Scroll type electric compressor

Abstract

To reduce the size of a scroll type electric compressor in an axial direction of a rotating shaft while regulating the movement of a seal member toward a bearing.SOLUTION: A pivot housing 13 is provided with a bearing 21 rotatably supporting a rotating shaft 15, and an annular seal member 40 having an internal peripheral seal part 41 for sealing between the rotating shaft 15 and itself and an external peripheral seal part 42 for sealing between the pivot housing 13 and itself, the annular seal member sealing between a backpressure chamber and a motor chamber S1. An end part 41a of the internal peripheral seal part 41 extends closer to the bearing 21 than an end part 42a of the external peripheral seal part 42. The pivot housing 13 has a locking part 45 that lies opposite the end part 42a of the external peripheral seal part 42 and limits the movement of the seal member 40 to the bearing 21 side by abutting on the end part 42a of the external peripheral seal part 42. The end part 41a of the internal peripheral seal part 41 extends closer to the bearing 21 than the locking part 45.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] The scroll-type electric compressor includes a housing, a rotating shaft rotatably supported relative to the housing, an electric motor for rotating the rotating shaft, and a compression unit. The compression unit includes a fixed scroll fixed to the housing and an orbiting scroll that revolves with rotation of the rotating shaft while meshing with the fixed scroll. The housing includes a partition wall that separates the housing into a back pressure chamber that applies back pressure to urge the orbiting scroll toward the fixed scroll and a motor chamber that houses the electric motor. The partition wall has an insertion hole through which the rotating shaft passes. The partition wall also includes a bearing that rotatably supports the rotating shaft and an annular seal member that seals between the back pressure chamber and the motor chamber. The seal member has an inner seal portion that seals against the rotating shaft and an outer seal portion that seals against the partition wall. For example, in the scroll-type electric compressor described in Patent Document 1, movement of the seal member is restricted by a circlip. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-128756 Summary of the Invention [Problem to be solved by the invention]

[0004] In a scroll-type electric compressor, it has been desired to further reduce the size in the axial direction of the rotary shaft while suppressing movement of the seal member. [Means for solving the problem]

[0005] A scroll-type electric compressor for solving the above-mentioned problems includes a housing, a rotating shaft rotatably supported by the housing, an electric motor for rotating the rotating shaft, a compression unit including a fixed scroll fixed to the housing, and an orbiting scroll that meshes with the fixed scroll and revolves by rotation of the rotating shaft, the housing is provided with a partition wall that partitions a back pressure chamber that applies back pressure to urge the orbiting scroll toward the fixed scroll, and a motor chamber that accommodates the electric motor, and the partition wall is provided with a bearing that rotatably supports the rotating shaft, and a bearing that supports the rotating shaft. a partition wall provided with an engaging portion that faces the end of the outer circumferential seal portion and abuts against the end of the outer circumferential seal portion to limit movement of the seal member toward the bearing, and the end of the inner circumferential seal portion extends closer to the bearing than the end of the outer circumferential seal portion, and the partition wall is provided with an engaging portion that faces the end of the outer circumferential seal portion and abuts against the end of the outer circumferential seal portion to limit movement of the seal member toward the bearing, and the end of the inner circumferential seal portion extends closer to the bearing than the engaging portion.

[0006] According to the above configuration, since the partition wall is provided with an engaging portion, the end of the outer circumferential seal portion abuts against the engaging portion, thereby restricting movement of the seal member toward the bearing. Since the end of the inner circumferential seal portion extends closer to the bearing than the engaging portion, the dimension of the outer circumferential seal portion in the axial direction of the rotating shaft is smaller than the dimension of the inner circumferential seal portion in the axial direction of the rotating shaft. The dimension of the seal member in the axial direction of the rotating shaft can be reduced compared to when the dimension of the outer circumferential seal portion in the axial direction of the rotating shaft is larger than the dimension of the inner circumferential seal portion in the axial direction of the rotating shaft. Therefore, the scroll-type electric compressor can be made smaller in size in the axial direction of the rotating shaft while restricting movement of the seal member toward the bearing.

[0007] In the scroll-type electric compressor, the dimension between the engaging portion and the end of the outer peripheral seal portion in the axial direction of the rotating shaft may be smaller than the dimension between the bearing and the end of the inner peripheral seal portion in the axial direction.

[0008] According to the above configuration, even if the seal member moves toward the bearing, the end of the outer seal portion abuts the locking portion before the end of the inner seal portion abuts against the bearing. Therefore, it is possible to prevent the end of the inner seal portion from abutting against the bearing, and therefore it is possible to prevent a decrease in the sealing ability of the inner seal portion against the rotating shaft.

[0009] In the scroll-type electric compressor, the outer diameter of the portion of the rotating shaft that is supported by the bearing may be the same as the outer diameter of the portion that is in contact with the inner periphery seal portion. The outer peripheral surface of the rotating shaft is polished using, for example, a polishing roller. If the rotating shaft has a large-diameter portion with a larger outer diameter and a small-diameter portion with a smaller outer diameter than the large-diameter portion, a recess must be formed at the boundary between the small-diameter portion and the large-diameter portion to prevent the polishing roller from contacting the large-diameter portion during polishing. According to the above configuration, the outer diameter of the portion of the rotating shaft supported by the bearing is the same as the outer diameter of the portion of the rotating shaft contacting the inner periphery seal portion. Therefore, it is not necessary to form the recess at the boundary between the portion of the rotating shaft supported by the bearing and the portion of the rotating shaft contacting the inner periphery seal portion. As a result, the dimension of the rotating shaft between the portion of the rotating shaft supported by the bearing and the portion of the rotating shaft contacting the inner periphery seal portion can be shortened by the amount corresponding to the elimination of the recess. This allows the scroll-type electric compressor to be further miniaturized in the axial direction of the rotating shaft.

