space on the side of the casing are double sealed sandwiching the first fixed scroll through-hole 1c. Thus, the exhausted gas from the work chamber is securely prevented from leaking into inside of the casing. Further, the exhausted gas is shut out from outside air by the outlet cover 113 and is discharged through an outside duct (not shown) connected to the outlet 108. Therefore, noxious or corrosive gas does not leak into outside air even though it may flow in the work chamber.

Second Embodiment

FIG. 5 shows a second embodiment. FIG. 6 is a cross-sectional view taken along line A-A. The same parts as those in the first embodiment employ the same symbols and names and the description is not repeated. The outlet cover 113 is attached to the outside face of the paneling of the second fixed scroll 2. A balance bearing (guide body) 51 is attached to the inside of the outlet cover 113. The outer periphery of one end 104b of the pivot shaft performs an orbiting motion while keeping in contact with the inner race 52 of the balance bearing. If the outer diameter of one end 104b of the pivot shaft is defined as d2, the inner diameter of the inner race 52 of the balance bearing is defined as D2 and the orbit radius of the pivot shaft 104 when this scroll fluid machine is driven, is defined as ε and an inner gap of the bearing is defined as δ, then d2, D2, ε and δ are determined so as to satisfy the following equation:

2ε−δ≦D2−d2≦2ε+δ  (Formula 2)

If the value of D2−d2 is determined as described above, one end 104b of the pivot shaft can keep substantially in contact with the inner race 52 of the balance bearing. Further, one end 104b of the pivot shaft cannot be bent inward by a strong force. As such, noise hardly occurs and machine loss is reduced. One end 104b of the pivot shaft, even if a centrifugal force of the orbiting scroll 10 is applied to the pivot drive part 104a, does not bend further when the bearing inner gap of balance bearing (guide body) 51 becomes zero. Thereby, contact of scroll wraps can be prevented. As such, the scroll fluid machine, having even a large orbiting scroll, can rotate at high speed faster than conventional machines.

A self-rotation prevention board 60 is fixed to another end 104c of the pivot shaft. The self-rotation prevention pin 61 is embedded in more than two locations of the self-rotation prevention board 60. A self-rotation prevention bearing 62 is attached to the bottom plate 100a of the casing 100. The self-rotation prevention pin 61 performs an orbiting motion while keeping in contact with an inner race 63 of the self-rotation prevention bearing.

If the outer diameter of the self-rotation prevention pin 61 is defined as d3, the inner diameter of the inner race 63 of the self-rotation prevention bearing is defined as D3 and the orbit radius of the pivot shaft 104 when this fluid machine is driven, is defined as ε and an inner gap of the bearing is defined as δ, then d3, D3, ε and δ are determined so as to satisfy the following equation:

2ε−δ≦D3−d3≦2ε+δ  (Formula 3)

If the value of D3−d3 is determined as described above, the self-rotation prevention pin 61 can keep substantially in contact with the inner race 63 of the self-rotation prevention bearing. Thus, the self-rotation of the orbiting scroll 10 can be securely prevented. Further, another end 104c of the pivot shaft cannot be bent inward by a strong force. As such, noise hardly occurs and machine loss is reduced.

FIG. 7 shows a modified example of the second embodiment. As shown in FIG. 7, one end 104b of the pivot shaft is barrel shaped, having a curved surface along the axis direction. This can prevent one end 104b of the pivot shaft from having partial contact with the inner race 52 of the balance bearing. As such, the contact surface between one end 104b of the pivot shaft and the inner race 52 of the balance bearing is prevented from causing scoring and galling. Therefore, reliability of the scroll fluid machine is improved. Further, a self-rotation prevention slide member 64 is used as a guide of the self-rotation prevention pin 61 attached to the self-rotation prevention board 60. The self-rotation prevention slide member 64 is formed of self-lubricating material such as resin. The self-rotation prevention slide member 64 may be formed of metal material, to which wear-resistance surface treatment is applied.

Third Embodiment

FIG. 8 shows a third embodiment. A cover 70 seals outer surface of the center part of the second fixed scroll 2, insulating the work chamber from outside air. Further, an outlet 71 is provided on the bottom side with respect to a stator 105 at the outer periphery of the casing 100. Fluid flowing through an inlet 107, is compressed in the first work chamber 21 and the second work chamber 22, flows in the casing 100 through the first fixed scroll through-hole 1c, and is discharged to the outside through the outlet 71 after passing through the inside of the casing 100. According to this configuration, the simply formed cover 70 can be used instead of outlet cover 113. As such, one work piece can be saved in the scroll fluid machine, thereby cost can be reduces. Further the total length can be shortened without projections. Also, the inside of the casing can be cooled down by circulating working fluid.

Fourth Embodiment

FIG. 9 shows a fourth embodiment. The fluid machine shown in FIG. 9 is a twin-type scroll fluid machine, which has scrolls at both ends of the pivot shaft 104. The opposite face of wraps of the first fixed scroll 1 is fixed to the right side of the casing 100. A first orbiting scroll 11 is provided over the first fixed scroll 1. The second fixed scroll 2 is provided over the first orbiting scroll 11 and is fixed to the first fixed scroll 1. The first fixed scroll 1, the first orbiting scroll 11 and the second fixed scroll 2 constitute a work part at one end of the pivot shaft.

The first fixed scroll wrap 1a and the first orbiting scroll wrap 11a are combined to constitute a set of first work chambers 21. The first orbiting scroll wrap 11b and the second fixed scroll wrap 2a are combined to constitute a set of second work chambers 22. A first orbiting paneling communication hole 11c is provided in the center of the paneling of the first orbiting scroll 11. Thereby, the first work chamber 21 is communicated with the second work chamber 22 through the first orbiting paneling communication hole 11c. As a result, fluid is taken in through a first inlet 107a, is compressed through a first intake chamber 131, jointly flows into the work chamber 22, flows into the outlet chamber 114a in a first outlet cover 113a through a second fixed scroll through-hole 2c, and discharged to the outside from the outlet 108a.

The opposite face of wraps of the third fixed scroll 3 is fixed to the left side of the casing 100. A second orbiting scroll 12 is provided over the third fixed scroll 3. The fourth fixed scroll 4 is provided over the second orbiting scroll 12 and is fixed to the third fixed scroll 3. The third fixed scroll 3, the second orbiting scroll 12 and the fourth fixed scroll 4 constitute a work part at another end of the pivot shaft. The third fixed scroll wrap 3a and the second orbiting scroll wrap 12a are combined to constitute a set of third work chambers 23. The second orbiting scroll wrap 12b and the fourth fixed scroll wrap 4a are combined to constitute a set of fourth work chambers 24.

The rotary shaft 102 rotates and the pivot shaft 104 is eccentrically driven without self-rotation. A second pivot drive part 104d, being a part of the pivot shaft 104, pivot drives the orbiting scroll 12. Working fluid moves from the outer periphery to the inner periphery of the third work chamber 23 and the fourth work chamber 24 and the volume is decreased and compressed.

A second orbiting paneling communication hole 12c is provided in the center part of the paneling of the second orbiting scroll 12. Thereby, the third work chamber 23 is communicated with the fourth work chamber 24 through the second orbiting paneling communication hole 12c. As a result, working fluid taken in through a second inlet 107b, is compressed through a second intake chamber 132, passes through the fourth fixed scroll through-hole 4c, flows into the second outlet chamber 114b in a second outlet cover 113b through a second fixed scroll through-hole 2c, and discharged to the outside from the second outlet 108b.

