Scroll compressor

Abstract

To suppress vibration of a rotational shaft.SOLUTION: When viewed in an axial direction of a rotational shaft 15, a portion of a shaft balancer 60 located on the same side, with respect to a second straight line L12, as a center of gravity W1 of a bush balancer 50 has lower rigidity than a portion of the shaft balancer 60 located on the opposite side of the center of gravity W1 of the bush balancer 50. When a centrifugal force Fc acts on the shaft balancer 60, when viewed from the axial direction of the rotational shaft 15, the shaft balancer 60 deforms from the portion located on the same side, with respect to the second straight line L12, as the center of gravity W1 of the bush balancer 50 toward the portion located on the opposite side of the center of gravity W1 of the bush balancer 50. Therefore, when viewed from the axial direction of the rotational shaft 15, the position of the center of gravity W2 of the shaft balancer 60 moves away from the center of gravity W1 of the bush balancer 50.SELECTED DRAWING: Figure 4

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 rotating shaft, an eccentric shaft, a fixed scroll, an orbiting scroll, and a bushing. The eccentric shaft protrudes from the tip of the rotating shaft. The eccentric shaft extends parallel to the rotating shaft at a position eccentric to the axis of the rotating shaft. The fixed scroll has a fixed base plate and a fixed spiral wall. The fixed spiral wall stands upright from the fixed base plate. The orbiting scroll has 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. The orbiting spiral wall meshes with the fixed spiral wall.

[0003] The bushing has a cylindrical portion that is inserted into the orbiting base plate so as to be rotatable relative to the base plate. An insertion hole is formed in the cylindrical portion. An eccentric shaft is inserted into the insertion hole. The axis of the eccentric shaft is disposed at a position offset from a first line that is a line passing through the axis of the cylindrical portion and the axis of the rotating shaft when viewed from the axial direction of the rotating shaft. The bushing is configured to be swingable about the eccentric shaft. In such a scroll compressor, the orbital radius of the orbiting scroll is varied by swinging the bushing about the eccentric shaft. The variable orbital radius of the orbiting scroll allows the orbiting scroll wall to be appropriately pressed against the fixed scroll wall.

[0004] In a scroll compressor, as the rotating shaft rotates and the orbiting scroll revolves, centrifugal force acts on the orbiting scroll, generating a moment around the eccentric shaft. This may cause the orbiting scroll wall to be excessively pressed against the fixed scroll wall. For this reason, scroll compressors have been known that use a bush balancer that protrudes radially outward from the cylindrical portion of the bushing, and a shaft balancer that protrudes radially outward from the rotating shaft and rotates integrally with the rotating shaft to offset the centrifugal force and moment. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-160313 Summary of the Invention [Problem to be solved by the invention]

[0006] In such scroll compressors, the rotation speed of the rotating shaft varies between low and high rotation speeds. When the rotation speed varies, the centrifugal force acting on the bush balancer changes the swing amount of the bush balancer. For example, if the design is such that the moment generated by the orbiting scroll is balanced when the rotating shaft rotates at a medium rotation speed, the centrifugal force acting on the bush balancer increases when the rotating shaft rotates at a high rotation speed, increasing the swing amount of the bush balancer. Therefore, the position of the center of gravity of the bush balancer shifts in the swing direction of the bush balancer, causing an imbalance with the moment generated by the orbiting scroll on the rotating shaft, which may make the rotating shaft more susceptible to vibration. [Means for solving the problem]

[0007] A scroll compressor that solves the above-mentioned problems includes a rotating shaft, an eccentric shaft that protrudes from a tip of the rotating shaft and extends parallel to the rotating shaft at a position eccentric with respect to the axis of the rotating shaft, a fixed scroll having a fixed base plate and a fixed spiral wall standing from the fixed base plate, an orbiting base plate that faces the fixed base plate, and an orbiting scroll having an orbiting spiral wall that rises from the orbiting base plate toward the fixed base plate and meshes with the fixed spiral wall, and a bushing that has an insertion hole into which the eccentric shaft is inserted and is swingable around the eccentric shaft, the bushing having a cylindrical portion that has the insertion hole formed therein and is inserted into the orbiting base plate so as to be rotatable relative to the orbiting base plate, and a bushing balancer that protrudes from the cylindrical portion radially outward, the center of gravity of the bushing balancer being located forward of a first line that is a line passing through an axis of the cylindrical portion and an axis of the rotating shaft when viewed in the axial direction of the rotating shaft. a shaft balancer located on the same side as the axis of the eccentric shaft, protruding radially outward from the rotating shaft and rotating integrally with the rotating shaft, wherein the center of gravity of the shaft balancer is located on the opposite side of the eccentric shaft across a line that passes through the axis of the rotating shaft and is perpendicular to the first line, as viewed in the axial direction of the rotating shaft, and a moment around the eccentric shaft that is generated by a centrifugal force acting on the bush balancer is directed away from the center of gravity of the shaft balancer, as viewed in the axial direction of the rotating shaft, and wherein a portion of the shaft balancer that is located on the same side as the center of gravity of the bush balancer has lower rigidity than a portion of the shaft balancer that is located on the opposite side of the center of gravity of the bush balancer, as viewed in the axial direction of the rotating shaft.

