Scroll type compressor

Abstract

To suppress excessive rise of pressure in a back pressure chamber while maintaining strength of a fixed scroll.SOLUTION: The groove part 55 receives elastic deformation of the elastic plate 30 so that the back pressure chamber 45 and the suction passage 35 communicate with each other when a pressure difference between the pressure of the back pressure chamber 45 and the pressure of the suction passage 35 exceeds a predetermined value. Thus, the refrigerant in the back pressure chamber 45 is discharged to the suction passage 35 through the groove 55, so that the pressure in the back pressure chamber 45 is prevented from excessively increasing. The groove 55 is formed in an end surface of the thick portion 50 on the elastic plate 30 side. Thus, the end surface of the thin portion 51 facing the elastic plate 30 does not make it difficult to receive the reactive force from the shaft support housing member 13, which is generated by the fastening force of the bolt B1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] For example, as disclosed in Patent Document 1, a scroll compressor includes a housing, a rotating shaft, a fixed scroll, an orbiting scroll, and an elastic plate. The rotating shaft is rotatably supported in the housing. The fixed scroll includes a fixed base plate, a fixed spiral wall, and a fixed peripheral wall. The fixed spiral wall stands upright from the fixed base plate. The fixed peripheral wall stands upright from the fixed base plate and surrounds the fixed spiral wall. The orbiting scroll includes an orbiting base plate and an orbiting spiral wall. The orbiting base plate faces the fixed base plate. The orbiting spiral wall stands upright from the orbiting base plate toward the fixed base plate and meshes with the fixed spiral wall. A compression chamber that compresses a refrigerant is defined by the fixed base plate, the fixed spiral wall, the orbiting base plate, and the orbiting spiral wall. The orbiting scroll revolves inside the fixed peripheral wall as the rotating shaft rotates. The elastic plate biases the orbiting scroll toward the fixed scroll.

[0003] The housing has a pivotal support housing, a discharge housing, and a suction housing. The pivotal support housing is arranged on the opposite side of the swivel base plate from the fixed base plate. The pivotal support housing supports the rotation shaft. The discharge housing has an end wall and a peripheral wall. The peripheral wall extends cylindrically from the end wall and surrounds the fixed peripheral wall. The discharge housing defines a discharge chamber between the end wall and the fixed base plate. Refrigerant compressed in the compression chamber is discharged into the discharge chamber. The suction housing, together with the pivotal support housing, defines a suction chamber into which refrigerant is drawn from the outside.

[0004] A suction passage is defined between the fixed peripheral wall of the fixed scroll and the peripheral wall of the discharge housing. The suction passage draws refrigerant from the suction chamber into the compression chamber. A back pressure chamber is defined between the orbiting base plate and the support housing. Refrigerant is introduced into the back pressure chamber to urge the orbiting scroll toward the fixed scroll. The outer periphery of the elastic plate is sandwiched between the fixed peripheral wall and the support housing.

[0005] The peripheral wall of the discharge housing has a plurality of bulging portions. The bulging portions are spaced apart from one another in the circumferential direction of the peripheral wall, and the inner peripheral surface of the peripheral wall is convex, causing the bulging portions to bulge toward the fixed peripheral wall. The discharge housing is fastened to the suction housing by fastening members that extend axially through portions of the peripheral wall that correspond to the bulging portions. The fixed scroll is fixed to the housing by being sandwiched between an end wall of the discharge housing and the support housing in the axial direction of the peripheral wall due to the fastening force of the fastening members.

[0006] The fixed peripheral wall has a plurality of thick portions and a plurality of thin portions. The thick portions are spaced apart from one another in the circumferential direction of the fixed peripheral wall. The thin portions are thinner than the thick portions, and allow the bulging portions to be disposed by forming a recessed shape on the outer peripheral surface of the fixed peripheral wall between adjacent thick portions in the circumferential direction of the fixed peripheral wall. This configuration contributes to the miniaturization of the scroll compressor. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2022-149824 Summary of the Invention [Problem to be solved by the invention]

[0008] In such scroll compressors, the refrigerant may be cooled and liquefied when the scroll compressor is stopped. If the liquefied refrigerant is present in the back pressure chamber when the scroll compressor is started, the heat of the refrigerant compressed in the compression chamber may be transferred to the liquid refrigerant in the back pressure chamber via the orbiting base plate. This may result in the liquid refrigerant in the back pressure chamber evaporating, causing the pressure in the back pressure chamber to rise excessively. If the pressure in the back pressure chamber rises too much, the biasing force that urges the orbiting scroll toward the fixed scroll, generated by the pressure in the back pressure chamber, becomes too large. As a result, the orbiting scroll becomes less revolvable, reducing the compression efficiency of the scroll compressor.

[0009] Furthermore, in Patent Document 1, the thin-walled portions are closer to the bulging portions than the thick-walled portions. The fastening members extend axially through the peripheral wall of the discharge housing at locations corresponding to the bulging portions. Therefore, the end faces of the thin-walled portions facing the elastic plate are more likely to be locally subjected to the reaction force from the support housing due to the fastening force of the fastening members than the end faces of the thick-walled portions facing the elastic plate. If grooves are formed in the end faces of the thin-walled portions facing the elastic plate, the end faces of the thin-walled portions facing the elastic plate are less likely to effectively receive the reaction force from the support housing due to the fastening force of the fastening members. This may make it difficult for the fixed peripheral wall to withstand the fastening force of the fastening members between the end wall of the discharge housing and the support housing. This reduction in the strength of the fixed scroll may result in problems such as deformation of the fixed scroll. Therefore, it is desirable to prevent excessive pressure increase in the back pressure chamber while maintaining the strength of the fixed scroll. [Means for solving the problem]

[0010] A scroll compressor that solves the above problem includes a housing, a rotary shaft rotatably supported by the housing, a fixed scroll fixed to the housing, the fixed scroll having a fixed base plate, a fixed spiral wall standing from the fixed base plate, and a fixed peripheral wall standing from the fixed base plate and surrounding the fixed spiral wall, and an orbiting scroll facing the fixed base plate, the orbiting scroll having an orbiting spiral wall standing from the orbiting base plate toward the fixed base plate and engaging with the fixed spiral wall, the orbiting scroll revolving inside the fixed peripheral wall by rotation of the rotary shaft. and an annular elastic plate that biases the orbiting scroll toward the fixed scroll, wherein a compression chamber that compresses a refrigerant is defined by the fixed base plate, the fixed spiral wall, the orbiting base plate, and the orbiting spiral wall, and the housing has a journal housing that is disposed on the opposite side of the orbiting base plate from the fixed base plate and supports the rotary shaft, and a discharge housing that has an end wall and a peripheral wall that extends cylindrically from the end wall and surrounds the fixed peripheral wall, and defines a discharge chamber between the end wall and the fixed base plate from which the refrigerant compressed in the compression chamber is discharged. and a suction housing which, together with the support housing, defines a suction chamber into which refrigerant is drawn from the outside, and between the fixed peripheral wall and the peripheral wall, a suction passage is defined which draws refrigerant from the suction chamber into the compression chamber, and between the orbiting base plate and the support housing, a back pressure chamber is defined into which refrigerant is introduced to urge the orbiting scroll toward the fixed scroll, and the outer periphery of the elastic plate is sandwiched between the fixed peripheral wall and the support housing, and the peripheral walls are arranged at intervals in the circumferential direction of the peripheral wall and are in contact with each other. The inner peripheral surface of the peripheral wall has a convex shape, and has a plurality of bulging portions that bulge toward the fixed peripheral wall, and the discharge housing is fastened to the suction housing by fastening members that extend through portions of the peripheral wall corresponding to the bulging portions in the axial direction of the peripheral wall, and the fixed scroll is fixed to the housing by the fixed peripheral wall being sandwiched between the end wall and the journal housing in the axial direction due to the fastening force of the fastening members, and the fixed peripheral wall has a plurality of thick portions that are spaced apart from each other in the circumferential direction of the fixed peripheral wall,a plurality of thin-walled portions thinner than the thick-walled portions, the outer peripheral surface of which is recessed between the thick-walled portions adjacent in the circumferential direction, allowing the bulging portions to be arranged, and a scroll compressor having such a configuration, wherein the thick-walled portions have grooves formed on their end surfaces on the elastic plate side to accommodate elastic deformation of the elastic plate so that the back pressure chamber and the suction passage communicate with each other when the pressure difference between the back pressure chamber and the suction passage exceeds a predetermined value;