[0010] In the scroll-type electric compressor, the rotating shaft may be provided with a balance weight for offsetting the centrifugal force acting on the orbiting scroll due to rotation of the rotating shaft, and the balance weight may be disposed between the partition wall and the electric motor in the axial direction of the rotating shaft.

[0011] According to the above configuration, the end of the inner circumferential seal extends closer to the bearing than the locking portion, thereby reducing the size of the scroll-type electric compressor in the axial direction of the rotating shaft, and therefore the balance weight can be brought closer to the bearing in the axial direction of the rotating shaft. The shorter the distance between the orbiting scroll and the balance weight in the axial direction of the rotating shaft, the lighter the balance weight required to offset the centrifugal force acting on the orbiting scroll due to rotation of the rotating shaft. Therefore, the lighter weight of the balance weight contributes to reducing the weight of the scroll-type electric compressor.

[0012] In the scroll-type electric compressor, the rotating shaft may be provided with a balance weight for offsetting the centrifugal force acting on the orbiting scroll due to rotation of the rotating shaft, and the balance weight may be disposed between the partition wall and the electric motor in the axial direction of the rotating shaft.

[0013] According to the above configuration, the dimension of the rotating shaft between the portion supported by the bearing and the portion in contact with the inner circumferential seal is shortened in the axial direction of the rotating shaft, allowing the balance weight to be closer to the bearing in the axial direction of the rotating shaft. The shorter distance between the orbiting scroll and the balance weight in the axial direction of the rotating shaft reduces the weight of the balance weight required to offset the centrifugal force acting on the orbiting scroll due to rotation of the rotating shaft. Therefore, the weight reduction of the balance weight allows for a reduction in the weight of the scroll-type electric compressor. [Effects of the Invention]

[0014] According to this invention, the scroll-type electric compressor can be made smaller in size in the axial direction of the rotary shaft while restricting movement of the seal member toward the bearing. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a cross-sectional view showing a scroll-type electric compressor according to an embodiment. [Figure 2] FIG. 2 is an enlarged cross-sectional view of a portion of the scroll-type electric compressor. [Figure 3] FIG. 2 is an enlarged cross-sectional view showing the periphery of a bearing and a seal member. DETAILED DESCRIPTION OF THE INVENTION

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a scroll type electric compressor will now be described with reference to the drawings. The scroll type electric compressor of this embodiment is used in, for example, a vehicle air conditioner. <Basic configuration of a scroll-type electric compressor> As shown in Fig. 1, the scroll-type electric compressor 10 has a cylindrical housing 11. The housing 11 has a motor housing 12, a support housing 13, and a discharge housing 14. The motor housing 12, the support housing 13, and the discharge housing 14 are made of a metal material. The motor housing 12, the support housing 13, and the discharge housing 14 are made of aluminum, for example.

[0017] The scroll-type electric compressor 10 has a rotary shaft 15 rotatably supported relative to a housing 11. Hereinafter, the direction in which an axis line L1 of the rotary shaft 15 extends will also be referred to as an axial direction X of the rotary shaft 15.

[0018] The motor 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 X of the rotary shaft 15. An intake port 12h is formed in the peripheral wall 12b. The intake port 12h is formed in a portion of the peripheral wall 12b that is located closer to the end wall 12a. The intake port 12h communicates between the inside and outside of the motor housing 12. The intake port 12h draws in refrigerant gas as a fluid.

[0019] The motor housing 12 has a cylindrical boss portion 12d. The boss portion 12d protrudes from the inner surface of the end wall 12a. A first end portion of the rotary shaft 15, which is the end portion in the axial direction X, is inserted into the boss portion 12d. A rolling bearing 16 is provided between the inner peripheral surface of the boss portion 12d and the outer peripheral surface 15a at the first end portion of the rotary shaft 15. The first end portion of the rotary shaft 15 is rotatably supported by the motor housing 12 via the rolling bearing 16.

[0020] The journal housing 13 has a disk-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 X of the rotary shaft 15. The journal housing 13 has an annular flange wall 19. The flange wall 19 extends radially outward from the end of the outer periphery of the peripheral wall 18 opposite the end wall 17. The outer periphery of the flange wall 19 contacts the open end of the peripheral wall 12b of the motor housing 12.

[0021] The peripheral wall 18 is formed with a peripheral wall recess 18a and a first accommodating recess 18b. The end wall 17 is formed with an insertion hole 17a. That is, the journal housing 13 is formed with the insertion hole 17a. Furthermore, the end wall 17 is formed with a second accommodating recess 17b. The axial directions of the peripheral wall recess 18a, the first accommodating recess 18b, the insertion hole 17a, and the second accommodating recess 17b coincide with the axial direction X of the rotating shaft 15.

[0022] The peripheral wall recess 18a opens to an end face 13e of the journal housing 13 opposite to the motor housing 12. The first accommodating recess 18b is adjacent to and communicates with the peripheral wall recess 18a in the axial direction X of the rotating shaft 15. The second accommodating recess 17b is adjacent to and communicates with the first accommodating recess 18b in the axial direction X of the rotating shaft 15. The insertion hole 17a is adjacent to and communicates with the second accommodating recess 17b in the axial direction X of the rotating shaft 15.

