Scroll compressor

Abstract

A scroll compressor capable of reducing the surface pressure acting on the front end of the winding end portion of the vortex wall of the swirling scroll. In the scroll compressor (10), a thrust plate (81) and an elastically deformable thrust piece (82) are provided between the opposing surface (237) as the thrust bearing portion and the swirling base plate (521) of the swirling scroll (52). The swirling base plate (521) and the thrust piece (82) are sealed by a first seal (83), and the opposing surface (237) of the second partition wall (232) and the thrust plate (81) are sealed by a second seal (84) having a diameter larger than that of the first seal (83). The back pressure chamber (H5) is divided into a suction pressure area (space (H6)) by the thrust plate (81), the thrust piece (82), the first seal (83) and the second seal (84). Furthermore, a circular recess (816) is formed on the surface of the thrust plate (81) on the thrust piece (82) side.

Description

Technical Field

[0001] The present invention relates to a scroll compressor. Background Art

[0002] A scroll compressor has a fixed scroll and an orbiting scroll, arranged with their scroll walls meshing with each other. A scroll compressor uses the orbiting scroll to orbit relative to the fixed scroll, changing the volume of the compression chamber formed between the two scroll walls. This compresses the fluid drawn into the compression chamber. Patent Document 1 describes an example of this type of scroll compressor.

[0003] Figure 5 This is a cross-sectional view of the scroll compressor described in Patent Document 1. In the scroll compressor described in Patent Document 1, a backpressure chamber 39 is formed on the back side of the base plate (mirror plate) 31 of the orbiting scroll (movable scroll) 22. This backpressure chamber 39 generates a backpressure load that presses the orbiting scroll 22 against the fixed scroll 21. The backpressure chamber 39 defines a suction portion 37, serving as a suction pressure region, by an annular thrust plate 38 disposed between the frame portion 7B of the compression mechanism housing 7 and the orbiting scroll 22 (i.e., on the back side of the orbiting scroll 22), an annular first seal 41, and an annular second seal 2. The thrust plate 38 is disposed between the frame portion 7B of the compression mechanism housing 7 and the orbiting scroll 22 (i.e., on the back side of the orbiting scroll 22). The first seal 41 is attached to the back side of the base plate 31 of the orbiting scroll 22 and abuts one surface of the thrust plate 38. The second seal 42 is attached to the surface of the frame portion 7B facing the thrust plate 38 and abuts the other surface of the thrust plate 38. The diameter of the second seal 42 is larger than that of the first seal 41.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2020-153295 Summary of the Invention

[0007] Technical problem to be solved by the invention

[0008] In the scroll compressor described in Patent Document 1, a centrifugal force generated by the orbiting motion acts on the orbiting scroll 22, causing the orbiting scroll 22 to tilt. In addition, in the scroll compressor described in Patent Document 1, when the thrust plate 38 is viewed from the axial direction of the drive shaft (rotating shaft) 14, the back pressure load pressing the orbiting scroll 22 against the fixed scroll 21 is as follows: Figure 6As shown by the middle hatching, the back pressure load acts on the other surface of the thrust plate 38, radially inward of the second seal 42 and radially outward of the first seal 41. In other words, the back pressure load acts on the orbiting scroll 22 in a biased state. Therefore, in addition to the overturning moment caused by the centrifugal force, the orbiting scroll 22 also experiences an overturning moment caused by the bias of the back pressure load.

[0009] When the orbiting scroll 22 tilts, the leading end of the orbiting scroll wall (surrounding member) 31 partially contacts the base plate (mirror plate) 23 of the fixed scroll 21, and the orbiting scroll wall (surrounding member) 24 of the fixed scroll 21 partially contacts the base plate (mirror plate) 31 of the orbiting scroll 22. In particular, contact force is concentrated at the leading end of the wraparound end of the orbiting scroll wall 31 of the orbiting scroll 22, which forms the thinnest part of the orbiting scroll wall (surrounding member). Therefore, when the orbiting scroll 22 tilts, a high surface pressure acts on the leading end of the wraparound end of the orbiting scroll wall 22.

[0010] In recent years, scroll compressors have been required to achieve higher efficiency, smaller size, and lighter weight. As scroll compressors continue to achieve higher efficiency, smaller size, and lighter weight, the tilt of the orbiting scroll creates a higher surface pressure on the leading end of the wrapping end of the orbiting scroll's vortex wall. This can result in wear and damage to the leading end of the wrapping end of the orbiting scroll's wrapping member.

[0011] Therefore, an object of the present invention is to provide a scroll compressor that can reduce the surface pressure acting on the front end portion of the winding end portion of the vortex wall of the orbiting scroll and suppress wear and damage to the front end portion of the winding end portion of the vortex wall of the orbiting scroll.