[0011] In a scroll compressor, the refrigerant may cool and liquefy when the scroll compressor is stopped. When the scroll compressor is started with the resulting liquid refrigerant present in the back pressure chamber, heat from the refrigerant compressed in the compression chamber may be transferred to the liquid refrigerant in the back pressure chamber via the rotating base plate. The liquid refrigerant in the back pressure chamber then vaporizes, increasing the pressure in the back pressure chamber. The groove accommodates elastic deformation of the elastic plate to connect the back pressure chamber to the suction passage when the pressure difference between the back pressure chamber and the suction passage exceeds a predetermined value. This allows the refrigerant in the back pressure chamber to be discharged into the suction passage through the groove, preventing excessive pressure increases in the back pressure chamber. The groove is formed on the end surface of the thick-walled portion facing the elastic plate. Therefore, the end surface of the thin-walled portion facing the elastic plate does not impede the reaction force from the support housing due to the fastening force of the fastening member. As a result, it is possible to prevent the pressure in the back pressure chamber from increasing too much while maintaining the strength of the fixed scroll.

[0012] In the scroll compressor, it is preferable that a pin insertion hole is formed in the end surface of any of the plurality of thick-walled portions facing the elastic plate, into which a positioning pin for positioning the elastic plate is inserted, and that the groove portion is formed in the end surface of the thick-walled portion facing the elastic plate in which the pin insertion hole is not formed.

[0013] The end face of the thick portion facing the elastic plate is more suitable as a location for forming the pin insertion hole than the end face of the thin portion, on the end face of the fixed peripheral wall facing the elastic plate. The groove is formed in the end face of the thick portion facing the elastic plate, on which no pin insertion hole is formed, among the multiple thick portions. This makes it easier to form the groove in the end face of the thick portion facing the elastic plate than when the groove is formed in the end face of the thick portion facing the elastic plate, on which the pin insertion hole is formed.

[0014] In the scroll compressor, the grooves may be formed in end surfaces of at least two of the thick portions on the side of the elastic plate. This allows the refrigerant in the back pressure chamber to be discharged more efficiently into the suction passage through the groove portion than when the groove portion is formed only on the end surface of one of the multiple thick-walled portions facing the elastic plate.

[0015] In the above scroll-type compressor, when the fixed scroll is viewed in the axial direction of the fixed peripheral wall, a straight line that passes through the axis of the fixed peripheral wall and passes over two of the plurality of thin-walled portions is defined as a virtual line, and when the fixed peripheral wall is viewed in the axial direction, the plurality of thick-walled portions are arranged on both sides of the virtual line, and the groove portion is preferably formed on an end face of at least one of the plurality of thick-walled portions arranged on one side of the virtual line, which faces the elastic plate, and on an end face of at least one of the plurality of thick-walled portions arranged on the other side of the virtual line, which faces the elastic plate.

[0016] With this, depending on the orbital position of the orbiting scroll, the refrigerant in the back pressure chamber can be efficiently discharged to the suction passage through a groove formed in the end face of at least one of the thick portions located on one side of the imaginary line, facing the elastic plate, or through a groove formed in the end face of at least one of the thick portions located on the other side of the imaginary line, facing the elastic plate, depending on the orbital position of the orbiting scroll.

[0017] In the scroll compressor, the width of the groove in the circumferential direction may be smaller than the width of the thick-walled portion in the circumferential direction. In this way, a configuration in which the circumferential width of the fixed peripheral wall in the groove portion is smaller than the circumferential width of the fixed peripheral wall in the thick-walled portion is a suitable configuration for forming a groove portion on the end surface of the thick-walled portion facing the elastic plate. [Effects of the Invention]

[0018] According to this invention, it is possible to prevent the pressure in the back pressure chamber from increasing too much while maintaining the strength of the fixed scroll. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a cross-sectional view of a scroll compressor according to an embodiment. [Figure 2] FIG. 2 is a front view of the discharge housing and the fixed scroll. [Figure 3] FIG. 3 is a perspective view of the fixed scroll. [Figure 4] FIG. 4 is an enlarged cross-sectional view of a part of the scroll compressor. [Figure 5] FIG. 5 is an enlarged perspective view of the groove portion. [Figure 6] FIG. 6 is an enlarged cross-sectional view of a part of the scroll compressor. [Figure 7] FIG. 7 is a cross-sectional view showing a state in which the elastic plate is elastically deformed. [Figure 8] FIG. 8 is a cross-sectional view showing a state in which the elastic plate is elastically deformed. DETAILED DESCRIPTION OF THE INVENTION

[0020] An embodiment of a scroll compressor will now be described with reference to Figures 1 to 8. The scroll compressor of this embodiment is used in, for example, a vehicle air conditioner. <Basic configuration of a scroll compressor> As shown in FIG. 1 , the scroll compressor 10 includes a cylindrical housing 11. The housing 11 has a suction housing 12, a support housing 13, and a discharge housing 14. The suction housing 12, the support housing 13, and the discharge housing 14 are made of a metal material. The suction housing 12, the support housing 13, and the discharge housing 14 are made of aluminum, for example. The scroll compressor 10 also includes a rotating shaft 15. The rotating shaft 15 is accommodated in the housing 11.

[0021] The suction housing 12 has a plate-shaped end wall 12a and a cylindrical peripheral wall 12b. The peripheral wall 12b extends cylindrically from the outer periphery of the end wall 12a. The axial direction of the peripheral wall 12b coincides with the axial direction of the rotation shaft 15. The suction housing 12 has a plurality of female threaded holes 12c. Six female threaded holes 12c are formed in the suction housing 12. Each female threaded hole 12c is formed at an open end of the peripheral wall 12b. The six female threaded holes 12c are arranged at equal intervals in the circumferential direction of the peripheral wall 12b. Note that for convenience of explanation, only one female threaded hole 12c is shown in FIG. 1. The suction housing 12 also has a suction port 12h. The suction port 12h draws refrigerant from the outside. The suction port 12h is formed in a portion of the peripheral wall 12b that is located on the end wall 12a side. The suction port 12h connects the inside and outside of the suction housing 12.