[0008] For example, when the rotating shaft rotates at a high rotation speed, the centrifugal force acting on the bush balancer increases, causing the bush balancer to swing more. The bush balancer swings in the direction of the moment around the eccentric shaft. Here, the direction of the moment around the eccentric shaft generated by the centrifugal force acting on the bush balancer is a direction away from the center of gravity of the shaft balancer when viewed from the axial direction of the rotating shaft. Therefore, when the rotating shaft rotates at a high rotation speed, the position of the center of gravity of the bush balancer shifts away from the center of gravity of the shaft balancer when viewed from the axial direction of the rotating shaft. In this case, the portion of the shaft balancer located on the same side of the second line as the center of gravity of the bush balancer when viewed from the axial direction of the rotating shaft has lower rigidity than the portion of the shaft balancer located on the opposite side of the center of gravity of the bush balancer. Therefore, when centrifugal force acts on the shaft balancer, the shaft balancer deforms from a portion located on the same side of the bush balancer's center of gravity as the second line to a portion located on the opposite side of the bush balancer's center of gravity as viewed from the axial direction of the rotating shaft. Therefore, the position of the shaft balancer's center of gravity moves away from the bush balancer's center of gravity as viewed from the axial direction of the rotating shaft. Therefore, the position of the shaft balancer's center of gravity moves in the opposite direction to the direction in which the bush balancer's center of gravity shifts. As a result, it is possible to prevent the moment due to the orbiting scroll from becoming unbalanced. Therefore, it is possible to suppress vibration of the rotating shaft.

[0009] In the scroll compressor, a notch may be formed in a side edge of a portion of the shaft balancer that is located on the same side as the center of gravity of the bush balancer with respect to the second straight line when viewed from the axial direction of the rotating shaft.

[0010] This allows the rigidity of the portion of the shaft balancer located on the same side of the second line as the center of gravity of the bush balancer, when viewed from the axial direction of the rotating shaft, to be lower than the rigidity of the portion of the shaft balancer located on the opposite side of the center of gravity of the bush balancer.

[0011] In the scroll compressor, a thin-walled portion may be provided in a portion of the shaft balancer that is located on the same side as the center of gravity of the bush balancer with respect to the second line when viewed in the axial direction of the rotating shaft.

[0012] This allows the rigidity of the portion of the shaft balancer located on the same side of the second line as the center of gravity of the bush balancer, when viewed from the axial direction of the rotating shaft, to be lower than the rigidity of the portion of the shaft balancer located on the opposite side of the center of gravity of the bush balancer.

[0013] In the scroll compressor, it is preferable that a through hole penetrating in the axial direction be formed in a portion of the shaft balancer that is located on the same side of the second line as the center of gravity of the bush balancer when viewed from the axial direction of the rotating shaft.

[0014] This allows the rigidity of the portion of the shaft balancer located on the same side of the second line as the center of gravity of the bush balancer, when viewed from the axial direction of the rotating shaft, to be lower than the rigidity of the portion of the shaft balancer located on the opposite side of the center of gravity of the bush balancer. [Effects of the Invention]

[0015] According to this invention, vibration of the rotating shaft can be suppressed. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a cross-sectional view of a scroll compressor according to a first embodiment. [Figure 2] FIG. 2 is a perspective view showing a part of the scroll compressor. [Figure 3] FIG. 3 is a perspective view showing a part of the scroll compressor. [Figure 4] FIG. 4 is a front view showing a part of the scroll compressor. [Figure 5] FIG. 5 is a front view showing a part of the scroll compressor according to the second embodiment. [Figure 6] FIG. 6 is a front view showing a part of a scroll compressor according to a modified example. [Figure 7] FIG. 7 is a perspective view showing a part of a scroll compressor according to a modified example. [Figure 8] FIG. 8 is a front view showing a part of a scroll compressor according to a modified example. [Figure 9] FIG. 9 is a front view showing a part of a scroll compressor according to a modified example. [Figure 10] FIG. 10 is a front view showing a part of a scroll compressor according to a modified example. [Figure 11] FIG. 11 is a front view showing a part of a scroll compressor according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0017] [First embodiment] A scroll compressor according to a first embodiment will be described below with reference to Figures 1 to 4. The scroll compressor according to the embodiment described below is used in, for example, a vehicle air conditioner.

[0018] <Outline of scroll compressor> As shown in FIG. 1 , the scroll compressor 10 includes 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. The scroll compressor 10 also includes a rotating shaft 15. The rotating shaft 15 is accommodated in the housing 11.