[0012] Technical solutions used to solve technical problems

[0013] According to one aspect of the present invention, a scroll compressor is provided. The scroll compressor comprises: a drive shaft; a fixed scroll having a fixed base plate and a fixed scroll wall disposed upright on the fixed base plate; and an orbiting scroll having an orbiting base plate and an orbiting scroll wall disposed upright on the orbiting base plate and meshing with the fixed scroll wall. As the drive shaft rotates, the orbiting scroll performs an orbiting motion relative to the fixed scroll, thereby changing the volume of a compression chamber formed between the fixed scroll and the orbiting scroll, thereby compressing fluid drawn into the compression chamber. The scroll compressor includes: an annular plate member, which is arranged on the back side of the above-mentioned revolving base plate of the above-mentioned revolving scroll and has a diameter larger than the diameter of the above-mentioned revolving base plate; an annular sheet member, which is arranged between the back side of the above-mentioned revolving base plate of the above-mentioned revolving scroll and the above-mentioned plate member and has a diameter substantially the same as that of the above-mentioned plate member and can be elastically deformed; an annular first seal, which is installed on the peripheral edge of the back side of the above-mentioned revolving base plate of the above-mentioned revolving scroll and has a front end in contact with the above-mentioned sheet member in a slidable manner; a thrust bearing portion, which receives the compression reaction force acting on the above-mentioned sheet member via the above-mentioned sheet member and the above-mentioned plate member. The thrust load of the orbiting scroll; a circular annular second seal, the second seal being formed to have a diameter larger than that of the first seal, being mounted on the surface of the plate member on the side of the thrust-bearing portion and one of the thrust-bearing portions, and having a front end in contact with the surface of the plate member on the side of the thrust-bearing portion and the other of the thrust-bearing portion; and a back-pressure chamber, the back-pressure chamber being divided into a suction pressure area by the plate member, the sheet member, the first seal and the second seal, and causing the back-pressure load that presses the orbiting scroll against the fixed scroll to act on the plate member and the orbiting scroll, and a circular recess being formed on the surface of the plate member on the side of the sheet member.

[0014] Effects of the Invention

[0015] According to one aspect of the present invention, a scroll compressor can be provided that can reduce the surface pressure acting on the front end portion of the winding end portion of the vortex wall of the orbiting scroll and suppress wear and damage to the front end portion of the winding end portion of the vortex wall of the orbiting scroll. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a cross-sectional view showing a schematic structure of a scroll compressor according to an embodiment.

[0017] Figure 2 yes Figure 1 Enlarged view of the main part.

[0018] Figure 3It is a perspective view showing the thrust plate and the thrust piece.

[0019] Figure 4 is a cross-sectional view of the thrust plate.

[0020] Figure 5 This is a diagram (cross-sectional view) showing an example of a conventional scroll compressor.

[0021] Figure 6 This is a diagram for explaining the back pressure load in a conventional scroll compressor. DETAILED DESCRIPTION

[0022] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0023] Figure 1 This is a cross-sectional view showing a schematic structure of a scroll compressor according to an embodiment of the present invention. The scroll compressor 10 according to the embodiment is assembled in a refrigerant circuit of a vehicle air-conditioning device, for example, and is configured to receive low-pressure gas refrigerant (fluid) from the refrigerant circuit, compress it, and then return it to the refrigerant circuit after increasing its pressure. Figure 1 The left side in FIG is the front side of the scroll compressor 10. Figure 1 The right side in FIG is the rear side of the scroll compressor 10. Figure 1 The upper side in FIG is the upper side of the scroll compressor 10, Figure 1 The lower side in FIG. 1 is the lower side of the scroll compressor 10 .

[0024] The scroll compressor 10 includes a housing 20, a drive shaft 30, a motor 40 that rotates the drive shaft 30, a scroll unit 50 that is driven by the drive shaft 30 to compress (low-pressure) gas refrigerant, and an inverter 60 that drives and controls the motor 40. The drive shaft 30, the motor 40, the scroll unit 50, and the inverter 60 are housed in the housing 20. The scroll unit 50 includes a fixed scroll 51 and an orbiting scroll 52 that orbits and revolves relative to the fixed scroll 51.

[0025] The housing 20 includes a front housing 21, a cover member 22, an intermediate housing 23, and a rear housing 24. These are fastened together by fasteners (not shown) and the like to form the housing 20 of the scroll compressor 10.

[0026] The front housing 21 has a cylindrical first circumferential wall portion 211 extending forward and backward, and a first partition wall portion 212 that separates the interior of the first circumferential wall portion 211 from front to back. The front end face of the first circumferential wall portion 211 constitutes the front end face of the front housing 21, and the rear end face of the first circumferential wall portion 211 constitutes the rear end face of the front housing 21. The interior of the first circumferential wall portion 211 (i.e., the internal space of the front housing 21) is divided by the first partition wall portion 212 into an inverter accommodating space on the front side for accommodating the inverter 60 and a motor accommodating space on the rear side for accommodating the motor 40. That is, in this embodiment, the motor 40 and the inverter 60 are accommodated in the front housing 21.

[0027] A support portion 213 is provided on the first partition wall 212 to support the front end portion of the drive shaft 30. The support portion 213 is formed to protrude cylindrically from the rear side of the first partition wall 212 into the motor housing space, and is configured to rotatably support the front end portion of the drive shaft 30 via a first bearing 214 installed therein.

[0028] A cover member 22 is joined to the front end of the front housing 21, thereby sealing the inverter housing space (forming an inverter housing chamber). The front end of the intermediate housing 23 is joined to the rear end of the front housing 21. Seal members may be provided between the front housing 21 and the cover member 22, and between the front housing 21 and the intermediate housing 23, as needed.

[0029] The intermediate housing 23 includes a cylindrical second circumferential wall portion 231 extending forward and backward, and a second partition wall portion 232 that separates the interior of the second circumferential wall portion 231 from front to back. The front end surface of the second circumferential wall portion 231 constitutes the front end surface of the intermediate housing 23, and the rear end surface of the second circumferential wall portion 231 constitutes the rear end surface of the intermediate housing 23. The interior of the second circumferential wall portion 231 (i.e., the interior space of the intermediate housing 23) is divided by the second partition wall portion 232 into a front connection space connected to the above-mentioned motor housing space of the front housing 21 and a rear scroll housing space that houses the scroll unit 50. That is, in this embodiment, the scroll unit 50 is housed in the intermediate housing 23.

