Double-rotating scroll compressor

Abstract

To provide a dual-rotation scroll compressor that exhibits high quietness while suppressing a decrease in efficiency. [Solution] The compressor of the present invention comprises a housing 6 and a compression mechanism 14. A discharge section 63 is formed in the housing 6. The compression mechanism 14 has a compression chamber 12 and a discharge chamber 91, as well as a rotating shaft section 37d. The rotating shaft section 37d is rotatably supported in the housing 6 via a bearing 52. The discharge chamber 91 is formed to have a larger diameter than the outer diameter of the bearing 52. A discharge connecting section 38 is formed in the rotating shaft section 37d. In this compressor, the flow resistance changes as the phase between the discharge section 63 and the discharge connecting section 38 changes with the rotation of the rotating shaft section 37d. Furthermore, the flow resistance between the discharge section 63 and the discharge connecting section 38 increases as the flow rate of the fluid discharged from the compression chamber 12 to the discharge chamber 91 approaches its maximum.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a conventional double-rotary scroll compressor (hereinafter simply referred to as a compressor). This compressor includes a housing and a compression mechanism provided within the housing. The housing is formed with a discharge portion for discharging fluid to the outside, a suction portion for sucking fluid from the outside, and a suction chamber communicating with the suction portion.

[0003] The compression mechanism has a driving scroll and a driven scroll. A drive shaft is formed on the driving scroll. The drive shaft is rotatably supported by the housing via a bearing. The driving scroll rotates around the rotation axis by a driving mechanism. The driving scroll has a driving end plate and a driving spiral body that is integral with the driving end plate and protrudes in a spiral shape toward the driven scroll.

[0004] The driven scroll faces the driving scroll. A driven shaft is formed on the driven scroll. The driven shaft is rotatably supported by the housing via a bearing. The driven scroll rotates around the driven axis by the driving scroll and a driven mechanism while being eccentric with respect to the driving scroll. Further, the driven scroll forms a compression chamber with the driving scroll. The driven scroll has a driven end plate and a driven spiral body that is integral with the driven end plate and protrudes in a spiral shape toward the driving scroll. Furthermore, a discharge chamber is formed inside the driven shaft. The discharge chamber communicates with the compression chamber and also communicates with the discharge portion.

[0005] In this compressor, fluid is drawn into the intake chamber from outside the housing through the intake section. In this compression mechanism, the volume of the compression chamber changes as the drive scroll and the driven scroll rotate. As a result, fluid is drawn from the intake chamber into the compression chamber, and this fluid is compressed within the compression chamber as the volume of the compression chamber decreases. The compressed fluid is then discharged from the compression chamber into the discharge chamber and out of the housing through the discharge section. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2002-310073 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] In this type of compressor, it is necessary to reduce noise caused by discharge pulsation during operation. Therefore, in the conventional compressor described above, it is conceivable to reduce discharge pulsation by increasing the volume of the discharge chamber and thereby increasing the muffler effect of the discharge chamber. However, in the conventional compressor described above, the discharge chamber is formed inside the driven shaft of the driven scroll, so as the volume of the discharge chamber increases, the diameter of the driven shaft increases, and the bearing supporting the driven shaft also increases in diameter accordingly. This leads to increased power loss in the bearing, resulting in a decrease in compressor efficiency.

[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 compressor that can exhibit high quietness and suppress a decrease in efficiency. [Means for solving the problem]

[0009] The double-rotating scroll compressor of the present invention comprises a housing with a discharge section formed therein for discharging fluid to the outside, The housing includes a compression mechanism, The compression mechanism includes a compression chamber for compressing a fluid while reducing its volume, and a discharge chamber communicating with the compression chamber, through which the fluid compressed in the compression chamber is discharged. The housing is also provided with a rotating shaft portion that is rotatably supported by bearings around a rotation axis. The discharge chamber is formed to have a larger diameter than the outer diameter of the bearing. The compression mechanism includes a drive scroll that rotates by a drive mechanism, The system includes a driven scroll that faces the drive scroll and rotates eccentrically with respect to the drive scroll by the drive scroll and the driven mechanism, thereby forming the compression chamber between itself and the drive scroll. The drive scroll comprises a drive end plate and a drive spiral body that is integral with the drive end plate and protrudes spirally toward the driven scroll. The driven scroll has a driven end plate and a driven spiral body that is integral with the driven end plate and projects spirally toward the drive scroll. The rotating shaft portion is formed with a discharge connecting portion that allows the fluid discharged into the discharge chamber to flow to the discharge portion. As the rotation of the rotating shaft changes the phase between the discharge section and the discharge connecting section, the flow resistance of the fluid flowing from the discharge connecting section to the discharge section changes. The discharge section and the discharge connecting section are characterized in that the flow resistance increases as the flow rate of the fluid discharged from the compression chamber to the discharge chamber approaches its maximum.

[0010] In the double-rotating scroll compressor of the present invention, a discharge connection is formed on the rotating shaft of the compression mechanism, and this discharge connection allows the fluid discharged into the discharge chamber to flow to the discharge section. As a result, in this compressor, the fluid compressed in the compression chamber and discharged into the discharge chamber flows from the discharge connection to the discharge section. Furthermore, in this compressor, the phase between the discharge section and the discharge connection changes as the rotating shaft rotates. Moreover, the flow resistance changes due to the change in phase between the discharge section and the discharge connection.

[0011] In this compressor, pulsation occurs due to flow resistance, and the magnitude of this pulsation changes as the flow resistance changes. Furthermore, in this compressor, the flow resistance between the discharge section and the discharge connection section increases as the flow rate of the fluid discharged from the compression chamber to the discharge chamber approaches its maximum. As a result, in this compressor, the pulsation caused by flow resistance acts to cancel out the discharge pulsation that occurs when the fluid is discharged from the compression chamber to the discharge chamber. Consequently, discharge pulsation can be reduced in this compressor. In the following explanation, the effect by which the pulsation caused by the flow resistance of the fluid flowing from the discharge connection section to the discharge section cancels out the discharge pulsation will be referred to as "pulsation cancellation effect" as appropriate.

[0012] Furthermore, in this compressor, the discharge chamber is formed with a diameter larger than the outer diameter of the bearing that rotatably supports the rotating shaft. As a result, this compressor can suitably secure the volume of the discharge chamber, and thus suitably reduce discharge pulsation in the discharge chamber when fluid is discharged from the compression chamber to the discharge chamber.

[0013] Here, when the compression mechanism rotates at low speeds, the volumetric flow rate of the fluid flowing from the discharge connection to the discharge section decreases. As a result, the change in flow velocity due to changes in flow resistance becomes smaller, and the resulting pressure change also becomes smaller. Therefore, when the compression mechanism rotates at low speeds, the pulsation reduction effect due to the pulsation cancellation action becomes smaller.

[0014] In this respect, this compressor can effectively reduce discharge pulsation in a discharge chamber with a suitable volume, even when the compression mechanism is rotating at a low speed.

[0015] Furthermore, in this compressor, the outer diameter of the bearing is smaller than that of the discharge chamber, so even if the diameter of the discharge chamber is increased, the increase in the diameter of the bearing can be suppressed. In other words, in this compressor, the bearing will never be the same diameter as or larger than that of the discharge chamber. This suppresses an increase in power loss in the bearing.

[0016] Therefore, the double-rotary scroll type compressor of the present invention can exhibit high quietness and suppress a decrease in efficiency.

[0017] The compression mechanism may have a cover body that is fixed to the drive scroll or the driven scroll and provided with a rotating shaft portion. And it is preferable that the discharge chamber is formed between the cover body and the drive end plate of the drive scroll to which the cover body is fixed or the driven end plate of the driven scroll to which the cover body is fixed.

[0018] In this case, for example, by forming a recess for partitioning the discharge chamber on at least one of the cover body and the drive end plate of the drive scroll to which the cover body is fixed, or at least one of the cover body and the driven end plate of the driven scroll to which the cover body is fixed, the discharge chamber can be provided in the compression mechanism. Therefore, the degree of freedom in the form of the discharge chamber in the compression mechanism can be increased.

[0019] Lubricating oil can be discharged into the discharge chamber together with the fluid compressed in the compression chamber. And it is preferable that the discharge chamber and a location in the housing that is at a lower pressure than the discharge chamber are communicated via a reflux path for refluxing the lubricating oil in the discharge chamber.

[0020] In this case, the lubricating oil discharged into the discharge chamber is refluxed via the reflux path to a location in the housing that is at a lower pressure than the discharge chamber, so that the sliding portions of the compression mechanism and the like can be suitably lubricated by the lubricating oil.

[0021] Here, when lubricating oil is discharged into the discharge chamber, the amount of lubricating oil discharged into the discharge chamber increases during high-speed rotation of the compression mechanism. Then, the volume that can exhibit a muffler effect in the discharge chamber and contribute to pulsation reduction becomes small. Therefore, during high-speed rotation of the compression mechanism, the pulsation reduction effect due to the muffler effect in the discharge chamber becomes small.

[0022] In this regard, in this compressor, even during high-speed rotation of the compression mechanism, the discharge pulsation can be suitably reduced by the pulsation cancellation action.

[0023] The discharge part and the discharge connection part are preferably in communication in the radial direction of the housing. In this case, the housing, and thus the entire compressor, can be downsized in the direction of the rotation axis.

[0024] Also, the discharge part and the discharge connection part are preferably in communication in the direction of the rotation axis. In this case, the housing, and thus the entire compressor, can be downsized in the radial direction of the housing.

[0025] Also, in this case, the discharge part can be formed in the housing while being eccentric with respect to the rotation axis. And the discharge connection part is preferably formed in the rotating shaft part while being eccentric with respect to the rotation axis. Thereby, the phase between the discharge part and the discharge connection part can be suitably changed.

[0026] When the flow rate of the fluid discharged from the compression chamber to the discharge chamber is at a minimum, the discharge part and the discharge connection part are preferably in a phase that minimizes the flow resistance.

[0027] [[ID=I8]]Also, when the flow rate of the fluid discharged from the compression chamber to the discharge chamber is at a maximum, the discharge part and the discharge connection part are preferably in a phase that maximizes the flow resistance.

[0028] In these cases, the pulsation caused by the flow resistance acts to more suitably cancel out the discharge pulsation, so that the discharge pulsation can be more suitably reduced. Note that "the flow rate of the fluid discharged from the compression chamber to the discharge chamber is at a minimum" includes not only the case where a small amount of fluid is discharged from the compression chamber to the discharge chamber but also the case where the flow rate of the fluid discharged from the compression chamber to the discharge chamber is zero.

[0029] The compression mechanism may be provided with a discharge valve that allows fluid to be discharged from the compression chamber to the discharge chamber while prohibiting fluid from flowing from the discharge chamber to the compression chamber. And the discharge connection part is preferably located downstream in the fluid flow direction from the discharge valve.