[0023] As shown in FIG. 2, the first accommodating recess 18b is defined by a first side surface 18c and a first end surface 18d of the peripheral wall 18. The first end surface 18d extends perpendicular to the axial direction X of the rotating shaft 15. The first side surface 18c extends from the outer edge of the first end surface 18d in the radial direction of the rotating shaft 15. The second accommodating recess 17b is defined by a second side surface 17c and a second end surface 17d of the end wall 17. The second end surface 17d extends perpendicular to the axial direction X of the rotating shaft 15. The second side surface 17c extends from the outer edge of the second end surface 17d in the radial direction of the rotating shaft 15.

[0024] 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. The rotating shaft 15 is inserted into the insertion hole 17a. An end face 15e located on the second end side, which is the end opposite to the first end of the rotating shaft 15, is located inside the peripheral wall 18. The second end of the rotating shaft 15 inserted into the insertion hole 17a passes through the insertion hole 17a and the second accommodating recess 17b, and is located within the first accommodating recess 18b.

[0025] As shown in Figure 1, a motor chamber S1 is formed within the housing 11. The motor chamber S1 is defined by a motor housing 12 and a journal housing 13. The motor chamber S1 communicates with an intake port 12h. Refrigerant gas is drawn into the motor chamber S1 through the intake port 12h.

[0026] The scroll-type electric compressor 10 has an electric motor 22 that rotates the rotary shaft 15. The electric motor 22 is housed in a motor chamber S1. The electric motor 22 has 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 has a rotor core 24a fixed to the rotary shaft 15 and a plurality of permanent magnets (not shown) provided on the rotor core 24a. The stator 23 has a cylindrical stator core 23a and a coil 23b. The stator core 23a is fixed to the inner circumferential surface of the peripheral wall 12b of the motor housing 12. The 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 coil 23b. As a result, the rotary shaft 15 rotates integrally with the rotor 24 .

[0027] 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 X of the rotation shaft 15. The open end of the peripheral wall 14b contacts the outer periphery of the flange wall 19.

[0028] The discharge housing 14, the support housing 13, and the motor housing 12 are fixed together by bolts B1. The bolts B1 pass through the peripheral wall 14b of the discharge housing 14 and the outer periphery of the flange wall 19, and are screwed into the peripheral wall 12b of the motor housing 12. This connects the support housing 13 to the peripheral wall 12b of the motor housing 12, and connects the discharge housing 14 to the flange wall 19 of the support housing 13. Therefore, the motor housing 12, the support housing 13, and the discharge housing 14 are arranged side by side in this order in the axial direction X of the rotating shaft 15.

[0029] The scroll-type electric compressor 10 has a discharge chamber S2. The discharge chamber S2 is formed in a discharge housing 14. 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 S2. The discharge port 14h discharges the refrigerant gas in the discharge chamber S2.

[0030] The discharge port 14h and the suction port 12h are connected by an external refrigerant circuit 20. The external refrigerant circuit 20 has a condenser, an expansion valve, and an evaporator, all of which are not shown. The refrigerant gas discharged from the discharge port 14h flows through the external refrigerant circuit 20. The refrigerant gas flowing through the external refrigerant circuit 20 passes through the condenser, the expansion valve, and the evaporator, and then returns to the motor chamber S1 via the suction port 12h. The scroll-type electric compressor 10 and the external refrigerant circuit 20 constitute a vehicle air conditioning system.

[0031] The scroll-type electric compressor 10 has a compression section 30. The compression section 30 includes a fixed scroll 25 and an orbiting scroll 26. The fixed scroll 25 and the orbiting scroll 26 are disposed inside the peripheral wall 14b of the discharge housing 14. The fixed scroll 25 is positioned closer to the end wall 14a than the orbiting scroll 26 in the axial direction X of the rotation shaft 15.

[0032] The fixed scroll 25 is fixed to the housing 11. More specifically, the fixed scroll 25 is fixed to the end wall 14a of the discharge housing 14. The fixed scroll 25 has a fixed base plate 25a and a fixed spiral wall 25b. The fixed base plate 25a is disk-shaped. The fixed spiral wall 25b stands up from the fixed base plate 25a toward the opposite side to the end wall 14a. The fixed scroll 25 has a fixed outer peripheral wall 25c. The fixed outer peripheral wall 25c stands up in a cylindrical shape from the outer periphery of the fixed base plate 25a. The fixed outer peripheral wall 25c surrounds the fixed spiral wall 25b. The open end face of the fixed outer peripheral wall 25c is located on the opposite side to the fixed base plate 25a than the tip end face of the fixed spiral wall 25b.

[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 upright from the orbiting base plate 26a toward the fixed base plate 25a. The orbiting spiral wall 26b meshes with the fixed spiral wall 25b. As a result, the orbiting scroll 26 revolves with the rotation of the rotary shaft 15 while meshing with the fixed scroll 25. The orbiting spiral wall 26b is located inside the fixed outer 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. A plurality of compression chambers 27 are defined by the fixed base plate 25a, the fixed spiral wall 25b, the orbiting base plate 26a, and the orbiting spiral wall 26b. Therefore, a plurality of compression chambers 27 are defined by the fixed scroll 25 and the orbiting scroll 26. Each compression chamber 27 compresses refrigerant gas.