[0030] The second partition wall portion 232 has a hollow protrusion 233 that protrudes toward the front housing 21 (motor housing space). The hollow protrusion 233 is provided at the radial center of the second partition wall portion 232 in a manner opposite to the support portion 213 of the first partition wall portion 212 provided on the front housing 21. A shaft insertion hole 234 is formed at the top of the hollow protrusion 233, which connects the inside and outside of the hollow protrusion 233 and allows the drive shaft 30 to be inserted. A second bearing 235 is installed inside the hollow protrusion 233, and the second bearing supports the rear end side of the drive shaft 30 so that it can rotate freely. That is, in this embodiment, the drive shaft 30 extends in the front-to-back direction within the housing 20 and is rotatably supported by the first bearing 214 provided on the front housing 21 side and the second bearing 235 provided on the intermediate housing 23 side.

[0031] The front end face of the rear housing 24 is joined to the rear end face of the intermediate housing 23. In this embodiment, a circular recess 236 is formed on the rear end face of the intermediate housing 23, that is, the rear end face of the second circumferential wall portion 231, to accommodate the outer edge (peripheral edge) of the fixed base plate 511 (described later) of the fixed scroll 51 constituting the scroll unit 50. Furthermore, the outer edge (peripheral edge) of the fixed base plate 511 is accommodated in the recess 236 and is clamped between the intermediate housing 23 and the rear housing 24. As a result, the fixed scroll 51 is fixed, and the opening on the rear side of the second circumferential wall portion 231 is sealed by the fixed base plate 511 of the fixed scroll 51. Furthermore, a sealing member can be arranged between the intermediate housing 23 and the rear housing 24 as needed.

[0032] The rear housing 24 is formed into a bottomed cylindrical shape and includes a cylindrical third peripheral wall portion 241 extending forward and backward, and a bottom wall portion 242 that closes the rear opening of the third peripheral wall portion 241. Furthermore, the front end surface of the third peripheral wall portion 241, which constitutes the front end surface of the rear housing 24, is joined to the rear end surface of the second peripheral wall portion 231, which constitutes the rear end surface of the intermediate housing 23. As a result, the front opening of the third peripheral wall portion 241 is closed by the fixed base plate 511 of the fixed scroll 51.

[0033] The electric motor 40 is constituted by, for example, a three-phase AC electric motor, and includes a stator core unit 41 and a rotor 42 .

[0034] The stator core unit 41 is fixed to the inner peripheral surface of the first peripheral wall portion 211 of the front housing 21. A direct current from a vehicle-mounted battery (not shown) or the like is converted into an alternating current by the inverter 60 and supplied to the stator core unit 41.

[0035] The rotor 42 is positioned radially inwardly of the stator core unit 41 with a predetermined clearance therebetween. Permanent magnets are incorporated into the rotor 42. The rotor 42 is cylindrical and fixed to the drive shaft 30 with the drive shaft 30 inserted through its hollow portion. In other words, the rotor 42 is integrated with the drive shaft 30 and rotates integrally therewith.

[0036] When the electric motor 40 generates a magnetic field in the stator core unit 41 by power supply from the inverter 60 , a rotational force acts on the permanent magnets of the rotor 42 to rotate the rotor 42 , thereby rotating (rotationally driving) the drive shaft 30 .

[0037] As described above, the scroll unit 50 includes the fixed scroll 51 and the orbiting scroll 52 that orbits relative to the fixed scroll 51 .

[0038] The fixed scroll 51 includes a circular fixed base plate 511 and a fixed scroll wall 512 erected on one surface of the fixed base plate 511. The fixed scroll wall 512 extends in a spiral shape (involute curve) from the radially inner end (the winding start point) to the radially outer end (the winding end point) of the fixed base plate 511. The fixed scroll 51 is fixed by being clamped between the center housing 23 and the rear housing 24, with the one surface of the fixed base plate 511 (the surface on which the fixed scroll wall 512 is erected) facing forward and the outer edge (peripheral edge) of the fixed base plate 511 housed in the recess 236.

[0039] The orbiting scroll 52 includes a circular plate-shaped orbiting base 521, an orbiting vortex wall 522 erected on one surface of the orbiting base 521, and a cylindrical portion 523 protruding from the other surface of the orbiting base 521. The orbiting vortex wall 522 extends in a spiral shape (involute curve) from the radially inner inner end (the winding start) to the radially outer outer end (the winding end) of the aforementioned surface of the orbiting base 521. The orbiting scroll 52 is configured so that the orbiting vortex wall 522 meshes with the fixed vortex wall 512 of the fixed scroll 51. In other words, the orbiting scroll 52 is arranged between the second partition wall 232 of the intermediate housing 23 and the fixed scroll 51, with the aforementioned surface of the orbiting base 521 (the surface on which the orbiting vortex wall 522 is erected) facing rearward. Hereinafter, the aforementioned other surface of the orbiting base 521 (the surface on which the cylindrical portion 523 is formed) is referred to as the back surface of the orbiting base 521.

[0040] The orbiting scroll 52 is driven by a driving force transmitted via the drive shaft 30 and the crank mechanism 70. The driven orbiting scroll 52 is configured to perform an orbiting motion relative to the fixed scroll 51 while its rotation is prevented. Specifically, the crank mechanism 70 is configured to couple the drive shaft 30 and the orbiting scroll 52 and convert the orbiting motion of the drive shaft 30 into the orbiting motion of the orbiting scroll 52.

[0041] The scroll unit 50 is configured to suck in and compress low-pressure gas refrigerant by causing the orbiting scroll 52 to perform an orbiting motion relative to the fixed scroll 51 .

[0042] Figure 2 yes Figure 1 Enlarged view of the main part.

[0043] Reference Figure 2 The crank mechanism 70 includes an eccentric pin 71 provided at the rear end of the drive shaft 30 and an eccentric bushing 72 mounted on the eccentric pin 71 .

