Double-rotating scroll compressor

Abstract

In this double-rotating scroll compressor, a drive scroll (30) is supported by a drive shaft support (51) on a second diametric portion (64b) of a protruding body (64) so as to be rotatable about a drive shaft center (O1). A driven scroll (40) is supported by a driven shaft support (13) on the second diametric portion (64b) so as to be rotatable about a driven shaft center (O2). The drive shaft support (51) rotatably supports the drive scroll (30) so that, by a differential pressure (F) of a thrust load acting on the drive scroll (30) from one side in a drive shaft center (O1) direction, the drive scroll (30) can be moved to the other side in the drive shaft center (O1) direction with respect to the protruding body (64).

Description

Double-rotation scroll compressor

[0001] The present invention relates to a double-rotation scroll compressor.

[0002] Patent Document 1 discloses a conventional double-rotation scroll compressor (hereinafter simply referred to as a compressor where appropriate). This compressor includes a housing, a driving scroll, a driven scroll, a driving mechanism, and a driven mechanism.

[0003] The housing has a scroll chamber that accommodates the driving scroll, the driven scroll, the driving mechanism, and the driven mechanism. The housing is formed with a suction port through which fluid is sucked in from the outside. The driving scroll can be rotationally driven around a driving axis by the driving mechanism. The driven scroll is eccentric with respect to the driving scroll, and can be rotationally driven around a driven axis by the driving scroll and the driven mechanism. The driving scroll and the driven scroll form a compression chamber that compresses fluid through the rotational driving of the driving scroll and the rotational driven movement of the driven scroll.

[0004] More specifically, in this compressor, the driving scroll is rotatably supported by the housing via a first radial ball bearing. The driving scroll is formed with a suction gas passage communicating with the suction port and a discharge gas passage communicating with the scroll chamber. The driving mechanism includes a stator and a rotor. The stator is fixed to the housing. The rotor has an auxiliary bearing extending toward the opposite side of the driving scroll in the direction of the driving axis. The auxiliary bearing, and thus the rotor, is rotatably supported by the housing via a second radial ball bearing on the side opposite to the driving scroll in the direction of the driving axis. The driven scroll is disposed between the driving scroll and the rotor in the direction of the driving axis.

[0005] In this compressor, the drive scroll rotates, and the driven scroll rotates in response, drawing fluid from the intake port through the intake gas passage into the compression chamber. The fluid drawn into the compression chamber is then compressed into compressed fluid. This compressed fluid is then discharged into the scroll chamber through the discharge gas passage. Thus, in this compressor, the scroll chamber also functions as the discharge chamber for the compressed fluid, and the scroll chamber is under high pressure due to the compressed fluid.

[0006] Japanese Patent Application Publication No. 7-229480

[0007] In the conventional compressor described above, a thrust load acts on the drive scroll and driven scroll during operation. Specifically, as the compression chamber becomes high-pressure, a thrust load acts on the drive scroll and driven scroll in a direction that causes them to move away from each other. Furthermore, in this compressor, if the surface of the driven scroll that slides with the auxiliary bearing and is perpendicular to the axis of rotation is considered the back surface, then the thrust load acting in the direction that causes them to move away from each other causes a thrust load that pushes the back surface of the driven scroll away from the drive scroll. As a result, sliding losses on the back surface of the driven scroll become large in this compressor.

[0008] This invention has been made in view of the above-mentioned conventional circumstances, and aims to solve the problem of providing a double-rotation scroll type compressor that can reduce the sliding loss of the driven scroll by reducing the thrust load acting on the back surface of the driven scroll.

[0009] The double-rotation scroll compressor of the present invention comprises a housing, a drive scroll, a driven scroll, a drive mechanism, and a driven mechanism, wherein the housing has a scroll chamber in which the drive scroll, the driven scroll, and the drive mechanism are housed, the drive scroll is rotationally driven around a drive axis by the drive mechanism, the driven scroll is rotationally driven around a driven axis by the drive scroll and the driven mechanism while being eccentric with respect to the drive scroll, and the drive scroll and the driven scroll form a compression chamber for compressing a fluid by the rotational drive and the rotational drive, wherein a projection is provided in the scroll chamber that projects toward the drive scroll and the driven scroll in the direction of the drive axis, the projection has a first diameter portion and a second diameter portion formed to be smaller in diameter than the first diameter portion, the second diameter portion is located on one side of the first diameter portion in the direction of the drive axis, and the drive scroll is rotatably supported in the second diameter portion by a drive shaft support portion in the direction of the drive axis. The driven scroll is rotatably supported by a driven shaft support in the second diameter portion so as to be rotatable around the driven axis, and is located on one side in the drive axis direction relative to the protruding body, and the drive shaft support is characterized in that the drive scroll is rotatably supported so that it can move to the other side in the drive axis direction relative to the second diameter portion when a differential thrust load is applied to the drive scroll from one side in the drive axis direction.

[0010] In the dual-rotation scroll compressor of the present invention, the drive scroll is rotatably supported around the drive axis by a drive shaft support on the second diameter portion of the projection, and the driven scroll is rotatably supported around the driven axis by a driven shaft support on the second diameter portion.

[0011] In this compressor, the drive shaft support rotatably supports the drive scroll so that it can move relative to the projection on the other side in the direction of the drive shaft, due to a differential thrust load acting on the drive scroll from one side in the direction of the drive shaft.

[0012] As a result, in this compressor, if a differential thrust load acts on the drive scroll from one side in the direction of the drive axis, the drive scroll can move to the other side in the direction of the drive axis relative to the second diameter portion. In this way, the thrust load acting on the back of the driven scroll can be reduced in this compressor.

[0013] Therefore, the dual-rotation scroll compressor of the present invention can reduce the thrust load acting on the back of the driven scroll and thereby reduce the sliding loss of the driven scroll.

[0014] In the compressor of the present invention, the driven shaft support can rotatably support the driven scroll so that it can move toward the second diameter portion toward the other side in the direction of the drive axis when a differential thrust load is applied to the drive scroll from one side in the direction of the drive axis. Preferably, a restricting portion is provided between the driven scroll and the driven shaft support to restrict the amount of movement of the driven scroll toward the other side in the direction of the drive axis.

[0015] In this case, if a differential thrust load acts on the drive scroll from one side in the direction of the drive axis, the driven scroll can also move in accordance with this to the other side in the direction of the drive axis towards the projection. This allows the thrust load acting on the driven scroll to be further reduced in this compressor. Furthermore, the regulating mechanism in this compressor prevents the driven scroll from moving excessively towards the projection.

[0016] The housing may have an intake port for drawing fluid into the scroll chamber from the outside. The drive scroll may have a drive end plate extending intersecting the drive axis, a drive spiral body projecting parallel to the drive axis from the drive end plate toward the driven scroll and forming a spiral, and a supported portion positioned spaced apart from the projecting body in the direction of the drive axis, extending toward the opposite side of the projecting body in the direction of the drive axis, and rotatably supported by the housing. Compressed fluid, which is fluid compressed in the compression chamber, may flow inside the supported portion. The supported portion may have an end face located in the atmosphere of compressed fluid and facing the housing in the direction of the drive axis. Preferably, the outer diameter of the end face is smaller than the outer diameter of the drive spiral body.

[0017] In this case, the scroll chamber can be kept at a low pressure by the fluid drawn into it from the outside through the intake port. Furthermore, by making the outer diameter of the end face of the supported part smaller than the outer diameter of the drive vortex, it is possible to suppress the differential pressure of the thrust load acting on the drive scroll through the end face of the supported part towards the other side in the direction of the drive axis, which is caused by the pressure difference between the pressure in the atmosphere where the end face of the supported part is located and the pressure in the scroll chamber. This makes it easy to prevent the thrust load acting on the other side due to this pressure difference from exceeding the thrust load acting on the drive scroll that pulls the drive scroll and the driven scroll apart. As a result, the differential pressure of the thrust load acting from one side can be reduced.

[0018] The drive scroll preferably has a cover body supported by a drive shaft support on the other side of the drive axis direction from the driven scroll. In this case, the drive scroll can be suitably supported by the drive shaft support on the protruding body.

[0019] Preferably, a gap is formed between the drive shaft support and the projection in the direction of the drive axis, or between the drive shaft support and the cover in the direction of the drive axis, that allows the drive scroll to move in the direction of the drive axis relative to the projection. In this case, the drive scroll can move suitably in the direction of the drive axis relative to the projection.