The outer race of the rotary shaft bearing 101 is provided at two locations in the casing 100. The rotary shaft 102 is fitted in the inner race of the rotary shaft bearing 101. A balancer 47 is attached at two locations of the rotary shaft 102 to keep a balance of the whole centrifugal forces. The stator 105 of a motor is fixed to the casing 100 and the rotor 106 of the motor is fixed to the rotary shaft 102. A balancer 47 for balancing the whole centrifugal forces is provided on the rotary shaft 102. Bearing housing is provided at both ends of the rotary shaft 102, eccentrically located from the center of rotation. The outer race of the pivot bearing 103 is provided in the bearing housing. The pivot shaft 104 is fitted in the inner race of the pivot bearing 103. The pivot shaft 104 passes through the first fixed scroll through-hole 1c. A hole is provided in the center of the first orbiting scroll 11. The hole is fitted to a pivot drive part 104a without relative rotation therebetween. One end of the pivot shaft 104b passes through the second fixed scroll through-hole 2c, extending outside. The self-rotation prevention board 109 is fixed to one end of the pivot shaft 104b. As shown in FIG. 2, a self-rotation prevention pin 110 is embedded at three locations on the inner side of the self-rotation prevention board 109. A self-rotation prevention bearing (guide body) 111 is provided on the front side of the second fixed scroll 2. The self-rotation prevention pin 110 is incorporated keeping in contact with the inner race 112 of the self-rotation prevention bearing. If the outer diameter of the self-rotation prevention pin 110 is defined as d1, the inner diameter of the inner race 112 of the self-rotation prevention bearing is defined as D1 and the orbit radius of the pivot shaft 104 when this fluid machine is driven, is defined as ε and the inner gap of the bearing is defined as δ, d1, D1, ε and δ are determined so as to satisfy the Formula 1.

The pivot shaft 104 passes through the third fixed scroll through-hole 3c. A hole is provided in the center of the second orbiting scroll 12. The hole is fitted to a second pivot drive part 104d without relative rotation therebetween. Another end 104c of the pivot shaft passes through a fourth fixed scroll through-hole 4c, extending outside. A bearing block 50 is attached to the outside face of the paneling of the fourth fixed scroll 4. A balance bearing (guide body) 51 is attached to the inside of the bearing block 50. The outer periphery of another end 104c of the pivot shaft performs an orbiting motion while keeping in contact with the inner race 52 of the balance bearing. If the outer diameter of another end 104c of the pivot shaft is defined as d2, the inner diameter of the inner race 52 of the balance bearing is defined as D2 and the orbit radius of the pivot shaft 104 when this scroll fluid machine is driven, is defined as ε and an inner gap of the bearing is defined as δ, d2, D2, ε and δ are determined so as to satisfy the Formula 2.

According to this embodiment, as described above, a set of scroll parts is provided at one end of the casing 100 while another set of scroll part is provided at another end of the casing 100. As such, this embodiment can produce twice the flow volume compared to a fluid machine provided with a single set of the scroll part at one end of the casing 100. A self-rotation prevention mechanism is provided at one end 104b of the pivot shaft, on the right side of the pivot shaft 104, Further, relationships among the outer diameter of the self-rotation prevention pin 110 and the inner diameter of the inner race 112 of the self-rotation prevention bearing 112 is determined by the Formula 1. Thus, the self-rotation of the pivot shaft 104 can be securely prevented. Further, deflection of one end 104b of the pivot shaft due to centrifugal force is prevented. The outer periphery of another end 104c of the pivot shaft performs an orbiting motion while keeping in contact with the inner race 52 of the balance bearing.

Further, the relationship between another end 104c of the pivot shaft and the inner race 52 of the balance bearing is determined by Formula 2. Therefore, deflection of another end 104c of the pivot shaft due to centrifugal force is prevented.

Fifth Embodiment

FIG. 10 shows a fifth embodiment. The structure of the drive part is the same as the fourth embodiment. The same components as the fourth embodiment employ the same symbols and names and the description is not repeated. A part of this embodiment, which is different than the fourth embodiment, is described. One end 104b of the pivot shaft passes through the through-hole 2c of the second fixed scroll and extends to outside. A first outlet cover 113a is attached to the outside face of the paneling of the second fixed scroll 2. A first balance bearing (guide body) 51a is attached to the inside of the first outlet cover 113a. The outer periphery of one end 104b of the pivot shaft performs an orbiting motion while keeping in contact with the inner race 52a of the first balance bearing. If the outer diameter of one end 104b of the pivot shaft is defined as d2, the inner diameter of the inner race 52a of the first balance bearing is defined as D2 and the orbit radius of the pivot shaft 104 when this scroll fluid machine is driven, is defined as ε and an inner gap of the bearing is defined as δ, then d2, D2, ε and δ are determined so as to satisfy Formula 2.

A second outlet cover 113b is attached to the outside face of the paneling of the fourth fixed scroll 4. A second balance bearing (guide body) 51b is attached to the inside of the second outlet cover 113b. The outer periphery of another end 104c of the pivot shaft performs an orbiting motion while keeping in contact with the inner race 52b of the second balance bearing. If the outer diameter of another end 104c of the pivot shaft is defined as d2, the inner diameter of the inner race 52b of the second balance bearing is defined as D2 and the orbit radius of the pivot shaft 104 when this fluid machine is driven, is defined as ε and an inner gap of the bearing is defined as δ, then d2, D2, ε and δ are determined so as to satisfy Formula 2.

A self-rotation prevention board 60 is provided between the right side of the pivot bearing 103 and the paneling of the first fixed scroll 1 to prevent relative rotation therebetween. A self-rotation prevention pin 61 is embedded at three locations in the outer periphery of the self-rotation prevention board. A self-rotation prevention bearing 62 is provided on the paneling of the first fixed scroll 1. A self-rotation prevention pin 61 performs an orbiting motion while keeping in contact with the inner race 63 of the self-rotation prevention bearing. If the outer diameter of the self-rotation prevention pin 61 is defined as d3, the inner diameter of the inner race 63 of the self-rotation prevention bearing is defined as D3 and the orbit radius of the pivot shaft 104 when this fluid machine is driven, is defined as ε and an inner gap of the bearing is defined as δ, then d3, D3, ε and δ are determined so as to satisfy Formula 3.

According to this embodiment, as described above, a set of scroll parts is provided at one end of the casing 100 while another set of scroll part is provided at another end of the casing 100. As such, this embodiment, similarly to the fourth embodiment according to the present invention, can produce twice the flow volume compared to a fluid machine provided with a single set of the scroll part at one end of the casing 100. The outer periphery of one end 104b of the pivot shaft performs an orbiting motion while keeping in contact with the inner race 52a of the first balance bearing. The relationship between one end 104b of the pivot shaft and the inner race 52a of the first balance bearing is determined by Formula 2. Therefore, deflection of one end 104b of the pivot shaft due to centrifugal force is prevented. Further, the outer periphery of another end 104c of the pivot shaft performs an orbiting motion while keeping in contact with the inner race 52b of the second balance bearing. Also, the relationship between another end 104c of the pivot shaft and the inner race 52b of the second balance bearing is determined by Formula 2. Therefore, deflection of another end 104c of the pivot shaft due to centrifugal force is prevented.