[0044] The eccentric pin 71 extends from the rear end surface of the drive shaft 30 in the axial direction of the drive shaft 30. The eccentric pin 71 is eccentric relative to the drive shaft 30. That is, the center line CL1 of the eccentric pin 71 is offset from the center line CL0 of the drive shaft 30.

[0045] The eccentric bushing 72 is rotatably mounted on the eccentric pin 71 and is rotatably inserted into the inner side of the cylindrical portion 523 of the orbiting scroll 52 via the bearing 73. Specifically, the eccentric bushing 72 is formed in a cylindrical shape. In addition, a pin insertion hole 72a is formed in the eccentric bushing 72, through which the eccentric pin 71 is rotatably inserted. The pin insertion hole 72a is formed at a position eccentric from the center line CL2 of the eccentric bushing 72 and penetrates the eccentric bushing 72 in the axial direction. Moreover, the eccentric bushing 72 is rotatably mounted on the eccentric pin 71 by inserting the eccentric pin 71 through the pin insertion hole 72a. Therefore, the center line of the pin insertion hole 72a coincides with the center line CL1 of the eccentric pin 71. The eccentric bushing 72 is rotatably inserted into the cylindrical portion 523 of the orbiting scroll 52 via the bearing 73 , with the outer peripheral surface 72 b being supported by a bearing 73 attached to the inner side of the cylindrical portion 523 of the orbiting scroll 52 .

[0046] A bushing counterweight 721 that rotates or swings integrally with the eccentric bushing 72 is installed on the outer peripheral surface near the front end of the eccentric bushing 72 (i.e., near the end on the drive shaft 30 side), and a shaft counterweight 31 that rotates integrally with the drive shaft 30 is installed on the outer peripheral surface near the rear end of the drive shaft 30 (i.e., near the end on the eccentric pin 71 side).

[0047] The bushing weight 721 counteracts the centrifugal force generated on the orbiting scroll 52 by the orbiting motion, and mainly appropriately maintains the pressing force of the orbiting scroll wall 522 against the fixed scroll wall 512. In addition, the bushing weight 721 and the shaft weight 31 are used to match the rotor weights 421 and 422 installed on the rotor 42 (see Figure 1 ) are arranged to cooperate to obtain the overall balance of the movable system components including the drive shaft 30 and the components fixed or connected to the drive shaft 30.

[0048] A circular opposing surface 237 is formed in the second partition wall portion 232 of the intermediate housing 23. This opposing surface is located radially outward from the hollow protrusion 233 and faces, spaced apart from each other, the back surface of the orbiting base plate 521 of the orbiting scroll 52. Furthermore, a thrust plate (plate member) 81 and a thrust piece (piece member) 82 are disposed in sequence, starting from the side closest to the opposing surface 237, between the opposing surface 237 of the second partition wall portion 232 and (the back surface of) the orbiting base plate 521. In other words, the thrust plate 81 is disposed on the back side of the orbiting base plate 521, and the thrust piece 82 is disposed between the thrust plate 81 and (the back surface of) the orbiting base plate 521.

[0049] The thrust plate 81 and the thrust piece 82 are formed in an annular shape and are arranged on the radially outer side of the cylindrical portion 523 formed on the back side of the rotating base plate 521. Specifically, the thrust plate 81 has an outer diameter larger than the outer diameter of the rotating base plate 521, and has an inner diameter larger than the outer diameter of the cylindrical portion 523. In addition, the thrust piece 82 is formed so that the inner and outer diameters are approximately equal to those of the thrust plate 81 (that is, the diameters are approximately the same). The thrust plate 81 is formed to have relatively high rigidity and is substantially non-flexible. On the other hand, the thrust piece 82 is formed of a metal sheet having spring properties, etc., has flexibility, and can be elastically deformed along the axial direction of the drive shaft 30.

[0050] A first annular seal 83 is provided between the back side of the orbiting substrate 521 of the orbiting scroll 52 and the thrust piece 82. The first seal 83 is formed of, for example, a synthetic resin having sliding properties. The first seal 83 is mounted on the peripheral portion of the back side of the orbiting substrate 521 of the orbiting scroll 52 so that the front end portion contacts the surface of the orbiting scroll 52 side of the thrust piece 82. Specifically, in the present embodiment, the first seal 83 is embedded in the annular groove formed on the peripheral portion of the back side of the orbiting substrate 521 of the orbiting scroll 52 in a manner that a portion protrudes from the back side of the orbiting substrate 521 of the orbiting scroll 52, and the front end of the protruding portion contacts the surface of the orbiting scroll 52 side of the thrust piece 82 in a manner that can slide. Furthermore, the first seal 83 slides on the surface of the thrust piece 82 on the orbiting scroll 52 side during the orbiting motion of the orbiting scroll 52 , thereby sealing between the thrust piece 82 and the back surface of the orbiting base plate 521 of the orbiting scroll 52 .

[0051] A circular annular second seal 84 is provided between the opposing surface 237 of the second partition wall portion 232 and the thrust plate 81. The second seal 84 is formed of, for example, synthetic rubber and has elasticity. The second seal 84 is formed to have a diameter larger than that of the first seal 83. Although there is no particular limitation, an O-ring, for example, can be used as the second seal 84. The second seal 84 is mounted on one of the opposing surface 237 of the second partition wall portion 232 and the surface on the side of the opposing surface 237 of the thrust plate 81, and the front end portion contacts the other side, thereby sealing the opposing surface 237 of the second partition wall portion 232 and the thrust plate 81. Specifically, in the present embodiment, the second seal 84 is embedded in the annular groove formed on the opposing surface 237 of the second partition wall portion 232 in a manner that a portion protrudes from the opposing surface 237 of the second partition wall portion 232, and the front end of the protruding portion contacts the peripheral portion of the surface on the side of the opposing surface 237 of the thrust plate 81.