[0019] 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 of the rotary shaft 15. The motor housing 12 has a plurality of female threaded holes 12c. Each female threaded hole 12c is formed at an open end of the peripheral wall 12b. Note that for convenience of explanation, only one female threaded hole 12c is shown in FIG. 1 . The motor housing 12 also has an intake port 12h. The intake port 12h draws in a refrigerant fluid. The intake port 12h is formed in a portion of the peripheral wall 12b that is located on the end wall 12a side. The intake port 12h connects the inside and outside of the motor housing 12.

[0020] The motor housing 12 has a cylindrical bearing holder 12d. The bearing holder 12d protrudes from the center of the inner surface of the end wall 12a. A first end, which is one axial end of the rotating shaft 15, is inserted into the bearing holder 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 bearing holder 12d and the outer circumferential surface of the first end of the rotating shaft 15. The first end of the rotating shaft 15 is rotatably supported by the motor housing 12 via the bearing 16.

[0021] 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 the end of the outer periphery of the peripheral wall 18 opposite the end wall 17.

[0022] 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. The rotary shaft 15 is inserted through the insertion hole 17a.

[0023] A tip end surface 15e located on the second end side, which is the other end in the axial direction of the rotating shaft 15, is located inside the peripheral wall 18. A press-fit hole 15h is formed in the tip end surface 15e of the rotating shaft 15. The press-fit hole 15h is a circular hole. The press-fit hole 15h is formed in the tip end surface 15e so that the axis of the press-fit hole 15h extends parallel to the axis L1 of the rotating shaft 15 at a position eccentric to the axis L1 of the rotating shaft 15.

[0024] 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 with respect to the housing 11.

[0025] The support housing 13 has a plurality of bolt insertion holes 19a. Each bolt insertion hole 19a is formed on the outer periphery of the flange wall 19. Each bolt insertion hole 19a penetrates the flange wall 19 in the thickness direction. Each bolt insertion hole 19a in the flange wall 19 communicates with each of the female threaded holes 12c in the motor housing 12. For ease of explanation, only one bolt insertion hole 19a is shown in FIG. 1.

[0026] The scroll compressor 10 has a motor chamber 20. The motor chamber 20 is defined by a motor housing 12 and a support housing 13. The motor housing 12 defines the motor chamber 20 together with the support housing 13. In this manner, the motor chamber 20 is formed within the housing 11. The motor chamber 20 communicates with an intake port 12h. Refrigerant is drawn into the motor chamber 20 from the intake port 12h.

[0027] The scroll compressor 10 includes a motor 22. The motor 22 is housed in the motor 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.

[0028] 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 motor housing 12. The motor coil 23b is wound around the stator core 23a. Electric power controlled by an inverter (not shown) is supplied to the motor coil 23b, causing the rotor 24 to rotate. This causes the rotating shaft 15 to rotate integrally with the rotor 24. Therefore, the motor 22 rotates the rotating shaft 15.

[0029] 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.

[0030] The fixed scroll 25 has a fixed base plate 25a and a fixed spiral wall 25b. 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. The fixed spiral wall 25b stands upright from the fixed base plate 25a. The fixed scroll 25 also has an outer circumferential wall 25c. The outer circumferential wall 25c stands upright from the outer periphery of the fixed base plate 25a. The outer circumferential wall 25c surrounds the fixed spiral wall 25b.

[0031] The scroll compressor 10 includes a valve mechanism 25v. The valve mechanism 25v is attached to the surface 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.

[0032] 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 outer peripheral wall 25c. The orbiting scroll 26 revolves inside the 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.

[0033] 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.

[0034] The scroll compressor 10 includes a boss portion 28. The boss portion 28 is cylindrical. The boss portion 28 protrudes in a cylindrical shape from the center of an end face 26e of the rotating base plate 26a, which is located on the opposite side from the fixed base plate 25a. The axial direction of the boss portion 28 coincides with the axial direction of the rotating shaft 15.

[0035] The orbiting base plate 26a has a plurality of grooves 26d. The grooves 26d are formed around the boss portions 28 on the end face 26e of the orbiting base plate 26a. The grooves 26d are arranged at predetermined intervals in the circumferential direction of the rotary shaft 15. For ease of explanation, only one groove 26d is shown in FIG. 1. An annular ring member 29 is fitted into each groove 26d. A pin 30 is inserted into each ring member 29. Each pin 30 protrudes from the end face 13e of the support housing 13 on the orbiting scroll 26 side.

[0036] The scroll compressor 10 includes an elastic plate 31. The elastic plate 31 is annular. The elastic plate 31 is sandwiched between the end face 13e of the support housing 13 and the open end face of the outer peripheral wall 25c. The elastic plate 31 constantly biases the orbiting scroll 26 toward the fixed scroll 25.

[0037] 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 scroll 25. Therefore, the fixed scroll 25 is accommodated within the housing 11.

[0038] The discharge housing 14 has a plurality of bolt insertion holes 14c. Each bolt insertion hole 14c is formed in the peripheral wall 14b. For ease of explanation, only one bolt insertion hole 14c is shown in FIG. 1. Each bolt insertion hole 14c communicates with a corresponding bolt insertion hole 19a in the flange wall 19.