[0030] In this case, the generation of pulsation caused by the flow of fluid from the discharge chamber to the compression chamber can be effectively prevented. In addition, the flow of fluid from the discharge connection to the discharge passage can assist in opening the discharge valve. [Effects of the Invention]

[0031] The dual-rotation scroll compressor of the present invention exhibits high quietness while suppressing a decrease in efficiency. [Brief explanation of the drawing]

[0032] [Figure 1] Figure 1 is a cross-sectional view of the double-rotation scroll compressor of Example 1. [Figure 2] Figure 2 is an enlarged cross-sectional view of the main parts of the double-rotating scroll compressor of Embodiment 1, showing the discharge connection section, the second insertion hole, and the discharge passage. [Figure 3] Figure 3 is a graph showing the relationship between the change in rotational phase of the driving scroll and the driven scroll and the change in the volume of the compression chamber, relating to the dual-rotation scroll type compressor of Example 1. [Figure 4] Figure 4 is a graph showing the relationship between the change in rotational phase of the driving scroll and the driven scroll and the change in pressure inside the compression chamber, relating to the dual-rotation scroll type compressor of Example 1. [Figure 5] Figure 5 is a cross-sectional view of the AA section of Figure 1, relating to the dual-rotation scroll compressor of Embodiment 1, when the rotational phase of the driving scroll and the driven scroll is phase X1. [Figure 6] Figure 6 is a cross-sectional view of the AA section of Figure 1, relating to the dual-rotation scroll compressor of Embodiment 1, when the rotational phase of the driving scroll and the driven scroll is phase X2. [Figure 7] Figure 7 is a cross-sectional view of the AA section of Figure 1, relating to the dual-rotation scroll compressor of Embodiment 1, when the rotational phase of the driving scroll and the driven scroll is phase X3. [Figure 8]Figure 8 is a cross-sectional view of the AA section of Figure 1, relating to the dual-rotation scroll compressor of Embodiment 1, when the rotational phase of the driving scroll and the driven scroll is phase X4. [Figure 9] Figure 9 is an enlarged cross-sectional view of the main part of the double-rotating scroll compressor of Embodiment 1, showing the BB section of Figure 1 when the rotational phase of the driving scroll and the driven scroll is phase X4. [Figure 10] Figure 10 is a cross-sectional view of the AA section of Figure 1, relating to the dual-rotation scroll compressor of Embodiment 1, when the rotational phase of the driving scroll and the driven scroll is phase X5. [Figure 11] Figure 11 is an enlarged cross-sectional view of the BB section of Figure 1, relating to the dual-rotation scroll compressor of Embodiment 1, when the rotational phase of the driving scroll and the driven scroll is phase X5. [Figure 12] Figure 12 is a graph showing the waveforms of discharge pulsation and cancellation pulsation during operation of the double-rotation scroll compressor of Example 1. [Figure 13] Figure 13 is a partial cross-sectional view relating to the double-rotation scroll compressor of Embodiment 1, showing the state in which lubricating oil has accumulated in the discharge chamber when the compression mechanism is rotating at high speed. [Figure 14] Figure 14 is a cross-sectional view of the double-rotation scroll compressor of Example 2. [Figure 15] Figure 15 is a schematic diagram relating to the double-rotation scroll compressor of Embodiment 2, showing the phase change between the discharge section and the discharge connection section when viewed from the D1 direction in Figure 14, due to the rotational drive of the drive scroll. Figure 15(A) shows the phase between the discharge section and the discharge connection section when the rotation angle of the drive scroll is zero degrees. Figure 15(B) shows the phase between the discharge section and the discharge connection section when the drive scroll has rotated approximately 90° from the state shown in Figure 15(A). Figure 15(C) shows the phase between the discharge section and the discharge connection section when the drive scroll has rotated approximately 90° from the state shown in Figure 15(B). Figure 15(D) shows the phase between the discharge section and the discharge connection section when the drive scroll has rotated approximately 90° from the state shown in Figure 15(C). [Figure 16] Figure 16 is an enlarged cross-sectional view of the main part of the double-rotation scroll compressor of Embodiment 3. [Figure 17] Figure 17 is a cross-sectional view of the double-rotation scroll compressor of Embodiment 4. [Figure 18] Figure 18 is a cross-sectional view of the double-rotation scroll compressor of Example 5. [Modes for carrying out the invention]

[0033] Examples 1 to 5 embodying the present invention will be described below with reference to the drawings. The double-rotation scroll compressors of Examples 1 to 5 are mounted on a vehicle (not shown) and constitute the vehicle's air conditioning system.

[0034] (Example 1) As shown in Figure 1, the double-rotation scroll compressor of Embodiment 1 comprises a housing 6, an electric motor 10, and a compression mechanism 14. The electric motor 10 is an example of a "drive mechanism" in the present invention.

[0035] 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 correspondence with Figure 1. Note that the 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.

[0036] 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.

[0037] 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 a rotation axis O1 as its center. The rotation axis O1 is parallel to the front-rear direction.

[0038] Furthermore, 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).

[0039] 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 rotation axis O1. The outer edge of the rear wall 60b is connected to the rear end of the outer wall 60a. The aforementioned intake port 68 may also be formed in the rear wall 60b.

[0040] A first support portion 64 is formed in the center of the inner surface of the rear wall 60b. The first support portion 64 protrudes forward from the center of the inner surface of the rear wall 60b. The first support portion 64 is cylindrical in shape with the rotation axis O1 as its center.

[0041] A pin hole 4 is formed in the first support portion 64. The pin hole 4 is cylindrical in shape and opens onto the front end surface of the first support portion 64, extending linearly towards the rear within the first support portion 64. This pin hole 4 does not penetrate the first support portion 64 in the front-rear direction.

[0042] Furthermore, a first sliding bearing 51 is provided on the outer circumferential surface of the first support portion 64. The first sliding bearing 51 is formed in a cylindrical shape with a larger diameter than the first support portion 64. The first sliding bearing 51 is positioned on the outer circumferential surface of the first support portion 64. Note that a ball bearing may be provided instead of the first sliding bearing 51.

[0043] The housing cover 62 is positioned in front of the housing body 60. The housing cover 62 is substantially disc-shaped with the rotation axis O1 as its center. The housing cover 62 has a front surface 62a facing forward, a rear surface 62b located on the opposite side of the front surface 62a and facing rear, and an outer peripheral surface 62c connected to the front surface 62a and the rear surface 62b and located between the front surface 62a and the rear surface 62b.

[0044] Furthermore, the housing cover 62 has a second support portion 66, a second insertion hole 61, and a discharge portion 63 formed therein.

[0045] The second support portion 66 is integrally formed approximately in the center of the rear surface 62b and protrudes rearward from the rear surface 62b. The second insertion hole 61 is formed in a cylindrical shape with the rotation axis O1 as its center and extends within the housing cover 62 in the direction of the rotation axis O1. The rear end of the second insertion hole 61 opens to the rear end of the second support portion 66, that is, the rear end of the housing cover 62. With the formation of the second insertion hole 61 in this way, the second support portion 66 has a cylindrical shape with the rotation axis O1 as its center.

[0046] On the other hand, the front end of the second insertion hole 61 does not open to the front end of the housing cover 62. A second sliding bearing 52 is provided inside the second insertion hole 61. The second sliding bearing 52 is an example of a "bearing" in the present invention. The length of the outer diameter of the second sliding bearing 52 is the first length L1, and is smaller in diameter than the outer diameter of the second support portion 66. The second sliding bearing 52 is formed in a cylindrical shape and is positioned in the front part of the second insertion hole 61. Note that a ball bearing or the like may be used as the "bearing" in the present invention.

[0047] The discharge section 63 consists of a discharge port 69 and a discharge passage 67. The discharge port 69 is formed on the outer circumferential surface 62c. The discharge port 69 opens radially from the outer circumferential surface 62c toward the outside of the housing cover 62. The discharge port 69 is connected to a condenser (not shown) through piping (not shown).

[0048] The discharge passage 67 is formed inside the housing cover 62. The discharge passage 67 extends radially within the housing cover 62. The discharge passage 67 is connected to the discharge port 69 at one end and to the second insertion hole 61 at the other end. Thus, the discharge passage 67 communicates with the discharge port 69 and the second insertion hole 61, while also connecting the second insertion hole 61 to the discharge port 69.

[0049] In housing 6, the housing cover 62 is positioned in front of the housing body 60, with the rear surface 62b of the housing cover 62 in contact with the front end of the outer peripheral wall 60a of the housing body 60. In this state, the housing cover 62 is fixed to the housing body 60 from the housing cover 62 side by multiple bolts (not shown). In this way, the housing body 60 and the housing cover 62 are integrated into one unit in housing 6.

[0050] Furthermore, in the housing 6, the front of the housing body 60 is closed by the housing cover 62, thereby forming an intake chamber 65 inside the housing body 60. The intake chamber 65 is in communication with the intake port 68. As a result, refrigerant gas is drawn into the intake chamber 65 from outside the housing 6 through the intake port 68. The refrigerant gas is an example of a "fluid" in this invention. The refrigerant gas drawn into the intake chamber 65 contains lubricating oil 18. The intake chamber 65 is also in communication with the intake port 35b, which will be described later. Therefore, the refrigerant gas in the intake chamber 65 is drawn into the intake space 30a, which will be described later, from the intake port 35b.

[0051] The electric motor 10 is housed within the intake chamber 65. Thus, the intake chamber 65 also serves as the motor chamber housing the electric motor 10.

[0052] The electric motor 10 consists of a stator 17 and a rotor 11. The stator 17 is cylindrical with a rotation axis O1 at its center and has windings 17a. The stator 17 is fixed to the housing body 60, and by extension the housing 6, by fitting into the inner surface of the outer wall 60a.

[0053] The rotor 11 is cylindrical around the rotation axis O1 and is located inside the stator 17. 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.

[0054] The compression mechanism 14 is located inside the housing 6. The compression mechanism 14 consists of a drive scroll 30, a driven scroll 40, a driven mechanism 20, and a first cover body 37. The first cover body 37 is an example of a "cover body" in the present invention.

[0055] The drive scroll 30 is made of aluminum alloy. The drive scroll 30 includes a drive end plate 31, a drive peripheral wall 32, a drive spiral body 33, and a closing body 35.

[0056] The drive end plate 31 extends in a substantially disc shape perpendicular to the rotation axis O1 and the driven axis O2. The driven axis O2 extends parallel to the rotation axis O1 while being eccentric with respect to the rotation axis O1. In other words, the driven axis O2 is also parallel in the front-rear direction. The drive end plate 31 also has a front surface 311 facing the first cover body 37 and a rear surface 312 located on the opposite side of the front surface 311.

[0057] Furthermore, the drive end plate 31 has a first recess 30b and a discharge port 30c. The first recess 30b is recessed in a substantially cylindrical shape from the front surface 311 toward the rear. The inner diameter of the first recess 30b is equal to or substantially equal to the inner diameter of the second recess 37e, which will be described later and is provided in the first cover body 37. The discharge port 30c is formed in the drive end plate 31 at a location within the first recess 30b and penetrates the drive end plate 31 in the front-rear direction. Also, in the first recess 30b, a discharge reed valve 57 and a retainer 58 are fixed to the drive end plate 31 by fixing bolts 59. The discharge reed valve 57 is an example of a "discharge valve" in the present invention.

[0058] The discharge reed valve 57 opens due to elastic deformation, allowing the refrigerant gas in the compression chamber 12 to be discharged into the discharge chamber 91 through the discharge port 30c. Conversely, the discharge reed valve 57 closes due to elastic deformation, preventing the refrigerant gas in the compression chamber 12 from being discharged into the discharge chamber 91 through the discharge port 30c. When the discharge reed valve 57 is closed, it prevents the refrigerant gas in the discharge chamber 91 from flowing into the compression chamber 12 through the discharge port 30c. The retainer 58 allows adjustment of the opening degree of the discharge reed valve 57. Further details regarding the compression chamber 12 and the discharge chamber 91 will be described later.