Sixth Embodiment

FIG. 11 shows a sixth embodiment. A first cover 70a seals outer surface of the center part of the second fixed scroll 2, insulating the work chamber from outside air. Further, a second cover 70b seals outer surface of the center part of the fourth fixed scroll 4, insulating the work chamber from outside air. Further, the outlet 71 is provided on a part of the lateral face of the casing 100. The fluid flowing out through the first work chamber 21 and the second work chamber 22 flows in the casing 100 via the through-hole 1c of the first fixed scroll. The fluid passes through the inside of the casing 100 and is discharged to the outside through the outlet 71. According to this configuration, as shown in FIG. 11, the simply formed first cover 70a and second cover 70b can be used instead of the first outlet cover 113a and the second outlet cover 113b as shown in FIG. 10. As such, two work pieces can be saved in this structure, thereby cost can be saved while the total length can be shortened without projections. Also, the inside of the casing can be cooled down by compressed working fluid.

Seventh Embodiment

FIG. 12 shows a seventh embodiment. FIG. 12 shows a fluid machine in which the pivot drive part 104a includes a pair of scrolls. The same components as the first embodiment employ the same symbols and names and the description is not repeated. The opposite face of wraps of the first fixed scroll 1 is fixed to the casing 100. The first orbiting scroll 11 is provided over the first fixed scroll 1. The third fixed scroll 3 is provided over the first orbiting scroll 11 and is fixed to the first fixed scroll 1. The second orbiting scroll 12 is provided over the third fixed scroll 3. The second fixed scroll 2 is provided over the second orbiting scroll 12 and is fixed to the first fixed scroll 1 together with the third fixed scroll 3. The first fixed scroll 1, the first orbiting scroll 11, the third fixed scroll 3, the second orbiting scroll 12 and the second fixed scroll 2 constitute a work part.

A set of first work chamber 21 is formed with a combination of the first fixed scroll wrap 1a and the first orbiting scroll wrap 11a. A set of second work chamber 22 is formed with a combination of the first orbiting scroll wrap 11b and the third fixed scroll wrap 3a. A set of third work chamber 23 is formed with a combination of the third fixed scroll wrap 3b and the second orbiting scroll wrap 12a. A set of fourth work chamber 24 is formed with a combination of the second orbiting scroll wrap 12b and the second fixed scroll wrap 2a.

An intake communication hole 3d is provided in the third fixed scroll 3 and thus a first intake chamber 131 and a second intake chamber 132 are communicated. A first orbiting paneling communication hole 11c is provided in the center part of the paneling of the first orbiting scroll 11. Thereby, the first work chamber 21 is communicated with the second work chamber 22 through the first orbiting paneling communication hole 11c. A second orbiting paneling communication hole 12c is provided in the center part of the paneling of the second orbiting scroll 12. Thereby, the third work chamber 23 is communicated with the fourth work chamber 24 through the second orbiting paneling communication hole 12c. Therefore, fluid is taken into every work chamber and is discharged to the outside through the outlet 108.

The pivot shaft 104 passes through the first fixed scroll through-hole 1c. A hole is provided in the center of the first orbiting scroll 11. The hole is fitted to the pivot drive part 104a without relative rotation. The pivot shaft 104 passes through the third fixed scroll through-hole 3c. A hole is provided in the center of the second orbiting scroll 12. The hole is fitted to the pivot drive part 104a without relative rotation. One end 104b of the pivot shaft passes through the second fixed scroll through-hole 2c and extends to the outside. An outlet cover 113 is attached to the outer surface of the paneling of the second fixed scroll 2. A balance bearing (guide body) 51 is attached to the inside the outlet cover 113. The outer periphery of one end 104b of the pivot shaft performs an orbiting motion while keeping in contact with the inner race 52 of the balance bearing. If the outer diameter of one end 104b of the pivot shaft is defined as d2, the inner diameter of the inner race 52 of the balance bearing is defined as D2 and the orbit radius of the pivot shaft 104 when this scroll fluid machine is driven, is defined as ε and an inner gap of the bearing is defined as δ, then d2, D2, ε and δ are determined so as to satisfy Formula 2. A self-rotation prevention mechanism similarly to the second embodiment is incorporated in another end 104 of the pivot shaft 104c. A self-rotation prevention bearing is attached to the bottom board 100a. The self-rotation prevention pin 61 is maintained substantially in contact with the inner race 63 of the self-rotation prevention bearing. As such, the self-rotation of the pivot shaft 104 is securely prevented.

According to this embodiment, one end 104b of the pivot shaft and the inner race 52 of the balance bearing are maintained substantially in contact with each other. Thereby, even if the centrifugal force of the first orbiting scroll 11 and the second orbiting scroll 12 is applied to the pivot drive part 104a, one end 104b of the pivot shaft is not bent more when the inner gap of the bearing in the inner race 52 of the balance bearing becomes zero. As such, contact between wraps is prevented. Further, even if the scroll fluid machine includes a large orbiting scroll, it can rotate faster than the conventional machines. Further, the scroll fluid machine can produce twice the flow volume compared to the fluid machine provided with a single set of the scroll at one end of the casing 100.

FIGS. 13 and 14 show an example in which phase is shifted between intake and discharge in the seventh embodiment. The scroll fluid machine can shift the phase of intake and discharge with respect to eccentric direction of the pivot shaft by changing rotational direction position of the wrap when installing the machine. As shown in FIG. 14, in combinations of the first fixed scroll wrap 1a and the first orbiting scroll wrap 11a, the third fixed scroll wrap 3a and the first orbiting scroll wrap 11b, the third fixed scroll wrap 3b and the second orbiting scroll wrap 12a, and the second fixed scroll wrap 2a and the second orbiting scroll wrap 12b, the phase of the wraps is shifted by 90 degrees respectively. Accordingly, the first orbiting scroll wrap 11a, the first orbiting scroll wrap 11b, the second orbiting scroll wrap 12a, the second orbiting scroll wrap 12b are all eccentric toward the same direction (in the right direction in the drawing). Nevertheless, the phase of the four work chambers is shifted by 90 degrees respectively.

Eighth Embodiment

FIG. 15 shows an eighth embodiment. The same components as the first embodiment employ the same symbols and names and the description is not repeated. The opposite face of wraps of the first fixed scroll 1 is fixed to the right side of the casing 100. The first orbiting scroll 11 is provided over the first fixed scroll 1. The third fixed scroll 3 is provided over the first orbiting scroll 11 and is fixed to the first fixed scroll 1. The second orbiting scroll 12 is provided over the third fixed scroll 3. The second fixed scroll 2 is provided over the second orbiting scroll 12 and is fixed to the first fixed scroll 1 together with the third fixed scroll 3. The first fixed scroll 1, the first orbiting scroll 11, the third fixed scroll 3, the second orbiting scroll 12 and the second fixed scroll 2 constitute a work part at one end of the pivot shaft. A set of first work chamber 21 is formed with a combination of the first fixed scroll wrap 1a and the first orbiting scroll wrap 11a. A set of second work chamber 22 is formed with a combination of the first orbiting scroll wrap 11b and the third fixed scroll wrap 3a. A first orbiting paneling communication hole 11c is provided in the center part of the paneling of the first orbiting scroll 11. The first work chamber 21 is communicated with the second work chamber 22 through the first orbiting paneling communication hole 11c. A set of third work chamber 23 is formed with a combination of the third fixed scroll wrap 3b and the second orbiting scroll wrap 12a. A set of fourth work chamber 24 is formed with a combination of the second orbiting scroll wrap 12b and the second fixed scroll wrap 2a. A second orbiting paneling communication hole 12c is provided in the center part of the paneling of the second orbiting scroll 12. The third work chamber 23 is communicated with the fourth work chamber 24 through the second orbiting paneling communication hole 12c. A third fixed scroll intake communication hole 3d is provided at the third fixed scroll 3, thereby the first intake chamber 131 and the second intake chamber 132 are communicated with each other.