[0022] The suction housing 12 has a cylindrical boss portion 12d. The boss portion 12d protrudes from the center of the inner surface of the end wall 12a. A first end portion, which is one axial end portion of the rotary shaft 15, is inserted into the boss portion 12d. The scroll compressor 10 is provided with a bearing 16. The bearing 16 is, for example, a rolling bearing. The bearing 16 is provided between the inner circumferential surface of the boss portion 12d and the outer circumferential surface of the first end portion of the rotary shaft 15. The first end portion of the rotary shaft 15 is rotatably supported by the suction housing 12 via the bearing 16.

[0023] The journal housing 13 has a plate-shaped end wall 17 and a cylindrical peripheral wall 18. The peripheral wall 18 extends cylindrically from the outer periphery of the end wall 17. The axial direction of the peripheral wall 18 coincides with the axial direction of the rotary shaft 15. The journal housing 13 also has an annular flange wall 19. The flange wall 19 extends radially outward from the rotary shaft 15 from an end of the outer periphery of the peripheral wall 18 opposite the end wall 17.

[0024] The support housing 13 has a circular insertion hole 17a. The insertion hole 17a is formed in the center of the end wall 17. The insertion hole 17a penetrates the end wall 17 in the thickness direction of the end wall 17. The rotary shaft 15 is inserted through the insertion hole 17a. An end face 15e located on the second end side, which is the other end of the rotary shaft 15 in the axial direction, is located inside the peripheral wall 18.

[0025] The scroll compressor 10 includes a bearing 21. The bearing 21 is, for example, a rolling bearing. The bearing 21 is provided between the inner circumferential surface of the peripheral wall 18 and the outer circumferential surface of the rotating shaft 15. The rotating shaft 15 is rotatably supported by the support housing 13 via the bearing 21. Therefore, the support housing 13 rotatably supports the rotating shaft 15. In this manner, the rotating shaft 15 is rotatably supported by the housing 11.

[0026] The journal housing 13 has a plurality of bolt insertion holes 19a. Six bolt insertion holes 19a are formed in the journal housing 13. Each bolt insertion hole 19a is formed on the outer periphery of the flange wall 19. The six bolt insertion holes 19a are arranged at equal intervals in the circumferential direction of the flange wall 19. Each bolt insertion hole 19a penetrates the flange wall 19 in the thickness direction of the flange wall 19. Each bolt insertion hole 19a in the flange wall 19 communicates with each female threaded hole 12c of the suction housing 12. For ease of explanation, only one bolt insertion hole 19a is shown in FIG. 1.

[0027] The scroll compressor 10 has a suction chamber 20. The suction chamber 20 is defined by the suction housing 12 and the support housing 13. Therefore, the suction housing 12 defines the suction chamber 20 together with the support housing 13. In this manner, the suction chamber 20 is formed within the housing 11. The suction chamber 20 communicates with the suction port 12h. Refrigerant is drawn into the suction chamber 20 from the suction port 12h. Therefore, refrigerant is drawn into the suction chamber 20 from the outside. In this manner, the suction chamber 20 is a suction pressure region.

[0028] The scroll compressor 10 includes a motor 22. The motor 22 is housed in the suction chamber 20. The motor 22 includes a cylindrical stator 23 and a cylindrical rotor 24. The rotor 24 is disposed inside the stator 23. The rotor 24 rotates integrally with the rotary shaft 15. The stator 23 surrounds the rotor 24. The rotor 24 includes a rotor core 24a fixed to the rotary shaft 15 and a plurality of permanent magnets (not shown) provided in the rotor core 24a.

[0029] The stator 23 has a cylindrical stator core 23a and a motor coil 23b. The stator core 23a is fixed to the inner circumferential surface of the peripheral wall 12b of the suction housing 12. The motor coil 23b is wound around the stator core 23a. The rotor 24 rotates when power controlled by an inverter (not shown) is supplied to the motor coil 23b. This causes the rotating shaft 15 to rotate integrally with the rotor 24. Therefore, the motor 22 rotates the rotating shaft 15.

[0030] The scroll compressor 10 includes a compression mechanism C1. The compression mechanism C1 has a fixed scroll 25 and an orbiting scroll 26. Therefore, the scroll compressor 10 includes the fixed scroll 25 and the orbiting scroll 26. The compression mechanism C1 is of a scroll type. The orbiting scroll 26 revolves around the fixed scroll 25 as the rotary shaft 15 rotates.

[0031] As shown in FIGS. 1 and 2, the fixed scroll 25 has a fixed base plate 25a, a fixed spiral wall 25b, and a fixed peripheral wall 25c. The fixed base plate 25a is disk-shaped. A discharge port 25h is formed in the center of the fixed base plate 25a. The discharge port 25h is a circular hole. The discharge port 25h penetrates the fixed base plate 25a in the thickness direction of the fixed base plate 25a. The fixed spiral wall 25b stands upright from the fixed base plate 25a. The fixed peripheral wall 25c stands upright from the outer periphery of the fixed base plate 25a. The fixed peripheral wall 25c surrounds the fixed spiral wall 25b.

[0032] 1, the scroll compressor 10 includes a valve mechanism 25v. The valve mechanism 25v is attached to the end face of the fixed base plate 25a opposite to the fixed spiral wall 25b. The valve mechanism 25v is configured to be able to open and close a discharge port 25h.

[0033] The orbiting scroll 26 has an orbiting base plate 26a and an orbiting spiral wall 26b. The orbiting base plate 26a is disk-shaped. The orbiting base plate 26a faces the fixed base plate 25a. The orbiting spiral wall 26b stands up from the orbiting base plate 26a toward the fixed base plate 25a. The orbiting spiral wall 26b meshes with the fixed spiral wall 25b. The orbiting scroll 26 is located inside the fixed peripheral wall 25c. The orbiting scroll 26 revolves inside the fixed peripheral wall 25c. The tip surface of the fixed spiral wall 25b contacts the orbiting base plate 26a. The tip surface of the orbiting spiral wall 26b contacts the fixed base plate 25a.

[0034] The scroll compressor 10 includes a compression chamber 27. The compression chamber 27 is defined by a fixed base plate 25a, a fixed spiral wall 25b, an orbiting base plate 26a, and an orbiting spiral wall 26b. Therefore, the compression chamber 27 is defined between the fixed scroll 25 and the orbiting scroll 26. The compression chamber 27 takes in and compresses a refrigerant from the outside.