[0020] The drive shaft support and driven shaft support are preferably rolling bearings. In this case, the configuration of the drive shaft support and driven shaft support can be simplified. Furthermore, by using clearance fitting, the drive scroll can be suitably moved in the direction of the drive axis relative to the projection while the drive scroll is supported by the drive shaft support, and the driven scroll can be suitably moved in the direction of the drive axis while the driven scroll is supported by the projection by the driven shaft support.

[0021] Preferably, the protruding part has a supply passage that supplies lubricating oil from the radially inner side of the housing toward the driven shaft support, rather than from the drive shaft support. In this case, the driven shaft support can be suitably lubricated by the lubricating oil.

[0022] The dual-rotation scroll compressor of the present invention can reduce the sliding loss of the driven scroll by reducing the thrust load acting on the back of the driven scroll.

[0023] Figure 1 is a cross-sectional view of the compressor of Example 1. Figure 2 is an enlarged cross-sectional view of the main part of the compressor of Example 1 when the thrust load acting on the drive scroll and driven scroll is small. Figure 3 is an enlarged cross-sectional view of the main part of the compressor of Example 1 when the thrust load acting on the drive scroll and driven scroll is large. Figure 4 is a cross-sectional view of the compressor of Example 2.

[0024] The following describes two embodiments of the present invention with reference to the drawings. The compressors of embodiments 1 and 2 are mounted on a vehicle (not shown) and constitute the vehicle's air conditioning system.

[0025] As shown in Figure 1, the compressor of Embodiment 1 comprises a housing 6, an electric motor 10, a drive scroll 30, a driven scroll 40, and a driven mechanism 20. The electric motor 10 is an example of a "drive mechanism" in the present invention.

[0026] In this embodiment, the front-to-rear direction of the compressor is defined by the solid arrow shown in Figure 1. Then, in Figures 2 and onward, the front-to-rear direction of the compressor is defined in accordance with Figure 1. Note that this front-to-rear direction is merely an example for illustrative purposes, and the compressor can appropriately change its orientation depending on the vehicle it is mounted on.

[0027] As shown in Figure 1, the housing 6 consists of a housing body 60 and a housing cover 62. Both the housing body 60 and the housing cover 62 are made of aluminum alloy.

[0028] The housing body 60 is a bottomed cylindrical member having an outer peripheral wall 60a and a rear wall 60b. The outer peripheral wall 60a is cylindrical with respect to the drive axis O1. The drive axis O1 is parallel to the front-rear direction. As a result, the front side of the compressor corresponds to "one side in the direction of the drive axis" in this invention, and the rear side of the compressor corresponds to "the other side in the direction of the drive axis" in this invention.

[0029] An intake port 68 is formed in the outer periphery wall 60a. The intake port 68 extends radially from the housing body 60. The intake port 68 is connected to an evaporator (not shown) through piping (not shown).

[0030] The rear wall 60b is located at the rear end of the housing body 60. The rear wall 60b extends in a substantially circular, flat shape perpendicular to the drive axis O1. The outer edge of the rear wall 60b is connected to the rear end of the outer wall 60a. A mounting recess 60c is also formed in the rear wall 60b. The mounting recess 60c is recessed toward the rear on the inner surface of the rear wall 60b.

[0031] Furthermore, a protruding body 64 is provided inside the housing body 60. The protruding body 64 is made of steel. The protruding body 64 has a first diameter portion 64a and a second diameter portion 64b. These first diameter portion 64a and second diameter portion 64b are formed integrally. The protruding body 64 may also be made of an aluminum alloy.

[0032] The first diameter portion 64a is located behind the second diameter portion 64b and constitutes the rear part of the projection 64. As shown in Figures 2 and 3, the first diameter portion 64a has a first end face 644 that connects to the second diameter portion 64b.

[0033] The second diameter portion 64b is formed in a substantially cylindrical shape, extending forward in the direction of the drive axis O1 from the first end face 644 of the first diameter portion 64a. Thus, the second diameter portion 64b constitutes the front part of the projection 64. Furthermore, the second diameter portion 64b is formed to have a smaller diameter than the first diameter portion 64a. The second diameter portion 64b has a second end face 645. The second end face 645 is located at the front end of the second diameter portion 64b, i.e., the front end of the projection 64.

[0034] Furthermore, a supply passage 64c is formed in the protruding body 64. The supply passage 64c is composed of a first fluid passage 641, a second fluid passage 642, and a third fluid passage 643. The first fluid passage 641 extends from the first diameter portion 64a in the radial direction of the protruding body 64, that is, in the radial direction of the housing 6. One end of the first fluid passage 641 opens to the outer circumferential surface of the first diameter portion 64a.

[0035] The second fluid passage 642 is formed in the first diameter portion 64a. The second fluid passage 642 is recessed from the rear end of the first diameter portion 64a toward the front. As a result, the second fluid passage 642 is in communication with the other end of the first fluid passage 641.

[0036] The third fluid passage 643 extends through the interior of the first diameter portion 64a and the second diameter portion 64b in the direction of the drive axis O1. The front end of the third fluid passage 643 opens to the second end face 645, and the rear end communicates with the second fluid passage 642. Thus, in the supply passage 64c, the first fluid passage 641 and the third fluid passage 643 are in communication through the second fluid passage 642.

[0037] The protruding body 64 is fixed to the rear wall 60b by fitting the rear portion of the first diameter portion 64a into the mounting recess 60c. In this way, the rear end of the second fluid passage 642 of the protruding body 64 is closed off by the rear wall 60b.

[0038] Furthermore, a first radial ball bearing 51 is provided in the second diameter portion 64b of the protruding body 64. The first radial ball bearing 51 is an example of a "rolling bearing" in the present invention, and by extension, an example of a "drive shaft support" in the present invention. The first radial ball bearing 51 has a first inner ring 51a and a first outer ring 51b. The first radial ball bearing 51 is provided in the second diameter portion 64b by inserting the first inner ring 51a through the second diameter portion 64b. More specifically, the first radial ball bearing 51 is provided in the second diameter portion 64b by clearance fitting the first inner ring 51a against the outer circumferential surface of the second diameter portion 64b. Note that in Figures 2 and 3, for the sake of ease of explanation, the gap between the first inner ring 51a of the first radial ball bearing 51 and the second diameter portion 64b in the radial direction of the housing 6 is exaggerated in the illustration.

[0039] Furthermore, the protruding body 64 has a first circlip 5a and a second circlip 5b. The first circlip 5a is mounted in front of the first radial ball bearing 51 in the second diameter portion 64b. On the other hand, the second circlip 5b is mounted in rear of the first radial ball bearing 51 in the second diameter portion 64b. In other words, the first circlip 5a and the second circlip 5b mounted on the second diameter portion 64b are spaced apart from each other in the direction of the drive axis O1.

[0040] Furthermore, the first radial ball bearing 51 is permitted to move relative to the second diameter portion 64b in the direction of the drive axis O1 within the range of the gap S1 provided between the first circlip 5a and the second circlip 5b. That is, as shown in Figure 2, when the first radial ball bearing 51 is moved furthest forward between the first circlip 5a and the second circlip 5b and is in contact with the first circlip 5a, a gap S1 is formed between the first radial ball bearing 51 and the second circlip 5b. On the other hand, as shown in Figure 3, when the first radial ball bearing 51 is moved furthest backward between the first circlip 5a and the second circlip 5b and is in contact with the second circlip 5b, a gap S1 is formed between the first radial ball bearing 51 and the first circlip 5a.

[0041] As shown in FIG. 1, the housing cover 62 is arranged in front of the housing main body 60. The housing cover 62 is formed in a substantially disc shape centered on the drive axis O1. The housing cover 62 has a front surface 62a facing forward, and a rear surface 62b located on the opposite side of the front surface 62a and facing rearward.

[0042] Further, a support portion 66 and a discharge communication port 69 are formed in the housing cover 62. The support portion 66 is integrally formed substantially at the center of the rear surface 62b, and protrudes rearward from the rear surface 62b. The support portion 66 is formed in a cylindrical shape centered on the drive axis O1, and a second radial ball bearing 52 and a shaft sealing member 63 are provided inside the support portion 66. Note that a slide bearing may be provided inside the support portion 66 instead of the second radial ball bearing 52.

[0043] The second radial ball bearing 52 has a second inner ring 52a and a second outer ring 52b. The second radial ball bearing 52 is fixed inside the support portion 66 by fitting the second outer ring 52b into the support portion 66, that is, by interference-fitting the second outer ring 52b to the support portion 66.

[0044] The shaft sealing member 63 is arranged forward of the second radial ball bearing 52 inside the support portion 66. The shaft sealing member 63 is formed in an annular shape.