[0052] Figure 3 81 and 82 are perspective views showing the thrust plate. Figure 4 It is a cross-sectional view of the thrust plate 81 and the thrust piece 82 .

[0053] like Figures 2 to 4 As shown, the thrust plate 81 has two positioning pins 812 projecting from a surface 811 on the side facing the surface 237 and six rotation preventing pins 814 projecting from a surface 813 on the side facing the orbiting scroll 52. Furthermore, six insertion holes 821 corresponding to the six rotation preventing pins 814 are formed in the thrust plate 82.

[0054] In this embodiment, the two positioning pins 812 are fixed by being pressed into two first press-fit holes formed on both sides of the hollow portion 815 of the thrust plate 81 so as to partially protrude from the surface 811 on the side of the opposing surface 237 of the thrust plate 81 .

[0055] Furthermore, the two positioning pins 812 are inserted into two corresponding positioning holes 238 (preferably one formed as a circular hole and the other formed as a long hole) formed on the opposing surface 237 of the second partition wall portion 232 in a manner movable in the axial direction.

[0056] Moreover, by inserting two positioning pins 812 into two positioning holes 238 formed on the opposing surface 237 of the second partition wall portion 232, the thrust plate 81 is mounted on the opposing surface 237 of the second partition wall portion 232 in a manner that allows it to move axially along the drive shaft 30 while being positioned in a non-rotating state.

[0057] A circular recess 816 is formed concentrically with the thrust plate 81 on the surface 813 of the thrust plate 81 on the orbiting scroll 52 side. In other words, in this embodiment, the surface 813 of the thrust plate 81 on the orbiting scroll 52 side includes a first annular surface 813a, which is formed by the bottom surface of the circular recess 816; and a second annular surface 813b, which is located radially outward of the circular recess 816 and one level higher than the first annular surface 813a. The circular recess 816 is formed to be the area where the first seal 83 slides on the surface of the thrust plate 82 on the orbiting scroll 52 side during the orbiting and swirling motion of the orbiting scroll 52, when viewed axially from the drive shaft 30. In other words, it is located inward of (the outline of) the sliding area of ​​the first seal 83 relative to the thrust plate 82 during the orbiting and swirling motion of the orbiting scroll 52. In this embodiment, the circular recess 816 is formed to have a diameter smaller than the outer diameter of the first seal 83. However, this is not limiting. The circular recess 816 may be formed to have a diameter substantially the same as the outer diameter of the first sealing member 83 .

[0058] The six rotation preventing pins 814 are secured by being pressed into six second press-fit holes formed at equal intervals along the circumferential direction, with portions of the six pins 814 protruding from the surface 813 of the thrust plate 81 on the orbiting scroll 52 side. Specifically, in this embodiment, the six second press-fit holes are formed at equal intervals along the circumferential direction on the first annular surface 813a formed by the bottom surface of the circular recess 816. The six rotation preventing pins 814 are secured by being pressed into the six second press-fit holes formed on the first annular surface 813a, with the six pins protruding further than the second annular surface 813b.

[0059] In addition, the six rotation preventing pins 814 are inserted through the six insertion holes 821 formed in the thrust piece 82 and penetrate the thrust piece 82, and are loosely fitted into the six circular holes 524 (in Figure 1 and Figure 2 Only one of them is shown in the figure), the six circular holes are formed at equal intervals on the back side of the orbiting substrate 521 of the orbiting scroll 52 in a manner that surrounds the cylindrical portion 523.

[0060] Moreover, by inserting the six rotation-preventing pins 814 into the six insertion holes 821 of the thrust plate 82, the thrust plate 82 is mounted on the surface 813 (the second annular surface 813b) on the side of the orbiting scroll 52 of the thrust plate 81 in a state where relative rotation with respect to the thrust plate 81 is prevented. At this time, a permissible space is formed between the thrust plate 81 and the thrust plate 82 by the inner space of the circular recess 816, that is, the step difference between the second annular surface 813b and the first annular surface 813a, which allows elastic deformation of the inner peripheral portion of the thrust plate 82. In addition, the six rotation-preventing pins 814 are loosely embedded in the six circular holes 524 formed on the back side of the orbiting base plate 521 to prevent the orbiting scroll 52 from rotating. In addition, as long as there are three or more rotation-preventing pins 814 (and circular holes 524), the number of rotation-preventing pins 814 (and circular holes 524) can be set arbitrarily.

[0061] return Figure 1 The scroll compressor 10 includes: a suction chamber H1, wherein the suction chamber H1 is for low-pressure gas refrigerant to flow in; a compression chamber H2, wherein the compression chamber H2 compresses the low-pressure gas refrigerant; a discharge chamber H3, wherein the gas refrigerant compressed in the compression chamber H2 is discharged; a gas-liquid separation chamber H4, wherein the gas-liquid separation chamber H4 separates lubricating oil from the gas refrigerant compressed in the compression chamber H2; and a back-pressure chamber H5, wherein the back-pressure chamber H5 is arranged on the back side of the orbiting base plate 521 of the orbiting scroll 52.