[0059] The drive circumferential wall 32 is integral with the drive end plate 31 and extends cylindrically from the outer peripheral edge of the drive end plate 31 towards the rear, i.e., toward the driven scroll 40. In this case, the drive circumferential wall 32 extends parallel to the rotation axis O1 and the driven axis O2.

[0060] The drive spiral body 33 is integral with the drive end plate 31 and is positioned inside the drive peripheral wall 32. The drive spiral body 33 extends from the rear surface 312 of the drive end plate 31 parallel to the drive peripheral wall 32 toward the driven scroll 40. As shown in Figure 5, the drive spiral body 33 has its spiral center on the center side of the drive end plate 31 and extends spirally from the spiral center toward the outer circumference. The outer end of the drive spiral body 33 is connected to the drive peripheral wall 32. Note that in Figure 5, the electric motor 10 is omitted from the illustration for ease of explanation. The same applies to Figures 6 to 8 and Figure 10, which will be described later.

[0061] As shown in Figure 1, the closure body 35 extends in a substantially disc shape perpendicular to the rotation axis O1 and the driven axis O2. The closure body 35 has a front surface 351 facing forward and a rear surface 352 located on the opposite side of the front surface 351.

[0062] Furthermore, the occluding body 35 has a first boss 35a and an intake port 35b formed therein. The first boss 35a is integrally formed in the center of the rear surface 352 and protrudes rearward in the direction of the rotation axis O1 and the driven axis O2. The first boss 35a is cylindrical with the rotation axis O1 as its center. The intake port 35b penetrates the occluding body 35 in the direction of the rotation axis O1.

[0063] As shown in Figure 1, the closure body 35 is provided with four rings 22 on its front surface 351. Each ring 22 is arranged at equal intervals in the circumferential direction of the closure body 35. Note that Figure 1 shows two of the four rings 22.

[0064] The first cover body 37 is a bottomed cylindrical member having an outer peripheral wall 37a, a front wall 37b, and a flange 37c. The outer peripheral wall 37a is cylindrical with the rotation axis O1 as the center. Here, the outer diameter of the outer peripheral wall 37a is formed to be larger than the outer diameter of the second sliding bearing 52. More specifically, the outer diameter of the outer peripheral wall 37a is formed to be smaller than the inner diameter of the rotor 11 and the outer diameter of the drive end plate 31 by the length of the flange 37c protruding radially outward from the outer peripheral wall 37a.

[0065] Furthermore, a return channel 370 is formed in the outer peripheral wall 37a. The return channel 370 is located in the front portion of the outer peripheral wall 37a and penetrates the outer peripheral wall 37a in the radial direction of the first cover body 37.

[0066] The front wall 37b is located at the front end of the first cover body 37. The front wall 37b extends in a substantially circular, flat shape perpendicular to the rotation axis O1. The outer edge of the front wall 37b is connected to the front end of the outer peripheral wall 37a. Thus, the first cover body 37 has a second recess 37e that is defined by the inner peripheral surface of the outer peripheral wall 37a and the rear surface of the front wall 37b, and extends in a substantially cylindrical shape in the direction of the rotation axis O1.

[0067] The first cover body 37 is provided with a second boss 37d. The second boss 37d is an example of a "rotating shaft portion" in the present invention. The second boss 37d is integrally formed in the center of the front wall 37b and protrudes forward from the front wall 37b in the direction of the rotation axis O1 and the driven axis O2.

[0068] As shown in Figure 2, the second boss 37d consists of a first diameter portion 371, a second diameter portion 372, and a third diameter portion 373. The first diameter portion 371 constitutes the rear part of the second boss 37d. The second diameter portion 372 is located between the first diameter portion 371 and the third diameter portion 373 and constitutes the central part of the second boss 37d. The third diameter portion 373 constitutes the front part of the second boss 37d.

[0069] The first diameter portion 371 has the largest outer diameter among the first diameter portion 371, the second diameter portion 372, and the third diameter portion 373. The second diameter portion 372 has a larger outer diameter than the third diameter portion 373. As a result, the second boss 37d has an outer diameter that decreases in three stages, in the order of the first diameter portion 371, the second diameter portion 372, and the third diameter portion 373. The outer diameter of the third diameter portion 373 is formed to be approximately the same as the inner diameter of the second sliding bearing 52.

[0070] Furthermore, a discharge connection section 38 is formed in the second boss 37d. The discharge connection section 38 allows the refrigerant gas discharged into the discharge chamber 91 to flow to the discharge section 63. The discharge connection section 38 consists of a connecting passage 38a and a discharge connection hole 38b.

[0071] The connecting passage 38a penetrates through the second boss 37d and the front wall 37b in the direction of the rotation axis O1. The connecting passage 38a is formed in a cylindrical shape with the rotation axis O1 as its center. As a result, the second boss 37d has a cylindrical shape with the rotation axis O1 as its center.

[0072] The discharge connecting hole 38b is connected to the connecting passage 38a and extends radially within the second boss 37d. The discharge connecting hole 38b opens onto the outer circumferential surface of the second boss 37d, more specifically, onto the outer circumferential surface of the second radial portion 372.

[0073] The flange 37c is integrally formed with the rear end of the outer peripheral wall 37a. The flange 37c protrudes radially from the first cover body 37, outward from the outer peripheral wall 37a. As a result, the flange 37c has a larger diameter than the outer peripheral wall 37a and is approximately the same diameter as the drive end plate 31 of the drive scroll 30. Note that the formation of the flange 37c may be omitted.

[0074] In this compressor, the first cover body 37 is fixed to the drive scroll 30. Specifically, in the drive scroll 30, the front surface 351 of the closing body 35 is facing the rear surface 312 of the drive end plate 31, and the closing body 35 is in contact with the rear end of the drive peripheral wall 32. The first cover body 37 has its peripheral wall 37a and flange 37c facing the drive end plate 31, and the flange 37c is in contact with the front surface 311 of the drive end plate 31.

[0075] In this state, the flange 37c of the first cover body 37, the drive end plate 31 and drive peripheral wall 32, and the closing body 35 are connected from the flange 37c side by multiple bolts 50. In this way, the drive end plate 31 and drive peripheral wall 32 and the closing body 35 are integrated into the drive scroll 30. Furthermore, the first cover body 37 is integrated with the drive end plate 31, and by extension, the drive scroll 30. Note that Figure 1 shows two of the multiple bolts 50.

[0076] As the first cover body 37 is fixed to the drive scroll 30 in this manner, a discharge chamber 91 is formed between the outer peripheral wall 37a and front wall 37b of the first cover body 37 and the drive end plate 31, partitioned by the first recess 30b and the second recess 37e.

[0077] The discharge chamber 91 communicates with the discharge port 30c, the recirculation channel 370, and the connecting passage 38a. Here, the discharge port 30c and the connecting passage 38a communicate with the discharge chamber 91 in the direction of the rotation axis O1. In contrast, the recirculation channel 370 communicates with the discharge chamber 91 in the radial direction of the first cover body 37, that is, in a direction perpendicular to the rotation axis O1. Furthermore, the discharge port 30c, the recirculation channel 370, and the connecting passage 38a all have smaller diameters than the discharge chamber 91. The recirculation channel 370 communicates the discharge chamber 91 and the suction chamber 65.

[0078] Thus, the first cover body 37 is housed within the intake chamber 65 and is rotatable around the rotation axis O1 together with the drive scroll 30. Furthermore, the first cover body 37 has its second boss 37d fitted into the second sliding bearing 52. As a result, the first cover body 37 is supported via the second sliding bearing 52 so as to be rotatable around the rotation axis O1 relative to the second support portion 66, i.e., the housing 6.

[0079] Furthermore, the drive scroll 30 is fixed to the rotor 11 while its drive peripheral wall 32 enters the rotor 11. As a result, the drive scroll 30 is fixed to the rotor 11 and becomes integrated with the rotor 11.

[0080] The driven scroll 40 is also made of aluminum alloy. The driven scroll 40 is housed within the drive scroll 30. The driven scroll 40 has a driven end plate 41 and a driven spiral body 43.

[0081] The driven end plate 41 extends in a substantially disc shape perpendicular to the rotation axis O1 and the driven axis O2. The driven end plate 41 has a front surface 411 and a rear surface 412. The front surface 411 faces the rear surface 312 of the driven end plate 31 within the driven scroll 30. The rear surface 412 is located on the opposite side of the front surface 411 and faces the front surface 351 of the closing body 35.

[0082] Furthermore, a housing portion 71 is formed in the driven end plate 41. The housing portion 71 is a cylindrical recess extending forward from the rear surface 412 of the driven end plate 41. A bush 53 is housed inside the housing portion 71. A driven pin 55 is inserted through the bush 53. More specifically, the driven pin 55 is inserted into the bush 53 at a position eccentric to the center of the bush 53. The driven pin 55 is cylindrical and protrudes rearward from the bush 53, and consequently from the driven end plate 41, toward the first support portion 64. The bush 53 may also be housed inside the housing portion 71 via a bearing such as a sliding bearing.

[0083] Furthermore, four rotation-preventing pins 21 are fixed to the rear surface 412. Each rotation-preventing pin 21 is positioned on the rear surface 412 at a location on the outer circumference of the housing portion 71, and opposite each ring 22. Each rotation-preventing pin 21 protrudes rearward from the rear surface 412. Note that Figure 1 illustrates two of the four rotation-preventing pins 21.

[0084] The driven spiral body 43 is integral with the driven end plate 41 and extends forward from the front surface 411 of the driven end plate 41 parallel to the rotation axis O1 and the driven axis O2. As shown in Figure 5, the driven spiral body 43 has the center of the driven end plate 41 as its spiral center and extends spirally from the spiral center toward the outer circumference.

[0085] The driven mechanism 20 shown in Figure 1 consists of four rotation-preventing pins 21 and four rings 22. Here, the number of rotation-preventing pins 21 and rings 22 can be designed as appropriate, as long as there are three or more of each.

[0086] In the compression mechanism 14, with the driven scroll 40 housed within the driven scroll 30, the driven spiral body 33 of the driven scroll 30 and the driven spiral body 43 of the driven scroll 40 are engaged. Additionally, each rotation-stopping pin 21 is inserted into each ring 22. In this way, the driven scroll 30 and the driven scroll 40 are assembled in the front-rear direction. More precisely, after the driven spiral body 33 and the driven spiral body 43 are engaged and each rotation-stopping pin 21 is inserted into each ring 22, the first cover body 37, the drive end plate 31, the drive peripheral wall 32, and the closing body 35 are connected to the driven scroll 30 and the first cover body 37 by bolts 50.

[0087] After assembling the drive scroll 30 and the driven scroll 40, the drive scroll 30 inserts the first sliding bearing 51 into the first insertion hole 35d of the closing body 35. As a result, the first boss 35a, and thus the closing body 35, is rotatably supported by the first support part 64 via the first sliding bearing 51.

[0088] Furthermore, in the first cover body 37, the second boss 37d of the first cover body 37 is inserted into the second insertion hole 61. As a result, as shown in Figure 2, the third diameter portion 373 of the second boss 37d is inserted into the second sliding bearing 52. The second sliding bearing 52 is then held by the second insertion hole 61 while abutting against the step between the third diameter portion 373 and the second diameter portion 372, which is formed by the difference in outer diameter. In this way, the second boss 37d, and by extension the first cover body 37, is rotatably supported by the second support portion 66 via the second sliding bearing 52. Thus, as shown in Figure 1, the drive scroll 30 and the first cover body 37 are rotatably supported by the housing 6 by both the first support portion 64 and the second support portion 66, so as to be about the rotation axis O1. As a result, the second boss 37d is rotatable about the rotation axis O1 within the second insertion hole 61.