[0045] The discharge communication port 69 penetrates the housing cover 62 in the direction of the drive axis O1, and communicates with the inside of the support portion 66. Further, the discharge communication port 69 is connected to a condenser (not shown) through a pipe (not shown).

[0046] In the housing 6, the rear surface 62b of the housing cover 62 is brought into contact with the front end of the outer peripheral wall 60a of the housing main body 60. Then, in this state, the housing cover 62 is fixed to the housing main body 60 with a plurality of bolts (not shown) from the housing cover 62 side. Thus, in the housing 6, the housing main body 60 and the housing cover 62 are integrated.

[0047] Further, in the housing 6, a scroll chamber 65 is formed in the housing body 60 by closing the front side of the housing body 60 with a housing cover 62. The scroll chamber 65 communicates with a suction communication port 68. Accordingly, the refrigerant is sucked into the scroll chamber 65 from the outside of the housing 6 through the suction communication port 68. The refrigerant is an example of the "fluid" in the present invention. Since the refrigerant is sucked from the outside of the housing 6 as described above, the inside of the scroll chamber 65 is in a low-pressure atmosphere.

[0048] Further, since the scroll chamber 65 is formed in the housing body 60 as described above, the protruding body 64 is disposed in the scroll chamber 65 while being fixed to the rear wall 60b. The protruding body 64 protrudes from the rear wall 60b into the scroll chamber 65 in the direction of the drive axis O1. More specifically, the protruding body 64 protrudes forward from the rear wall 60b toward the driving scroll 30 and the driven scroll 40. Further, the first fluid passage 641 of the supply path 64c is in a state of communicating with the inside of the scroll chamber 65. Accordingly, the supply path 64c communicates with the scroll chamber 65.

[0049] The electric motor 10 is housed in the scroll chamber 65. Accordingly, the scroll chamber 65 also serves as a motor chamber that houses the electric motor 10.

[0050] The electric motor 10 is configured by a stator 17 and a rotor 11. The stator 17 includes a stator core 17a and a winding 17b. The stator core 17a is formed in a cylindrical shape centered on the drive axis O1. The winding 17b is wound around the stator core 17a. Accordingly, the winding 17b forms a first coil end 171 and a second coil end 172.

[0051] In the stator 17, the stator core 17a is fitted onto the outer circumferential surface of the first diameter portion 64a. In this way, the stator core 17a is fixed to the first diameter portion 64a, and consequently to the protruding body 64. Although not shown in the figures, multiple slits extending in the direction of the drive axis O1 are formed on the inner circumferential surface of the stator core 17a. As a result, the slits form a gap between the stator core 17a and the outer circumferential surface of the first diameter portion 64a when the stator core 17a is fixed to the second diameter portion 64b.

[0052] The rotor 11 is cylindrical around the drive axis O1. Although detailed illustrations are omitted, the rotor 11 is composed of multiple permanent magnets corresponding to the stator 17 and laminated steel plates that fix each permanent magnet. The rotor 11 is also formed to be larger in diameter than the stator core 17a. As a result, the rotor 11 covers the stator core 17a from the outside within the scroll chamber 65. Furthermore, the rotor 11 has multiple first bolt holes 11a. Each first bolt hole 11a penetrates the rotor 11 in the direction of the drive axis O1.

[0053] The drive scroll 30 is housed within the scroll chamber 65. The drive scroll 30 is made of a metal such as an aluminum alloy. The drive scroll 30 includes a drive end plate 31, a drive spiral body 33, a drive peripheral wall 35, a cover body 37, and a case 39.

[0054] The drive end plate 31 extends in a substantially disc shape perpendicular to the drive axis O1 and the driven axis O2. The driven axis O2 extends parallel to the drive axis O1 while being eccentric with respect to the drive axis O1. In other words, the driven axis O2 is also parallel in the front-rear direction. The drive end plate 31 has a first front surface 311 facing forward and a first rear surface 312 located on the opposite side of the first front surface 311 and facing rear.

[0055] Furthermore, a discharge port 32 is formed in the drive end plate 31. The discharge port 32 penetrates the drive end plate 31 in the direction of the drive axis O1. In addition, a discharge reed valve 57 and a retainer 58 are fixed to the first front surface 311 of the drive end plate 31 by fixing bolts 59. As a result, the discharge reed valve 57 can open and close the discharge port 32. The retainer 58 can adjust the opening degree of the discharge reed valve 57.

[0056] The drive spiral body 33 is integral with the drive end plate 31 and protrudes from the first rear surface 312 toward the rear, i.e., toward the driven scroll 40, parallel to the drive axis O1 and the driven axis O2. Although detailed illustration is omitted, the drive spiral body 33 has the center of the drive end plate 31 as its spiral center and protrudes outward from the spiral center in a spiral shape.

[0057] The drive peripheral wall 35 is formed in a cylindrical shape, extending parallel to the drive axis O1 and the driven axis O2, with the drive axis O1 as its center. The front end of the drive peripheral wall 35 is integral with the outer peripheral edge of the drive end plate 31. As a result, the drive peripheral wall 35 surrounds the drive spiral body 33 from the outside and protrudes cylindrically toward the rear from the first rear surface 312. Although not shown in the illustration, the outer peripheral end of the spiral in the drive spiral body 33 is connected to the inner peripheral surface of the drive peripheral wall 35. The drive scroll body 301 is formed by the drive end plate 31, the drive spiral body 33, and the drive peripheral wall 35.

[0058] As shown in Figures 2 and 3, the cover body 37 has a wall portion 37a, an inner cylindrical portion 37b, and an outer cylindrical portion 37c. The wall portion 37a extends in a substantially plate-like shape in the radial direction of the drive scroll 30. The wall portion 37a has a second front surface 371 facing forward and a second rear surface 372 located on the opposite side of the second front surface 371 and facing rear.

[0059] Furthermore, a recess 373 and an intake port 374 are formed in the wall portion 37a. The recess 373 is located approximately in the center of the second front surface 371 and is recessed toward the rear from the second front surface 371.

[0060] The intake port 374 is located radially outward of the drive scroll 30, i.e., radially outward of the housing 6, relative to the recess 373. The intake port 374 penetrates the wall portion 37a in the front-rear direction, with its front end opening to the second front surface 371 and its rear end opening to the second rear surface 372. Multiple intake ports 374 may be formed in the wall portion 37a.

[0061] Furthermore, in the wall portion 37a, multiple rings 22 are attached between the recess 373 and the intake port 374. Although detailed illustrations are omitted, each ring 22 is arranged at equal intervals in the circumferential direction of the recess 373 when facing forward, and surrounds the recess 373 from the outside. In this embodiment, there are six rings 22. Figures 1 to 4 illustrate one of the six rings 22.

[0062] As shown in Figures 2 and 3, the inner cylindrical portion 37b is located inside the stator 17 in the radial direction of the drive scroll 30, and extends cylindrically backward from the second rear surface 372 of the wall portion 37a in the direction of the drive axis O1. The inner cylindrical portion 37b is in communication with the recess 373 in the direction of the drive axis O1. The inner diameter of the inner cylindrical portion 37b is larger than the outer diameter of the second diameter portion 64b of the projection 64, and slightly smaller than the outer diameter of the first radial ball bearing 51. The outer diameter of the inner cylindrical portion 37b is smaller than the outer diameter of the first diameter portion 64a.

[0063] The outer cylindrical portion 37c is integral with the wall portion 37a at its outer peripheral edge. As a result, the outer cylindrical portion 37c is connected to the wall portion 37a and extends cylindrically backward from the wall portion 37a in the direction of the drive axis O1. The outer diameter of the outer cylindrical portion 37c is formed to be approximately the same as the outer diameter of the drive peripheral wall 35 and the outer diameter of the rotor 11.

[0064] Furthermore, the inner diameter of the outer cylindrical portion 37c is formed to be larger than the outer diameter of the inner cylindrical portion 37b. As a result, in the cover body 37, the inner cylindrical portion 37b is positioned on the inner circumference side of the outer cylindrical portion 37c, separated from the outer cylindrical portion 37c in the radial direction of the drive scroll 30. In this way, the cover body 37 has a housing portion 38 formed by the wall portion 37a, the inner cylindrical portion 37b, and the outer cylindrical portion 37c. The housing portion 38 has a bottomed annular shape that opens at the rear.

[0065] Furthermore, the intake port 374 formed in the wall portion 37a is located radially to the drive scroll 30, outside the inner cylindrical portion 37b and inside the outer cylindrical portion 37c. In this way, the intake port 374 communicates with the housing portion 38 between the inner cylindrical portion 37b and the outer cylindrical portion 37c.