[0035] The swivel base plate 26a has a cylindrical boss portion 26c. The boss portion 26c protrudes from an end face 26e of the swivel base plate 26a opposite the fixed base plate 25a toward the inside of the peripheral wall 18 of the pivot housing 13. The pivot housing 13 is disposed on the opposite side of the swivel base plate 26a from the fixed base plate 25a. The axial direction of the boss portion 26c coincides with the axial direction of the rotating shaft 15. The swivel base plate 26a also has a plurality of grooves 26d. The plurality of grooves 26d are formed around the boss portion 26c on the end face 26e of the swivel base plate 26a. The plurality of grooves 26d are disposed at predetermined intervals around the rotating shaft 15. Note that for ease of explanation, only one groove portion 26d is shown in FIG. 1. An annular ring member 28 is fitted into each groove portion 26d. A pin 29 is inserted into each ring member 28. Each pin 29 is provided to protrude from the end face 13 e of the support housing 13 on the orbiting scroll 26 side.

[0036] The scroll compressor 10 includes an elastic plate 30. The elastic plate 30 is annular. The outer periphery of the elastic plate 30 is sandwiched between the open end face of the fixed peripheral wall 25c and the end face 13e of the support housing 13. The elastic plate 30 constantly biases the orbiting scroll 26 toward the fixed scroll 25.

[0037] The scroll compressor 10 includes an eccentric shaft 31. The eccentric shaft 31 protrudes toward the orbiting scroll 26 from a position on the end face 15e of the rotary shaft 15 that is eccentric with respect to the axis L1 of the rotary shaft 15. The eccentric shaft 31 is formed integrally with the rotary shaft 15. The axial direction of the eccentric shaft 31 coincides with the axial direction of the rotary shaft 15. The eccentric shaft 31 is inserted into the boss portion 26c.

[0038] The scroll compressor 10 includes a balance weight 32 and a bushing 33. The bushing 33 is fitted onto the outer peripheral surface of the eccentric shaft 31. The balance weight 32 is integrated with the bushing 33. The balance weight 32 is formed integrally with the bushing 33. The balance weight 32 is housed within the peripheral wall 18 of the support housing 13. The orbiting scroll 26 is supported by the eccentric shaft 31 via the bushing 33 and a rolling bearing 34 so as to be rotatable relative to the eccentric shaft 31.

[0039] The rotation of the rotating shaft 15 is transmitted to the orbiting scroll 26 via the eccentric shaft 31, the bushing 33, and the rolling bearing 34. This causes the orbiting scroll 26 to rotate on its axis. Contact between each pin 29 and the inner circumferential surface of each ring member 28 prevents the orbiting scroll 26 from rotating on its axis, allowing only the orbiting scroll 26 to revolve. This causes the orbiting scroll 26 to revolve while the orbiting spiral wall 26b is in contact with the fixed spiral wall 25b. As the orbiting scroll 26 revolves, the volume of the compression chamber 27 decreases, compressing the refrigerant in the compression chamber 27. As the rotating shaft 15 rotates, the orbiting scroll 26 revolves inside the fixed circumferential wall 25c. The balance weight 32 offsets the centrifugal force acting on the orbiting scroll 26 as it revolves. This reduces the amount of imbalance in the orbiting scroll 26.

[0040] As shown in Figures 1 and 2, the discharge housing 14 has a plate-shaped end wall 14a and a cylindrical peripheral wall 14b. The peripheral wall 14b extends cylindrically from the outer periphery of the end wall 14a. The axial direction of the peripheral wall 14b coincides with the axial direction of the rotation shaft 15. The peripheral wall 14b surrounds the fixed peripheral wall 25c. Therefore, the peripheral wall 14b surrounds the fixed scroll 25. In this manner, the fixed scroll 25 is accommodated within the housing 11.

[0041] As shown in FIG. 2, the peripheral wall 14b has a plurality of bulging portions 14d. The peripheral wall 14b has six bulging portions 14d. The six bulging portions 14d are arranged at equal intervals in the circumferential direction of the peripheral wall 14b. In this manner, the six bulging portions 14d are arranged at intervals in the circumferential direction of the peripheral wall 14b. Each bulging portion 14d bulges toward the fixed peripheral wall 25c because the inner peripheral surface of the peripheral wall 14b has a convex shape. The outer surface of each bulging portion 14d is a curved surface that is curved in an arc shape that is convex toward the fixed peripheral wall 25c.

[0042] As shown in Figures 1 and 2, the discharge housing 14 has a plurality of bolt insertion holes 14c. Six bolt insertion holes 14c are formed in the discharge housing 14. Each bolt insertion hole 14c is formed to extend axially through a portion of the peripheral wall 14b corresponding to each bulge portion 14d. For convenience of explanation, only one bolt insertion hole 14c is shown in Figure 1. Each bolt insertion hole 14c is connected to a corresponding bolt insertion hole 19a in the flange wall 19.

[0043] As shown in FIG. 1 , bolts B1 serving as fastening members passing through each bolt insertion hole 14c pass through each bolt insertion hole 19a in the flange wall 19 and are threaded into each female threaded hole 12c of the suction housing 12. As a result, the support housing 13 is connected to the peripheral wall 12b of the suction housing 12, and the discharge housing 14 is connected to the peripheral wall 12b of the suction housing 12 via the flange wall 19 of the support housing 13. In this manner, the discharge housing 14 is fastened to the suction housing 12 by the bolts B1 that extend axially through the peripheral wall 14b at locations corresponding to each bulge portion 14d. The suction housing 12, the support housing 13, and the discharge housing 14 are arranged in this order in the axial direction of the rotary shaft 15. The flange wall 19 of the support housing 13 is sandwiched between the peripheral wall 14b of the discharge housing 14 and the peripheral wall 12b of the suction housing 12.

[0044] The fixed peripheral wall 25c of the fixed scroll 25 is sandwiched between the end wall 14a of the discharge housing 14 and the support housing 13 in the axial direction of the peripheral wall 14b by the axial force, which is the fastening force of each bolt B1. In this way, the fixed scroll 25 is fixed to the housing 11 by the fixed peripheral wall 25c being sandwiched between the end wall 14a of the discharge housing 14 and the support housing 13 in the axial direction of the peripheral wall 14b due to the fastening force of the bolt B1.

[0045] The scroll compressor 10 includes a discharge chamber 40. The discharge chamber 40 is defined between the end wall 14a of the discharge housing 14 and the fixed base plate 25a. In this manner, the discharge housing 14 defines the discharge chamber 40 between the end wall 14a and the fixed base plate 25a. Refrigerant compressed in the compression chamber 27 is discharged into the discharge chamber 40 through the discharge port 25h. The area between the end wall 14a of the discharge housing 14 and the fixed base plate 25a, and around the discharge chamber 40, is sealed by a gasket 41.

[0046] The discharge housing 14 has a discharge port 14h. The discharge port 14h is formed in an end wall 14a of the discharge housing 14. The discharge port 14h communicates with the discharge chamber 40. The discharge port 14h discharges the refrigerant in the discharge chamber 40 to the outside.

[0047] <Back pressure chamber> A back pressure chamber 45 is defined between the orbiting base plate 26a of the orbiting scroll 26 and the support housing 13. The back pressure chamber 45 is formed on the opposite side of the orbiting base plate 26a from the fixed base plate 25a side within the housing 11. The support housing 13 separates the back pressure chamber 45 from the suction chamber 20. The inside of the peripheral wall 18 of the support housing 13 is part of the back pressure chamber 45. Furthermore, the gap between the elastic plate 30 and the support housing 13 is part of the back pressure chamber 45.