[0089] Here, as shown in Figure 2, the second diameter portion 372 of the second boss 37d is formed to be smaller in diameter than the second insertion hole 61. Therefore, when the second boss 37d is supported by the second support portion 66, the second diameter portion 372 is spaced radially away from the inner circumferential surface of the second insertion hole 61. As a result, the inner circumferential surface of the second insertion hole 61 and the second diameter portion 372 are not in contact. Furthermore, with the second boss 37d supported by the second support portion 66, the discharge communication hole 38b faces into the second insertion hole 61. Consequently, the discharge communication hole 38b communicates with the discharge passage 67 of the discharge section 63 through the second insertion hole 61. Thus, in this compressor, the discharge passage 67 and the discharge communication hole 38b, and consequently the discharge section 63 and the discharge communication hole 38b, communicate radially with each other in the housing 6.

[0090] As shown in Figure 1, in the driven scroll 40, the driven pin 55 is inserted into the pin hole 4 of the first support portion 64. As a result, the driven scroll 40 is rotatably supported by the first support portion 64 by the driven pin 55, so as to be driven around the driven axis O2. In other words, unlike the drive scroll 30, the driven scroll 40 is rotatably supported by the housing 6 by the first support portion 64 alone, so as to be driven around the driven axis O2.

[0091] Furthermore, in the compression mechanism 14, the drive scroll 30 and the driven scroll 40 are assembled in the front-rear direction, forming two compression chambers 12 between the drive spiral body 33 of the drive scroll 30 and the driven spiral body 43 of the driven scroll 40, as shown in Figure 5. Also, as shown in Figure 1, the assembly of the drive scroll 30 and the driven scroll 40 in the front-rear direction forms an intake space 30a within the drive peripheral wall 32. The intake space 30a communicates with the intake port 35b and can also communicate with each compression chamber 12 when the compressor is operating. Each compression chamber 12 and the intake space 30a are separated from the intake chamber 65 by the drive scroll 30 and the driven scroll 40.

[0092] In this compressor configured as described above, as shown by the dashed arrow in Figure 1, low-temperature, low-pressure refrigerant gas that has passed through the evaporator is drawn into the intake chamber 65 from the intake port 68. When the electric motor 10 operates and the rotor 11 rotates, the drive scroll 30 and the first cover body 37 are driven to rotate around the rotation axis O1 within the intake chamber 65. In other words, the drive scroll 30, the first cover body 37 and the rotor 11 are driven to rotate as a single unit. At this time, in the driven mechanism 20, each rotation-stopping pin 21 slides against the inner circumferential surface of each ring 22, causing each ring 22 to rotate relatively around the center of each rotation-stopping pin 21. In this way, the driven mechanism 20 transmits the torque of the drive scroll 30 to the driven scroll 40.

[0093] As a result, the driven scroll 40 is rotated by the drive scroll 30 and the driven mechanism 20 around the driven axis O2. In this case, the driven mechanism 20 restricts the driven scroll 40 from rotating on its own axis. Thus, the driven scroll 40 revolves relative to the drive scroll 30 around the driven axis O2. In this compressor, the drive scroll 30 and the driven scroll 40 rotate in the rotational direction R1 shown in Figure 5, etc.

[0094] Furthermore, as the drive scroll 30 is driven to rotate around the rotation axis O1, the discharge communication hole 38b rotates relative to the discharge passage 67 in the rotation direction R1, as shown in Figures 9 and 11.

[0095] In this way, the phase between the drive scroll 30, which rotates around the rotation axis O1, and the driven scroll 40, which rotates around the driven axis O2 (hereinafter, the phase between the drive scroll 30 and the driven scroll 40 is referred to as the rotational phase) changes, causing each compression chamber 12 to change volume. As a result, as shown by the dashed arrows in Figure 1, the refrigerant gas in the intake chamber 65 is drawn in from the intake port 35b into the intake space 30a and into each compression chamber 12.

[0096] The refrigerant gas drawn into each compression chamber 12 flows from the outer circumference of the spirals of the driving spiral body 33 and the driven spiral body 43 toward the center of the spiral, and is compressed within each compression chamber 12. The refrigerant gas, compressed to the discharge pressure within each compression chamber 12, is then discharged from the discharge port 30c into the discharge chamber 91.

[0097] The refrigerant gas discharged into the discharge chamber 91 flows through the connection passage 38a and the discharge connecting hole 38b, through the second insertion hole 61, and through the discharge passage 67, and is discharged from the discharge connecting port 69 toward the condenser. In this way, air conditioning is performed by the vehicle air conditioning system.

[0098] Thus, since high-pressure refrigerant gas is discharged into the discharge chamber 91, the discharge chamber 91 is at a higher pressure than the suction chamber 65 and the suction space 30a. In other words, the suction chamber 65 and the suction space 30a have a lower-pressure suction atmosphere than the discharge chamber 91.

[0099] Incidentally, in this compressor, discharge pulsation inevitably occurs due to the discharge of refrigerant gas from each compression chamber 12 to the discharge chamber 91. In this respect, this compressor is capable of suitably reducing discharge pulsation through the muffler effect and pulsation cancellation action in the discharge chamber 91. These actions will be explained in detail below.

[0100] In this compressor, a discharge chamber 91 is formed between the drive end plate 31 and the first cover body 37. The inner diameter of this discharge chamber 91 is larger than the outer diameter of the second sliding bearing 52, with an inner diameter equal to a second length L2. Furthermore, the length of the discharge chamber 91 in the direction of the rotation axis O1 is a third length L3. As a result, this compressor can suitably secure the volume of the discharge chamber 91, and the muffler effect is effectively exerted within the discharge chamber 91.

[0101] As described above, the refrigerant gas compressed in the compression chamber 12 flows through the discharge port 30c and is discharged into the discharge chamber 91. Here, since the discharge port 30c has a smaller diameter than the discharge chamber 91, the refrigerant gas compressed in the compression chamber 12 flows through the discharge port 30c and is then discharged into the discharge chamber 91, which is a space with a larger volume than the discharge port 30c.

[0102] Furthermore, the refrigerant gas in the discharge chamber 91 is discharged to the outside of the discharge chamber 91, i.e., to the outside of the compressor, by flowing through the connecting passage 38a, etc. Here, the second boss 37d of the first cover body 37 is inserted into the second sliding bearing 52 and supported by the second sliding bearing 52. For this reason, the second boss 37d, and furthermore, the connecting passage 38a formed within the second boss 37d, have a smaller diameter than the second sliding bearing 52. In other words, in this compressor, the inner diameter of the discharge chamber 91 is larger than the outer diameter of the second sliding bearing 52, so that the difference between the inner diameter of the discharge chamber 91 and the inner diameter of the connecting passage 38a is sufficiently large.

[0103] Therefore, the refrigerant gas compressed in the compression chamber 12 flows through the discharge port 30c, the discharge chamber 91, and the connecting passage 38a in that order, passing through narrow spaces to wider spaces, and then passing through narrow spaces again before being discharged to the outside of the compressor. In this way, the muffler effect in the discharge chamber 91 is fully utilized in this compressor.

[0104] Furthermore, since the length in the direction of the rotation axis O1 in the discharge chamber 91 becomes the third length L3, this compressor makes it possible to suitably secure the length in the direction of the rotation axis O1 in the discharge chamber 91. As a result, the compressor is able to suitably cancel out the low-frequency wavelengths of the refrigerant gas compressed in the compression chamber 12 within the discharge chamber 91.

[0105] As a result, this compressor makes it possible to suitably reduce the discharge pulsation when refrigerant gas is discharged from the compression chamber 12 to the discharge chamber 91 through a muffler effect in the discharge chamber 91.

[0106] Next, we will focus on one of the two compression chambers 12 and specifically explain the effect of reducing discharge pulsation through the pulsation cancellation action.

[0107] As shown in Figure 3, the rotational phase of the drive scroll 30 and the driven scroll 40 changes, causing the volume of the compression chamber 12 to gradually increase from its minimum state. After the volume of the compression chamber 12 reaches its maximum, the rotational phase of the drive scroll 30 and the driven scroll 40 changes, causing the volume of the compression chamber 12 to gradually decrease. During the process of increasing the volume of the compression chamber 12 from minimum to maximum, refrigerant gas is drawn into the compression chamber 12. That is, as described above, the refrigerant gas in the intake chamber 65 is drawn into the compression chamber 12 from the intake port 35b through the intake space 30a.

[0108] In this compressor, when the rotational phase of the drive scroll 30 and the driven scroll 40 is phase X1, the drive scroll 30, the driven scroll 40, and the compression chamber 12 are in the state shown in Figure 5. Furthermore, as the volume of the compression chamber 12 increases from minimum to maximum, the flow rate of the refrigerant gas drawn into the compression chamber 12 changes, and the flow rate of the refrigerant gas drawn into the compression chamber 12 is maximum when the rotational phase of the drive scroll 30 and the driven scroll 40 is phase X1. Note that when the rotational phase of the drive scroll 30 and the driven scroll 40 is phase X1, the compression chamber 12 is in the process of increasing its volume toward maximum, and the volume of the compression chamber 12 has not yet reached its maximum.

[0109] Then, as shown in Figure 3, when the rotational phase of the drive scroll 30 and the driven scroll 40 becomes phase X2, which is larger than phase X1, the volume of the compression chamber 12 becomes maximum (see Figure 6). Here, when the volume of the compression chamber 12 is maximum, the drive vortex 33 and the driven vortex 43 deconnect the compression chamber 12 and the intake space 30a. As a result, when the volume of the compression chamber 12 is maximum, no refrigerant gas is drawn into the compression chamber 12, and the refrigerant gas inside the compression chamber 12 is confined within the compression chamber 12.

[0110] Then, as shown in Figure 3, the rotational phase between the drive scroll 30 and the driven scroll 40 becomes phase X3, which is larger than phase X2, causing the volume of the compression chamber 12 to become smaller than its maximum (see Figure 7). As a result, the refrigerant gas in the compression chamber 12 begins to be compressed because the volume of the compression chamber 12 becomes smaller than its maximum.

[0111] Furthermore, as shown in Figure 4, as the rotational phase between the drive scroll 30 and the driven scroll 40 increases beyond phase X3, the compression of the refrigerant gas in the compression chamber 12 progresses, and the pressure inside the compression chamber 12 increases. Then, as the rotational phase between the drive scroll 30 and the driven scroll 40 becomes phase X4, the compression chamber 12 begins to communicate with the discharge port 30c, as shown in Figure 8. However, at this point, the discharge reed valve 57 is still closed.

[0112] Then, as shown in Figure 4, the rotational phase of the drive scroll 30 and the driven scroll 40 becomes phase X5, causing further compression of the refrigerant gas in the compression chamber 12. As a result, the pressure in the compression chamber 12 exceeds the pressure in the discharge chamber 91, causing the discharge reed valve 57 to open. Thus, the discharge of refrigerant gas from the compression chamber 12 to the discharge chamber 91 begins.