[0062] The suction chamber H1 is divided and formed by the first circumferential wall portion 211 of the front housing 21, the first partition wall portion 212 of the front housing 21, the first circumferential wall portion 231 of the intermediate housing 23, and the second partition wall portion 232 of the intermediate housing 23. That is, in the present embodiment, the suction chamber H1 is formed by the above-mentioned motor accommodating space of the front housing 21 and the above-mentioned connecting space of the intermediate housing 23. A suction port P1 is formed in the first circumferential wall portion 211. The suction port P1 is connected to the above-mentioned refrigerant circuit (the low-pressure side) via a connecting pipe or the like not shown in the figure. Therefore, the low-pressure refrigerant from the above-mentioned refrigerant reflux flows into the suction chamber H1 via the suction port P1. In addition, a refrigerant passage L1 is formed in the intermediate housing 23 for guiding the low-pressure gas refrigerant in the suction chamber H1 to the space H6 radially outside the scroll unit 50.

[0063] The compression chamber H2 is formed between the fixed scroll 51 and the orbiting scroll 52. Specifically, in the scroll unit 50, when the orbiting scroll 52 orbits and revolves relative to the fixed scroll 51, the orbiting scroll wall 522 contacts the fixed scroll wall 512, forming a crescent-shaped enclosed space radially outward through the fixed base plate 511, the fixed scroll wall 512, the orbiting base plate 521, and the orbiting scroll wall 522. The resulting crescent-shaped enclosed space moves radially inward while gradually reducing its volume. The crescent-shaped enclosed space formed between the fixed scroll 51 and the orbiting scroll 52 constitutes the compression chamber H2. The scroll unit 50 is configured to compress the low-pressure gas refrigerant by sucking low-pressure gas refrigerant from space H6 when forming the above-mentioned crescent-shaped enclosed space (i.e., compression chamber H2).

[0064] The discharge chamber H3 is divided and formed by the third circumferential wall portion 241 of the rear housing 24, the bottom wall portion 242 of the rear housing 24, and the fixed base plate 511 of the fixed scroll 51. That is, the interior of the third circumferential wall portion 241 of the rear housing 24 constitutes the discharge chamber H3. A discharge hole L2 is formed in the radial center of the fixed base plate 511 of the fixed scroll 51 to connect the compression chamber H2 moving toward the innermost side with the discharge chamber H3. Therefore, the gas refrigerant compressed in the compression chamber H2 of the scroll unit 50 is discharged to the discharge chamber H3 through the discharge hole L2. In addition, a check valve (reed valve) 95 is installed on the discharge hole L2. The above-mentioned check valve allows the gas refrigerant to flow from the compression chamber H2 to the discharge chamber H3, but restricts the gas refrigerant from flowing from the discharge chamber H3 to the compression chamber H2.

[0065] The gas-liquid separation chamber H4 is provided in the rear housing 24. Specifically, in the present embodiment, the gas-liquid separation chamber H4 is formed as a cylindrical space extending downward from the outer peripheral surface toward the interior in the bottom wall portion 242 of the rear housing 24. The discharge chamber H3 and the gas-liquid separation chamber H4 are connected via the connecting hole L3. An oil separator 100 for separating the lubricating oil contained in the gas refrigerant is arranged in the gas-liquid separation chamber H4. A centrifugal separation type oil separator is used here, but it is not limited to this, and other types of oil separators can also be used. A discharge port P2 is provided on the upper part of the oil separator 100 in the gas-liquid separation chamber H4. The discharge port P2 is connected to the above-mentioned refrigerant circuit (the high-pressure side) via a connecting pipe or the like not shown in the figure.

[0066] The back-pressure chamber H5 is formed between the orbiting base plate 521 of the orbiting scroll 52 and the second partition wall portion 232 of the intermediate housing 23. In the present embodiment, the back-pressure chamber H5 includes the interior space of the hollow protrusion 233 of the second partition wall portion 232. The back-pressure chamber H5 is divided into a space H6 radially outside the scroll unit 50, which serves as the pressure region (suction pressure region) of the suction chamber H1, by the thrust plate 81, the thrust piece 82, the first seal 83, and the second seal 84.

[0067] A lubricating oil passage L4 is formed on the intermediate housing 23 and the rear housing 24. The lubricating oil passage L4 connects the discharge chamber H3 with the back pressure chamber H5, and connects the gas-liquid separation chamber H4 with the back pressure chamber H5. A throttle hole (throttle portion) OL is arranged in the middle of the lubricating oil passage L4. In addition, the back pressure chamber H5 is connected to the suction chamber H1 via a small gap between the inner peripheral surface of the shaft insertion hole 234 and the outer peripheral surface of the drive shaft 30. However, it is not limited to this. It can also be configured so that the gap between the inner peripheral surface of the shaft insertion hole 234 and the outer peripheral surface of the drive shaft 30 is sealed, and the back pressure chamber H5 is connected to the suction chamber H1 via a pressure relief passage in which a throttle hole or a back pressure control valve is provided in the middle.

[0068] Here, the operation of the scroll compressor 10 will be described.

[0069] When the motor 40 rotates the drive shaft 30 using power from the inverter 60, the rotation of the drive shaft 30 is transmitted to the orbiting scroll 52 via the crank mechanism 70, causing the orbiting scroll 52 to orbit relative to the fixed scroll 51. Low-pressure gas refrigerant from the refrigerant circuit then flows into the suction chamber H1 through the suction port P1, passes through the refrigerant passage L1, and reaches the space H6. It is then drawn into the compression chamber H2 formed between the fixed scroll 51 and the orbiting scroll 52 and compressed. The compressed gas refrigerant (high-pressure gas refrigerant) in the compression chamber H2 is discharged through the discharge port L2 (and the check valve 95) into the discharge chamber H3, and then flows through the communication port L3 into the gas-liquid separation chamber H4. The lubricating oil contained in the gas refrigerant flowing into the gas-liquid separation chamber H4 is separated by the oil separator 100. The gas refrigerant, free of lubricating oil by the oil separator 100, is then discharged from the discharge port P2 into the refrigerant circuit. On the other hand, the lubricating oil separated from the gas refrigerant by the oil separator 100 is stored in the bottom of the gas-liquid separation chamber H4. In addition, part of the lubricating oil contained in the gas refrigerant discharged into the discharge chamber H3 is stored in the bottom of the discharge chamber H3.