[0048] The scroll compressor 10 includes an air supply passage 46. The air supply passage 46 is formed in the orbiting scroll 26. A first end of the air supply passage 46 opens to the tip of the orbiting volute wall 26b. The first end of the air supply passage 46 can communicate with the compression chamber 27. A second end of the air supply passage 46 communicates with the back pressure chamber 45. The air supply passage 46 penetrates the inner end of the orbiting volute wall 26b, which converges in a spiral shape toward the center of the orbiting scroll 26, and the orbiting base plate 26a.

[0049] The supply passage 46 supplies a portion of the refrigerant compressed in the compression chamber 27 to the back pressure chamber 45. As a result, the pressure in the back pressure chamber 45 becomes higher than that in the suction chamber 20. As the pressure in the back pressure chamber 45 increases, the orbiting scroll 26 is urged toward the fixed scroll 25 so that the tip of the orbiting spiral wall 26b is pressed against the fixed base plate 25a. In this way, refrigerant for urging the orbiting scroll 26 toward the fixed scroll 25 is introduced into the back pressure chamber 45.

[0050] <Suction passage> The scroll compressor 10 has a suction passage 35. The suction passage 35 has a first groove 36, a first hole 37, and a second groove 38. A plurality of first grooves 36 are formed in the inner circumferential surface of the peripheral wall 12b of the suction housing 12. Six first grooves 36 are formed in the inner circumferential surface of the peripheral wall 12b of the suction housing 12. Each first groove 36 opens to an open end of the peripheral wall 12b. A plurality of first holes 37 are formed in the outer circumferential portion of the flange wall 19 of the support housing 13. Six first holes 37 are formed in the outer circumferential portion of the flange wall 19. Each first hole 37 penetrates the flange wall 19 in the thickness direction of the flange wall 19. Each first hole 37 communicates with a corresponding first groove 36.

[0051] As shown in FIGS. 1 and 2, multiple second grooves 38 are formed on the inner circumferential surface of the peripheral wall 14b of the discharge housing 14. Six second grooves 38 are formed on the inner circumferential surface of the peripheral wall 14b. As shown in FIG. 2, one second groove 38 is formed on the inner circumferential surface of the peripheral wall 14b between adjacent bulging portions 14d in the circumferential direction of the peripheral wall 14b. The second grooves 38 communicate with each other via a gap between the bulging portions 14d and the outer circumferential surface of the fixed peripheral wall 25c. As shown in FIG. 1, each second groove 38 communicates with a corresponding first hole 37. Each second groove 38 forms a part of the suction passage 35. Therefore, the suction passage 35 is defined between the fixed peripheral wall 25c and the peripheral wall 14b of the discharge housing 14.

[0052] <Thick and thin sections> As shown in Figures 2 and 3, the fixed peripheral wall 25c has a plurality of thick portions 50 and a plurality of thin portions 51. The fixed peripheral wall 25c has six thick portions 50. The six thick portions 50 are arranged at equal intervals in the circumferential direction of the fixed peripheral wall 25c. In this manner, the six thick portions 50 are arranged at intervals from one another in the circumferential direction of the fixed peripheral wall 25c. As shown in Figure 2, each thick portion 50 is located inside a corresponding second groove 38. Therefore, the suction passage 35 is located outside each thick portion 50.

[0053] The fixed peripheral wall 25c has six thin-walled portions 51. Each thin-walled portion 51 is formed by the outer peripheral surface of the fixed peripheral wall 25c being concave between adjacent thick-walled portions 50 in the circumferential direction of the fixed peripheral wall 25c. The outer surface of each thin-walled portion 51 is a curved surface that is curved in an arc shape that is concave relative to the peripheral wall 14b of the discharge housing 14. The outer surface of each thin-walled portion 51 extends along the outer surface of each bulge portion 14d. Each thin-walled portion 51 is thinner than the thick-walled portions 50, and allows the bulge portions 14d to be disposed therein by the outer peripheral surface of the fixed peripheral wall 25c being concave between adjacent thick-walled portions 50 in the circumferential direction of the fixed peripheral wall 25c.

[0054] Here, when the fixed scroll 25 is viewed from the axial direction of the fixed peripheral wall 25c, a line that passes through the axis L2 of the fixed peripheral wall 25c and passes over two of the plurality of thin-walled portions 51 is defined as an imaginary line L10. When the fixed peripheral wall 25c is viewed from the axial direction of the fixed peripheral wall 25c, three thick-walled portions 50 are arranged on one side of the imaginary line L10. When the fixed peripheral wall 25c is viewed from the axial direction of the fixed peripheral wall 25c, three thick-walled portions 50 are arranged on the other side of the imaginary line L10. In this way, when the fixed peripheral wall 25c is viewed from the axial direction of the fixed peripheral wall 25c, the plurality of thick-walled portions 50 are arranged on both sides of the imaginary line L10.

[0055] Two suction ports 39 are formed in the fixed peripheral wall 25c. Each suction port 39 is formed in the fixed peripheral wall 25c so as to penetrate in the thickness direction through two thin-walled portions 51, through which the imaginary line L10 passes, when the fixed peripheral wall 25c is viewed in the axial direction of the fixed peripheral wall 25c. Each suction port 39 communicates with a corresponding second groove 38 via a gap between the bulging portion 14d and the outer peripheral surface of the fixed peripheral wall 25c. Therefore, each suction port 39 communicates with the suction passage 35. Each suction port 39 communicates with the outermost peripheral portion of the compression chamber 27. Therefore, the suction passage 35 communicates with the compression chamber 27 via the suction port 39.

[0056] The refrigerant in the suction chamber 20 passes through the first groove 36, the first hole 37, the second groove 38, and the suction port 39 and is drawn into the compression chamber 27. Therefore, the suction passage 35 draws the refrigerant in the suction chamber 20 into the compression chamber 27. The suction passage 35 is a suction pressure region through which the refrigerant drawn into the compression chamber 27 flows. The refrigerant drawn into the compression chamber 27 is compressed in the compression chamber 27 by the orbital motion of the orbiting scroll 26. In this way, the compression mechanism C1 compresses the refrigerant drawn into the housing 11.

[0057] <Pin insertion hole> A pin insertion hole 52 is formed in the end surface of each thick portion 50 facing the elastic plate 30. One pin insertion hole 52 is formed in each end surface of two of the six thick portions 50 facing the elastic plate 30. Therefore, a pin insertion hole 52 is formed in the end surface facing the elastic plate 30 of any of the multiple thick portions 50. Two pin insertion holes 52 are formed in the end surface facing the elastic plate 30 of two of the three thick portions 50 arranged on one side of the imaginary line L10 when the fixed peripheral wall 25c is viewed in the axial direction of the fixed peripheral wall 25c. Each thick portion 50 having a pin insertion hole 52 formed therein is adjacent to each of the two thin portions 51 through which the imaginary line L10 passes when the fixed peripheral wall 25c is viewed in the axial direction of the fixed peripheral wall 25c.