[0066] Furthermore, multiple second bolt holes 376 are formed in the outer cylindrical portion 37c and the wall portion 37a. Each second bolt hole 376 penetrates the outer cylindrical portion 37c and the wall portion 37a in the direction of the drive axis O1. Although not shown in the figures, the number of second bolt holes 376 is equal to the number of first bolt holes 11a formed in the rotor 11. In Figures 1 to 4, one of the multiple first bolt holes 11a and one of the second bolt holes 376 are shown.

[0067] As shown in Figure 1, the cover body 37 has its second front surface 371 of the wall portion 37a in contact with the rear end of the drive peripheral wall 35. The cover body 37 also has the rotor 11 in contact with the rear end of the outer cylindrical portion 37c. In this state, the first bolts 34a are inserted from the rotor 11 side through the first bolt holes 11a and the second bolt holes 376 in that order, and the first bolts 34a are screwed into the drive peripheral wall 35. In this way, the cover body 37 is fixed to the drive peripheral wall 35 and the rotor 11, while being sandwiched in the front-rear direction between the drive peripheral wall 35 and the rotor 11. As a result, the drive scroll 30 is integrated with the rotor 11.

[0068] Case 39 is a bottomed cylindrical member having an outer peripheral wall 39a and a front wall 39b. The outer peripheral wall 39a is cylindrical with the drive axis O1 as its center. Here, the outer diameter of the outer peripheral wall 39a is formed to be approximately the same as the outer diameter of the drive peripheral wall 35.

[0069] The front wall 39b is located at the front end of the case 39. The front wall 39b extends in a substantially disc shape perpendicular to the drive axis O1 and the driven axis O2. The outer edge of the front wall 39b is connected to the front end of the outer wall 39a. A boss 39c is also formed on the front wall 39b. The boss 39c is an example of a "supported portion" in the present invention.

[0070] The boss 39c is integrally formed in the center of the front wall 39b and protrudes forward from the front wall 39b in the direction of the drive axis O1. The outer diameter of the boss 39c is formed to be slightly smaller than the inner diameter of the second radial ball bearing 52. The outer diameter of the boss 39c is also formed to be approximately the same as the inner diameter of the shaft sealing member 63. A discharge passage 390 is formed in the boss 39c. The discharge passage 390 penetrates the boss 39c in the direction of the drive axis O1. The discharge passage 390 opens to the front end face 391 of the boss 39c. The front end face 391 is an example of an "end face" in this invention.

[0071] Furthermore, third bolt holes 39d are formed in the outer periphery wall 39a and the front wall 39b. The third bolt holes 39d penetrate the outer periphery wall 39a and the front wall 39b in the direction of the drive axis O1. Although not shown in the figures, multiple third bolt holes 39d are formed in the outer periphery wall 39a and the front wall 39b. Figures 1 and 4 show one of these multiple third bolt holes 39d.

[0072] As shown in Figure 1, the case 39 has its rear end surface of the outer peripheral wall 39a in contact with the front end of the drive peripheral wall 35. In this state, the second bolts 34b are inserted through each of the third bolt holes 39d and screwed into the drive peripheral wall 35. In this way, the case 39 is fixed to the drive peripheral wall 35 in the drive scroll 30.

[0073] As the case 39 is fixed to the drive peripheral wall 35, a discharge chamber 14 is formed inside the case 39, that is, inside the outer peripheral wall 39a, between the front wall 39b of the case 39 and the drive end plate 31. The discharge chamber 14 is in communication with the discharge port 32 and also with the discharge passage 390.

[0074] Furthermore, because the case 39 is fixed to the drive peripheral wall 35 in this manner, in the drive scroll 30, the case 39 and the cover body 37 are positioned separated in the front-rear direction, with the drive end plate 31, the drive spiral body 33, and the drive peripheral wall 35 in between. Also, the boss 39c formed on the front wall 39b of the case 39 protrudes forward from the front wall 39b in the direction of the drive axis O1. In other words, the boss 39c extends toward the opposite side of the cover body 37 in the direction of the drive axis O1.

[0075] In the drive scroll 30, the outer diameter of the drive spiral body 33, more specifically, the length of the outer diameter of the drive spiral body 33 at the outer peripheral end of the spiral, is the first length L1. In contrast, the outer diameter of the front end face 391 of the boss 39c, that is, the length of the outer diameter of the boss 39c, is the second length L2, which is shorter than the first length L1.

[0076] The driven scroll 40 is also made of aluminum alloy. The driven scroll 40 has a driven end plate 41 and a driven spiral body 43.

[0077] The driven end plate 41 extends in a substantially disc shape perpendicular to the drive axis O1 and the driven axis O2. The driven end plate 41 has a third front surface 411 facing forward and a third rear surface 412 located on the opposite side of the third front surface 411 and facing rear. In other words, the third rear surface 412 corresponds to the back surface of the driven scroll 40.

[0078] As shown in Figures 2 and 3, a receiving recess 15 is formed in the driven end plate 41. The receiving recess 15 is located in the center of the driven end plate 41. The receiving recess 15 is recessed in a cylindrical shape from the third rear surface 412 of the driven end plate 41 toward the front, with the driven axis O2 as the center. As a result, the receiving recess 15 opens toward the rear of the driven end plate 41, and consequently toward the second diameter portion 64b of the protruding body 64. A regulating surface 15a is also formed inside the receiving recess 15. The regulating surface 15a is an example of a "regulating portion" in the present invention.

[0079] A driven shaft portion 16 and a third radial ball bearing 13 are provided within the housing recess 15. The third radial ball bearing 13 is an example of a "rolling bearing" in the present invention, and by extension, an example of a "driven shaft support" in the present invention. The third radial ball bearing 13 has a third inner ring 13a and a third outer ring 13b. The outer diameter of the third outer ring 13b, that is, the outer diameter of the third radial ball bearing 13, is formed to be smaller than the inner diameter of the housing recess 15. As a result, the third radial ball bearing 13 is fitted with clearance in the housing recess 15. Note that in Figures 2 and 3, for the sake of ease of explanation, the gap between the third outer ring 13b of the third radial ball bearing 13 and the housing recess 15 in the radial direction of the housing 6 is exaggerated in the illustration.

[0080] The driven shaft portion 16 has a bush 53 and a driven pin 55. The bush 53 is fitted into the third inner ring 13a of the third radial ball bearing 13. As a result, the bush 53 is fixed to the third radial ball bearing 13 and integrated with the third radial ball bearing 13.

[0081] The driven pin 55 is inserted through the bush 53. More specifically, the driven pin 55 is inserted through the bush 53 at its center, i.e., at a position eccentric to the driven axis O2. As a result, the driven pin 55 protrudes rearward from the bush 53 and, consequently, from the driven end plate 41. The driven pin 55 has an axial hole 55a formed through it in the direction of the drive axis O1.

[0082] Furthermore, the driven end plate 41 has a third circlip 5c. The third circlip 5c is attached to the driven end plate 41 at a location behind the third radial ball bearing 13. As a result, the third radial ball bearing 13 and the bush 53 are positioned between the regulating surface 15a and the third circlip 5c in the direction of the drive axis O1.

[0083] Furthermore, a pivot pin 21 is fixed to the driven end plate 41 at the location facing the ring 22. The pivot pin 21 protrudes rearward from the third rear surface 412. Six pivot pins 21 are fixed to the driven end plate 41, the same number as the rings 22. Figures 1 to 4 illustrate one of the six pivot pins 21.

[0084] As shown in Figure 1, the driven mechanism 20 is composed of these pivot pins 21 and rings 22. Here, the number of pivot pins 21 and rings 22 can be designed as appropriate, as long as there are three or more of each.

[0085] The driven spiral body 43 is integral with the driven end plate 41 and extends forward from the third front surface 411 of the driven end plate 41 parallel to the drive axis O1 and the driven axis O2. The driven spiral body 43 has the center of the driven end plate 41 as its spiral center and extends outward from the spiral center.

[0086] In this compressor, a driven scroll 40 is housed within the drive scroll 30, more specifically, between the drive end plate 31 and the drive peripheral wall 35 and the cover body 37. The drive spiral body 33 and the driven spiral body 43 are meshed together. As a result, the drive spiral body 33 and the driven spiral body 43 face each other to form a compression chamber 12.

[0087] Furthermore, a suction section 30a is formed between the drive peripheral wall 35 and the driven scroll 40. In other words, the drive spiral body 33 and the driven spiral body 43 are located within the suction section 30a. The suction section 30a is separated from the scroll chamber 65 by the drive peripheral wall 35 and the cover body 37, and is also separated from the discharge chamber 14 by the drive end plate 31. The suction section 30a is also in communication with the suction port 374.