[0034] The orbiting scroll 26 has a cylindrical boss portion 26c. The boss portion 26c protrudes from an end face 26e of the orbiting base plate 26a opposite the fixed base plate 25a. The axial direction of the boss portion 26c coincides with the axial direction X of the rotary shaft 15. A plurality of boss recesses 26d are formed around the boss portion 26c on the end face 26e of the orbiting base plate 26a. The plurality of boss recesses 26d are arranged at predetermined intervals in the circumferential direction of the rotary shaft 15. For convenience of explanation, only one boss recess 26d is shown in FIG. 1. An annular ring member 28 is fitted into each boss recess 26d. The scroll-type electric compressor 10 has a plurality of pins 29. Each pin 29 is provided in the support housing 13. Each pin 29 protrudes from the end face 13e of the support housing 13. Each pin 29 is inserted into each ring member 28.

[0035] 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. A first end of the discharge port 25h is connected to the compression chamber 27. A second end of the discharge port 25h is connected to the discharge chamber S2. The discharge port 25h discharges the refrigerant gas compressed in the compression chamber 27 to the discharge chamber S2. A valve mechanism 50 is attached to the surface of the fixed base plate 25a opposite to the fixed spiral wall 25b. The valve mechanism 50 is configured to be able to open and close the discharge port 25h.

[0036] The scroll-type electric compressor 10 includes an eccentric shaft 31. The eccentric shaft 31 protrudes toward the orbiting scroll 26 from a portion of 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 X of the rotary shaft 15. The eccentric shaft 31 is inserted into the boss portion 26c.

[0037] The rotating shaft 15 is provided with a balance weight 32. The balance weight 32 is formed integrally with the rotating shaft 15. The balance weight 32 is disposed on the rotating shaft 15 at a position eccentric from the axis L1 of the rotating shaft 15. More specifically, the balance weight 32 is disposed on the opposite side of the axis L1 of the rotating shaft 15 from the eccentric shaft 31. The balance weight 32 is formed in a substantially fan-shaped plate shape. The balance weight 32 extends from the rotating shaft 15 radially outward of the rotating shaft 15. In other words, the balance weight 32 extends from the rotating shaft 15 toward the peripheral wall 12b of the motor housing 12.

[0038] The balance weight 32 is composed of a base end 32a, an inclined portion 32b, and a tip end 32c. The base end 32a is connected to the rotary shaft 15 and extends from the rotary shaft 15 so as to be approximately perpendicular to the rotary shaft 15. The inclined portion 32b is connected to the base end 32a. The inclined portion 32b extends at an incline so as to approach the journal housing 13 the further away from the base end 32a in the radial direction of the rotary shaft 15. The tip end 32c is connected to the inclined portion 32b and extends from the inclined portion 32b so as to be approximately perpendicular to the rotary shaft 15.

[0039] The balance weight 32 is located in the motor chamber S1 because the rotating shaft 15 is provided in the housing 11. The balance weight 32 is disposed between the shaft support housing 13, which serves as a partition wall, and the electric motor 22 in the axial direction X of the rotating shaft 15.

[0040] The orbiting scroll 26 is supported on the eccentric shaft 31 via a bushing 33 and a rolling bearing 34 so as to be rotatable relative to the eccentric shaft 31. The rotation of the rotary shaft 15 is transmitted to the orbiting scroll 26 via the eccentric shaft 31, the bushing 33, and the rolling bearing 34, causing the orbiting scroll 26 to rotate on its axis. Contact between the pins 29 and the inner circumferential surfaces of the ring members 28 prevents the orbiting scroll 26 from rotating on its axis, allowing only the orbiting scroll 26 to revolve. As a result, the orbiting scroll 26 revolves while the orbiting spiral wall 26b is in contact with the fixed spiral wall 25b, reducing the volume of the compression chamber 27 and compressing the refrigerant gas. Therefore, the orbiting scroll 26 revolves in conjunction with the rotation of the rotary shaft 15. The balance weight 32 is intended to offset the centrifugal force acting on the orbiting scroll 26 due to the rotation of the rotary shaft 15. More specifically, the balance weight 32 offsets the centrifugal force acting on the orbiting scroll 26 when the orbiting scroll 26 revolves, thereby reducing the amount of imbalance of the orbiting scroll 26 .

[0041] The scroll-type electric compressor 10 has first grooves 35, first holes 36, and second grooves 37. A plurality of first grooves 35 are formed on the inner circumferential surface of the peripheral wall 12b of the motor housing 12. Each first groove 35 opens to an open end of the peripheral wall 12b. A plurality of first holes 36 are formed on the outer circumferential portion of the flange wall 19 of the journal housing 13. Each first hole 36 penetrates the flange wall 19 in the thickness direction. Each first hole 36 is connected to a respective first groove 35. A plurality of second grooves 37 are formed on the inner circumferential surface of the peripheral wall 14b of the discharge housing 14. Each second groove 37 is connected to a respective first hole 36. Note that for convenience of illustration, FIG. 1 shows one each of the first groove 35, the first hole 36, and the second groove 37.

[0042] The fixed scroll 25 has a plurality of suction ports 38. For convenience of illustration, only one suction port 38 is shown in FIG. 1 . Each suction port 38 is formed in the fixed outer peripheral wall 25c of the fixed scroll 25. Each suction port 38 penetrates the fixed outer peripheral wall 25c in the thickness direction. Each suction port 38 communicates with one of the second grooves 37. For example, two suction ports 38 are formed in the fixed outer peripheral wall 25c so as to be positioned 180 degrees apart in the circumferential direction of the fixed outer peripheral wall 25c.