Further, the third fixed scroll through-hole 3c is provided in the center part of the third fixed scroll 3, thereby the fluid taken in through the first inlet 107 is compressed in the work chamber 21. 22, 23 and 24, joins together into the outlet chamber 114 in a first outlet cover 113a and is discharged to the outside from the first outlet 108a.

The opposite face of wraps of the fourth fixed scroll 4 is fixed to the left side of the casing 100. The third orbiting scroll 13 is provided over the fourth fixed scroll 4. The sixth fixed scroll 6 is provided over the third orbiting scroll 13 and is fixed to the fourth fixed scroll 4. The fourth orbiting scroll 14 is provided over the sixth fixed scroll 6. The fifth fixed scroll 5 is provided over the fourth orbiting scroll 14 and is fixed to the fourth fixed scroll 4 together with the sixth fixed scroll 6. The fourth fixed scroll 4, the third orbiting scroll 13, the sixth fixed scroll 6, the fourth orbiting scroll 14 and the fifth fixed scroll 5 constitute a work part at another end of the pivot shaft.

A set of the fifth work chamber 25 is formed with a combination of the fourth fixed scroll wrap 4a and the third orbiting scroll wrap 13a. A set of the sixth work chamber 26 is formed with a combination of the third orbiting scroll wrap 13b and the sixth fixed scroll wrap 6a.

A third orbiting paneling communication hole 13c is provided in the center part of the paneling of the third orbiting scroll 13. The fifth work chamber 25 is communicated with the sixth work chamber 26 through the third orbiting paneling communication hole 13c.

A set of the seventh work chamber 27 is formed with a combination of the sixth fixed scroll wrap 6b and the fourth orbiting scroll wrap 14a. A set of eighth work chamber 28 is formed with a combination of the fourth orbiting scroll wrap 14b and the fifth fixed scroll wrap 5a. A fourth orbiting paneling communication hole 14c is provided in the center part of the paneling of the fourth orbiting scroll 14. Thereby, the seventh work chamber 27 is communicated with the eighth work chamber 28 through the fourth orbiting paneling communication hole 14c.

A sixth fixed scroll intake communication hole 6d is provided at the sixth fixed scroll 6, thereby the third intake chamber 133 and the fourth intake chamber 134 are communicated with each other. Further, the sixth fixed scroll through-hole 6c is provided in the center part of the sixth fixed scroll 6, thereby fluid taken in through the second inlet 107b is compressed in the work chamber 25. 26, 27 and 28, and is discharged to the outside from the second outlet 108b provided at the second outlet cover 113b.

The structure of the drive part is the same as the first embodiment. The pivot shaft 104 passes through the first fixed scroll through-hole 1c. A hole is provided in the center of the first orbiting scroll 11 and the second orbiting scroll 12. The hole is fitted to the pivot drive part 104a without relative rotation. One end of the pivot shaft 104 passes through the second fixed scroll through-hole 2c and extends to the outside. A self-rotation prevention board 109 is fixed to one end 104b of the pivot shaft.

As shown in FIG. 2, a self-rotation prevention pin 110 is embedded at three locations on the inner side of the self-rotation prevention board 109. A self-rotation prevention bearing (guide body) 111 is provided on the front side of the second fixed scroll 2 as a self-rotation prevention guide.

The self-rotation prevention board 109, self-rotation prevention pin 110 and the self-rotation prevention bearing (guide body) 111 constitute a self-rotation prevention means. The self-rotation prevention pin 110 is incorporated keeping in contact with the inner race 112 of the self-rotation prevention bearing. If the outer diameter of the self-rotation prevention pin 110 is defined as d1, the inner diameter of the inner race 112 of the self-rotation prevention bearing is defined as D1 and the orbit radius of the pivot shaft 104 when this fluid machine is driven, is defined as ε and the inner gap of the bearing is defined as δ, then d1, D1, ε and δ are determined so as to satisfy Formula 1.

The pivot shaft 104 passes through a fourth fixed scroll through-hole 4c. A hole is provided in the center of the third orbiting scroll 13 and the fourth orbiting scroll 14. The hole is fitted to a second pivot drive part 104d without relative rotation therebetween. Another end 104c of the pivot shaft passes through a fifth fixed scroll through-hole 5c, extending outside. A second outlet cover 113b is attached to the outer surface of the paneling of the fifth fixed scroll 5. A balance bearing (guide body) 51 is attached to the inside of the outlet cover 113. The outer periphery of another end 104c of the pivot shaft performs an orbiting motion while keeping in contact with the inner race 52 of the balance bearing. If the outer diameter of another end 104c of the pivot shaft is defined as d2, the inner diameter of the inner race 52 of the balance bearing is defined as D2 and the orbit radius of the pivot shaft 104 when this scroll fluid machine is driven, is defined as ε and an inner gap of the bearing is defined as δ, then d2, D2, ε and δ are determined so as to satisfy Formula 2.

This embodiment configured as described above can produce four times as large as the flow volume compared to a fluid machine provided with a single set of the scroll part at one end of the casing 100. The self-rotation of the pivot shaft 104 is securely prevented by a self-rotation prevention mechanism provided at one end 104b of the pivot shaft, on the right side of the pivot shaft 104. Further, deflection of one end 104b of the pivot shaft due to centrifugal force is prevented. The outer periphery of another end 104c of the pivot shaft performs an orbiting motion while keeping in contact with the inner race 52 of the balance bearing. The relationship between another end 104c of the pivot shaft and the inner race 52 of the balance bearing is determined by Formula 2. Therefore, deflection of another end 104c of the pivot shaft due to centrifugal force is prevented.

FIG. 16 shows a modified example of an eighth embodiment. The structure of the drive part is the same as the eighth embodiment. The same components as the eighth embodiment employ the same symbols and names and the description is not repeated. A part of this embodiment, which is different than the eighth embodiment, is described. One end 104b of the pivot shaft passes through the through-hole 2c of the second fixed scroll and extends to the outside. A first outlet cover 113a is attached to the outside face of the paneling of the second fixed scroll 2. A first balance bearing (guide body) 51a is attached to the inside of the first outlet cover 113a. The outer periphery of one end 104b of the pivot shaft performs an orbiting motion while keeping in contact with the inner race 52a of the balance bearing. If the outer diameter of one end 104b of the pivot shaft is defined as d2, the inner diameter of the inner race 52a of the first balance bearing is defined as D2 and the orbit radius of the pivot shaft 104 when this scroll fluid machine is driven, is defined as ε and an inner gap of the bearing is defined as δ, then d2, D2, ε and δ are determined so as to satisfy Formula 2. Therefore, deflection of one end 104b of the pivot shaft due to centrifugal force is prevented.