[0088] Furthermore, by housing the driven scroll 40 within the driven scroll 30, each orbital pin 21 is positioned within each ring 22. In this way, the driven scroll 30 and the driven scroll 40 are assembled in the front-rear direction, and the driven scroll 30 and the driven scroll 40 constitute the scroll compression section 100. More precisely, after the driven spiral body 33 and the driven spiral body 43 are meshed and each orbital pin 21 is inserted into each ring 22, the cover body 37 of the driven scroll 30 is fixed to the drive peripheral wall 35 and the rotor 11.

[0089] Furthermore, when the drive scroll 30 and the driven scroll 40 are assembled, the housing recess 15 and driven shaft portion 16 of the driven end plate 41 face the recess 373 of the cover body 37.

[0090] The drive scroll 30 is positioned in front of the stator 17 within the scroll chamber 65. As shown in Figures 2 and 3, in the drive scroll 30, the inner cylindrical portion 37b of the cover body 37 is inserted into the inner circumference of the first coil end 171. In this state, the second diameter portion 64b of the protruding body 64 and the first radial ball bearing 51 are inserted into the inner cylindrical portion 37b.

[0091] Here, as described above, the inner diameter of the inner cylinder portion 37b is formed to be slightly smaller than the outer diameter of the first radial ball bearing 51. As a result, in the first radial ball bearing 51, the first outer ring 51b is fitted onto the inner circumferential surface of the inner cylinder portion 37b. In this way, the first radial ball bearing 51 is integrated with the inner cylinder portion 37b and, by extension, the drive scroll 30. The cover body 37 is rotatably supported on the second diameter portion 64b via the first radial ball bearing 51. In other words, the cover body 37 is rotatably supported on the second diameter portion 64b and, by extension, the protruding body 64, behind the driven scroll 40 via the first radial ball bearing 51.

[0092] Furthermore, because the cover body 37 is rotatably supported on the second diameter portion 64b in this manner, the housing portion 38 is in communication with the scroll chamber 65. The first coil end 171 is housed within the housing portion 38. As a result, within the housing portion 38, the first coil end 171 is covered from the front by the wall portion 37a and covered from the radially inner side of the drive scroll 30 by the inner cylindrical portion 37b. The first coil end 171 is also covered from the radially outer side of the drive scroll 30 by the outer cylindrical portion 37c within the housing portion 38.

[0093] Furthermore, as shown in Figure 1, in the drive scroll 30, the boss 39c of the case 39 is inserted through the second radial ball bearing 52 and the shaft sealing member 63. Here, as described above, the outer diameter of the boss 39c is formed to be slightly smaller than the inner diameter of the second radial ball bearing 52. For this reason, the boss 39c is clearance-fitted to the second inner ring 52a of the second radial ball bearing 52. The boss 39c also has a fourth circlip 5d. The fourth circlip 5d is attached to the boss 39c at a location behind the second radial ball bearing 52.

[0094] Thus, the case 39 is rotatably supported by the support portion 66 via the second radial ball bearing 52. As a result, the drive scroll 30 is positioned within the scroll chamber 65 and is rotatably supported by the housing 6 by both the projection 64 and the support portion 66, so as to be around the drive axis O1.

[0095] Furthermore, by inserting the boss 39c through the second radial ball bearing 52 and the shaft sealing member 63 in this manner, a discharge communication chamber 88 is formed inside the support portion 66. The discharge communication chamber 88 communicates with the discharge chamber 14 through the discharge passage 390. The discharge communication chamber 88 also communicates with the discharge port 69. In other words, the discharge chamber 14 and the discharge port 69 communicate with each other through the discharge passage 390 and the discharge communication chamber 88.

[0096] Furthermore, the front portion of the boss 39c enters the discharge communication chamber 88. As a result, the front end surface 391 of the boss 39c faces the discharge communication chamber 88. In addition, the shaft sealing member 63 seals the space between the discharge communication chamber 88 and the scroll chamber 65.

[0097] On the other hand, in the driven scroll 40, the driven pin 55 of the driven shaft portion 16 is inserted into the third fluid passage 643. As a result, the driven scroll 40 is positioned in front of the projection 64 within the scroll chamber 65, and is rotatably supported around the driven axis O2 with respect to the second diameter portion 64b of the projection 64. In other words, unlike the drive scroll 30, the driven scroll 40 is rotatably supported around the driven axis O2 in the housing 6 by the projection 64 alone. Furthermore, because the driven pin 55 is inserted into the third fluid passage 643, the shaft hole 55a of the driven pin 55 is in communication with the third fluid passage 643. Thus, through the shaft hole 55a, the supply passage 64c and the housing recess 15 are in communication radially inside the housing 6 beyond the first radial ball bearing 51.

[0098] As described above, in this compressor, the first radial ball bearing 51 is integrated with the drive scroll 30 by being fitted into the inner cylindrical portion 37b. Therefore, in this compressor, as shown in Figures 2 and 3, as the first radial ball bearing 51 moves relative to the second diameter portion 64b in the direction of the drive axis O1 within the range of the gap S1 provided between the first circlip 5a and the second circlip 5b, the drive scroll 30 is also allowed to move relative to the second diameter portion 64b, and consequently to the protruding body 64, in the direction of the drive axis O1. Although detailed illustrations are omitted, the boss 39c also moves relative to the second radial ball bearing 52 in the direction of the drive axis O1 at this time.

[0099] Furthermore, in this compressor, the bush 53 is fitted into the third radial ball bearing 13, and the third radial ball bearing 13 is fitted into the housing recess 15. As a result, the driven scroll 40 is allowed to move relative to the third radial ball bearing 13 and the driven shaft portion 16 in the direction of the drive axis O1 within the range between the third circlip 5c and the regulating surface 15a. In other words, the driven scroll 40 is allowed to move in the direction of the drive axis O1 within the range between the third circlip 5c and the regulating surface 15a, corresponding to the movement of the drive scroll 30 in the direction of the drive axis O1 as described above.

[0100] In this compressor configured as described above, as shown by the dashed arrows in Figures 1 to 3, low-temperature, low-pressure refrigerant that has passed through the evaporator is drawn into the scroll chamber 65 from the intake port 68. When the electric motor 10 operates and the rotor 11 rotates, the rotation of the rotor 11 is transmitted to the drive scroll 30, causing the drive scroll 30 to rotate around the drive axis O1 within the scroll chamber 65. In other words, the drive scroll 30 and the rotor 11 rotate together as a single unit. At this time, in the driven mechanism 20, each orbital pin 21 slides against the inner circumferential surface of each ring 22, causing each ring 22 to rotate relatively around the center of each orbital pin 21. In this way, the driven mechanism 20 transmits the torque of the drive scroll 30 to the driven scroll 40.

[0101] As a result, the driven scroll 40 is rotated by the drive scroll 30 and the driven mechanism 20 around the driven axis O2. At this time, the driven mechanism 20 restricts the driven scroll 40 from rotating relative to the drive scroll 30. This causes the driven scroll 40 to revolve relative to the drive scroll 30 around the driven axis O2. Then, as the drive vortex 33 and the driven vortex 43 rotate within the intake section 30a, the drive vortex 33 and the driven vortex 43 change the volume of the compression chamber 12.

[0102] The refrigerant drawn into the scroll chamber 65 flows between the rotor 11 and the stator 17 to the storage section 38, and is then drawn into the compression chamber 12 through the intake port 374 and the intake section 30a. Alternatively, the refrigerant drawn into the scroll chamber 65 can also reach the storage section 38 by flowing through the slits formed in the stator core 17a, and is then drawn into the compression chamber 12 through the intake port 374 and the intake section 30a.

[0103] Furthermore, the refrigerant drawn into the scroll chamber 65 contains lubricating oil 18. In this compressor, as described above, the drive scroll 30 and rotor 11 rotate within the scroll chamber 65. Therefore, the refrigerant drawn into the scroll chamber 65 is affected by the centrifugal force of the rotating drive scroll 30 and rotor 11, which separates the lubricating oil 18 contained within it. The lubricating oil 18 thus separated from the refrigerant flows from the scroll chamber 65 to the supply passage 64c. In other words, the lubricating oil 18 in the scroll chamber 65 flows from the first fluid passage 641 to the second fluid passage 642, and from the second fluid passage 642 to the third fluid passage 643. The lubricating oil 18 that reaches the third fluid passage 643 then flows through the shaft hole 55a of the driven pin 55. Note that a portion of the lubricating oil 18 that flows from the first fluid passage 641 to the second fluid passage 642 is stored in the second fluid passage 642.