[0043] The scroll-type electric compressor 10 includes a suction chamber 39. The suction chamber 39 is connected to each of the two suction ports 38. The suction chamber 39 is formed inside the fixed outer peripheral wall 25c. The suction chamber 39 is a space inside the fixed outer peripheral wall 25c that is connected to at least one of the two suction ports 38 as the orbiting scroll 26 revolves. Depending on the position of the orbiting scroll 26, the suction chamber 39 may be connected to one of the two suction ports 38 but not to the other of the two suction ports 38. Furthermore, depending on the position of the orbiting scroll 26, the suction chamber 39 may be connected to both of the two suction ports 38.

[0044] The refrigerant gas in the motor chamber S1 passes through the first grooves 35, the first holes 36, the second grooves 37, and the suction ports 38, and is drawn into the suction chamber 39. The refrigerant gas drawn into the suction chamber 39 is compressed in the compression chamber 27 by the orbital motion of the orbiting scroll 26.

[0045] A back pressure chamber S3 is formed within the housing 11. The back pressure chamber S3 is located inside the peripheral wall 18 of the journal housing 13. Therefore, the back pressure chamber S3 is formed at a position within the housing 11 on the opposite side of the fixed base plate 25a with respect to the swivel base plate 26a. The journal housing 13 functions as a partition wall that separates the back pressure chamber S3 from the motor chamber S1.

[0046] A back pressure introduction passage 26f is formed in the orbiting scroll 26. The back pressure introduction passage 26f penetrates the orbiting base plate 26a and the orbiting spiral wall 26b. The back pressure introduction passage 26f introduces a portion of the refrigerant gas in the compression chamber 27 into the back pressure chamber S3. Because a portion of the refrigerant gas in the compression chamber 27 is introduced through the back pressure introduction passage 26f, the back pressure chamber S3 has a higher pressure than the motor chamber S1. The back pressure chamber S3 applies back pressure to urge the orbiting scroll 26 toward the fixed scroll 25. Specifically, as the pressure in the back pressure chamber S3 increases, the orbiting scroll 26 is urged toward the fixed scroll 25 so that the tip end surface of the orbiting spiral wall 26b is pressed against the fixed base plate 25a.

[0047] <Bearings> As shown in Fig. 2, the bearing 21 that rotatably supports the rotating shaft 15 is provided in the support housing 13 serving as a partition wall. The bearing 21 in this embodiment is a rolling bearing. The bearing 21 is located in the first accommodating recess 18b of the peripheral wall 18. The bearing 21 is provided between a first side surface 18c of the peripheral wall 18 and the outer peripheral surface 15a of the rotating shaft 15. The bearing 21 is fixed to the first side surface 18c and a first end face 18d of the peripheral wall 18.

[0048] The bearing 21 supports a portion of the rotating shaft 15 in the axial direction X. The portion of the rotating shaft 15 that is supported by the bearing 21 is also referred to as a first shaft portion 15b. The rotating shaft 15 is rotatably supported by the support housing 13 via the bearing 21. Therefore, the rotating shaft 15 is rotatably supported with respect to the housing 11.

[0049] <Sealing material> An annular seal member 40 is provided on the support housing 13 serving as a partition wall. The seal member 40 is made of resin. The seal member 40 is located within the second accommodating recess 17b of the end wall 17. The seal member 40 is provided between the second side surface 17c of the end wall 17 and the outer peripheral surface 15a of the rotating shaft 15. The seal member 40 is provided closer to the motor chamber S1 than the bearing 21 in the axial direction X of the rotating shaft 15.

[0050] The seal member 40 contacts the second side surface 17c of the end wall 17. The seal member 40 contacts a portion of the rotating shaft 15 in the axial direction X. The portion of the rotating shaft 15 that contacts the seal member 40 is also referred to as the second shaft portion 15c. The outer diameter L2 of the first shaft portion 15b and the outer diameter L3 of the second shaft portion 15c are the same size. The outer diameter of the rotating shaft 15 is the same between the first shaft portion 15b and the second shaft portion 15c in the axial direction X of the rotating shaft 15.

[0051] The seal member 40 seals the back pressure chamber S3 and the motor chamber S1 by contacting the support housing 13 and the rotating shaft 15. Therefore, the seal member 40 suppresses the flow of refrigerant gas between the back pressure chamber S3 and the motor chamber S1 via the second accommodating recess 17b and the insertion hole 17a.

[0052] When the scroll-type electric compressor 10 is in a steady state in which the pressure in the back pressure chamber S3 exceeds the pressure in the motor chamber S1, the pressure difference between the motor chamber S1 and the back pressure chamber S3 presses the seal member 40 against the second end face 17d of the second accommodating recess 17b.

[0053] As shown in Fig. 3, the seal member 40 has an inner circumferential seal portion 41 and an outer circumferential seal portion 42. Furthermore, the seal member 40 has an annular connecting portion 43. The connecting portion 43 extends in the radial direction of the rotating shaft 15. The connecting portion 43 connects the inner circumferential seal portion 41 and the outer circumferential seal portion 42. The inner circumferential seal portion 41, the outer circumferential seal portion 42, and the connecting portion 43 are integrally formed with one another.

[0054] The inner circumferential seal portion 41 is annular and extends from the inner circumferential edge of the connecting portion 43 toward the bearing 21, and approaches the outer circumferential surface 15a of the rotating shaft 15 as it moves away from the connecting portion 43.