[0058] As shown in Fig. 4, two positioning pins 53 protrude from the end surface 13e of the journal housing 13. Note that, for convenience of illustration, only one positioning pin 53 is shown in Fig. 4. A hole 30a into which the positioning pin 53 is inserted is formed in the elastic plate 30. The positioning pin 53 is inserted into the pin insertion hole 52 through the hole 30a of the elastic plate 30. In this manner, the positioning pin 53 is inserted into the pin insertion hole 52. The positioning pin 53 positions the elastic plate 30 by being inserted into the pin insertion hole 52 through the hole 30a of the elastic plate 30.

[0059] <Groove> 2 and 3, a groove 55 is formed in the end surface of the thick-walled portion 50 facing the elastic plate 30. The groove 55 is formed in the end surface of the thick-walled portion 50 facing the elastic plate 30, of the multiple thick-walled portions 50, in which the pin insertion hole 52 is not formed. The groove 55 is formed in the end surface of two of the multiple thick-walled portions 50 facing the elastic plate 30. Therefore, two grooves 55 are formed in the fixed peripheral wall 25c.

[0060] One of the two grooves 55 is formed in the elastic plate 30-side end face of one of the multiple thick portions 50 located on one side of the imaginary line L10 when the fixed peripheral wall 25c is viewed in the axial direction of the fixed peripheral wall 25c. The other of the two grooves 55 is formed in the elastic plate 30-side end face of one of the multiple thick portions 50 located on the other side of the imaginary line L10 when the fixed peripheral wall 25c is viewed in the axial direction of the fixed peripheral wall 25c. The two grooves 55 are formed in the elastic plate 30-side end faces of the two thick portions 50 located opposite each other in a direction perpendicular to the imaginary line L10 when the fixed peripheral wall 25c is viewed in the axial direction of the fixed peripheral wall 25c. In this way, the grooves 55 are formed in the elastic plate 30-side end face of one of the multiple thick portions 50 located on one side of the imaginary line L10 and in the elastic plate 30-side end face of one of the multiple thick portions 50 located on the other side of the imaginary line L10.

[0061] 5 and 6, the groove 55 opens to the inner circumferential surface of the fixed peripheral wall 25c. The groove 55 opens to the outer circumferential surface of the fixed peripheral wall 25c. The inside of the groove 55 communicates with the suction passage 35. Therefore, the inside of the groove 55 forms a suction pressure region. As shown in FIG. 2, the circumferential width W1 of the fixed peripheral wall 25c at the groove 55 is smaller than the circumferential width W2 of the fixed peripheral wall 25c at the thick-walled portion 50.

[0062] 7 and 8, the portion of the elastic plate 30 that overlaps with the groove 55 elastically deforms toward the groove 55 when the pressure difference between the back pressure chamber 45 and the suction passage 35 exceeds a predetermined value. At this time, the groove 55 accepts the elastic deformation of the elastic plate 30 so that the back pressure chamber 45 and the suction passage 35 communicate with each other when the pressure difference between the back pressure chamber 45 and the suction passage 35 exceeds the predetermined value.

[0063] The portion of the elastic plate 30 that overlaps with the groove 55 is the elastically deforming portion 30b. When the elastically deforming portion 30b elastically deforms toward the groove 55, a communication passage 56 that connects the back pressure chamber 45 and the suction passage 35 is formed between the elastically deforming portion 30b and the journal housing 13. It can be said that the pressure difference between the pressure in the back pressure chamber 45 and the pressure in the suction passage 35 causes the elastically deforming portion 30b to elastically deform, opening and closing the communication passage 56. The elastically deforming portion 30b curves into the groove 55 and protrudes.

[0064] The circumferential width W1 of the fixed peripheral wall 25c at the groove 55 is preset to a width that allows elastic deformation of the portion of the elastic plate 30 that overlaps with the groove 55 toward the groove 55 when the pressure difference between the pressure in the back pressure chamber 45 and the pressure in the suction passage 35 exceeds a predetermined value. The circumferential width W1 of the fixed peripheral wall 25c at the groove 55 is determined in advance by experiment or the like.

[0065] [Operation of the embodiment] Next, the operation of this embodiment will be described. A portion of the refrigerant compressed in the compression chamber 27 is supplied to the back pressure chamber 45 via the supply passage 46. This increases the pressure in the back pressure chamber 45. Then, the orbiting scroll 26 is urged toward the fixed scroll 25, making it less likely that refrigerant will leak from the compression chamber 27. As a result, the compression efficiency of the scroll compressor 10 is improved.

[0066] In such a scroll compressor 10, the refrigerant may be cooled and liquefied when the scroll compressor 10 is stopped. When the scroll compressor 10 is started in a state in which the liquid refrigerant resulting from the liquefaction of the refrigerant is present, for example, in the back pressure chamber 45, the heat of the refrigerant compressed in the compression chamber 27 may be transferred to the liquid refrigerant in the back pressure chamber 45 via the swivel base plate 26a. As a result, the liquid refrigerant in the back pressure chamber 45 vaporizes, and the pressure in the back pressure chamber 45 increases.

[0067] Here, each groove 55 accommodates elastic deformation of the elastic plate 30 so that the back pressure chamber 45 and the suction passage 35 communicate with each other when the pressure difference between the back pressure chamber 45 and the suction passage 35 exceeds a predetermined value. As a result, as shown in FIG. 7 , a communication passage 56 is formed between the elastically deforming portion 30b and the support housing 13, and refrigerant in the back pressure chamber 45 is discharged to the suction passage 35 through the communication passage 56, as indicated by arrow A1 in FIG. 7 . In this way, because the refrigerant in the back pressure chamber 45 is discharged to the suction passage 35 through each groove 55, an excessive increase in pressure in the back pressure chamber 45 is suppressed. As a result, a problem such as difficulty in revolving the orbiting scroll 26 and a decrease in the compression efficiency of the scroll compressor 10 is avoided.

[0068] Each thin portion 51 is closer to each bulging portion 14d than each thick portion 50. Each bolt B1 extends axially through the peripheral wall 14b at a location corresponding to each bulging portion 14d on the peripheral wall 14b of the discharge housing 14. Therefore, the end face of each thin portion 51 facing the elastic plate 30 is more likely to be locally subjected to a reaction force from the support housing 13 associated with the fastening force of each bolt B1 than the end face of each thick portion 50 facing the elastic plate 30.

[0069] Here, each groove 55 is formed on the end surface of the thick-walled portion 50 on the elastic plate 30 side. Therefore, the end surface of the thin-walled portion 51 on the elastic plate 30 side can preferably receive the reaction force from the support housing 13 that accompanies the fastening force of the bolt B1.

[0070] [Effects of the embodiment] The above embodiment can provide the following effects. (1) The groove 55 accommodates the elastic deformation of the elastic plate 30 so that the back pressure chamber 45 and the suction passage 35 communicate with each other when the pressure difference between the back pressure chamber 45 and the suction passage 35 exceeds a predetermined value. This allows the refrigerant in the back pressure chamber 45 to be discharged into the suction passage 35 through the groove 55, preventing the pressure in the back pressure chamber 45 from rising too high. The groove 55 is also formed on the end surface of the thick-walled portion 50 facing the elastic plate 30. Therefore, the end surface of the thin-walled portion 51 facing the elastic plate 30 does not impede the reaction force from the support housing 13 due to the fastening force of the bolt B1. As a result, the strength of the fixed scroll 25 is maintained while preventing the pressure in the back pressure chamber 45 from rising too high.