[0104] In this way, the supply passage 64c supplies lubricating oil 18 from inside the first radial ball bearing 51 towards the third radial ball bearing 13 in the housing recess 15 via the shaft hole 55a. The lubricating oil 18 supplied into the housing recess 15 lubricates the third radial ball bearing 13 and the bush 53, as well as the sliding points between the bush 53 and the third radial ball bearing 13, the sliding points between the bush 53 and the housing recess 15, and the sliding points between the third radial ball bearing 13 and the housing recess 15. The lubricating oil that has lubricated the third radial ball bearing 13 and the like is then drawn into the compression chamber 12 along with the refrigerant that has flowed through the intake port 374, while also lubricating the sliding points between the first radial ball bearing 51 and the second diameter portion, and the sliding points between the first radial ball bearing 51 and the inner cylindrical portion 37b.

[0105] The compression chamber 12 compresses the refrigerant by reducing its own volume while confining it within itself, through the rotational drive of the drive scroll 30 and the rotational movement of the driven scroll 40. The high-pressure refrigerant, thus compressed to the discharge pressure, is discharged as compressed refrigerant from the discharge port 32 into the discharge chamber 14. As a result, the discharge chamber 14 is filled with the atmosphere of compressed refrigerant, and the pressure inside the discharge chamber 14 is higher than inside the scroll chamber 65. Compressed refrigerant is an example of a "compressible fluid" in this invention.

[0106] The compressed refrigerant discharged into the discharge chamber 14 flows through the discharge port 69 to the discharge port 88, and is then discharged to the outside of the compressor through piping connected to the discharge port 69 from the discharge port 88.

[0107] As the compressed refrigerant flows through the discharge communication chamber 88, the atmosphere inside the discharge communication chamber 88 is that of compressed refrigerant. In other words, the pressure inside the discharge communication chamber 88 is approximately the same as the pressure inside the discharge chamber 14, and the pressure inside the discharge communication chamber 88 is higher than that inside the scroll chamber 65. In this compressor, the space between the discharge communication chamber 88 and the scroll chamber 65 is sealed by the shaft seal member 63, so leakage of compressed fluid from the discharge communication chamber 88 into the scroll chamber 65 is prevented.

[0108] On the other hand, in this compressor, the front portion of the boss 39c, which is inserted through the second radial ball bearing 52 and the shaft sealing member 63, is located inside the discharge communication chamber 88. The front end surface 391 of the boss 39c faces the discharge communication chamber 88. As a result, the front end surface 391 is located in the atmosphere of compressed refrigerant, and the pressure of the compressed refrigerant acts on the front end surface 391.

[0109] Therefore, due to the pressure of the compressed refrigerant, a thrust load F10 acts on the front end surface 391, as shown in Figure 1, due to the pressure difference between the pressure in the discharge communication chamber 88 and the pressure in the scroll chamber 65, moving from the front to the rear in the direction of the drive axis O1. In addition, in this compressor, as the refrigerant is compressed in the compression chamber 12, a thrust load acts on the drive scroll 30 and the driven scroll 40, pulling them apart from each other. Specifically, a thrust load F21 acts on the drive scroll 30 during operation, moving from the rear to the front in the direction of the drive axis O1, and a thrust load F22 acts on the driven scroll 40 during operation, moving from the front to the rear in the direction of the drive axis O1.

[0110] In this compressor, the drive scroll 30 has a cover body 37 and a case 39, and the driven scroll 40 is sandwiched between the drive scroll body 301 and the cover body 37. Therefore, thrust loads F10, F21, and F22 act on the drive scroll 30, more specifically the drive scroll assembly which includes the drive scroll body 301, the driven scroll 40, the cover body, and the case 39. Furthermore, in this compressor, the thrust load acting on the drive scroll assembly on the driven scroll 40 causes the third rear surface 412 of the driven end plate 41 to be pressed against the second front surface 371 of the cover body 37 during operation. Therefore, a thrust load F31 acting from the front to the rear in the direction of the drive axis O1 is applied to the second front surface 371 of the cover body 37 and, consequently, to the drive scroll 30 by the driven scroll 40. Then, a thrust load F32 acting from the rear to the front in the direction of the drive axis O1 is applied to the third rear surface 412 of the driven end plate 41, and consequently to the driven scroll 40, due to the reaction force from the cover body 37.

[0111] In this compressor, the differential thrust pressure F acts on the drive scroll 30 from the front to the rear. More specifically, the sum of the thrust loads acting on the drive scroll assembly from the front to the rear is greater than the sum of the thrust loads acting on the drive scroll assembly from the rear to the front. That is, thrust load F10 + thrust load F22 > thrust load F21. Here, the differential thrust pressure F is the difference between the sum of the thrust loads acting on the drive scroll assembly from the front to the rear and the sum of the thrust loads acting from the rear to the front. That is, differential thrust pressure F = thrust load F10 + thrust load F22 - thrust load F21. When this differential thrust pressure F acts from the front to the rear, the drive scroll 30, together with the first radial ball bearing 51, can move relative to the second diameter portion 64b from the position shown in Figure 2 to the position shown in Figure 3, in the direction of the drive axis O1. In other words, the drive scroll 30 can move relative to the second diameter portion 64b while maintaining its position supported by the second diameter portion 64b via the first radial ball bearing 51. Here, the relative movement of the drive scroll 30 and the first radial ball bearing 51 is restricted when the first radial ball bearing 51 comes into contact with the second circlip 5b.

[0112] As a result of the drive scroll 30 moving backward relative to the second diameter portion 64b, this compressor can mitigate the pressure exerted on the third rear surface 412 of the driven end plate 41 against the second front surface 371 of the cover body 37. In other words, the force with which the driven end plate 41 presses against the cover body 37 (the thrust load F31 acting on the cover body 37) can be reduced. This reduces the reaction force from the cover body 37 to the driven end plate 41, thereby reducing the thrust load F32 acting on the third rear surface 412 of the driven end plate 41 during operation. Consequently, this compressor can prevent the drive scroll 30 and the driven scroll 40 from sliding against the second front surface 371 of the cover body 37 while the third rear surface 412 of the driven end plate 41 is strongly pressed against it during operation.

[0113] Therefore, the compressor of Example 1 can reduce the thrust load F32 acting on the back surface of the driven scroll 40 and thereby reduce the sliding loss of the driven scroll 40.

[0114] In particular, in this compressor, a differential thrust pressure F acts on the drive scroll 30, causing the drive scroll 30 and the first radial ball bearing 51 to move backward relative to the second diameter portion 64b. As a result, the driven scroll 40 can also move backward relative to the third radial ball bearing 13 and the driven shaft portion 16 in the direction of the drive axis O1. In other words, the driven scroll 40 can move backward toward the second diameter portion 64b, and consequently toward the protruding body 64, while maintaining its position of being supported by the second diameter portion 64b via the third radial ball bearing 13 and the driven shaft portion 16. This reduces the thrust load F22 acting on the driven scroll 40 during operation in this compressor.

[0115] In this compressor, the restricting surface 15a of the housing recess 15 restricts the amount of backward movement of the driven scroll 40. That is, the restricting surface 15a allows the driven scroll 40 to move backward toward the projection 64 until it contacts the third radial ball bearing 13, and after contacting the third radial ball bearing 13, it prohibits the driven scroll 40 from moving backward toward the projection 64. This prevents the driven scroll 40 from moving excessively backward toward the projection 64. As a result, in this compressor, the driven scroll 40 can be moved backward toward the projection 64, while effectively preventing the third rear surface 412 of the driven end plate 41 from being excessively pressed against the second front surface 371 of the cover body 37. In this compressor, if the differential pressure F of the thrust load acting on the drive scroll 30 decreases, the drive scroll 30 and the first radial ball bearing 51 can move forward relative to the second diameter portion 64b from the position shown in Figure 3 to the position shown in Figure 2 due to vibrations generated during operation. Similarly, the driven scroll 40 can also move forward relative to the third radial ball bearing 13 and the driven shaft portion 16 from the position shown in Figure 3 to the position shown in Figure 2.

[0116] Furthermore, in this compressor, the outer diameter of the front end face 391 of the boss 39c is smaller than the outer diameter of the drive volute body 33. This prevents the thrust load F10 acting on the drive scroll 30 through the front end face 391 of the boss 39c due to the pressure difference between the pressure in the discharge communication chamber 88 and the pressure in the scroll chamber 65 from exceeding the thrust load F21 acting on the drive scroll 30. In this way, this compressor prevents an excessively large thrust load F10 from acting on the drive scroll 30.