[0039] The bolts B1 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 motor housing 12. As a result, the journal housing 13 is connected to the peripheral wall 12b of the motor housing 12, and the discharge housing 14 is connected to the flange wall 19 of the journal housing 13. Therefore, the motor housing 12, journal housing 13, and discharge housing 14 are arranged in this order in the axial direction of the rotating shaft 15. The fixed scroll 25 is sandwiched between the end wall 14a of the discharge housing 14 and the journal housing 13. In this manner, the fixed scroll 25 is fixed to the housing 11.

[0040] The scroll compressor 10 includes a suction passage 35. The suction passage 35 has a first groove 36, a first hole 37, a second groove 38, and a second hole 39. The first groove 36 is formed in a portion of the inner circumferential surface of the peripheral wall 12b of the motor housing 12. The first groove 36 opens to an open end of the peripheral wall 12b. The first hole 37 is formed in the outer circumferential portion of the flange wall 19 of the journal housing 13. The first hole 37 penetrates the flange wall 19 in the thickness direction. The first hole 37 communicates with the first groove 36. The second groove 38 is formed in a portion of the inner circumferential surface of the peripheral wall 14b of the discharge housing 14. The second groove 38 communicates with the first hole 37. The second hole 39 is formed in the outer circumferential wall 25c of the fixed scroll 25. The second hole 39 penetrates the outer circumferential wall 25c in the thickness direction. The second hole 39 communicates with the second groove 38. The second hole 39 communicates with the outermost peripheral portion of the compression chamber 27.

[0041] The refrigerant in the motor chamber 20 passes through the first groove 36, the first hole 37, the second groove 38, and the second hole 39 and is drawn into the compression chamber 27. The refrigerant drawn into the compression chamber 27 is compressed within the compression chamber 27 by the orbital motion of the orbiting scroll 26. In this manner, the compression mechanism C1 compresses the refrigerant drawn into the housing 11. The orbiting scroll 26 forms the compression chamber 27 together with the fixed scroll 25 by the rotation of the rotary shaft 15.

[0042] The scroll compressor 10 has a discharge chamber 40. The discharge chamber 40 is defined between the fixed base plate 25a and the end wall 14a of the discharge housing 14. The discharge chamber 40 is in communication with the discharge port 25h. The refrigerant compressed in the compression chamber 27 is discharged into the discharge chamber 40. The discharge housing 14 has a discharge port 14h. The discharge port 14h is formed in the end wall 14a of the discharge housing 14. The discharge port 14h discharges the refrigerant discharged into the discharge chamber 40 to the outside of the housing 11.

[0043] <Eccentric shaft> The scroll compressor 10 includes an eccentric shaft 41. The eccentric shaft 41 is press-fitted into the press-fit hole 15h and protrudes from the tip end surface 15e of the rotating shaft 15. The eccentric shaft 41 extends parallel to the rotating shaft 15 at a position eccentric to the axis L1 of the rotating shaft 15. The eccentric shaft 41 is a separate member from the rotating shaft 15. The axial direction of the eccentric shaft 41 coincides with the axial direction of the rotating shaft 15. The eccentric shaft 41 protrudes from the tip end surface 15e of the rotating shaft 15 toward the orbiting scroll 26. Therefore, the eccentric shaft 41 protrudes from the tip of the rotating shaft 15. The eccentric shaft 41 is inserted into the boss portion 28.

[0044] <Bush> The scroll compressor 10 includes a bushing 42. The bushing 42 has a cylindrical portion 43 that is inserted into the rotating base plate 26a so as to be rotatable relative to the rotating base plate 26a. An insertion hole 44 is formed in the cylindrical portion 43. Thus, the bushing 42 has the insertion hole 44. The insertion hole 44 penetrates the cylindrical portion 43 in the axial direction of the cylindrical portion 43. An eccentric shaft 41 is inserted into the insertion hole 44. The eccentric shaft 41 is inserted into the insertion hole 44 with the axis L2 of the eccentric shaft 41 coinciding with the axis of the insertion hole 44. The bushing 42 can swing around the eccentric shaft 41. A majority of the cylindrical portion 43 is disposed inside the boss portion 28. The end of the cylindrical portion 43 on the rotary shaft 15 side protrudes from the boss portion 28.

[0045] The bushing 42 has a swing restricting portion 45. The swing restricting portion 45 protrudes from a part of the outer circumferential surface of the cylindrical portion 43 that protrudes from the boss portion 28. The swing restricting portion 45 is disposed radially outward of the rotating shaft 15. The swing restricting portion 45 is configured to be able to come into contact with the outer circumferential surface of the rotating shaft 15 when the bushing 42 swings about the eccentric shaft 41. By coming into contact with the rotating shaft 15, the swing restricting portion 45 restricts the swing of the bushing 42 from exceeding a specified range.