Another end 104c of the pivot shaft passes through the through-hole 5c of the fifth fixed scroll and extends to the outside. A second outlet cover 113b is attached to the outside face of the paneling of the second fixed scroll 2. A second balance bearing (guide body) 51b is attached to the inside of the second outlet cover 113b. The outer periphery of another end 104c of the pivot shaft performs an orbiting motion while keeping in contact with the inner race 52b of the second balance bearing. The relationship of another end 104c of the pivot shaft and the inner race 52b of the second balance bearing is also determined by Formula 2. Therefore, deflection of another end 104c of the pivot shaft due to centrifugal force is prevented.

A self-rotation prevention board 60 is provided between the right side of the pivot bearing 103 and the paneling of the first fixed scroll 1 to prevent relative rotation therebetween. A self-rotation prevention pin 61 is embedded at three locations in the outer periphery of the self-rotation prevention board 60. A self-rotation prevention bearing 62 is provided on the paneling of the first fixed scroll 1. The self-rotation prevention board 60, the self-rotation prevention pin 61 and the self-rotation prevention bearing 62 constitute a self-rotation prevention means. The self-rotation prevention pin 61 performs an orbiting motion while keeping in contact with the inner race 63 of the self-rotation prevention bearing. If the outer diameter of the self-rotation prevention pin 61 is defined as d3, the inner diameter of the inner race 63 of the self-rotation prevention bearing is defined as D3 and the orbit radius of the pivot shaft 104 when this fluid machine is driven, is defined as ε and an inner gap of the bearing is defined as δ, then d3, D3, ε and δ are determined so as to satisfy Formula 3.

Similarly to the eighth embodiment of the present invention, this embodiment configured as described above can produce four times as large as the flow volume compared to a fluid machine provided with a single set of the scroll part at one end of the casing 100.

Ninth Embodiment

FIG. 17 shows a ninth embodiment. The same components as the seventh embodiment employ the same symbols and names and the description is not repeated. The third fixed scroll 3 is divided into two parts. The first paneling 3e of the third fixed scroll and the second paneling 3f of the third fixed scroll are integrally joined back to back. A gap is provided at the center part between the first paneling 3e of the third fixed scroll and the second paneling 3f of the third fixed scroll. A seal board 44 fixed to the pivot drive part 104a is slidably fitted in this gap. Both surfaces of the seal board 44 are sealed by a first seal 45 attached to the first paneling 3e of the third fixed scroll and a second seal 46 attached to the second paneling 3f of the third fixed scroll. By this seal, the through-hole 3c of the third fixed scroll is obstructed halfway.

The first work chamber 21 and the second work chamber 22, which are formed by combination of the first fixed scroll wrap 1a, the first orbiting scroll wraps 11a, 11b and the third fixed scroll wrap 3a, constitute a compressor. Further, the third work chamber 23 and the fourth work chamber 24, which are formed by combination of the third fixed scroll wrap 3b, the second orbiting scroll wraps 12a, 12b and the second fixed scroll wrap 2a, constitute an expander.

Working fluid flows through an expander entrance 207b provided at the outlet cover 113 that is provided on the second fixed scroll. The working fluid enters the center part of the fourth work chamber 24 through the through-hole 2c of the second fixed scroll, also enters the third work chamber 23 through the communication hole 12c of the second orbiting paneling, and expand while moving toward the outer periphery, when the working fluid applies an orbiting force to the second orbiting scroll 12. An expander exit 208b is provided at the outer periphery of the second fixed scroll 2. The working fluid fully expanded is discharged from the expander exit 208b. A compressor inlet 207a is provided at the outer periphery of the first fixed scroll 1. The entrance of a cooler (water heater) 121 is connected to the expander exit 208b, and the exit is connected to the compressor inlet 207a. The working fluid cooled down to a low temperature by the cooler 121, enters the first work chamber 21 and the second work chamber 23 and is compressed while moving toward the inner periphery. The working fluid fully compressed jointly flows through the communication hole 11c of the first orbiting paneling, enters the inside of the casing 100 through the through-hole 1c of the first fixed scroll and is discharged to the outside from the compressor outlet 208a. The entrance of a heater (collector) 120 is connected to the compressor outlet 208a, and the exit is connected to the expander entrance 207b.

The working fluid discharged from the compressor outlet 208a is heated to high temperature by the heater 120, flowing into the expander through the expander entrance 207b. In this process, the workload of the expander becomes larger than power of the compressor, thus the expander drives the compressor. Also, the expander drives the pivot drive part 104a and pivot drives the pivot shaft 104. The pivot shaft 104 rotates the rotary shaft 102. The rotary shaft 102 rotates the attached rotor 105, thereby an electromotive force is generated in the winding of the stator 106. As a result, electric power is generated at the winding. That is, this fluid machine can be used as a generator.

Generally, when driving the compressor using the expander, power is transmitted in the form of torque, and thus loss occurs at the bearing supporting respective drive shafts. However, in this embodiment, the expander and the compressor are attached to the common pivot drive part 104a, thereby power is transmitted in the form of load, therefore, no loss occurs between the expander and the compressor. Further, stable gases, which are unliquefied at room temperature such as air, nitrogen, helium, etc. are preferably used as working fluid.

Tenth Embodiment

FIG. 18 shows a tenth embodiment. This embodiment shows an example in which two of the four sets of work chambers are used as expanders and the other two sets are used as blowers, thus applying this configuration to a system of fuel battery in the same scroll fluid machine as the ninth embodiment.

A blower inlet 307 is provided at the outer periphery of the first fixed scroll 1. Air is taken in the first work chamber 21 and the second work chamber 22 through the blower inlet 307 and is compressed while moving toward the inner periphery. Fully compressed air enters the inside of the casing 100 through the through-hole 1c of the first fixed scroll, and is discharged to the outside through a blower outlet 308. An expander entrance 207b is provided at the center of the second fixed scroll 2. The entrance of fuel battery 122 is connected to the blower outlet 308 while the exit is connected to the expander entrance 207b. The exhaust air discharged from the fuel battery 122 yet keeps somewhat high pressure, enters the center of the third work chamber and the fourth work chamber through the through-hole 2c of the second fixed scroll and expands while moving toward the outer periphery, when the air applies an orbiting force to the second orbiting scroll 12. An expander exit 208b is provided at the outer periphery of the second fixed scroll 2. Fully expanded air is discharged from the expander exit 208b. In this process, the workload of the expander supplements power of the blower driving the first orbiting scroll 11, thus energy is regenerated as a total fuel battery system.

FIG. 19 shows a modified example of the tenth embodiment. FIG. 19 shows an example of the scroll fluid machine using the same structure as FIG. 15, in which the four of the eight sets of work chambers are used as expanders, and the other four sets of work chambers are used as blowers, thus applying this configuration to a system of fuel battery.