[0117] Furthermore, in this compressor, the "drive shaft support" and "driven shaft support" in the present invention are a first radial ball bearing 51 and a third radial ball bearing 13, respectively. As a result, this compressor is able to simplify the configuration of the "drive shaft support" and "driven shaft support" while suitably achieving the above-mentioned functions.

[0118] Furthermore, in this compressor, the lubricating oil 18 supplied through the supply passage 64c effectively lubricates not only the third radial ball bearing 13 but also the bush 53 and the first radial ball bearing 51, etc. Therefore, wear on the third radial ball bearing 13 and other components can be effectively suppressed in this compressor.

[0119] As shown in Figure 4, in the compressor of Embodiment 2, unlike the compressor of Embodiment 1, an intake port 374 is not formed in the wall portion 37a of the cover body 37. In addition, in this compressor, an intake connection port 68 is not formed in the outer peripheral wall 60a of the housing body 60, while an intake connection port 68a is formed in the rear wall 60b of the housing body 60. The intake connection port 68a penetrates the rear wall 60b to the drive shaft center O1. The intake connection port 68a is also connected to an evaporator (not shown) through piping (not shown).

[0120] Furthermore, in this compressor, a fluid passage 64d and a pin hole 4 are formed in the protruding body 64. The fluid passage 64d is composed of a fourth fluid passage 648 and a fifth fluid passage 649. The fourth fluid passage 648 is formed in the first diameter portion 64a, similar to the second fluid passage 642. The fourth fluid passage 648 is recessed from the rear end of the first diameter portion 64a toward the front.

[0121] The fifth fluid passage 649 extends through the interior of the first diameter portion 64a and the second diameter portion 64b in the direction of the drive axis O1. The front end of the fifth fluid passage 649 opens to the second end face 645, and the rear end communicates with the fourth fluid passage 648.

[0122] The pin hole 4 extends in the direction of the drive axis O1 through the interior of the first diameter portion 64a and the second diameter portion 64b at a position different from that of the fifth fluid passage 649. The front end of the pin hole 4 opens to the second end face 645, and the rear end communicates with the fourth fluid passage 648. However, the pin hole 4 may not communicate with the fourth fluid passage 648.

[0123] The fluid passage 64d is in communication with the suction port 68a because the protruding body 64 is fixed to the rear wall 60b.

[0124] Furthermore, unlike the compressor of Embodiment 1, this compressor does not have a shaft sealing member 63 in the support portion 66. As a result, in this compressor, the discharge communication chamber 88 and the scroll chamber 65 are in communication through the second radial ball bearing 52 itself and through the space between the second radial ball bearing 52 and the boss 39c.

[0125] Furthermore, in this compressor, a communication port 39e is formed in the front wall 39b of the case 39. The communication port 39e penetrates the front wall 39b in the direction of the drive axis O1. As a result, the communication port 39e connects the scroll chamber 65 and the discharge chamber 14. In this compressor, a sealing member 71 is provided between the first diameter portion 64a and the mounting recess 60c in the direction of the drive axis O1. As a result, the sealing member 71 seals the space between the fourth fluid passage 648, and by extension the fluid passage 64d, and the scroll chamber 65. The sealing member 71 may also be provided between the first diameter portion 64a and the mounting recess 60c in the radial direction of the housing 6.

[0126] Furthermore, in this compressor, a driven pin 550 is inserted through the bush 53. Unlike the driven pin 55, the driven pin 550 is solid. By inserting the driven pin 550 into the pin hole 4, the driven scroll 40 is rotatably supported around the driven axis O2 with respect to the second diameter portion 64b of the projection 64 in this compressor. Other components of this compressor are the same as those of the compressor in Embodiment 1, and the same reference numerals are used for the same components, and detailed descriptions of the components are omitted.

[0127] In this compressor, the fluid passage 64d is separated from the scroll chamber 65 by the protruding body 64. As shown by the dashed arrow in Figure 4, refrigerant is drawn into the fluid passage 64d from outside the housing 6 through the suction port 68a. Therefore, in this compressor, the fluid passage 64d is under low pressure.

[0128] The refrigerant in the fluid passage 64d flows through the fifth fluid passage 649 and reaches the recess 373 in the cover body 37. At this time, the lubricating oil (not shown) contained in the refrigerant also reaches the recess 373. The refrigerant then flows through the gap between the second front surface 371 of the cover body 37 and the third rear surface 412 of the driven end plate 41 to reach the suction section 30a, and is drawn from the suction section 30a into the compression chamber 12. The lubricating oil that has reached the recess 373 also lubricates the third radial ball bearing 13, etc., and is drawn together with the refrigerant from the suction section 30a into the compression chamber 12.

[0129] The compressed refrigerant compressed in the compression chamber 12 is then discharged into the discharge chamber 14, and further flows through the discharge port 69 before being discharged outside the compressor via the discharge port 88 and the discharge port 69. In this compressor, the discharge chamber 14 and the scroll chamber 65 are connected by a communication port 39e formed in the case 39, so a portion of the compressed refrigerant in the discharge chamber 14 flows into the scroll chamber 65 via the communication port 39e. Furthermore, in this compressor, the scroll chamber 65 is also connected to the discharge port 88, so a portion of the compressed fluid in the discharge port 88 also flows into the scroll chamber 65.

[0130] For these reasons, in this compressor, the compressed fluid creates a high-pressure atmosphere inside the scroll chamber 65. Thus, a pressure difference is created between the scroll chamber 65 and the fluid passage 64d in this compressor. As a result, similar to the compressor in Example 1, in this compressor as well, the pressure difference between the pressure in the discharge communication chamber 88 and the pressure in the scroll chamber 65 causes a thrust load F10 to act on the drive scroll 30 during operation, moving from the front to the rear in the direction of the drive axis O1. And in this compressor as well, the thrust load differential pressure F = thrust load F10 + thrust load F22 > thrust load F21, so the thrust load differential pressure F acts from the front to the rear.

[0131] In this respect, similar to the compressor in Embodiment 1, the differential pressure F of the thrust load acting from the front to the rear of this compressor allows the drive scroll 30, together with the first radial ball bearing 51, to move relative to the drive axis O1 direction. Similarly, the driven scroll 40 can also move relative to the third radial ball bearing 13 and the driven shaft portion 16 in the direction of the drive axis O1 direction. Thus, this compressor can perform the same function as the compressor in Embodiment 1.

[0132] Although the present invention has been described above in reference to Examples 1 and 2, it goes without saying that the present invention is not limited to Examples 1 and 2, and can be applied with appropriate modifications without departing from its spirit.

[0133] For example, in the compressors of Embodiments 1 and 2, the first inner ring 51a of the first radial ball bearing 51 may be fitted onto the outer circumferential surface of the second diameter portion 64b of the protruding body 64, and the first outer ring 51b of the first radial ball bearing 51 may be fitted in a gap fit into the inner cylindrical portion 37b of the cover body 37. Alternatively, both the first inner ring 51a and the first outer ring 51b may be fitted in a gap fit.

[0134] Furthermore, in the compressors of Examples 1 and 2, the third outer ring 13b of the third radial ball bearing 13 may be fitted into the housing recess 15 of the driven end plate 41, and the third inner ring 13a of the third radial ball bearing 13 may be fitted with the bush 53 in a clearance fit. Alternatively, both the third inner ring 13a and the third outer ring 13b may be fitted with a clearance fit.

[0135] Furthermore, in the compressors of Examples 1 and 2, the second inner ring 52a of the second radial ball bearing 52 may be fitted onto the outer circumferential surface of the boss 39c of the case 39, and the second outer ring 52b of the second radial ball bearing 52 may be fitted in a gap fit to the support portion 66 of the housing cover 62. Alternatively, both the second inner ring 52a and the second outer ring 52b may be fitted in a gap fit.

[0136] Furthermore, in the compressors of Examples 1 and 2, the first radial ball bearing 51 is used as the "drive shaft support" in the present invention, and the third radial ball bearing 13 is used as the "driven shaft support" in the present invention. However, the invention is not limited to this, and at least one of the "drive shaft support" and the "driven shaft support" may be a sliding bearing or the like.

[0137] Furthermore, in the compressors of Examples 1 and 2, instead of the second circlip 5b, a step that can contact the first radial ball bearing 51 may be formed on the second diameter portion 64b. Similarly, instead of the fourth circlip 5d, a step that can contact the second radial ball bearing 52 may be formed on the boss 39c.