[0046] The scroll compressor 10 includes a bearing 46. The bearing 46 is, for example, a cylindrical plain bearing. The bearing 46 is disposed inside the boss portion 28. The bearing 46 is disposed between the inner peripheral surface of the boss portion 28 and the outer peripheral surface of the cylindrical portion 43 of the bushing 42. The bushing 42 is rotatably supported by the boss portion 28 via the bearing 46.

[0047] The rotation of the rotary shaft 15 is transmitted to the orbiting scroll 26 via the eccentric shaft 41, the bushing 42, and the bearing 46. This causes the orbiting scroll 26 to rotate on its axis. Then, contact between each pin 30 and the inner peripheral surface of each ring member 29 prevents the orbiting scroll 26 from rotating on its axis, and only allows 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. As the orbiting scroll 26 revolves, the volume of the compression chamber 27 decreases, and the refrigerant is compressed in the compression chamber 27. As the rotary shaft 15 rotates, the orbiting scroll 26 revolves inside the outer peripheral wall 25c.

[0048] <Bush Balancer> The bushing 42 has a bushing balancer 50. The bushing balancer 50 protrudes radially outward from the cylindrical portion 43. The bushing balancer 50 protrudes from a portion of the outer circumferential surface of the cylindrical portion 43, at a portion that protrudes from the boss portion 28. The bushing balancer 50 is provided integrally with the cylindrical portion 43. The bushing balancer 50 is formed integrally with the cylindrical portion 43. The bushing balancer 50 is housed within the peripheral wall 18 of the journal support housing 13.

[0049] As shown in Figures 2 and 3, the bush balancer 50 is plate-shaped. When viewed in the axial direction of the rotating shaft 15, the bush balancer 50 is fan-shaped. The bush balancer 50 has a pair of extending edges 51 and a connecting edge 52. The pair of extending edges 51 extend from the outer circumferential surface of the cylindrical portion 43. The pair of extending edges 51 extend straight in directions that move away from each other as they move away from the outer circumferential surface of the cylindrical portion 43. The connecting edge 52 connects the ends of each extending edge 51 on the opposite side from the outer circumferential surface of the cylindrical portion 43. The connecting edge 52 extends in an arc shape along the outer circumferential surface of the cylindrical portion 43.

[0050] 4, when viewed in the axial direction of the rotating shaft 15, the axis L2 of the eccentric shaft 41 is disposed at a position offset from a first line L11 that is a line passing through the axis L3 of the cylindrical portion 43 and the axis L1 of the rotating shaft 15. The insertion hole 44 is formed in the cylindrical portion 43 such that, when viewed in the axial direction of the rotating shaft 15, the axis of the insertion hole 44 is disposed on the trailing side of the first line L11 in the rotation direction R1 of the rotating shaft 15 and closer to the axis L1 of the rotating shaft 15 than the axis L3 of the cylindrical portion 43. Therefore, when viewed in the axial direction of the rotating shaft 15, the axis L2 of the eccentric shaft 41 is disposed on the trailing side of the first line L11 in the rotation direction R1 of the rotating shaft 15 and closer to the axis L1 of the rotating shaft 15 than the axis L3 of the cylindrical portion 43. The axis L3 of the cylindrical portion 43 coincides with the center of the orbiting base plate 26a of the orbiting scroll 26 when viewed in the axial direction of the rotation shaft 15. The center of the orbiting base plate 26a of the orbiting scroll 26 coincides with the center of gravity of the orbiting scroll 26 when viewed in the axial direction of the rotation shaft 15. The center of gravity W1 of the bush balancer 50 is located on the same side of the first straight line L11 as the axis L2 of the eccentric shaft 41 when viewed in the axial direction of the rotation shaft 15. The center of gravity W1 of the bush balancer 50 is located on the opposite side of the center of gravity of the orbiting scroll 26 across the axis L2 of the eccentric shaft 41 when viewed in the axial direction of the rotation shaft 15.

[0051] A centrifugal force Fa acts on the orbiting scroll 26 as the orbiting scroll 26 revolves. The vector of the centrifugal force Fa acting on the orbiting scroll 26 is located on an extension of the first straight line L11. When the centrifugal force Fa acts on the orbiting scroll 26, a moment Ma is generated around the eccentric shaft 41 in the orbiting scroll 26. Furthermore, a centrifugal force Fb acts on the bush balancer 50 as the rotating shaft 15 rotates. The vector of the centrifugal force Fb acting on the bush balancer 50 is located on an extension of a line passing through the axis L1 of the rotating shaft 15 and the center of gravity W1 of the bush balancer 50. When the centrifugal force Fb acts on the bush balancer 50, a moment Mb is generated around the eccentric shaft 41 in the bush balancer 50.

[0052] Here, when viewed from the axial direction of the rotary shaft 15, the axis L2 of the eccentric shaft 41 is located on the trailing side of the first straight line L11 in the rotation direction R1 of the rotary shaft 15 and is closer to the axis L1 of the rotary shaft 15 than the axis L3 of the cylindrical portion 43. Therefore, the moment Ma around the eccentric shaft 41 of the orbiting scroll 26 is directed in the opposite direction to the rotation direction R1 of the rotary shaft 15, and the moment Mb around the eccentric shaft 41 of the bush balancer 50 is directed in the same direction as the rotation direction R1 of the rotary shaft 15. Therefore, the moment Ma around the eccentric shaft 41 of the orbiting scroll 26 and the moment Mb around the eccentric shaft 41 of the bush balancer 50 are directed in opposite directions to each other.