[0071] (2) The end surface of the thick portion 50 facing the elastic plate 30 is more suitable as a location for forming the pin insertion hole 52 than the end surface of the thin portion 51 facing the elastic plate 30, at the end surface of the fixed peripheral wall 25c facing the elastic plate 30. The groove 55 is formed in the end surface of the thick portion 50 facing the elastic plate 30, at which no pin insertion hole 52 is formed, among the multiple thick portions 50. This makes it easier to form the groove 55 in the end surface of the thick portion 50 facing the elastic plate 30 than when the groove 55 is formed in the end surface of the thick portion 50 facing the elastic plate 30, at which the pin insertion hole 52 is formed.

[0072] (3) The grooves 55 are formed on the end surfaces of two of the thick portions 50 that face the elastic plate 30. This allows the refrigerant in the back pressure chamber 45 to be more efficiently discharged into the suction passage 35 through the grooves 55 than when the grooves 55 are formed on only the end surface of one of the thick portions 50 that faces the elastic plate 30.

[0073] (4) The grooves 55 are formed on an end surface of one of the thick portions 50 located on one side of the imaginary line L10, facing the elastic plate 30, and on an end surface of one of the thick portions 50 located on the other side of the imaginary line L10, facing the elastic plate 30. This allows the refrigerant in the back pressure chamber 45 to be efficiently discharged to the suction passage 35 via the grooves 55 formed on the end surface of one of the thick portions 50 located on one side of the imaginary line L10, facing the elastic plate 30, depending on the orbital position of the orbiting scroll 26. Furthermore, the refrigerant in the back pressure chamber 45 can be efficiently discharged to the suction passage 35 via the grooves 55 formed on the end surface of one of the thick portions 50 located on the other side of the imaginary line L10, facing the elastic plate 30, depending on the orbital position of the orbiting scroll 26.

[0074] (5) A configuration in which the circumferential width W1 of the fixed peripheral wall 25c in the groove portion 55 is smaller than the circumferential width W2 of the fixed peripheral wall 25c in the thick-walled portion 50 is a suitable configuration for forming the groove portion 55 on the end surface of the thick-walled portion 50 facing the elastic plate 30.

[0075] [Example of change] The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0076] In the embodiment, the grooves 55 may be formed on the end surfaces of three or more of the thick-walled portions 50 facing the elastic plate 30. Therefore, three or more grooves 55 may be formed in the fixed peripheral wall 25c. In short, it is sufficient that the grooves 55 are formed on the end surfaces of at least two of the thick-walled portions 50 facing the elastic plate 30.

[0077] In the embodiment, the grooves 55 may be formed in the end surfaces of two or more of the thick portions 50 arranged on one side of the imaginary line L10, the end surfaces facing the elastic plate 30. Alternatively, the grooves 55 may be formed in the end surfaces of two or more of the thick portions 50 arranged on the other side of the imaginary line L10, the end surfaces facing the elastic plate 30. In short, it is sufficient that the grooves 55 are formed in the end surface facing the elastic plate of at least one of the thick portions arranged on one side of the imaginary line L10, the end surface facing the elastic plate of at least one of the thick portions arranged on the other side of the imaginary line L10.

[0078] In the embodiment, the groove portion 55 may be formed only on the end surface of one of the thick-walled portions 50 facing the elastic plate 30. Therefore, only one groove portion 55 may be formed in the fixed peripheral wall 25c.

[0079] In the embodiment, the groove 55 may be formed on the end surface of the thick-walled portion 50 on the elastic plate 30 side, in which the pin insertion hole 52 is formed, among the plurality of thick-walled portions 50 . In the embodiment, the number of thick portions 50 and thin portions 51 is not particularly limited as long as they are two or more.

[0080] In the above-described embodiment, a press-fit pin, for example, may be used as a fastening member instead of the bolt B1. In the embodiment, the bolt insertion holes 19a do not have to be formed on the outer periphery of the flange wall 19 of the support housing 13. Furthermore, the flange wall 19 does not have to be sandwiched between the peripheral wall 14b of the discharge housing 14 and the peripheral wall 12b of the suction housing 12. For example, the flange wall 19 may be press-fitted onto the inner periphery of the peripheral wall 12b of the suction housing 12. Therefore, the support housing 13 does not have to be fastened to the suction housing 12 by the fastening member, that is, the bolt B1.

[0081] In the above-described embodiment, the number of suction ports 39 is not particularly limited. In the above-described embodiment, the scroll compressor 10 does not have to be a type that is driven by the motor 22, but may be a type that is driven by, for example, a vehicle engine.

[0082] In the above embodiment, the scroll compressor 10 is used in a vehicle air conditioner, but the use of the scroll compressor 10 is not limited thereto. In short, the scroll compressor 10 may be used in any application as long as it compresses a refrigerant, and the use of the scroll compressor 10 may be changed as appropriate.

[0083] [Note] The technical ideas that can be understood from the above-described embodiment and modifications will be described below. <Appendix 1> Housing and a rotation shaft rotatably supported by the housing; a fixed scroll having a fixed base plate, a fixed spiral wall standing from the fixed base plate, and a fixed peripheral wall standing from the fixed base plate and surrounding the fixed spiral wall, the fixed scroll being fixed to the housing; an orbiting scroll having an orbiting base plate facing the fixed base plate, and an orbiting spiral wall that stands from the orbiting base plate toward the fixed base plate and engages with the fixed spiral wall, and that revolves inside the fixed peripheral wall by rotation of the rotation shaft; an annular elastic plate that urges the orbiting scroll toward the fixed scroll, a compression chamber for compressing a refrigerant is defined by the fixed base plate, the fixed spiral wall, the rotating base plate, and the rotating spiral wall; The housing includes: a support housing that is disposed on the opposite side of the swivel base plate from the fixed base plate and supports the rotation shaft; a discharge housing having an end wall and a peripheral wall extending cylindrically from the end wall to surround the fixed peripheral wall, the discharge housing defining a discharge chamber between the end wall and the fixed base plate into which the refrigerant compressed in the compression chamber is discharged; a suction housing that defines, together with the support housing, a suction chamber into which a refrigerant is drawn from the outside, a suction passage for drawing refrigerant from the suction chamber into the compression chamber is defined between the fixed peripheral wall and the peripheral wall; a back pressure chamber into which a refrigerant is introduced for urging the orbiting scroll toward the fixed scroll is defined between the orbiting base plate and the journal housing; The outer periphery of the elastic plate is sandwiched between the fixed peripheral wall and the journal housing, The peripheral wall has a plurality of bulging portions that are arranged at intervals in the circumferential direction of the peripheral wall and bulge toward the fixed peripheral wall by forming an inner peripheral surface of the peripheral wall into a convex shape, the discharge housing is fastened to the suction housing by fastening members that extend through the peripheral wall in the axial direction at locations corresponding to the bulging portions, the fixed scroll is fixed to the housing by the fixed peripheral wall being sandwiched between the end wall and the journal housing in the axial direction due to the fastening force of the fastening member, The fixed peripheral wall is a plurality of thick-walled portions arranged at intervals in the circumferential direction of the fixed peripheral wall; a plurality of thin-walled portions each having a thickness thinner than the thick-walled portions, wherein the outer peripheral surface of the fixed peripheral wall has a concave shape between the thick-walled portions adjacent to each other in the circumferential direction, thereby enabling the bulging portions to be arranged; a groove formed on an end surface of the thick-walled portion facing the elastic plate, the groove accepting elastic deformation of the elastic plate so that the back pressure chamber and the suction passage communicate with each other when a pressure difference between the back pressure chamber and the suction passage exceeds a predetermined value.