[0113] In this compressor, the discharge connecting hole 38b is formed in the second boss 37d of the first cover body 37. As a result, as the first cover body 37 rotates in conjunction with the rotational drive of the drive scroll 30, the discharge connecting hole 38b rotates within the second insertion hole 61 in the rotational direction R1 around the rotation axis O1, as shown in Figures 9 and 11. Therefore, as the first cover body 37 rotates together with the drive scroll 30, the phase between the discharge passage 67 and the discharge connecting hole 38b changes.

[0114] As a result of this change in phase between the discharge passage 67 and the discharge connecting hole 38b, the flow resistance of the refrigerant gas flowing from the discharge connecting hole 38b to the discharge passage 67 (discharge-side flow resistance) changes in this compressor. In addition, this compressor generates a pulsation different from the discharge pulsation due to the flow resistance (hereinafter referred to as "cancellation pulsation"). And as the flow resistance changes, the magnitude of the cancellation pulsation changes.

[0115] Here, when the rotational phase of the drive scroll 30 and the driven scroll 40 is phase X4, the discharge connecting hole 38b is located almost directly opposite the discharge passage 67, as shown in Figure 9. Therefore, as indicated by the dashed arrow in Figure 9, the refrigerant gas discharged from the discharge chamber 91 to the connecting passage 38a can flow almost directly from the discharge connecting hole 38b to the discharge passage 67. In other words, when the phase between the discharge passage 67 and the discharge connecting hole 38b is as shown in Figure 9, the flow resistance is minimized. To put it another way, in this compressor, the discharge connecting hole 38b is formed in the second boss 37d such that the flow resistance is minimized when the rotational phase of the drive scroll 30 and the driven scroll 40 is phase X4. Here, as described above, when the rotational phase of the drive scroll 30 and the driven scroll 40 is phase X4, the discharge reed valve 57 is closed. Therefore, the flow rate of the refrigerant gas discharged from the compression chamber 12 to the discharge chamber 91 is the minimum of zero. As a result, in this compressor, when the flow rate of refrigerant gas discharged from the compression chamber 12 to the discharge chamber 91 is at its minimum, the discharge passage 67 and the discharge connecting hole 38b are in a phase that minimizes flow resistance.

[0116] Then, as shown in Figure 4, when the rotational phase of the drive scroll 30 and the driven scroll 40 becomes phase X5, which is greater than phase X4, the pressure in the compression chamber 12 reaches the discharge pressure, and the discharge reed valve 57 opens. As a result, refrigerant gas is discharged from the compression chamber 12 to the discharge chamber 91. At this time, the flow rate of refrigerant gas discharged from the compression chamber 12 to the discharge chamber 91 is at its maximum. Also, when the rotational phase of the drive scroll 30 and the driven scroll 40 is phase X5, the two compression chambers 12 become one, as shown in Figure 10.

[0117] Here, when the rotational phase of the drive scroll 30 and the driven scroll 40 is phase X5, as shown in Figure 11, the discharge communication hole 38b is located almost on the opposite side of the rotational direction R1 from the discharge passage 67, with the rotational axis O1 in between. Therefore, as shown by the dashed arrow in Figure 11, the refrigerant gas discharged from the discharge chamber 91 to the connection passage 38a flows through the discharge communication hole 38b, approximately half a turn in the rotational direction R1 within the second insertion hole 61, and then through the discharge passage 67.

[0118] Therefore, when the phase between the discharge passage 67 and the discharge connecting hole 38b is as shown in Figure 11, the flow resistance is maximized. As a result, in this compressor, when the flow rate of refrigerant gas discharged from the compression chamber 12 to the discharge chamber 91 is at its maximum, the phase between the discharge passage 67 and the discharge connecting hole 38b is such that the flow resistance is maximized.

[0119] Thus, in this compressor, the discharge passage 67 and the discharge connecting hole 38b are shifted in the rotational direction R1 from their nearly directly facing position (see Figure 9), making it difficult for refrigerant gas to flow from the discharge connecting hole 38b to the discharge passage 67. As a result, the flow resistance becomes greater than the minimum. In this way, in this compressor, the flow resistance between the discharge passage 67 and the discharge connecting hole 38b increases as the flow rate of refrigerant gas discharged from the compression chamber 12 to the discharge chamber 91 approaches its maximum. More specifically, in this compressor, as the rotational phase of the drive scroll 30 and the driven scroll 40 approaches the rotational phase in which the flow rate of refrigerant gas discharged to the discharge chamber 91 is maximum, the flow resistance between the discharge passage 67 of the discharge section 63 and the discharge connecting hole 38b increases.

[0120] As described above, in this compressor, the flow resistance changes due to the phase change between the discharge passage 67 and the discharge connecting hole 38b, and consequently, the phase change between the discharge section 63 and the discharge connecting hole 38b. This change in flow resistance changes the magnitude of the cancellation pulsation. As shown in Figure 12, in this compressor, the cancellation pulsation has a waveform that is in opposite phase to the waveform of the discharge pulsation. As a result, although discharge pulsation is unavoidable due to the discharge of refrigerant gas from each compression chamber 12 to the discharge chamber 91, the cancellation pulsation acts to cancel out the discharge pulsation, thus reducing the discharge pulsation.

[0121] Here, when the rotor 11 rotates at a low speed, the volumetric flow rate of the refrigerant gas flowing from the discharge communication hole 38b to the discharge passage 67 decreases. As a result, the change in flow velocity due to the change in flow resistance becomes smaller, and the pressure change caused by this also becomes smaller. Therefore, when the compression mechanism 14 rotates at a low speed, the pulsation reduction effect due to the pulsation cancellation action becomes smaller.

[0122] In this respect, this compressor can suitably reduce discharge pulsation in the discharge chamber 91, which has a suitably secured volume, even when the compression mechanism 14 is rotating at a low speed. That is, when the compression mechanism 14 is rotating at a low speed, as shown in Figure 1, the amount of lubricating oil 18 that accumulates in the discharge chamber 91 is small, so a large volume can be secured in the discharge chamber 91 that exerts a muffler effect and contributes to pulsation reduction. For this reason, this compressor can suitably reduce discharge pulsation by the muffler effect that is effectively exerted in the discharge chamber 91, even when the compression mechanism 14 is rotating at a low speed.

[0123] On the other hand, as shown in Figure 13, when the compression mechanism 14 rotates at high speed with the rotor 11, the amount of lubricating oil 18 that accumulates in the discharge chamber 91 increases. Consequently, the volume in the discharge chamber 91 that can exert a muffler effect and contribute to pulsation reduction becomes smaller. Therefore, when the compression mechanism 14 rotates at high speed, the pulsation reduction effect due to the muffler effect in the discharge chamber 91 decreases.

[0124] In this respect, the pulsation cancellation effect is more effectively exerted when the compression mechanism 14 is rotating at high speed in this compressor. Therefore, even when the compression mechanism 14 is rotating at high speed in this compressor, the discharge pulsation can be suitably reduced by the pulsation cancellation effect.

[0125] Furthermore, in this compressor, since the outer diameter of the second sliding bearing 52 is smaller than that of the discharge chamber 91, even if the diameter of the discharge chamber 91 is increased as described above, it is possible to suppress an increase in the diameter of the second sliding bearing 52. In other words, in this compressor, the second sliding bearing 52 will never be the same diameter as or larger than that of the discharge chamber 91. As a result, in this compressor, it is possible to suppress an increase in power loss in the second sliding bearing 52, and consequently, suppress a decrease in compressor efficiency. Moreover, in this compressor, even if the first cover body 37 rotates at high speed in conjunction with the high-speed rotation of the rotor 11, the second sliding bearing 52 can suitably support the first cover body 37, and furthermore, the drive scroll 30 through the first cover body 37.

[0126] Therefore, the compressor of Example 1 can exhibit high quietness while suppressing a decrease in efficiency.

[0127] In particular, in this compressor, the first cover body 37 is fixed to the drive scroll 30, and a discharge chamber 91 is formed between the drive end plate 31 and the first cover body 37. Therefore, when the compression mechanism 14 is operated, the drive scroll 30 and the first cover body 37 rotate, and the centrifugal force of the rotating first cover body 37 acts on the fluid discharged into the discharge chamber 91. As a result, the refrigerant gas and the lubricating oil 18 can be suitably separated in the discharge chamber 91. The lubricating oil 18 separated from the refrigerant gas is more likely to adhere to the inner surface of the discharge chamber 91 due to the centrifugal force of the first cover body 37, and is also more likely to remain in the discharge chamber 91 on the radially outer side of the first cover body 37. As a result, the refrigerant gas discharged to the outside of the compressor via the discharge connection section 38 and the discharge section 63 is less likely to contain the lubricating oil 18.

[0128] Furthermore, the discharge chamber 91 is positioned in front of the compression chamber 12, with the drive end plate 31 in between. Because the discharge chamber 91 is close to the compression chamber 12, it is possible to sufficiently separate the refrigerant gas and the lubricating oil 18 in the discharge chamber 91.

[0129] Furthermore, a return channel 370 is formed in the outer peripheral wall 37a of the first cover body 37. Therefore, in this compressor, the centrifugal force acting on the first cover body 37, etc., more specifically, the centrifugal force acting on the first cover body 37, etc., in addition to the pressure difference between the discharge chamber 91 and the suction chamber 65, allows the lubricating oil 18 in the discharge chamber 91 to flow out into the suction chamber 65 along with some of the refrigerant gas through the return channel 370. In this way, the lubricating oil 18 that has flowed out from the discharge chamber 91 into the suction chamber 65 is returned to the suction space 30a and, consequently, to the compression chamber 12, along with the refrigerant gas being drawn in at the suction port 35b. As a result, in this compressor, the inside of the compression chamber 12 can be lubricated by the lubricating oil 18, making the drive end plate 31, drive volute body 33, driven end plate 41 and driven volute body 43 less prone to wear. Furthermore, the lubricating oil 18 that flows from the discharge chamber 91 into the suction chamber 65 can also lubricate the rotor 11, the first sliding bearing 51, the second sliding bearing 52, and the like.

[0130] Furthermore, since the discharge chamber 91 is formed by the first recess 30b provided in the drive end plate 31 and the second recess 37e provided in the first cover body 37, the size, shape, and position of the discharge chamber 91 can be easily changed by changing the size, shape, and position of the first recess 30b and the second recess 37e according to the purpose, thereby increasing the degree of freedom in the shape of the discharge chamber 91 in the compression mechanism 14.

[0131] Furthermore, since the first cover body 37 fixed to the drive scroll 30 is provided with a second boss 37d having a discharge contact portion 38, the formation of the discharge contact portion 38 with respect to the drive scroll 30 is facilitated.

[0132] Furthermore, in this compressor, a discharge reed valve 57 is provided on the drive scroll 30. The discharge reed valve 57 allows refrigerant gas to be discharged from each compression chamber 12 to the discharge chamber 91, while prohibiting the flow of refrigerant gas from the discharge chamber 91 to each compression chamber 12. As a result, this compressor effectively prevents the generation of pulsation caused by the backflow of refrigerant gas from the discharge chamber 91 to each compression chamber 12. In addition, since the discharge connecting hole 38b is formed in the second boss 37d, the discharge connecting hole 38b is located downstream of the discharge reed valve 57 in the direction of refrigerant gas flow. As a result, in this compressor, pressure fluctuations when refrigerant gas flows from the discharge connecting hole 38b to the discharge passage 67 can assist in opening the discharge reed valve 57. As a result, this compressor can effectively open and close the discharge reed valve 57.