A blower inlet 307 is provided at the outer periphery of the fifth fixed scroll 5. Air is taken in the fifth work chamber 25, the sixth work chamber 26, the seventh work chamber 27 and the eighth work chamber 28 through the blower inlet 307 and is compressed while moving toward the inner periphery. Fully compressed air passes through the through-hole 5c of the fifth fixed scroll and is discharged to the outside through the blower outlet 308 provided at the second outlet cover 113b. An expander entrance 207b is provided at the center of the first outlet cover 113a provided on the second fixed scroll 2. The entrance of fuel battery 122 is connected to the blower outlet 308 while the exit is connected to the expander entrance 207b. The exhaust air discharged from the fuel battery 122 yet keeps somewhat high pressure, enters the center of the fourth work chamber 24, the fourth work chamber 23, the second work chamber 22 and the first work chamber 21 through the through-hole 2c of the second fixed scroll and expands while moving toward the outer periphery, when the air applies an orbiting force to the first orbiting scroll 11 and the second orbiting scroll 12. An expander exit 208b is provided at the outer periphery of the second fixed scroll 2. Fully expanded air is discharged from the expander exit 208b. In this process, the workload of the expander supplements power of the blower driving the third orbiting scroll 13 and the fourth orbiting scroll 14, thus energy is regenerated as a total fuel battery system.

FIG. 20 shows modified examples of the ninth or the tenth embodiments. A heat insulating plate 3g is sandwiched between the first paneling 3e of the third fixed scroll and the second paneling 3f of the third fixed scroll. If supplied with high-temperature fluid heated as high as possible, the expander can increase generated power. In contrast, if low-temperature fluid cooled down as low as possible is taken in, the compressor can reduce consumed power. Thus, high-temperature fluid heated as high as possible by a heater 120 is taken in the work chambers 23, 24 through the expander entrance 207b and the through-hole 2c of the second fixed scroll. On the other hand, low-temperature fluid sufficiently cooled down by the cooler 121 is taken in the work chambers 21, 22 through the compressor inlet 207a.

In this case, for the compressor, the temperature is comparatively lowered in the first fixed scroll 1, the first orbiting scroll 11, the third fixed scroll wrap 3a and the first paneling 3e of the third fixed scroll. Further, for the expander, the temperature is comparatively raised in the second fixed scroll 2, the second orbiting scroll 12, the third fixed scroll wrap 3b and the second paneling 3f of the third fixed scroll. However, if a large amount of heat transfer occurs due to heat conduction between the third fixed scroll wrap 3a of the compressor and the third fixed scroll wrap 3b of the expander, the third fixed scroll wrap 3a cannot keep the low temperature, thus the consumed power of the compressor is increased, while the third fixed scroll wrap 3b cannot keep the high-temperature, thus the generated power of the expander is lowered. That is, production of electricity generated as power difference between the expander and the compressor is lowered.

As such, in this embodiment, a heat insulating plate 3g is inserted between the first paneling 3e of the third fixed scroll of the compressor and the second paneling 3f of the third fixed scroll of the expander, thereby the amount of heat transfer due to heat conduction is reduced therebetween. Thereby, production of electricity generated as power difference between the expander and the compressor cannot be lowered.

Eleventh Embodiment

FIG. 21 shows an eleventh embodiment. The same parts as those in the second embodiment employ the same symbols and names and the description is not repeated. The outlet cover 113 is attached to the outside face of the paneling of the second fixed scroll 2. A balance bearing (guide body) 51 is attached to the inside of the outlet cover 113. A rotational cylinder 80 is integrally attached to the inner race 52 of the balance bearing. A fan shaft 81 is integrally attached to the rotational cylinder 80. A fan 82 is attached to the fan shaft 81. The outer periphery of one end 104b of the pivot shaft performs an orbiting motion while keeping in contact with the inner surface of the rotational cylinder 80. As such, the rotational cylinder 80 rotates along with the balance bearing inner race 52 and the fan shaft 81 also rotates, thus the fan 82 rotates. The rotational cylinder 80 is sealed between the inside and the outside with a seal ring 83 attached to the outlet cover 113. Thus, in the case of the compressor, fluid is taken in through the inlet 107, compressed in the first work chamber 21 and the second work chamber 22, flows in the casing 100 through the first fixed scroll through-hole 1c, and is discharged to the outside through the outlet 108. When the fan 82 rotates, outside air is taken in through the inlet 84, blown against the outside surface of the second fixed scroll 2, and is discharged through an exhaust outlet 85 after the second fixed scroll 2 is cooled down. According to this configuration, the fan 82 rotates based on the orbiting motion of the pivot shaft 104 without a specific drive device, for example, a motor, etc, cooling down the second fixed scroll 2. Therefore, the number of parts for the scroll fluid machine can be reduced and the cost is saved.

FIGS. 22 to 24 show a method of attaching the orbiting scroll to the pivot drive part 104a or the second pivot drive part 104d in all the embodiments. The cross-section of the pivot drive part 104a and the second pivot drive part 104d has a noncircular shape. The holes opened in the center of the orbiting scroll 10 and the first to fourth orbiting scrolls 11, 12, 13 and 14, which are fitted to the pivot drive part 104a and the second pivot drive part 104d, also have the same noncircular shapes. The cross-section of the pivot drive part and the hole of the orbiting scroll have a triangularly curved shape in the example shown in FIG. 22, a circular shape partially having a flat cut in the example shown in FIG. 23, and a rectangular shape in the example shown in 24. With the fit-in shape formed like this, the pivot drive part 104a and the second pivot drive part 104d do not rotate relative to the orbiting scroll. Accordingly, if the self-rotation of the pivot shaft 104 is prevented, the self-rotation of the orbiting scrolls 10, 11, 12, 13 and 14 can be prevented as well.

Further, the pivot drive part 104a or the second pivot drive part 104d is loosely fitted in the hole of the orbiting scroll. Thus, the orbiting scrolls 10, 11, 12, 13 and 14 can move in the axis direction on the pivot drive part 104a or the second pivot drive part 104d. Thus, even if the pivot shaft 104 changes in dimension due to heat expansion, the orbiting scrolls 10, 11, 12, 13 and 14 are not subjected a load in the axis direction. The orbiting scrolls 10, 11, 12, 13 and 14 are positioned sandwiched by the fixed scrolls with a slight gap provided between a tip of each wrap and the paneling surface. As such, the tip of wraps is not subjected to excessive force, thereby loss, wear, galling, etc. due to friction of the tip of wraps can be prevented.

Twelfth Embodiment

FIGS. 25 and 26 show a twelfth embodiment. In FIG. 25, a self-lubricant cylinder member 116 is attached to the inner race 112 of the self-rotation prevention bearing. The self-rotation prevention pin 110 performs an orbiting motion while keeping in contact with the inner surface of the cylinder member 116. In this case, if the outer diameter of the self-rotation prevention pin 110 is defined as d1, the inner diameter of the cylinder member 116 is defined as D1 and the orbit radius of the pivot shaft 104 when this fluid machine is driven, is defined as ε and an inner gap of the bearing is defined as δ, then d1, D1, ε and δ are determined so as to satisfy Formula 1.

In FIG. 26, a self-lubricant cylinder member 53 is attached to the inner race 52 of the balance bearing. One end 104b of the pivot shaft or another end 104c of the pivot shaft performs an orbiting motion while keeping in contact with the inner surface of the cylinder member 53. In this case, if the outer diameter of one end 104b or another end 104c of the pivot shaft is defined as d2, the inner diameter of the cylinder member 53 is defined as D2 and the orbit radius of the pivot shaft 104 when this scroll fluid machine is driven, is defined as ε and an inner gap of the bearing is defined as δ, then d2, D2, ε and δ are determined so as to satisfy Formula 2.