[0053] Specifically, when viewed in the axial direction of the rotary shaft 15, the center of gravity W1 of the bush balancer 50 is located on the opposite side of the center of gravity of the orbiting scroll 26 with respect to a line Lb connecting the axis L1 of the rotary shaft 15 and the axis L2 of the eccentric shaft 41. Therefore, the moment Ma around the eccentric shaft 41 generated by the centrifugal force Fa acting on the orbiting scroll 26 and the moment Mb around the eccentric shaft 41 generated by the centrifugal force Fb acting on the bush balancer 50 are directed in opposite directions. In this way, the moment Mb around the eccentric shaft 41 generated by the centrifugal force Fb acting on the bush balancer 50 as the rotary shaft 15 rotates is directed in the opposite direction to the moment Ma around the eccentric shaft 41 generated by the centrifugal force Fa acting on the orbiting scroll 26 as the orbiting scroll 26 revolves. As a result, the moment Ma around the eccentric shaft 41 in the orbiting scroll 26 is offset by the moment Mb around the eccentric shaft 41 in the bush balancer 50 .

[0054] <Shaft balancer> As shown in FIG. 1 , the scroll compressor 10 includes a shaft balancer 60. The shaft balancer 60 protrudes radially outward from the rotating shaft 15. The shaft balancer 60 protrudes from a portion of the outer circumferential surface of the rotating shaft 15 between the rotor core 24a and the support housing 13. The shaft balancer 60 is disposed in the motor chamber 20, between the motor 22 and the support housing 13. The shaft balancer 60 rotates integrally with the rotating shaft 15. The weight of the shaft balancer 60 is greater than the weight of the bush balancer 50.

[0055] As shown in Figures 2 and 3, the shaft balancer 60 has an attachment portion 61 and a weight portion 62. The attachment portion 61 is cylindrical. The attachment portion 61 has a first end face 61a and a second end face 61b. The first end face 61a is an end face located on one side in the axial direction of the attachment portion 61. The first end face 61a is a flat surface. The second end face 61b is an end face located on the other side in the axial direction of the attachment portion 61. The second end face 61b is a flat surface.

[0056] The mounting portion 61 has a press-fit hole 61h. The press-fit hole 61h penetrates the mounting portion 61 in the axial direction of the mounting portion 61. A first end of the press-fit hole 61h opens to a first end face 61a of the mounting portion 61. A second end of the press-fit hole 61h opens to a second end face 61b of the mounting portion 61. The rotating shaft 15 is press-fitted into the press-fit hole 61h. The rotating shaft 15 penetrates the press-fit hole 61h. The shaft balancer 60 is fixed to the rotating shaft 15 by press-fitting the rotating shaft 15 into the press-fit hole 61h.

[0057] The weight portion 62 is plate-shaped. The weight portion 62 protrudes radially outward from the outer peripheral surface of the mounting portion 61. When viewed in the axial direction of the rotating shaft 15, the weight portion 62 has an elongated plate-like shape. The weight portion 62 has a first side edge 63, a second side edge 64, and a connecting edge 65. The first side edge 63 and the second side edge 64 extend from the outer peripheral surface of the mounting portion 61. The first side edge 63 and the second side edge 64 extend parallel to each other from the outer peripheral surface of the mounting portion 61. The connecting edge 65 connects the end of the first side edge 63 opposite the outer peripheral surface of the mounting portion 61 to the end of the second side edge 64 opposite the outer peripheral surface of the mounting portion 61. The connecting edge 65 extends in an arc-like shape so as to be convex in a direction away from the mounting portion 61.

[0058] The weight portion 62 has a first surface 62a and a second surface 62b. The first surface 62a is located on one side in the thickness direction of the weight portion 62. The second surface 62b is located on the other side in the thickness direction of the weight portion 62. The first surface 62a is continuous with a first end surface 61a of the mounting portion 61. The second surface 62b is continuous with a second end surface 61b of the mounting portion 61. The first surface 62a extends from the first end surface 61a of the mounting portion 61 radially outward of the rotating shaft 15 and extends obliquely toward the tip surface 15e of the rotating shaft 15 as it moves away from the first end surface 61a of the mounting portion 61. The second surface 62b extends along the first surface 62a.