[0133] Furthermore, in this compressor, the discharge section 63 has a discharge passage 67 and a discharge connecting port 69, and the discharge passage 67 and the discharge connecting port 38b are in communication in the radial direction of the housing 6. As a result, in this compressor, compared to a configuration in which the discharge passage 67 and the discharge connecting port 38b are in communication in the direction of the rotation axis O1, it is possible to miniaturize the entire compressor, including the housing 6, in the direction of the rotation axis O1. In this way, in this compressor, the length of the discharge chamber 91 in the direction of the rotation axis O1 is set as the third length L3, and while the volume of the discharge chamber 91 is increased while making it longer in the direction of the rotation axis O1, it is possible to suppress the housing 6 from becoming excessively axially elongated as a whole.

[0134] (Example 2) As shown in Figure 14, the compressor of Embodiment 2 has a housing 6 composed of a housing body 60 and a housing cover 70. In addition, the compression mechanism 14 has a second cover body 81 instead of the first cover body 37. The second cover body 81 is an example of a "cover body" in the present invention.

[0135] The housing cover 70 is also made of aluminum alloy. The housing cover 70 is located in front of the housing body 60. The housing cover 70 is roughly disc-shaped with the rotation axis O1 as its center. The housing cover 70 has a front surface 70a facing forward, a rear surface 70b located opposite the front surface 70a and facing rear, and an outer peripheral surface 70c connected to the front surface 70a and the rear surface 70b and located between the front surface 70a and the rear surface 70b. The housing cover 70 is fixed to the outer peripheral wall 60a of the housing body 60, similar to the housing cover 62 in the compressor of Embodiment 1.

[0136] Furthermore, the housing cover 70 has a second insertion hole 72 and a discharge connection port 73. The discharge connection port 73 is an example of a "discharge section" in the present invention.

[0137] The second insertion hole 72 is formed in a cylindrical shape with the rotation axis O1 as the center and extends within the housing cover 70 in the direction of the rotation axis O1. The rear end of the second insertion hole 72 opens to the rear surface 70b. A second sliding bearing 52 is provided inside the second insertion hole 72, similar to the compressor in Embodiment 1.

[0138] The discharge port 73 penetrates the housing cover 70 in the direction of the rotation axis O1. As a result, the front end of the discharge port 73 opens to the front surface 70a, and the rear end communicates with the second insertion hole 72. As shown in Figure 15, the discharge port 73 is formed in a cylindrical shape that is eccentric with respect to the rotation axis O1. In other words, the discharge port 73 is formed in the housing cover 70 at a position eccentric with respect to the rotation axis O1. The discharge port 73 is connected to a condenser (not shown) through piping (not shown).

[0139] As shown in Figure 14, the second cover body 81 has the same configuration as the first cover body 37 in the compressor of Example 1, except that it has a second boss 81d instead of the second boss 37d in the compressor of Example 1. The second boss 81d is an example of the "rotating shaft portion" in the present invention.

[0140] In other words, the second cover body 81 is a bottomed cylindrical member having an outer peripheral wall 81a, a front wall 81b, and a flange 81c, similar to the first cover body 37 in the compressor of Embodiment 1. Furthermore, a return channel 810 similar to the return channel 370 in the compressor of Embodiment 1 is formed in the outer peripheral wall 81a. The second cover body 81 has a second recess 81e that is defined by the inner peripheral surface of the outer peripheral wall 81a and the rear surface of the front wall 81b, and extends in a substantially cylindrical shape in the direction of the rotation axis O1.

[0141] The drive end plate 31 has the same configuration as the drive end plate 31 in the compressor of Embodiment 1. That is, the drive end plate 31 has a first recess 30b formed in a substantially cylindrical shape extending from the front surface 311 of the drive end plate 31 toward the rear, and a discharge reed valve 57 or the like is fixed within the first recess 30b.

[0142] Furthermore, a discharge chamber 92 is formed between the drive end plate 31 and the second cover body 81, partitioned by the first recess 30b and the second recess 81e. The second length L2 and third length L3 of this discharge chamber 92 are the same as the second length L2 and third length L3 of the discharge chamber 91 in the compressor of Embodiment 1, respectively.

[0143] The second boss 81d is integrally formed in the center of the front wall 81b and protrudes forward from the front wall 81b in the direction of the rotation axis O1 and the driven axis O2. As a result, the center of the second boss 81d is coaxial with the rotation axis O1.

[0144] Furthermore, a connecting passage 82 is formed in the second cover body 81. The connecting passage 82 is an example of a "discharge connection part" in the present invention. The connecting passage 82 penetrates the front wall 81b of the second cover body 81 in the direction of the rotation axis O1, including within the second boss 81d. As shown in Figures 14 and 15, the connecting passage 82 is formed in a cylindrical shape that is eccentric with respect to the rotation axis O1. In other words, the connecting passage 82 is formed in the second cover body 81 at a position eccentric with respect to the rotation axis O1. Also, the connecting passage 82 is formed to have a smaller diameter than the discharge connection port 73. Note that in Figure 15, for the sake of ease of explanation, the discharge connection port 73 and the connecting passage 82 are shown in a simplified manner, and the second boss 81d and other parts are omitted from the illustration.

[0145] As shown in Figure 14, in this compressor, similar to the compressor in Embodiment 1, the second cover body 81, the drive end plate 31, the drive peripheral wall 32, and the closing body 35 are connected by a plurality of bolts 50. As a result, the second cover body 81 covers the drive end plate 31 from the front. In this way, the connection passage 82 communicates with the discharge chamber 92 from the front. Furthermore, the connection passage 82 is located downstream of the discharge reed valve 57 in the direction of refrigerant gas flow.

[0146] In this compressor, the second boss 81d is inserted into the second insertion hole 72. As a result, the second boss 81d is rotatably supported within the second insertion hole 72 by the second sliding bearing 52. Furthermore, the discharge port 73 and the connecting passage 82 are in communication in the direction of the rotation axis O1. Other components of this compressor are the same as those of the compressor in Embodiment 1, and the same reference numerals are used for identical components, omitting detailed descriptions of the components.

[0147] In this compressor, the refrigerant gas compressed in the compression chamber 12 is discharged from the discharge port 30c into the discharge chamber 92. The refrigerant gas discharged into the discharge chamber 92 is then discharged from the discharge port 73 towards the condenser via the connecting passage 82.

[0148] Furthermore, in this compressor, as shown in Figure 15, the discharge port 73 and the connecting passage 82 are eccentric with respect to the rotation axis O1. Therefore, in this compressor, the phase between the discharge port 73 and the connecting passage 82 changes during one rotation of the drive scroll 30 in the rotation direction R1 shown in Figure 15.

[0149] In other words, in this compressor, when the rotation angle of the drive scroll 30 is zero degrees, the discharge port 73 and the connecting passage 82 are in the phase shown in Figure 15(A). Then, when the drive scroll 30 rotates approximately 90° in the rotation direction R1 from the position shown in Figure 15(A), the discharge port 73 and the connecting passage 82 are in the phase shown in Figure 15(B). Then, when the drive scroll 30 rotates approximately 90° in the rotation direction R1 from the position shown in Figure 15(B) (when the drive scroll 30 rotates approximately 180° in the rotation direction R1 from the position shown in Figure 15(A)), the discharge port 73 and the connecting passage 82 are in the phase shown in Figure 15(C). Then, when the drive scroll 30 rotates approximately 90° in the rotational direction R1 from the position shown in Figure 15(C) (or when the drive scroll 30 rotates approximately 270° in the rotational direction R1 from the position shown in Figure 15(A)), the discharge port 73 and the connecting passage 82 are in the phase shown in Figure 15(D).

[0150] In this way, as the drive scroll 30 rotates once, the communication area between the discharge port 73 and the connecting passage 82 changes, which in turn changes the flow resistance of the refrigerant gas flowing from the connecting passage 82 to the discharge port 73 in this compressor.

[0151] Specifically, the larger the communication area between the discharge port 73 and the connecting passage 82, the lower the flow resistance, and the smaller the communication area between the discharge port 73 and the connecting passage 82, the higher the flow resistance. Therefore, in this compressor, when the phase between the discharge port 73 and the connecting passage 82 is as shown in Figure 15(A), the communication area between the discharge port 73 and the connecting passage 82 is maximized, and the flow resistance is minimized. On the other hand, when the phase between the discharge port 73 and the connecting passage 82 is as shown in Figure 15(C), the communication area between the discharge port 73 and the connecting passage 82 is minimized, and the flow resistance is maximized.

[0152] In this compressor, when the flow rate of refrigerant gas discharged from the compression chamber 12 to the discharge chamber 92 is at its minimum, the discharge port 73 and the connecting passage 82 are in a phase that minimizes flow resistance (see Figure 15(A)). Then, in this compressor, when the flow rate of refrigerant gas discharged from the compression chamber 12 to the discharge chamber 92 is at its maximum, the discharge port 73 and the connecting passage 82 are in a phase that maximizes flow resistance (see Figure 15(C)).

[0153] As a result, although discharge pulsation inevitably occurs in this compressor as well, due to the discharge of refrigerant gas from each compression chamber 12 to the discharge chamber 92, the discharge pulsation can be reduced by the pulsation cancellation effect.

[0154] Furthermore, in this compressor, the discharge port 73 and the connecting passage 82 are in communication in the direction of the rotation axis O1. Compared to a configuration in which the discharge port 73 and the connecting passage 82 are in communication in the radial direction of the housing 6, it is possible to make the entire compressor, including the housing 6, smaller in the radial direction. Other functions of this compressor are the same as those of the compressor in Example 1.

[0155] (Example 3) As shown in Figure 16, in the compressor of Embodiment 3, the housing 6 is composed of a housing body 60 and a housing cover 75. In addition, in this compressor, the compression mechanism 14 has a third cover body 83 instead of the first cover body 37. The third cover body 83 is an example of a "cover body" in the present invention.

[0156] The housing cover 75 consists of a main body member 75a and a retaining member 75b. The main body member 75a is made of aluminum alloy. The main body member 75a is substantially disc-shaped with the rotation axis O1 as its center, similar to the housing cover 70 in the compressor of Embodiment 2. The main body member 75a has a front surface 751 facing forward, a rear surface 752 located on the opposite side of the front surface 751 and facing rear, and an outer peripheral surface 753 connected to the front surface 751 and the rear surface 752 and located between the front surface 751 and the rear surface 752.

[0157] The main body component 75a is fixed to the outer peripheral wall 60a of the housing body 60, similar to the housing cover 62 in the compressor of Embodiment 1. In this way, the housing body 60 and the housing cover 75 are also fixed together in this compressor.

[0158] Furthermore, the main body member 75a has a second insertion hole 76 and a first connecting port 77a. The second insertion hole 76 is formed in a cylindrical shape with the rotation axis O1 as its center and extends within the main body member 75a in the direction of the rotation axis O1. The rear end of the second insertion hole 76 opens to the rear surface 752. Here, the second insertion hole 76 is formed with a larger diameter than the second insertion hole 72 in the compressor of Embodiment 2.

[0159] The first connecting port 77a penetrates the main body member 75a in the direction of the rotation axis O1. As a result, the front end of the first connecting port 77a opens to the front surface 751, and the rear end communicates with the second insertion hole 76. Although detailed illustration is omitted, the first connecting port 77a is formed in a cylindrical shape that is eccentric with respect to the rotation axis O1, similar to the discharge connecting port 73 in the compressor of Embodiment 2. In other words, the first connecting port 77a is formed in the main body member 75a at a position eccentric with respect to the rotation axis O1.