[0055] The inner circumferential seal portion 41 has an end portion 41a facing the bearing 21. The end portion 41a of the inner circumferential seal portion 41 is located on the opposite side of the inner circumferential seal portion 41 from the connection portion with the connecting portion 43. The portion of the end portion 41a of the inner circumferential seal portion 41 that is closer to the inner circumferential surface of the inner circumferential seal portion 41 functions as a contact portion 41b that contacts the outer circumferential surface 15a of the rotating shaft 15. By bringing the contact portion 41b into close contact with the outer circumferential surface 15a of the rotating shaft 15, the seal member 40 seals between itself and the rotating shaft 15. The portion of the rotating shaft 15 that is in contact with the contact portion 41b corresponds to the second shaft portion 15c, which is the portion of the rotating shaft 15 that is in contact with the seal member 40.

[0056] The outer circumferential seal portion 42 is annular. The outer circumferential seal portion 42 is disposed radially outward of the rotating shaft 15 relative to the inner circumferential seal portion 41. The outer circumferential seal portion 42 extends from the outer circumferential edge of the connecting portion 43 toward the bearing 21. The outer circumferential seal portion 42 has an end portion 42a facing the bearing 21 side. The end portion 42a of the outer circumferential seal portion 42 is located on the opposite side of the outer circumferential seal portion 42 from the connection portion with the connecting portion 43.

[0057] The outer peripheral surface of the outer peripheral seal portion 42 is in close contact with the second side surface 17c of the end wall 17. The seal member 40 is fitted into the second accommodating recess 17b with the outer peripheral surface of the outer peripheral seal portion 42 in close contact with the second side surface 17c of the end wall 17. By bringing the outer peripheral surface of the outer peripheral seal portion 42 into close contact with the second side surface 17c of the end wall 17, the outer peripheral seal portion 42 seals against the journal housing 13, which serves as a partition wall.

[0058] When the seal member 40 is fitted into the second accommodating recess 17b, the end 41a of the inner circumferential seal portion 41 and the end 42a of the outer circumferential seal portion 42 face the bearing 21 in the axial direction X of the rotating shaft 15. A dimension L4 between the bearing 21 and the end 41a of the inner circumferential seal portion 41 in the axial direction X of the rotating shaft 15 is shorter than a dimension L5 between the bearing 21 and the end 42a of the outer circumferential seal portion 42 in the axial direction X of the rotating shaft 15. Therefore, the end 41a of the inner circumferential seal portion 41 extends closer to the bearing 21 than the end 42a of the outer circumferential seal portion 42.

[0059] <Latching part> The support housing 13 has a protrusion 46 that protrudes from the second side surface 17c of the end wall 17 toward the rotating shaft 15. The protrusion 46 is annular. The protrusion 46 is located closer to the bearing 21 than the outer periphery seal portion 42 in the axial direction X of the rotating shaft 15. The protrusion 46 has a locking portion 45 that faces the end 42a of the outer periphery seal portion 42. In other words, the support housing 13, which serves as a partition wall, is provided with the locking portion 45. The locking portion 45 is integrally formed with the support housing 13. The locking portion 45 is an end face of the protrusion 46 in the axial direction X of the rotating shaft 15 and is a flat annular surface. The locking portion 45 faces the end 42a of the outer periphery seal portion 42. The locking portion 45 abuts against the end 42a of the outer periphery seal portion 42, thereby limiting movement of the seal member 40 toward the bearing 21.

[0060] <Sealing position and dimensions> Dimension L7 between the locking portion 45 and the end 42a of the outer circumferential seal portion 42 in the axial direction X of the rotating shaft 15 is smaller than dimension L4 between the bearing 21 and the end 41a of the inner circumferential seal portion 41 in the axial direction X of the rotating shaft 15. Dimension L4 between the bearing 21 and the end 41a of the inner circumferential seal portion 41 in the axial direction X of the rotating shaft 15 is shorter than dimension L6 between the bearing 21 and the locking portion 45 in the axial direction X of the rotating shaft 15. Therefore, the end 41a of the inner circumferential seal portion 41 extends closer to the bearing 21 than the locking portion 45. The dimension of the outer circumferential seal portion 42 in the axial direction X of the rotating shaft 15 is smaller than the dimension of the inner circumferential seal portion 41 in the axial direction X of the rotating shaft 15.

[0061] If the dimension of the inner circumferential seal portion 41 in the axial direction X of the rotating shaft 15 is too large, there is a risk that the inner circumferential seal portion 41 will come into excessive contact with the rotating shaft 15. If the dimension of the inner circumferential seal portion 41 in the axial direction X of the rotating shaft 15 is too small, there is a risk that the seal member 40 will fall out of the second accommodating recess 17b. Therefore, in this embodiment, the dimension of the inner circumferential seal portion 41 in the axial direction X of the rotating shaft 15 is set to a size that can prevent the inner circumferential seal portion 41 from coming into excessive contact with the rotating shaft 15 and the seal member 40 from falling out of the second accommodating recess 17b.

[0062] The larger of the dimension of the inner circumferential seal portion 41 in the axial direction X of the rotating shaft 15 and the dimension of the outer circumferential seal portion 42 in the axial direction X of the rotating shaft 15 is the dimension of the seal member 40 in the axial direction X of the rotating shaft 15. In this embodiment, the dimension of the outer circumferential seal portion 42 in the axial direction X of the rotating shaft 15 is smaller than the dimension of the inner circumferential seal portion 41 in the axial direction X of the rotating shaft 15, and therefore the dimension of the inner circumferential seal portion 41 in the axial direction X of the rotating shaft 15 is the dimension of the seal member 40 in the axial direction X of the rotating shaft 15.