[0059] 4, the weight portion 62 is located on the opposite side of the eccentric shaft 41 across the axis L1 of the rotary shaft 15 when viewed in the axial direction of the rotary shaft 15. The center of gravity W2 of the shaft balancer 60 is located on the opposite side of the eccentric shaft 41 across the axis L1 of the rotary shaft 15 when viewed in the axial direction of the rotary shaft 15. The center of gravity W2 of the shaft balancer 60 is located on the opposite side of the axis L3 of the cylindrical portion 43 across a line L10 that passes through the axis L1 of the rotary shaft 15 and is perpendicular to the first line L11 when viewed in the axial direction of the rotary shaft 15. Therefore, the center of gravity W2 of the shaft balancer 60 is located on the opposite side of the center of gravity of the orbiting scroll 26 across the axis L1 of the rotary shaft 15.

[0060] When viewed in the axial direction of the rotating shaft 15, the first side edge 63 of the weight portion 62 is located on the same side as the center of gravity W1 of the bush balancer 50 with respect to a second straight line L12, which is a straight line passing through the center of gravity W2 of the shaft balancer 60 and the axis L1 of the rotating shaft 15. Therefore, when viewed in the axial direction of the rotating shaft 15, the first side edge 63 of the weight portion 62 is the side edge of the portion of the shaft balancer 60 located on the same side as the center of gravity W1 of the bush balancer 50 with respect to the second straight line L12.

[0061] As the orbiting scroll 26 revolves, a centrifugal force Fa acts on the orbiting scroll 26 in the direction opposite to the weight portion 62. As the orbiting scroll 26 revolves, a centrifugal force Fc acts on the shaft balancer 60. The direction of the centrifugal force Fc acting on the shaft balancer 60 is opposite to the direction of the centrifugal force Fa acting on the orbiting scroll 26. As a result, when the orbiting scroll 26 revolves, the centrifugal force Fa acting on the orbiting scroll 26 is offset by the centrifugal force Fc acting on the shaft balancer 60. In this way, the centrifugal force Fa acting on the orbiting scroll 26 is balanced, and vibration of the rotating shaft 15 is suppressed.

[0062] <Driven crank mechanism> The axis L3 of the cylindrical portion 43 of the bushing 42 is located radially outward of the axis L1 of the rotary shaft 15. Since the center of the orbiting base plate 26a coincides with the axis L3 of the cylindrical portion 43, the distance between the axis L3 of the cylindrical portion 43 and the axis L1 of the rotary shaft 15 is the orbital radius of the orbiting scroll 26.

[0063] When the bushing 42 swings around the eccentric shaft 41, the distance between the axis L3 of the cylindrical portion 43 and the axis L1 of the rotary shaft 15 changes, thereby varying the orbital radius of the orbiting scroll 26. In this way, the eccentric shaft 41, the bushing 42, and the bearing 46 constitute a so-called driven crank mechanism 32 that varies the orbital radius of the orbiting scroll 26. Such a driven crank mechanism 32 is already known.

[0064] <Function of the driven crank mechanism> Since minute processing errors and assembly errors occur in the fixed scroll 25 and the orbiting scroll 26, a gap (gap) is provided in advance between the fixed spiral wall 25b and the orbiting spiral wall 26b.

[0065] When the rotating shaft 15 rotates in the forward direction, the bushing 42 swings about the eccentric shaft 41 due to the compressive load acting on the orbiting scroll 26. When the bushing 42 swings about the eccentric shaft 41, the distance between the axis L3 of the cylindrical portion 43 and the axis L1 of the rotating shaft 15 increases, and the orbital radius of the orbiting scroll 26 increases. Then, when the orbiting spiral wall 26b comes into contact with the fixed spiral wall 25b, the swing of the bushing 42 about the eccentric shaft 41 is restricted. This fixes the orbital radius of the orbiting scroll 26.

[0066] Furthermore, the rotation of the rotating shaft 15 is transmitted to the orbiting scroll 26 via the eccentric shaft 41, the bushing 42, and the bearing 46, causing the orbiting scroll 26 to rotate in the forward direction. Then, when the orbiting spiral wall 26b contacts the fixed spiral wall 25b, the pin 30 and the ring member 29 come into contact. This prevents the orbiting scroll 26 from rotating on its axis, allowing only the orbiting scroll 26 to revolve in the forward direction. The orbiting scroll 26 then revolves in the forward direction while the orbiting spiral wall 26b contacts the fixed spiral wall 25b. This prevents refrigerant leakage from the compression chamber 27, reduces the volume of the compression chamber 27, and compresses the refrigerant.

[0067] When assembling the orbiting scroll 26 to the fixed scroll 25, the bushing 42 is swung about the eccentric shaft 41 in the direction opposite to the direction in which the rotary shaft 15 rotates in the forward direction. This reduces the distance between the axis L3 of the cylindrical portion 43 and the axis L1 of the rotary shaft 15, thereby reducing the orbital radius of the orbiting scroll 26. As a result, the relative position of the orbiting spiral wall 26b with respect to the fixed spiral wall 25b becomes a position where the orbiting spiral wall 26b does not come into contact with the fixed spiral wall 25b. This makes it possible to easily assemble the orbiting scroll 26 to the fixed scroll 25.