[0084] <Appendix 2> a pin insertion hole into which a positioning pin for positioning the elastic plate is inserted is formed in an end surface of any of the plurality of thick-walled portions facing the elastic plate, The scroll compressor according to <Appendix 1>, characterized in that the groove portion is formed on an end surface of the thick-walled portion, among the plurality of thick-walled portions, in which the pin insertion hole is not formed, that faces the elastic plate.

[0085] <Appendix 3> The scroll compressor according to <Appendix 1> or <Appendix 2>, characterized in that the groove portion is formed on an end surface of at least two of the plurality of thick-walled portions that faces the elastic plate.

[0086] <Appendix 4> When the fixed scroll is viewed from the axial direction of the fixed peripheral wall, a line passing through the axis of the fixed peripheral wall and passing through two of the plurality of thin-walled portions is defined as a virtual line. When the fixed peripheral wall is viewed from the axial direction, the plurality of thick-walled portions are arranged on both sides of the imaginary straight line, The scroll compressor described in <Appendix 3>, characterized in that the groove portion is formed on an end surface of at least one of a plurality of thick portions arranged on one side of the imaginary line that faces the elastic plate, and on an end surface of at least one of a plurality of thick portions arranged on the other side of the imaginary line that faces the elastic plate.

[0087] <Appendix 5> The scroll compressor according to any one of <Appendix 1> to <Appendix 4>, wherein the circumferential width of the groove portion is smaller than the circumferential width of the thick portion. [Explanation of symbols]

[0088] 10...Scroll compressor, 11...Housing, 12...Suction housing, 13...Support housing, 14...Discharge housing, 14a...End wall, 14b...Circumferential wall, 14d...Bulge portion, 15...Rotating shaft, 20...Suction chamber, 25...Fixed scroll, 25a...Fixed base plate, 25b...Fixed spiral wall, 25c...Fixed peripheral wall, 26...Orbiting scroll, 26a...Orbiting base plate, 26b...Orbiting spiral wall, 27...Compression chamber, 30...Elastic plate, 35...Suction passage, 40...Discharge chamber, 45...Back pressure chamber, 50...Thick-walled portion, 51...Thin-walled portion, 52...Pin insertion hole, 53...Positioning pin, 55...Groove portion, B1...Bolt as fastening member.

Claims

1. Housing and a rotation shaft rotatably supported by the housing; a fixed scroll having a fixed base plate, a fixed spiral wall standing from the fixed base plate, and a fixed peripheral wall standing from the fixed base plate and surrounding the fixed spiral wall, the fixed scroll being fixed to the housing; an orbiting scroll having an orbiting base plate facing the fixed base plate, and an orbiting spiral wall that stands from the orbiting base plate toward the fixed base plate and engages with the fixed spiral wall, and that revolves inside the fixed peripheral wall by rotation of the rotation shaft; an annular elastic plate that urges the orbiting scroll toward the fixed scroll, a compression chamber for compressing a refrigerant is defined by the fixed base plate, the fixed spiral wall, the rotating base plate, and the rotating spiral wall; The housing includes: a support housing that is disposed on the opposite side of the swivel base plate from the fixed base plate and supports the rotation shaft; a discharge housing having an end wall and a peripheral wall extending cylindrically from the end wall to surround the fixed peripheral wall, the discharge housing defining a discharge chamber between the end wall and the fixed base plate into which the refrigerant compressed in the compression chamber is discharged; a suction housing that defines, together with the support housing, a suction chamber into which a refrigerant is drawn from the outside, a suction passage for drawing refrigerant from the suction chamber into the compression chamber is defined between the fixed peripheral wall and the peripheral wall; a back pressure chamber into which a refrigerant is introduced for urging the orbiting scroll toward the fixed scroll is defined between the orbiting base plate and the journal housing; The outer periphery of the elastic plate is sandwiched between the fixed peripheral wall and the journal housing, The peripheral wall has a plurality of bulging portions that are arranged at intervals in the circumferential direction of the peripheral wall and bulge toward the fixed peripheral wall by forming an inner peripheral surface of the peripheral wall into a convex shape, the discharge housing is fastened to the suction housing by fastening members that extend through the peripheral wall in the axial direction at locations corresponding to the bulging portions, the fixed scroll is fixed to the housing by the fixed peripheral wall being sandwiched between the end wall and the journal housing in the axial direction due to the fastening force of the fastening member, The fixed peripheral wall is a plurality of thick-walled portions arranged at intervals in the circumferential direction of the fixed peripheral wall; a plurality of thin-walled portions each having a thickness thinner than the thick-walled portions, wherein the outer peripheral surface of the fixed peripheral wall has a concave shape between the thick-walled portions adjacent to each other in the circumferential direction, thereby enabling the bulging portions to be arranged; a groove formed on an end surface of the thick-walled portion facing the elastic plate, the groove accepting elastic deformation of the elastic plate so that the back pressure chamber and the suction passage communicate with each other when a pressure difference between the back pressure chamber and the suction passage exceeds a predetermined value.

2. a pin insertion hole into which a positioning pin for positioning the elastic plate is inserted is formed in an end surface of any of the plurality of thick-walled portions facing the elastic plate, 2. The scroll compressor according to claim 1, wherein the groove is formed in an end surface of a thick-walled portion, among the plurality of thick-walled portions, in which the pin insertion hole is not formed, that faces the elastic plate.

3. 3. The scroll compressor according to claim 1, wherein the grooves are formed in end surfaces of at least two of the thick-walled portions that are closer to the elastic plate.

4. When the fixed scroll is viewed from the axial direction of the fixed peripheral wall, a line passing through the axis of the fixed peripheral wall and passing over two of the plurality of thin-walled portions is defined as a virtual line. When the fixed peripheral wall is viewed from the axial direction, the plurality of thick-walled portions are arranged on both sides of the imaginary straight line, 4. The scroll compressor according to claim 3, wherein the grooves are formed in an end face of at least one of the plurality of thick-walled portions arranged on one side of the imaginary line, the end face being closer to the elastic plate, and in an end face of at least one of the plurality of thick-walled portions arranged on the other side of the imaginary line, the end face being closer to the elastic plate.

5. 3. The scroll compressor according to claim 1, wherein the width of the groove in the circumferential direction is smaller than the width of the thick-walled portion in the circumferential direction.

Images