[0063] [Operation of the embodiment] Next, the operation of this embodiment will be described. In the scroll-type electric compressor 10, for example, when refrigerant gas is to be filled into the scroll-type electric compressor 10, a vacuum pumping operation is performed to remove air from the interior of the scroll-type electric compressor 10 before the refrigerant gas is filled. After the vacuum pumping operation is performed, the refrigerant gas is gradually filled starting from the motor chamber S1. When an unsteady state occurs in which the pressure in the motor chamber S1 exceeds the pressure in the back pressure chamber S3, the pressure difference between the motor chamber S1 and the back pressure chamber S3 may cause the seal member 40 to move toward the bearing 21, as shown by the two-dot chain line in FIG. 3. At this time, the end 42a of the outer circumferential seal portion 42 abuts against the engaging portion 45, thereby restricting the movement of the seal member 40 toward the bearing 21.

[0064] [Effects of the embodiment] The above embodiment can provide the following effects. (1) The bearing support housing 13, which serves as a partition wall, is provided with a locking portion 45 that faces the end 42a of the outer circumferential seal portion 42 and abuts against the end 42a of the outer circumferential seal portion 42 to limit movement of the seal member 40 toward the bearing 21. Therefore, when the end 42a of the outer circumferential seal portion 42 abuts against the locking portion 45, movement of the seal member 40 toward the bearing 21 is restricted. The end 41a of the inner circumferential seal portion 41 extends closer to the bearing 21 than the locking portion 45. Therefore, the dimension of the outer circumferential seal portion 42 in the axial direction X of the rotating shaft 15 is smaller than the dimension of the inner circumferential seal portion 41 in the axial direction X of the rotating shaft 15. Compared to when the dimension of the outer circumferential seal portion 42 in the axial direction X of the rotating shaft 15 is larger than the dimension of the inner circumferential seal portion 41 in the axial direction X of the rotating shaft 15, the dimension of the seal member 40 in the axial direction X of the rotating shaft 15 can be made smaller. Therefore, the movement of the seal member 40 toward the bearing 21 can be restricted, and the scroll-type electric compressor 10 can be made smaller in size in the axial direction X of the rotary shaft 15.

[0065] (2) The dimension L7 between the locking portion 45 and the end 42a of the outer circumferential seal portion 42 in the axial direction X of the rotating shaft 15 is smaller than the dimension L4 between the bearing 21 and the end 41a of the inner circumferential seal portion 41 in the axial direction X of the rotating shaft 15. Therefore, even if the seal member 40 moves toward the bearing 21, the end 42a of the outer circumferential seal portion 42 abuts against the locking portion 45 before the end 41a of the inner circumferential seal portion 41 abuts against the bearing 21. Therefore, since it is possible to prevent the end 41a of the inner circumferential seal portion 41 from abutting against the bearing 21, it is possible to prevent a decrease in the sealing ability of the inner circumferential seal portion 41 with respect to the rotating shaft 15.

[0066] (3) The outer diameter L2 of the first shaft portion 15b of the rotating shaft 15, which is the portion supported by the bearing 21, and the outer diameter L3 of the second shaft portion 15c, which is the portion in contact with the inner circumferential seal portion 41, are the same size. Therefore, it is not necessary to form a recess at the boundary between the first shaft portion 15b and the second shaft portion 15c of the rotating shaft 15 to allow the grinding roller to escape when grinding the rotating shaft 15. As a result, the dimension of the rotating shaft 15 between the first shaft portion 15b and the second shaft portion 15c in the axial direction X of the rotating shaft 15 can be shortened by the amount of the recess not formed. Therefore, the scroll-type electric compressor 10 can be further downsized in the axial direction X of the rotating shaft 15.

[0067] (4) The rotating shaft 15 is provided with a balance weight 32 for offsetting the centrifugal force acting on the orbiting scroll 26 due to rotation of the rotating shaft 15. The balance weight 32 is disposed between the support housing 13, which serves as a partition wall, and the electric motor 22 in the axial direction X of the rotating shaft 15. The scroll-type electric compressor 10 is reduced in size in the axial direction X of the rotating shaft 15 because the end 41a of the inner circumferential seal portion 41 extends closer to the bearing 21 than the locking portion 45. This allows the balance weight 32 to be positioned closer to the bearing 21 in the axial direction X of the rotating shaft 15. The shorter distance between the orbiting scroll 26 and the balance weight 32 in the axial direction X of the rotating shaft 15 reduces the weight of the balance weight 32 required to offset the centrifugal force acting on the orbiting scroll 26 due to rotation of the rotating shaft 15. Therefore, the reduction in the weight of the balance weight 32 contributes to the reduction in weight of the scroll-type electric compressor 10.

[0068] (5) The rotating shaft 15 includes a balance weight 32 for offsetting the centrifugal force acting on the orbiting scroll 26 due to rotation of the rotating shaft 15. The balance weight 32 is disposed between the support housing 13, which serves as a partition wall, and the electric motor 22 in the axial direction X of the rotating shaft 15. In the axial direction X of the rotating shaft 15, the dimension of the rotating shaft 15 between the first shaft portion 15b, which is the portion supported by the bearing 21, and the second shaft portion 15c, which is the portion contacting the inner periphery seal portion 41, is shortened. This allows the balance weight 32 to be positioned closer to the bearing 21 in the axial direction X of the rotating shaft 15. The shortened distance between the orbiting scroll 26 and the balance weight 32 in the axial direction X of the rotating shaft 15 reduces the weight of the balance weight 32 required to offset the centrifugal force acting on the orbiting scroll 26 due to rotation of the rotating shaft 15. Therefore, the weight reduction of the balance weight 32 allows the weight of the scroll-type electric compressor 10 to be reduced.