[0070] During the operation of the scroll compressor 10, a thrust load acts on the orbiting scroll 52 in a direction that causes the orbiting scroll 52 to move away from the fixed scroll 51 due to the compression reaction force. The thrust load acting on the orbiting scroll 52 is transmitted to the opposing surface 237 of the second partition wall portion 232 via the thrust piece 82 and the thrust plate 81. In other words, the opposing surface 237 opposite the second partition wall portion 232 is configured to receive the thrust load acting on the orbiting scroll 52 due to the compression reaction force via the thrust piece 82 and the thrust plate 81. Therefore, in this embodiment, the opposing surface 237 opposite the second partition wall portion 232 corresponds to the "thrust receiving portion" of the present invention.

[0071] The backpressure chamber H5 is connected to the discharge chamber H3 and the gas-liquid separation chamber H4 via the lubricating oil passage L4, and to the suction chamber H1 via a small gap between the inner circumference of the shaft insertion hole 234 and the outer circumference of the drive shaft 30. Therefore, lubricating oil (and a portion of the refrigerant gas) accumulated at the bottom of the discharge chamber H3 and / or the bottom of the gas-liquid separation chamber H4 is supplied to the backpressure chamber H5 via the lubricating oil passage L4, but at this time, the pressure is reduced by the orifice OL. Furthermore, the backpressure chamber H5 is connected to the suction chamber H1 via the small gap, restricting the flow of lubricating oil (and / or refrigerant gas) from the backpressure chamber H5 to the suction chamber H1. Therefore, the pressure in the backpressure chamber H5 is maintained at an intermediate pressure Pm between the pressure Ps of the suction chamber H1 and the pressure Pd of the discharge chamber H3 (which is equal to the pressure of the gas-liquid separation chamber H4). This intermediate pressure (backpressure) Pm applies a backpressure load to the thrust plate 81 and the orbiting scroll 52, pressing the orbiting scroll 52 against the fixed scroll 51. That is, the back pressure chamber H5 applies a back pressure load in a direction of pressing the orbiting scroll 52 against the fixed scroll 51 to the thrust plate 81 and the orbiting scroll 52 .

[0072] Furthermore, the orbiting scroll 52 is pressed mainly by the back pressure load acting on the thrust plate 81 and the orbiting scroll 52, resisting the compression reaction force and being pressed against the fixed scroll 51. This maintains the contact between the fixed scroll wall 512 and the orbiting base plate 521, and the contact between the orbiting scroll wall 521 and the fixed base plate 511, and prevents a decrease in the compression efficiency of the gas refrigerant in the compression chamber H2.

[0073] As described above, in the scroll compressor 10 of the embodiment, an annular thrust plate 81 and an annular thrust piece 82 are provided on the back side of the orbiting substrate 521 of the orbiting scroll 52, more specifically, between the opposing surface (thrust bearing portion) 237 of the second partition wall portion 232 and the orbiting substrate 521 of the orbiting substrate 521. The thrust plate 81 is formed to be larger than the diameter of the orbiting substrate 512. The thrust piece 82 is provided between the orbiting substrate 512 and the thrust plate 81, and is formed to have a diameter substantially the same as that of the thrust plate 81, and is capable of elastic deformation along the axial direction of the drive shaft 30. The orbiting substrate 521 and the thrust piece 82 are sealed by a first annular seal 83 having sliding properties installed on the peripheral portion of the back side of the orbiting substrate 521. The opposing surface (thrust bearing portion) 234 of the second partition wall portion 232 and the thrust plate 81 are sealed by a second seal 84 installed on the opposing surface (thrust bearing portion) 234. The second seal 84 is elastic and has a larger diameter than the first seal 83. The back-pressure chamber H5 is divided into a space H6 (suction pressure region) near the outer end of the scroll unit 50 by the thrust plate 81, the thrust piece 82, the first seal 83, and the second seal 84. Furthermore, a circular recess 816 is formed on the thrust piece 82 side of the thrust plate 81. The circular recess 816 is located inward of (the outline of) the sliding area of ​​the first seal member 83 relative to the thrust piece 82 as the orbiting scroll 52 orbits, as viewed from the axial direction of the drive shaft 30.

[0074] According to the scroll compressor 10 of the embodiment, the following effects can be obtained.

[0075] A circular recess 816 is formed on the surface of the thrust plate 81 on the thrust piece 82 side. Furthermore, through (the internal space of) the circular recess 816, a permissible space is formed between the thrust plate 81 and the thrust piece 82 to allow elastic deformation of the thrust piece 82. Therefore, even when the orbiting scroll 52 is pressed against the fixed scroll 51 in an inclined state, the elastic deformation of the thrust piece 81 within the circular recess 816 can prevent the orbiting scroll wall 521 of the orbiting scroll 52 from contacting the fixed base plate 511 of the fixed scroll 51 with excessive contact force. As a result, the surface pressure acting on the front end portion of the winding end portion of the orbiting scroll wall 522 of the orbiting scroll 52 can be reduced, and wear and damage to the front end portion of the winding end portion of the orbiting scroll wall 522 of the orbiting scroll 52 can be suppressed.