The material generally referred to as dry bearing or non-lubricant bearing is suitable for the cylinder member 116 or 53. The examples of the material include a resin containing component such as tetrafluoroethylene, which is self-lubricant and has superior slidability, metal coated with this resin, resin or sintered metal impregnated with oil, resin or metal impregnated or coated with molybdenum disulfide.

With this configuration, lubrication of the contact surface between the cylinder member 116 and the self-rotation prevention pin 110 is improved, and wear of the self-rotation prevention pin 110 can be reduced. Otherwise, lubrication of the contact surface between the cylinder member 53 and another end 104c of the pivot shaft is improved, and thus wear of another end 104c of the pivot shaft can be reduced.

Thirteenth Embodiment

FIG. 27 shows a thirteenth embodiment. A sealing 48 is attached to both surfaces in the center part 10d of the orbiting scroll. The sealing 48 has a diameter such that it does not run over to the through-hole 1c of the first fixed scroll and the through-hole 2c of the second fixed scroll, even if the orbiting scroll 10 performs an orbiting motion. The sealing 48 slides on the bottom land of the first fixed scroll 1 and the second fixed scroll 2, sealing the work chambers 21 and 22 from the outside. An outlet 108 is provided on the paneling part of the second fixed scroll 2, communicating with the work chamber in the center part. Further, the communication hole 10c of the orbiting paneling is provided in the center part of the paneling of the orbiting scroll 10. As such, the fluid taken in through the inlet 107 and compressed in the work chambers 21 and 22 is discharged to the outside through the outlet 108 without escaping to the outside from the through-hole 1c of the first fixed scroll and the through-hole 2c of the second fixed scroll. Although a cover 117 is attached to the fixed scroll 2, fluid does not flow into the inside of the cover. According to the thirteenth embodiment, the self-rotation prevention bearing (guide body) 111 is not in the fluid route. As such, the self-rotation prevention bearing (guide body) 111 is not subjected to high temperature, and is not corroded even when handling corrosive fluid.

INDUSTRIAL APPLICABILITY

In the conventional structure of the pivot drive mechanism, the tip of an orbiting drive shaft is displaced by a centrifugal force at high-speed rotation, causing the orbiting scroll wrap to contact tightly to the fixed scroll wrap, thereby wear and galling of the wrap occur or noise occurs. This problem is solved by the present invention, thereby the scroll fluid machine can be downsized with specification of high-speed rotation. Therefore, the present invention is likely to be used for a device such as a vacuum pump, a blower used for a fuel battery, a refrigeration compressor, a home and packaged air-conditioner, an industrial air compressor, etc. that are desired to be compact.

Claims

1. A scroll fluid machine, comprising:

a rotary shaft, having a stator fixed to a casing, rotatably supported by said casing;

a rotor fixed to said rotary shaft;

a pivot shaft eccentrically and rotatably supported by said rotary shaft;

a self-rotation prevention means for preventing the self-rotation of said pivot shaft; and

a work part configured with combination of an orbiting scroll, fitted in a pivot drive part of said pivot shaft, having spiral wraps on both surfaces, and a pair of fixed scrolls fixed to one end of said casing, wherein:

said pivot shaft passes through said work part;

a fixed scroll located at the most outer part has a guide body; and

one end of said pivot shaft performs an orbiting motion guided by said guide body.

2. The scroll fluid machine according to claim 1, wherein:

said guide body is a self-rotation prevention guide fixed to said fixed scroll located at the most outer part; and

said self-rotation prevention means is configured with a self-rotation prevention board fixed to one end of said pivot shaft, self-rotation prevention pins attached to more than two locations of said self-rotation prevention board, and said self-rotation prevention guide; and

said self-rotation prevention pin performs an orbiting motion while keeping in contact with the inner surface of said self-rotation prevention guide.

3. The scroll fluid machine according to claim 2, wherein:

said self-rotation prevention guide is a self-rotation prevention bearing; and

said self-rotation prevention pin performs an orbiting motion while keeping in contact with the inner surface of the inner race of the self-rotation prevention bearing.

4. The scroll fluid machine according to claim 2, wherein:

said self-rotation prevention guide is a self-rotation prevention slide member having a circular hole, and;

said self-rotation prevention pin performs an orbiting motion while keeping in contact with the inner surface of the self-rotation prevention slide member.

5. The scroll fluid machine according to claim 2, wherein:

said self-rotation prevention guide produces a reaction force equivalent to the load radially produced at one end of said pivot shaft; thereby

preventing said pivot shaft from being radially displaced.

6-7. (not entered)

8. The scroll fluid machine according to claim 1, wherein: said guide body is a balance bearing, and;

the outer periphery of the pivot shaft tip performs an orbiting motion while keeping in contact with the inner race of said balance bearing provided in the center part of the fixed scroll located at the most outer part.

9. The scroll fluid machine according to claim 8, wherein:

said balance bearing produces a reaction force equivalent to the load radially produced at one end of said pivot shaft, thereby preventing said pivot shaft from being radially displaced.

10. The scroll fluid machine according to claim 8, wherein:

said self-rotation prevention means is configured with a self-rotation prevention board attached to the other end of said pivot shaft, self-rotation prevention pins attached to more than two locations of the self-rotation prevention board, and a self-rotation prevention bearing fixed to the casing; and

said self-rotation prevention pin performs an orbiting motion while keeping in contact with the inner race of the self-rotation prevention bearing.

11. The scroll fluid machine according to claim 8, wherein:

said self-rotation prevention means is configured with a self-rotation prevention board attached to the other end of said pivot shaft, self-rotation prevention pins attached to more than two locations of the self-rotation prevention board, and a self-rotation prevention slide member, having a circular hole and fixed to the casing; and

said self-rotation prevention pin performs an orbiting motion while keeping in contact with the self-rotation prevention slide member.

12. The scroll fluid machine according to claim 8, wherein one end of said pivot shaft having contact with said inner race of the balance bearing has a curved surface in the axis direction.

13. The scroll fluid machine according to claim 8, wherein:

a cover insulating the work chamber from outside air is provided in the center part of the fixed scroll located at the most outer part, and

an outlet is provided at a part of the casing.

14. A scroll fluid machine, comprising:

a rotary shaft, having a stator fixed to a casing, rotatably supported by said casing;

a rotor fixed to said rotary shaft;

a pivot shaft eccentrically and rotatably supported by said rotary shaft;

a self-rotation prevention means for preventing the self-rotation of said pivot shaft; and

a pair or pairs of work parts configured with combination of an orbiting scroll, fitted in a pivot drive part of said pivot shaft, having spiral wraps on both surfaces, and a fixed scroll, fixed to one end of said casing, having spiral wraps, and

a pair or pairs of work parts configured with combination of an orbiting scroll, fitted in a second pivot drive part of said pivot shaft, having spiral wraps on both surfaces, and a fixed scroll, fixed to the other end of said casing, having spiral wraps, wherein:

one end of said pivot shaft passes through said work part on one end side, a fixed scroll located at the most outer part on one end side has a guide body, and one end outer periphery of said pivot shaft performs an orbiting motion guided by said guide body on one end side; and

the other end of said pivot shaft passes through said work part on the other end side, a fixed scroll located at the most outer part on the other end side has a guide body, and the other end outer periphery of said pivot shaft performs an orbiting motion guided by said guide body on the other end side.