[0138] Furthermore, in the compressors of Examples 1 and 2, the first and second circlips 5a and 5b may be omitted. Even in this case, by restricting the amount of movement of the driven scroll 40 in the direction of the drive axis O1, the amount of movement of the drive scroll 30 in the direction of the drive axis O1 can also be restricted through the driven scroll 40.

[0139] Furthermore, in the compressors of Examples 1 and 2, the stator 17 is fixed to the second diameter portion 64b, and the stator 17 is covered from the outside by the rotor 11. However, the invention is not limited to this, and the stator 17 may be fixed to the housing 6, and the rotor 11 may be fixed to the cover body 37 inside the stator 17.

[0140] Furthermore, in the compressor of Embodiment 1, a driven pin 550 may be inserted into the third fluid passage 643 instead of the driven pin 55, and a fluid passage communicating with the second fluid passage 642 may be formed at a different position from the third fluid passage 643, thereby allowing lubricating oil 18 to flow from the second fluid passage 642 to the third radial ball bearing 13, etc., through this fluid passage.

[0141] Furthermore, in the compressor of Example 1, the protruding body 64 may be integrally formed on the rear wall 60b of the housing body 60.

[0142] Furthermore, in the compressor of Example 1, the formation of the supply passage 64c may be omitted, and the protruding body 64 may be formed as a solid.

[0143] Furthermore, this specification includes the following invention: (Note 1) A double-rotation scroll compressor comprising a housing, a drive scroll, a driven scroll, a drive mechanism and a driven mechanism, wherein the housing has a scroll chamber in which the drive scroll, the driven scroll and the drive mechanism are housed, the drive scroll is rotationally driven about a drive axis by the drive mechanism, the driven scroll is rotationally driven about a driven axis by the drive scroll and the driven mechanism while being eccentric with respect to the drive scroll, and the drive scroll and the driven scroll form a compression chamber for compressing a fluid by the rotational drive and the rotational drive, wherein a projection is provided in the scroll chamber that projects toward the drive axis toward the drive scroll and the driven scroll, the projection has a first diameter portion and a second diameter portion formed to be smaller in diameter than the first diameter portion, the second diameter portion is located on one side toward the drive axis toward the first diameter portion, and the drive scroll is rotatably supported by a drive shaft support in the second diameter portion toward the drive axis, A double-rotation scroll compressor characterized in that the driven scroll is rotatably supported by a driven shaft support in the second diameter portion so as to be rotatable around the driven axis, and is located on one side in the drive axis direction relative to the projection in the drive axis direction, and the drive shaft support rotatably supports the driven scroll so that it can move toward the other side in the drive axis direction relative to the second diameter portion when a differential thrust load is applied to the driven scroll from one side in the drive axis direction. (Note 2) The double-rotation scroll compressor according to Note 1, characterized in that the driven shaft support rotatably supports the driven scroll so that it can move toward the other side in the drive axis direction relative to the second diameter portion when a differential thrust load is applied to the driven scroll from one side in the drive axis direction, and a restricting portion is provided between the driven scroll and the driven shaft support to restrict the amount of movement of the driven scroll toward the other side in the drive axis direction.(Note 3) The double-rotating scroll compressor according to Note 1 or 2, wherein the housing has an intake port for drawing fluid into the scroll chamber from the outside, the drive scroll has a drive end plate extending intersecting the drive axis, a drive spiral body projecting from the drive end plate toward the driven scroll parallel to the drive axis and forming a spiral, and a supported portion positioned at a distance from the projecting body in the direction of the drive axis, extending toward the opposite side of the projecting body in the direction of the drive axis and rotatably supported by the housing, a compressed fluid which is a fluid compressed in the compression chamber flows inside the supported portion, the supported portion has an end face located in the atmosphere of the compressed fluid and facing the housing in the direction of the drive axis, and the outer diameter of the end face is smaller than the outer diameter of the drive spiral body. (Note 4) The double-rotation scroll compressor according to any one of Notes 1 to 3, wherein the drive scroll has a cover body supported by the drive shaft support on the other side of the drive axis direction from the driven scroll. (Note 5) The double-rotation scroll compressor according to Note 4, wherein a gap is formed between the drive shaft support and the protruding body in the drive axis direction, or between the drive shaft support and the cover body in the drive axis direction, allowing movement of the drive scroll relative to the protruding body in the drive axis direction. (Note 6) The double-rotation scroll compressor according to any one of Notes 1 to 5, wherein the drive shaft support and the driven shaft support are rolling bearings. (Note 7) The double-rotation scroll compressor according to any one of Notes 1 to 6, wherein a supply passage is formed in the protruding body to supply lubricating oil from the inside of the housing radially relative to the drive shaft support toward the driven shaft support.

[0144] This invention can be used in vehicle air conditioning systems and the like.

[0145] 6 Housing 10 Electric motor (drive mechanism) 11 Rotor 12 Compression chamber 13 Third radial ball bearing (driven shaft support, rolling bearing) 15a Regulating surface (regulating part) 18 Lubricating oil 20 Driven mechanism 30 Driven scroll 31 Driven end plate 33 Driven spiral body 37 Cover body 39c Boss (supported part) 40 Driven scroll 51 First radial ball bearing (drive shaft support, rolling bearing) 64 Projection 64a First diameter part 64b Second diameter part 64c Supply passage 65 Scroll chamber 68 Intake connection port 391 Front end face (end face) O1 Drive shaft center O2 Driven shaft center S1 Gap

Claims

1. A double-rotation scroll compressor comprising a housing, a drive scroll, a driven scroll, a drive mechanism, and a driven mechanism, wherein the housing has a scroll chamber in which the drive scroll, the driven scroll, and the drive mechanism are housed, the drive scroll is rotationally driven around a drive axis by the drive mechanism, the driven scroll is rotationally driven around a driven axis by the drive scroll and the driven mechanism while being eccentric with respect to the drive scroll, and the drive scroll and the driven scroll form a compression chamber for compressing fluid by the rotational drive and the rotational drive, wherein a projection is provided in the scroll chamber that projects toward the drive axis toward the drive scroll and the driven scroll, the projection has a first diameter portion and a second diameter portion formed to be smaller in diameter than the first diameter portion, the second diameter portion is located on one side toward the drive axis toward the first diameter portion, and the drive scroll is rotatably supported by a drive shaft support in the second diameter portion toward the drive axis, A double-rotating scroll compressor characterized in that the driven scroll is rotatably supported in the second diameter portion by a driven shaft support so as to be about the driven axis, and is located on one side in the drive axis direction relative to the protruding body in the drive axis direction, and the drive shaft support rotatably supports the drive scroll so that it can move to the other side in the drive axis direction relative to the second diameter portion when a differential pressure of thrust load acts on the drive scroll from one side in the drive axis direction.

2. The driven shaft support rotatably supports the driven scroll so that it can move toward the second diameter portion toward the other side in the direction of the drive axis when the differential pressure of the thrust load acts on the driven scroll from one side in the direction of the drive axis, and a restricting portion is provided between the driven scroll and the driven shaft support for restricting the amount of movement of the driven scroll toward the other side in the direction of the drive axis, as described in claim 1.

3. The double-rotating scroll compressor according to claim 1 or 2, wherein the housing has an intake port for drawing fluid into the scroll chamber from the outside, the drive scroll has a drive end plate extending intersecting the drive axis, a drive spiral body projecting from the drive end plate toward the driven scroll parallel to the drive axis and forming a spiral, and a supported portion positioned at a distance from the projecting body in the direction of the drive axis, extending toward the opposite side of the projecting body in the direction of the drive axis and rotatably supported by the housing, a compressed fluid which is a fluid compressed in the compression chamber flows inside the supported portion, the supported portion has an end face located in the atmosphere of the compressed fluid and facing the housing in the direction of the drive axis, and the outer diameter of the end face is smaller than the outer diameter of the drive spiral body.

4. The dual-rotation scroll compressor according to claim 1 or 2, wherein the drive scroll has a cover body supported by the drive shaft support on the other side of the drive axis direction from the driven scroll.

5. The double-rotating scroll compressor according to claim 4, wherein a gap is formed between the drive shaft support and the projection in the direction of the drive axis, or between the drive shaft support and the cover in the direction of the drive axis, allowing movement of the drive scroll relative to the projection in the direction of the drive axis.

6. The double-rotating scroll compressor according to claim 1, wherein the drive shaft support and the driven shaft support are rolling bearings.

7. The double-rotating scroll compressor according to claim 1, wherein the protruding body has a supply passage for supplying lubricating oil from the radially inner side of the housing toward the driven shaft support than the drive shaft support.

Images