[0076] Furthermore, the thrust plate 81 is mounted to the opposing surface (thrust receiving portion) 237 of the second bulkhead portion 232 so as to be movable in the axial direction of the drive shaft 30. A second elastic seal 84, mounted thereon, seals the opposing surface (thrust receiving portion) 237 and the thrust plate 81. Specifically, the second seal 84 is elastically deformed by being pressed between the thrust plate 81 and the opposing surface 237 of the second bulkhead portion 232. Its elastic restoring force presses the thrust plate 81 in a direction that presses the orbiting scroll 52 against the fixed scroll 51. Consequently, while maintaining contact between the orbiting scroll wall 521 and the fixed baseplate 511, it is possible to prevent the orbiting scroll wall 521 from contacting the fixed baseplate 511 with excessive force. This also reduces the surface pressure acting on the tip of the wrapping end portion of the orbiting scroll wall 522 of the orbiting scroll 52 , and suppresses wear and damage to the tip of the wrapping end portion of the orbiting scroll wall 522 of the orbiting scroll 52 .

[0077] The thrust plate 81 also has two positioning pins 812 protruding from a surface 811 on the opposing surface (thrust receiving portion) 237 side. The two positioning pins 812 are inserted axially into two positioning holes 238 formed in the opposing surface (thrust receiving portion) 237 so as to be movable. This prevents the thrust plate 81 from rotating and thereby positions the thrust plate 81 on the opposing surface (thrust receiving portion) 237. This allows the thrust plate 81 to be moved axially relative to the drive shaft 30 and easily assembled to the opposing surface (thrust receiving portion) 237.

[0078] The thrust plate 81 also has a plurality (six) of rotation-preventing pins 814 protruding from a surface 813 on the orbiting scroll 52 side. Each of the plurality of rotation-preventing pins 814 extends through the thrust plate 82 and loosely engages with a corresponding circular hole 524 formed on the back surface of the orbiting base plate 521 of the orbiting scroll 52, thereby preventing the orbiting scroll 52 from rotating. This prevents the thrust plate 82 from shifting or rotating, and prevents the orbiting scroll 52 from rotating during its orbital motion.

[0079] As mentioned above, although embodiment of this invention was demonstrated, this invention is not limited to the said embodiment, It is a matter of course that further deformation|transformation and change can be made based on the technical idea of ​​this invention.

[0080] Explanation of symbols

[0081] 10…Scroll compressor, 30…Drive shaft, 50…Scroll unit, 51…Fixed scroll, 52…Orbiting scroll, 81…Thrust plate (plate member), 82…Thrust sheet (sheet member), 83…First seal, 84…Second seal, 237…Opposing surface (thrust bearing portion), 511…Fixed base plate, 512…Fixed scroll wall, 521…Orbiting base plate, 522…Orbiting scroll wall, 812…Locking pin, 814…Rotation preventing pin, 816…Circular recess, H2…Compression chamber, H5…Back pressure chamber.

Claims

1. A scroll compressor, The scroll compressor is configured to include: a drive shaft; a fixed scroll, the fixed scroll including a fixed base plate and a fixed scroll wall erected on the fixed base plate; and an orbiting scroll having an orbiting base plate and an orbiting scroll wall disposed upright on the orbiting base plate and meshing with the fixed scroll wall. As the drive shaft rotates, the orbiting scroll performs an orbiting motion relative to the fixed scroll, thereby changing the volume of a compression chamber formed between the fixed scroll and the orbiting scroll to compress the fluid sucked into the compression chamber. The scroll compressor comprises: an annular plate member, the plate member being provided on the back side of the orbiting base plate of the orbiting scroll and having a diameter larger than that of the orbiting base plate; an annular sheet member, the sheet member being disposed between the back surface of the orbiting base plate of the orbiting scroll and the plate member, having a diameter substantially the same as that of the plate member and being elastically deformable; an annular first seal member, the first seal member being attached to a peripheral edge portion of a back surface of the orbiting base plate of the orbiting scroll, and having a front end portion slidably in contact with the sheet member; a thrust receiving portion that receives a thrust load acting on the orbiting scroll due to a compression reaction force via the sheet member and the plate member; a second annular seal having a larger diameter than that of the first seal, the second seal being attached to one of the surface of the plate member on the thrust receiving portion side and the thrust receiving portion, with a front end portion in contact with the other of the surface of the plate member on the thrust receiving portion side and the thrust receiving portion; and a back pressure chamber, wherein a suction pressure region is defined by the plate member, the sheet member, the first seal, and the second seal, and a back pressure load for pressing the orbiting scroll against the fixed scroll acts on the plate member and the orbiting scroll; A circular recess is formed on a surface of the plate member on the sheet member side.

2. The scroll compressor according to claim 1, wherein The circular recess is located inside a sliding range of the first seal relative to the sheet member accompanying the orbiting motion of the orbiting scroll when viewed in the axial direction of the drive shaft.

3. The scroll compressor according to claim 1 or 2, wherein: The circular recess is formed to have a diameter substantially the same as or smaller than an outer diameter of the first seal.

4. The scroll compressor according to any one of claims 1 to 3, wherein: The plate member is configured to be movable in the axial direction of the drive shaft. The second seal has elasticity and is pressed between the plate member and the thrust receiving portion to be elastically deformed.

5. The scroll compressor according to claim 4, wherein: The plate member has two positioning pins protruding from the surface on the thrust receiving portion side, and the two positioning pins are inserted into positioning holes formed in the thrust receiving portion in a manner that allows them to move in the axial direction, thereby positioning the plate member in the thrust receiving portion in a manner that prevents the plate member from rotating.

6. The scroll compressor according to claim 4 or 5, wherein: The plate member has a plurality of rotation preventing pins protruding from the surface of the swirling scroll side, and the plurality of rotation preventing pins are respectively constructed to pass through the sheet member and extend, and are loosely engaged in corresponding circular holes formed on the back side of the swirling substrate of the swirling scroll to prevent the swirling scroll from rotating.

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