[0160] The retaining member 75b is made of resin. The retaining member 75b is formed in a roughly cylindrical shape with a bottom. A second connecting port 77b is formed at the front of the retaining member 75b. The second connecting port 77b penetrates the front of the retaining member 75b in the direction of the rotation axis O1. The second connecting port 77b is formed in a cylindrical shape that is coaxial with and has the same diameter as the first connecting port 77a. In other words, the second connecting port 77b is formed at the front of the retaining member 75b at a position eccentric with respect to the rotation axis O1.

[0161] The retaining member 75b is housed within the second insertion hole 76. At this time, the retaining member 75b is housed within the second insertion hole 76 in a non-rotatable state. Thus, in the housing cover 75, neither the main body member 75a nor the retaining member 75b is rotatable. Furthermore, because the retaining member 75b is housed within the second insertion hole 76, the second communication port 77b is located behind the first communication port 77a while communicating with the first communication port 77a. In this way, the discharge communication port 77 is formed by the first communication port 77a and the second communication port 77b. In other words, the discharge communication port 77 is formed in the housing cover 75 at a position eccentric with respect to the rotation axis O1. The discharge communication port 77 is an example of a "discharge section" in the present invention.

[0162] Furthermore, a radial ball bearing 78 is provided inside the retaining member 75b. The radial ball bearing 78 is an example of a "bearing" in the present invention. The retaining member 75b holds the radial ball bearing 78 while it is housed within the second insertion hole 76. The length of the outer diameter of the radial ball bearing 78 is a fourth length L4. The fourth length L4 of the radial ball bearing 78 is longer than the first length L1 of the second sliding bearing 52 in the compressor of Embodiment 2. In addition, seal rings 79a and 79b are provided on the outer circumferential surface of the retaining member 75b. The seal rings 79a and 79b seal the space between the outer circumferential surface of the retaining member 75b and the inner circumferential surface of the second insertion hole 76. Note that a sliding bearing may be provided inside the retaining member 75b instead of the radial ball bearing 78. Also, the retaining member 75b may be made of synthetic rubber or a metal with lower rigidity than the main body member 75a.

[0163] The third cover body 83 has the same configuration as the second cover body 81 in the compressor of Embodiment 2. That is, the third cover body 83 is a bottomed cylindrical member having an outer peripheral wall 83a, a front wall 83b, and a flange (not shown), similar to the second cover body 81 in the compressor of Embodiment 2, and a return channel 830 is formed in the outer peripheral wall 83a. In addition, the third cover body 83 has a second recess 83e that is defined by the inner circumferential surface of the outer peripheral wall 83a and the rear surface of the front wall 83b, and extends in a substantially cylindrical shape in the direction of the rotation axis O1.

[0164] A discharge chamber 93 is formed between the drive end plate (not shown) and the third cover body 83, partitioned by a first recess (not shown) and a second recess 83e. The second length L2 and third length L3 in this discharge chamber 93 are the same as the second length L2 and third length L3 of the discharge chamber 92 in the compressor of Embodiment 2, respectively. The second length L2, which is the length of the inner diameter of the discharge chamber 93, is longer than the fourth length L4, which is the length of the outer diameter of the radial ball bearing 78.

[0165] Furthermore, the third cover body 83 has a second boss 83d, similar to the second cover body 81 in the compressor of Example 2. The second boss 83d is an example of the "rotating shaft portion" in the present invention. The second boss 83d is integrally formed in the center of the front wall 83b and protrudes forward from the front wall 83b in the direction of the rotation axis O1 and the driven axis O2. As a result, the center of the second boss 83d is coaxial with the rotation axis O1. Here, the second boss 83d protrudes forward for a shorter distance than the second boss 81d in the compressor of Example 2.

[0166] The third cover body 83 has a connecting passage 84, similar to the second cover body 81 in the compressor of Embodiment 2. The connecting passage 84 is an example of a "discharge connection section" in the present invention. The connecting passage 84 penetrates the front wall 83b of the third cover body 83 in the direction of the rotation axis O1, including within the second boss 83d. The connecting passage 84 is formed in a cylindrical shape that is eccentric with respect to the rotation axis O1, similar to the connecting passage 82 in the compressor of Embodiment 2. In other words, the connecting passage 84 is formed in the third cover body 83 at a position eccentric with respect to the rotation axis O1. Furthermore, the connecting passage 84 is formed to have a smaller diameter than the discharge connection port 77.

[0167] The third cover body 83 is connected to the drive end plate (not shown) by a plurality of bolts (not shown), similar to the second cover body 81 in the compressor of Embodiment 2. As a result, the connection passage 84 communicates with the discharge chamber 93 from the front. Furthermore, the connection passage 84 is located downstream of the discharge reed valve (not shown) in the direction of refrigerant gas flow.

[0168] In this compressor, the second boss 83d is inserted into the radial ball bearing 78. As a result, the second boss 83d is rotatably supported within the retaining member 75b and further within the second insertion hole 76 of the main body member 75a. The discharge port 77 and the connecting passage 84 are in communication in the direction of the rotation axis O1. The other configurations of this compressor are the same as those of the compressor in Embodiment 2.

[0169] In this compressor, the discharge port 77 and the connecting passage 84 are eccentric with respect to the rotation axis O1. Therefore, similar to the compressor in Example 2, in this compressor, the phase between the discharge port 77 and the connecting passage 84 changes during one rotation of the drive scroll 30 in the rotation direction R1 (see Figure 15). Thus, in this compressor as well, discharge pulsation can be reduced by the pulsation cancellation action, similar to the compressor in Example 2.

[0170] In this compressor, the drive scroll 30 and other components inevitably vibrate when compressing the refrigerant gas in each compression chamber (not shown). In this compressor, a resin retaining member 75b provided in the second insertion hole 76 holds the radial ball bearing 78. As a result, in this compressor, the retaining member 75b can suppress the transmission of vibrations from the drive scroll 30 to the main body member 75a through the second boss 83d and the radial ball bearing 78. Therefore, in this compressor, vibrations of the housing cover 75 and, consequently, the housing 6 during operation can be suppressed as much as possible. Other functions of this compressor are the same as those of the compressor in Embodiment 2.

[0171] (Example 4) As shown in Figure 17, in the compressor of Embodiment 4, the compression mechanism 14 has a fourth cover body 85 in place of the first cover body 37 in the compressor of Embodiment 1. The fourth cover body 85 is an example of a "cover body" in the present invention. In addition, in this compressor, the drive scroll 30 has a drive end plate 310 in place of the drive end plate 31 in the compressor of Embodiment 1.

[0172] The drive end plate 310 has a shorter length in the direction of the rotation axis O1 compared to the drive end plate 31 in the compressor of Embodiment 1. Also, the first recess 30b that is present on the drive end plate 310 is not formed on the front surface 311 of the drive end plate 310. Except for these differences, the drive end plate 310 has the same configuration as the drive end plate 31 in the compressor of Embodiment 1.

[0173] The fourth cover body 85 has the same configuration as the first cover body 37 in the compressor of Example 1, except that it has an outer peripheral wall 85a instead of the outer peripheral wall 37a in the compressor of Example 1. The outer peripheral wall 85a of the fourth cover body 85 has a longer length in the direction of the rotation axis O1 compared to the outer peripheral wall 37a in the compressor of Example 1.

[0174] In other words, the fourth cover body 85 is a bottomed cylindrical member having an outer peripheral wall 85a, a front wall 85b, and a flange 85c, similar to the first cover body 37 in the compressor of Embodiment 1. Furthermore, a return channel 850 similar to the return channel 370 in the compressor of Embodiment 1 is formed in the outer peripheral wall 85a. The fourth cover body 85 has a second recess 85e that is defined by the inner peripheral surface of the outer peripheral wall 85a and the rear surface of the front wall 85b, and extends in a substantially cylindrical shape in the direction of the rotation axis O1.

[0175] Furthermore, a discharge chamber 94 is formed between the drive end plate 310 and the fourth cover body 85, partitioned by the front surface 311 of the drive end plate 310 and the second recess 85e. The second length L2 and third length L3 in this discharge chamber 94 are the same as the second length L2 and third length L3 of the discharge chamber 91 in the compressor of Embodiment 1, respectively.

[0176] Furthermore, the fourth cover body 85 has a second boss 85d, similar to the first cover body 37 in the compressor of Embodiment 1. The second boss 85d is an example of a "rotating shaft portion" in the present invention. The fourth cover body 85 has a discharge connecting portion 86 formed therein, similar to the first cover body 37 in the compressor of Embodiment 1, which consists of a connecting passage 86a and a discharge connecting hole 86b.

[0177] In this compressor, the front surface 311 of the drive end plate 310 is formed as a flat surface, which facilitates the manufacture of the drive scroll 30.

[0178] The other configurations and effects of this compressor are the same as those of the compressor in Example 1.

[0179] (Example 5) As shown in Figure 18, in the compressor of Embodiment 5, the compression mechanism 14 has a fifth cover body 87 in place of the first cover body 37 in the compressor of Embodiment 1. The fifth cover body 87 is an example of a "cover body" in the present invention. In addition, in this compressor, the drive scroll 30 has a drive end plate 320 in place of the drive end plate 31 in the compressor of Embodiment 1.

[0180] The drive end plate 320 has a longer length in the direction of the rotation axis O1 compared to the drive end plate 31 in the compressor of Embodiment 1. Also, the first recess 30d formed on the front surface 311 of the drive end plate 320 has a longer length in the direction of the rotation axis O1 compared to the first recess 30b in the compressor of Embodiment 1. Except for these differences, the drive end plate 320 has the same configuration as the drive end plate 31 in the compressor of Embodiment 1.

[0181] The fifth cover body 87 has a cover body 87a and a second boss 87b. The second boss 87b is an example of a "rotating shaft portion" in the present invention. The cover body 87a extends in a substantially disc shape perpendicular to the rotation axis O1 and the driven axis O2. The cover body 87a is also formed to be approximately the same diameter as the drive end plate 320. The second boss 87b is integrally formed with the cover body 87a and protrudes forward from the cover body 87a in the direction of the rotation axis O1 and the driven axis O2. Other configurations of the second boss 87b are the same as those of the second boss 37d in the compressor of Embodiment 1.

[0182] Furthermore, the fifth cover body 87 has a discharge connecting section 88 formed therein, which consists of a connecting passage 88a and a discharge connecting hole 88b, similar to the first cover body 37 in the compressor of Embodiment 1.

[0183] In the drive scroll 30, the cover body 87a of the fifth cover body 87 is in contact with the front surface 311 of the drive end plate 320, and the fifth cover body 87, the drive end plate 320, the drive peripheral wall 32, and the closing body 35 are connected by a plurality of bolts 50. As a result, in the drive scroll 30, the drive end plate 320, the drive peripheral wall 32, the closing body 35, and the fifth cover body 87 are integrated into one unit.

[0184] Thus, a discharge chamber 95 is formed between the drive end plate 320 and the fifth cover body 87, partitioned by the first recess 30d and the rear surface of the cover body 87a. The fifth length L5, which is the length of the inner diameter of this discharge chamber 95, is longer than the second length L2, which is the length of the inner diameter of the discharge chamber 91 in the compressor of Embodiment 1, and the sixth length L6, which is the length in the direction of the rotation axis O1 in the discharge chamber 95, is shorter than the third length L3 of the discharge chamber 91 in the compressor of Embodiment 1. Note that the fifth length L5, which is the length of the inner diameter of the discharge chamber 95, may be set to the second length L2, or shorter than the second length L2. Also, the sixth length L6, which is the length in the direction of the rotation axis O1 in the discharge chamber 95, may be set to the third length L3, or longer than the third length L3.