[0069] [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.

[0070] The position of the balance weight 32 is not limited to between the support housing 13 and the electric motor 22 in the axial direction X of the rotary shaft 15. For example, the balance weight 32 may be disposed in the back pressure chamber S3.

[0071] The balance weight 32 may be omitted from the rotating shaft 15. The outer diameter L2 of the first shaft portion 15b may be larger or smaller than the outer diameter L3 of the second shaft portion 15c. In this case, a recess may be formed at the boundary between the first shaft portion 15b and the second shaft portion 15c in the rotating shaft 15 to allow the grinding roller to escape when grinding the rotating shaft 15.

[0072] The dimension L7 between the locking portion 45 and the end 42a of the outer circumferential seal portion 42 in the axial direction X of the rotating shaft 15 may be equal to or greater than the dimension L4 between the bearing 21 and the end 41a of the inner circumferential seal portion 41 in the axial direction X of the rotating shaft 15.

[0073] The locking portion 45 may be separate from the journal housing 13. For example, a circlip may be disposed on the journal housing 13 as a partition wall, and the locking portion 45 may be provided on this circlip, making the locking portion 45 separate from the journal housing 13. In this case, for example, an annular groove is formed on the second side surface 17c of the end wall 17, and the circlip is attached to this groove. The locking portion 45 of the circlip is an end surface of the circlip in the axial direction X of the rotary shaft 15, and is an annular flat surface. In this case as well, the locking portion 45 faces the end portion 42a of the outer circumferential seal portion 42.

[0074] The bearing 21 does not have to be a rolling bearing. For example, the bearing 21 may be a sliding bearing. In the above embodiment, the scroll type electric compressor 10 is used in a vehicle air conditioner, but the present invention is not limited to this. For example, the scroll type electric compressor 10 may be installed in a fuel cell vehicle and compress air as a fluid to be supplied to the fuel cell. [Explanation of symbols]

[0075] L2, L3...outer diameter, L4, L5, L6, L7...dimension, S1...motor chamber, S3...back pressure chamber, X...axial direction, 10...scroll type electric compressor, 11...housing, 13...shaft support housing, 15...rotating shaft, 15b...first shaft portion, 15c...second shaft portion, 17a...insertion hole, 21...bearing, 22...electric motor, 25...fixed scroll, 26...orbiting scroll, 30...compression portion, 32...balance weight, 40...sealing member, 41...inner circumferential seal portion, 41a...end portion (of inner circumferential seal portion), 42...outer circumferential seal portion, 42a...end portion (of outer circumferential seal portion), 45...engaging portion.

Claims

1. Housing and a rotation shaft rotatably supported relative to the housing; an electric motor that rotates the rotary shaft; a compression unit including a fixed scroll fixed to the housing and an orbiting scroll that revolves by rotation of the rotation shaft while meshing with the fixed scroll, the housing includes a partition wall that partitions a back pressure chamber that applies back pressure to urge the orbiting scroll toward the fixed scroll and a motor chamber that accommodates the electric motor, the partition wall having an insertion hole through which the rotating shaft is inserted; a bearing that rotatably supports the rotating shaft, and an annular seal member that has an inner circumferential seal portion that seals between the rotating shaft and the partition wall and an outer circumferential seal portion that seals between the partition wall and the back pressure chamber, wherein the partition wall is provided with: the inner circumferential seal portion and the outer circumferential seal portion each have an end portion facing the bearing, and the end portion of the inner circumferential seal portion extends closer to the bearing than the end portion of the outer circumferential seal portion; the partition wall is provided with a locking portion that faces an end of the outer circumferential seal portion and abuts against the end of the outer circumferential seal portion to limit movement of the seal member toward the bearing, an end of the inner circumferential seal portion extends closer to the bearing than the locking portion; a dimension between the locking portion and an end of the outer circumferential seal portion in an axial direction of the rotating shaft is smaller than a dimension between an inner ring of the bearing and an end of the inner circumferential seal portion in the axial direction, In a steady state in which the pressure in the back pressure chamber exceeds the pressure in the motor chamber, an end of the outer circumferential seal portion is separated from the engaging portion, a motor chamber that is provided with a back pressure ...

2. 2. The scroll-type electric compressor according to claim 1, wherein an outer diameter of the portion of the rotary shaft supported by the bearing is the same as an outer diameter of a portion of the rotary shaft that comes into contact with the inner periphery seal portion.

3. The rotating shaft includes a balance weight for offsetting a centrifugal force acting on the orbiting scroll due to rotation of the rotating shaft, 2. The electric scroll compressor according to claim 1, wherein the balance weight is disposed between the partition wall and the electric motor in the axial direction of the rotary shaft.

4. The rotating shaft includes a balance weight for offsetting a centrifugal force acting on the orbiting scroll due to rotation of the rotating shaft, 3. The electric scroll compressor according to claim 2, wherein the balance weight is disposed between the partition wall and the electric motor in the axial direction of the rotary shaft.

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