15. The scroll fluid machine according to claim 14, wherein:

said guide body is a balance bearing or a self-rotation prevention means;

said balance bearing is provided in the center part of the fixed scroll located at the most outer part at one side;

the tip outer periphery of said pivot shaft performs an orbiting motion while keeping in contact with said inner race of the balance bearing; and

said self-rotation prevention means is configured with a self-rotation prevention board fixed to the other end of said pivot shaft, self-rotation prevention pins attached to more than two locations of said self-rotation prevention board, and said self-rotation prevention guide fixed to the fixed scroll located at the most outer part located at the other side of said pivot shaft; and

said self-rotation prevention pin performs an orbiting motion while keeping in contact with the inner surface of said self-rotation prevention guide.

16. The scroll fluid machine according to claim 15, wherein said self-rotation prevention guide is a self-rotation prevention bearing and said self-rotation prevention pin performs an orbiting motion while keeping in contact with the inner surface of the inner race of the self-rotation prevention bearing.

17. The scroll fluid machine according to claim 15, wherein said self-rotation prevention guide is a self-rotation prevention slide member having a circular hole, and said self-rotation prevention pin performs an orbiting motion while keeping in contact with the inner surface of the self-rotation prevention slide member.

18-19. (not entered)

20. The scroll fluid machine according to claim 14, wherein said guide body is a balance bearing, and the outer periphery of both ends of the pivot shaft performs an orbiting motion while keeping in contact with the inner race of said balance bearing provided in the center part of the fixed scroll located at the most outer part at both sides.

21. The scroll fluid machine according to claim 20, wherein:

said self-rotation prevention means is configured with a self-rotation prevention guide fixed to the fixed scroll at the most inner side that is fixed to one end or the other end of the casing, a self-rotation prevention board attached to said pivot shaft near the self-rotation prevention guide, and a self-rotation prevention pins attached to at least two or more locations of the self-rotation prevention board; and

the self-rotation prevention pins perform an orbiting motion while keeping in contact with the inner surface of said self-rotation prevention guide.

22. The scroll fluid machine according to claim 21, wherein said self-rotation prevention guide is a self-rotation prevention bearing, and said self-rotation prevention pins perform an orbiting motion while keeping in contact with the inner surface of the inner race of the self-rotation prevention bearing.

23. The scroll fluid machine according to claim 21, wherein said self-rotation prevention guide is a self-rotation prevention slide member having a circular hole, and said self-rotation prevention pins perform an orbiting motion while keeping in contact with the inner surface of the self-rotation prevention slide member.

24. The scroll fluid machine according to claim 21, wherein a cover insulating the work chamber from outside air is provided in the center part of the fixed scroll located at the most outer part, and an outlet is provided at a part of the casing.

25. A scroll fluid machine, comprising:

(1) a rotary shaft, having a stator fixed to a casing, rotatably supported by said casing;

(2) a rotor fixed to said rotary shaft;

(3) a pivot shaft eccentrically and rotatably supported by said rotary shaft;

a self-rotation prevention means for preventing the self-rotation of said pivot shaft;

(4) a self-rotation prevention means for preventing the self-rotation of said pivot shaft; and

(5) four sets of work chambers configured with combination of a fixed scroll having wraps on one surface, an orbiting scroll having wraps on both surfaces, a fixed scroll having wraps on both surfaces, an orbiting scroll having wraps on both surfaces, and a fixed scroll having wraps on one surface, with the wraps combined with each other in this order, wherein: said two orbiting scrolls are attached in series to said pivot shaft; a hole that allows said pivot shaft to pass through and perform an orbiting motion, is provided at the paneling of said three fixed scroll; a balance bearing is provided in the center part of the paneling of the fixed scroll that is located at the most outer part; and the outer periphery of the pivot shaft tip performs an orbiting motion while keeping in contact with the inner surface of the inner race of said balance bearing.

26. The scroll fluid machine according to claim 25, wherein the phases of starting the inlet or the outlet are all shifted in said four sets of work chambers and the shifted amounts are multiples of 90 degrees.

27. The scroll fluid machine according to claim 25, wherein: two sets of the work chambers on one side of said four sets of the work chambers are expanders, and the other two sets of the work chambers adjacently provided on the other side are compressors, and

a seal mechanism sealing between the expander and the compressor is provided at a through-hole of the pivot shaft in the center part of the paneling of the fixed scroll that is located between said expander and said compressor, having wraps on both sides of the paneling.

28. (not entered)

29. The scroll fluid machine according to claim 25, wherein the paneling is divided in the fixed scroll that is located in the middle of said four sets of the work chamber, having wraps on both sides, and a heat insulating plate is inserted between said divided paneling.

30. The scroll fluid machine according to claim 1, wherein a seal mechanism sealing between the work chamber and the casing is provided in the center part of the paneling of the fixed scroll that is directly connected to the casing.

31. The scroll fluid machine according to claim 27, wherein said seal seals both surfaces of a disk integrally attached to the pivot shaft with a ring-shaped sealing member.

32. The scroll fluid machine according to claim 1, wherein an outlet cover configuring an outlet separating the outlet chamber from outside air is provided at the paneling of the fixed scroll at the most outer side.

33. (not entered)

34. The scroll fluid machine according to claim 1, wherein the cross-section of a fitting part between a pivot drive part or a second pivot drive part and a hole in the center part of the orbiting scroll, has a noncircular shape.

35. The scroll fluid machine according to claim 34, wherein the fitting parts of the pivot drive part or the second pivot drive part and the hole of the center part of said orbiting scroll, are slidable to each other in the axis direction.

36. The scroll fluid machine according to claim 2, wherein:

if the outer diameter of said self-rotation prevention pin provided at the self-rotation prevention board that is attached to one end of said pivot shaft, is defined as d1, the inner diameter of the inner race of said self-rotation prevention bearing or the inner diameter of said self-rotation prevention slide member is defined as D1, and the orbit radius of the pivot shaft is defined as ε; then

the difference between the values of D1−d1 and 2ε is determined so as to be smaller than the bearing inner gap of said self-rotation prevention bearing.

37. The scroll fluid machine according to claim 8; wherein:

if the outer diameter of one end or the other end of said pivot shaft is defined as d2, the inner diameter of the inner race of said balance bearing is defined as D2, and the orbit radius of the pivot shaft is defined as ε; then

the difference between the values of D2−d2 and 2ε is determined so as to be smaller than the bearing inner gap of said balance bearing.

38. The scroll fluid machine according to claim 10, wherein:

if the outer diameter of said self-rotation prevention pin attached to the self-rotation prevention board that is attached to the other end or the middle part of said pivot shaft, is defined as d3, the inner diameter of the inner race of said self-rotation prevention bearing or the inner diameter of the self-rotation prevention slide member is defined as D3, and the orbit radius of the pivot shaft is defined as ε; then

the difference between the values of D3−d3 and 2ε is determined so as to be smaller than the bearing inner gap of said self-rotation prevention bearing.

39. (not entered)