[0185] In the fifth cover body 87, the cover body 87a covers the first recess 30d of the drive end plate 320 from the front. As a result, the discharge contact section 88 communicates with the discharge chamber 95 partitioned by the first recess 30d from the front.

[0186] In this compressor, the cover body 87a does not have an outer periphery wall or flange, which simplifies the manufacturing of the fifth cover body 87. Furthermore, since the sixth length L6 of the discharge chamber 95 is shortened, this compressor allows for a shorter housing 6 compared to the compressor of Embodiment 1.

[0187] The other configurations and effects of this compressor are the same as those of the compressor in Example 1.

[0188] Although the present invention has been described above in reference to Examples 1 to 5, it goes without saying that the present invention is not limited to Examples 1 to 5, and can be applied with appropriate modifications without departing from its spirit.

[0189] For example, in the compressor of Example 1, the driven scroll 30 and the driven scroll 40 are assembled with the driven scroll 40 housed inside the driven scroll 30. However, the configuration is not limited to this, and the driven scroll 30 and the driven scroll 40 may be assembled with the driven scroll 40 positioned outside the driven scroll 30. In this case, the driven end plate 41 may be fixed to the "cover body" in the present invention. The same applies to the compressors of Examples 2 to 5.

[0190] Furthermore, in the compressor of Example 1, the second boss 37d is designated as the "rotating shaft portion" in the present invention. By inserting this second boss 37d into the second insertion hole 61, the second boss 37d is rotatably supported by the second support portion 66. However, the invention is not limited to this configuration; the second boss 37d may also be rotatably supported by the second support portion 66 by inserting the second support portion 66 into the interior of the second boss 37d. The same applies to the compressors of Examples 2 to 5.

[0191] Furthermore, in the compressor of Example 2, the discharge port 73 is formed in a cylindrical shape that is eccentric with respect to the rotation axis O1. However, the discharge port 73 is not limited to this and may have other shapes. The same applies to the discharge port 77 in the compressor of Example 3.

[0192] Furthermore, in the compressor of Example 1, the drive peripheral wall 32 is fixed to the rotor 11, and the drive scroll 30 is integrated with the rotor 11. However, the compressor is not limited to this, and the rotor 11 may be fixed to the peripheral wall 37a, and the first cover body 37 may be integrated with the rotor. The same applies to the compressors of Examples 2 to 4, and the rotor 11 may be fixed to the "cover body" in the present invention.

[0193] Furthermore, in the compressor of Embodiment 1, the drive scroll 30 and the rotor 11 may be connected by a shaft to enable power transmission, thereby arranging them at a distance from each other in the direction of the rotation axis O1. The same applies to the compressors of Embodiments 2 to 5.

[0194] Furthermore, in the compressor of Example 1, the driven mechanism 20 is composed of a rotation-preventing pin 21 and a ring 22. However, the driven mechanism 20 is not limited to this, and may be composed of a pin-ring-pin system in which two pins slide against the inner surface of one free ring, a pin-pin system in which the outer surfaces of two pins slide against each other, or a system using an Oldham joint. The same applies to the compressors of Examples 2 to 5.

[0195] Furthermore, this specification includes the following inventions.

[0196] (Note 1) A housing having a discharge section formed for discharging fluid to the outside, The housing includes a compression mechanism, The compression mechanism includes a compression chamber for compressing a fluid while reducing its volume, and a discharge chamber communicating with the compression chamber, through which the fluid compressed in the compression chamber is discharged. The housing is also provided with a rotating shaft portion that is rotatably supported by bearings around a rotation axis. The discharge chamber is formed to have a larger diameter than the outer diameter of the bearing. The compression mechanism includes a drive scroll that rotates by a drive mechanism, The system includes a driven scroll that faces the drive scroll and rotates eccentrically with respect to the drive scroll by the drive scroll and the driven mechanism, thereby forming the compression chamber between itself and the drive scroll. The drive scroll comprises a drive end plate and a drive spiral body that is integral with the drive end plate and protrudes spirally toward the driven scroll. The driven scroll has a driven end plate and a driven spiral body that is integral with the driven end plate and projects spirally toward the drive scroll. The rotating shaft portion is formed with a discharge connecting portion that allows the fluid discharged into the discharge chamber to flow to the discharge portion. As the rotation of the rotating shaft changes the phase between the discharge section and the discharge connecting section, the flow resistance of the fluid flowing from the discharge connecting section to the discharge section changes. A double-rotation scroll compressor characterized in that the discharge section and the discharge connecting section are in a phase where the flow resistance increases as the flow rate of the fluid discharged from the compression chamber to the discharge chamber approaches its maximum.

[0197] (Note 2) The compression mechanism has a cover body that is fixed to the drive scroll or the driven scroll and is provided with the rotating shaft portion. The discharge chamber is formed between the cover body and the drive end plate of the drive scroll to which the cover body is fixed, or the driven end plate of the driven scroll to which the cover body is fixed, in the double-rotation scroll compressor as described in Appendix 1.

[0198] (Note 3) Lubricating oil is discharged into the discharge chamber along with the fluid compressed in the compression chamber. The rotary scroll compressor described in Appendix 1 or 2, wherein the discharge chamber and a location within the housing where the pressure is lower than that of the discharge chamber are in communication via a recirculation channel that recirculates the lubricating oil in the discharge chamber.

[0199] (Note 4) The discharge section and the discharge connecting section are in communication in the radial direction of the housing, as described in any one of the appendices 1 to 3, for a double-rotation scroll compressor.

[0200] (Note 5) The discharge section and the discharge connecting section are in communication in the direction of the rotation axis, as described in any one of the appendices 1 to 3, for a double-rotation scroll compressor.

[0201] (Note 6) The discharge portion is formed in the housing while being eccentric with respect to the rotation axis, The discharge connecting section is formed on the rotating shaft while being eccentric with respect to the rotation axis, as described in Appendix 5 of the double-rotating scroll compressor.

[0202] (Note 7) A double-rotating scroll compressor according to any one of the appendices 1 to 6, wherein when the flow rate of the fluid discharged from the compression chamber to the discharge chamber is at its minimum, the discharge section and the discharge connecting section are in a phase that minimizes the discharge-side flow resistance.

[0203] (Note 8) A double-rotating scroll compressor according to any one of the appendices 1 to 7, wherein when the flow rate of the fluid discharged from the compression chamber to the discharge chamber is at its maximum, the discharge section and the discharge connecting section are in a phase that maximizes the discharge-side flow resistance.

[0204] (Note 9) The compression mechanism is provided with a discharge valve that allows fluid to be discharged from the compression chamber to the discharge chamber, while prohibiting fluid from flowing from the discharge chamber to the compression chamber. The discharge connection section is located downstream of the discharge valve in the direction of fluid flow in the double-rotation scroll compressor according to any one of the appendices 1 to 8. [Industrial applicability]

[0205] This invention can be used in vehicle air conditioning systems and the like. [Explanation of symbols]

[0206] 6… Housing 10…Electric motor (drive mechanism) 12... Compression chamber 14…Compression mechanism 20...Following mechanism 30…Drive Scroll 31…Drive end plate 33…Driving vortex 37…First cover (cover) 37d, 81d, 83d, 85d, 87b... Second boss (rotating axis section) 38, 86, 88... Discharge Contact Section 40...Driven Scroll 41…Driven end plate 43... Driven vortex 52…Second sliding bearing (bearing) 57…Discharge reed valve (discharge valve) 63…Discharge part 73, 77... Discharge connection port (discharge section) 78…Radial ball bearing (bearing) 81...Second cover body (cover body) 82, 84... Connecting passage (discharge connection section) 83...Third cover body (cover body) 85...Fourth cover (cover) 87...Fifth cover (cover) 91~95…Discharge chamber O1... Rotation axis

Claims

1. A housing having a discharge section formed for discharging fluid to the outside, The housing includes a compression mechanism, The compression mechanism includes a compression chamber for compressing a fluid while reducing its volume, and a discharge chamber communicating with the compression chamber, through which the fluid compressed in the compression chamber is discharged. The housing is also provided with a rotating shaft portion that is rotatably supported by bearings around a rotation axis. The discharge chamber is formed to have a larger diameter than the outer diameter of the bearing. The compression mechanism includes a drive scroll that rotates by a drive mechanism, The system includes a driven scroll that faces the drive scroll and rotates eccentrically with respect to the drive scroll by the drive scroll and the driven mechanism, thereby forming the compression chamber between itself and the drive scroll. The drive scroll comprises a drive end plate and a drive spiral body that is integral with the drive end plate and protrudes spirally toward the driven scroll. The driven scroll has a driven end plate and a driven spiral body that is integral with the driven end plate and projects spirally toward the drive scroll. The rotating shaft portion is formed with a discharge connecting portion that allows the fluid discharged into the discharge chamber to flow to the discharge portion. As the rotation of the rotating shaft changes the phase between the discharge section and the discharge connecting section, the flow resistance of the fluid flowing from the discharge connecting section to the discharge section changes. A double-rotation scroll compressor characterized in that the discharge section and the discharge connecting section are in a phase where the flow resistance increases as the flow rate of the fluid discharged from the compression chamber to the discharge chamber approaches its maximum.

2. The compression mechanism has a cover body that is fixed to the drive scroll or the driven scroll and is provided with the rotating shaft portion. The double-rotating scroll compressor according to claim 1, wherein the discharge chamber is formed between the cover body and the drive end plate of the drive scroll to which the cover body is fixed, or the driven end plate of the driven scroll to which the cover body is fixed.

3. Lubricating oil is discharged into the discharge chamber along with the fluid compressed in the compression chamber. The double-rotating scroll compressor according to claim 1, wherein the discharge chamber and a location within the housing where the pressure is lower than that of the discharge chamber are in communication via a recirculation channel that recirculates the lubricating oil in the discharge chamber.

4. The double-rotating scroll compressor according to any one of claims 1 to 3, wherein the discharge section and the discharge connecting section are in communication in the radial direction of the housing.

5. The compressor according to any one of claims 1 to 3, wherein the discharge section and the discharge connecting section are in communication in the direction of the rotation axis.

6. The discharge portion is formed in the housing while being eccentric with respect to the rotation axis, The discharge connecting section is formed on the rotating shaft while being eccentric with respect to the rotation axis, as described in claim 5 for the double-rotating scroll compressor.

7. The double-rotating scroll compressor according to any one of claims 1 to 3, wherein when the flow rate of the fluid discharged from the compression chamber to the discharge chamber is at its minimum, the discharge section and the discharge connecting section are in a phase that minimizes the flow resistance.

8. A double-rotating scroll compressor according to any one of claims 1 to 3, wherein when the flow rate of the fluid discharged from the compression chamber to the discharge chamber is at its maximum, the discharge section and the discharge connecting section are in a phase that maximizes the flow resistance.

9. The compression mechanism is provided with a discharge valve that allows fluid to be discharged from the compression chamber to the discharge chamber, while prohibiting fluid from flowing from the discharge chamber to the compression chamber. The double-rotation scroll compressor according to any one of claims 1 to 3, wherein the discharge connection section is located downstream of the discharge valve in the direction of fluid flow.

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