[0068] When the bushing 42 swings about the eccentric shaft 41 in the direction opposite to when the rotating shaft 15 is rotating in the forward direction, the swing of the bushing 42 is restricted by the swing restricting portion 45 before the distance between the axis L3 of the cylindrical portion 43 and the axis L1 of the rotating shaft 15 increases. When the bushing 42 swings about the eccentric shaft 41 in the direction opposite to when the rotating shaft 15 is rotating in the forward direction, the swing of the bushing 42 is restricted by the swing restricting portion 45 when the distance between the axis L3 of the cylindrical portion 43 and the axis L1 of the rotating shaft 15 becomes the shortest.

[0069] <Notch> A notch 66 is formed in the shaft balancer 60. The notch 66 is formed in the first side edge 63 of the weight portion 62. Therefore, when viewed in the axial direction of the rotating shaft 15, the notch 66 is formed in the side edge of a portion of the shaft balancer 60 that is located on the same side as the center of gravity W1 of the bush balancer 50 with respect to the second straight line L12. The notch 66 is formed by cutting out a portion of the first side edge 63 in an arc shape toward the second side edge 64. In this way, when viewed in the axial direction of the rotating shaft 15, the portion of the shaft balancer 60 that is located on the same side as the center of gravity W1 of the bush balancer 50 with respect to the second straight line L12 has lower rigidity than the portion of the shaft balancer 60 that is located on the opposite side of the center of gravity W1 of the bush balancer 50.

[0070] [Operation of the first embodiment] Next, the operation of the first embodiment will be described. The moment Ma of the orbiting scroll 26 around the eccentric shaft 41 is offset by the moment Mb of the bush balancer 50 around the eccentric shaft 41. Therefore, even if a centrifugal force Fa acts on the orbiting scroll 26 as the rotating shaft 15 rotates and the orbiting scroll 26 revolves, the orbiting scroll wall 26b is prevented from being pressed excessively against the fixed scroll wall 25b. Furthermore, the centrifugal force Fa acting on the orbiting scroll 26 is offset by the centrifugal force Fc acting on the shaft balancer 60. Therefore, even if the bush 42 swings and the bush balancer 50 swings at the same time, the moment Ma of the orbiting scroll 26 on the rotating shaft 15 is balanced, thereby suppressing vibration of the rotating shaft 15.

[0071] In this scroll compressor 10, the rotation speed of the rotating shaft 15 varies between a low rotation speed range and a high rotation speed range. As the rotation speed varies, the swing amount of the bush balancer 50 changes due to the influence of centrifugal force Fb acting on the bush balancer 50. For example, the rotating shaft 15 is designed to balance the moment Ma using the orbiting scroll 26 when rotating at a medium rotation speed range. When the rotating shaft 15 rotates at a high rotation speed range, the centrifugal force Fb acting on the bush balancer 50 increases, thereby increasing the swing amount of the bush balancer 50. The bush balancer 50 swings in the direction of moment Mb about the eccentric shaft 41. Here, the direction of moment Mb about the eccentric shaft 41 generated by centrifugal force Fb acting on the bush balancer 50 is a direction away from the center of gravity W2 of the shaft balancer 60 when viewed from the axial direction of the rotating shaft 15. Therefore, when the rotating shaft 15 rotates at a high rotation speed, the position of the center of gravity W1 of the bush balancer 50 shifts away from the center of gravity W2 of the shaft balancer 60 when viewed in the axial direction of the rotating shaft 15.

[0072] At this time, when centrifugal force Fc acts on the shaft balancer 60, the shaft balancer 60 deforms from a portion located on the same side as the center of gravity W1 of the bush balancer 50 with respect to the second straight line L12, toward a portion located on the opposite side of the center of gravity W1 of the bush balancer 50, as viewed in the axial direction of the rotating shaft 15. Therefore, the position of the center of gravity W2 of the shaft balancer 60 moves in a direction away from the center of gravity W1 of the bush balancer 50, as viewed in the axial direction of the rotating shaft 15. Therefore, the position of the center of gravity W2 of the shaft balancer 60 moves in the opposite direction to the direction in which the position of the center of gravity W1 of the bush balancer 50 shifts. As a result, an imbalance with the moment Ma due to the orbiting scroll 26 is prevented from occurring.

[0073] [Effects of the first embodiment] The first embodiment can provide the following effects. (1-1) For example, when the rotating shaft 15 rotates in a high rotation speed range, the centrifugal force Fb acting on the bush balancer 50 increases, and the swing amount of the bush balancer 50 increases. The bush balancer 50 swings in the direction of the moment Mb about the eccentric shaft 41. Here, the direction of the moment Mb about the eccentric shaft 41 generated by the centrifugal force Fb acting on the bush balancer 50 is a direction away from the center of gravity W2 of the shaft balancer 60, as viewed from the axial direction of the rotating shaft 15. Therefore, when the rotating shaft 15 rotates in a high rotation speed range, the position of the center of gravity W1 of the bush balancer 50 shifts in a direction away from the center of gravity W2 of the shaft balancer 60, as viewed from the axial direction of the rotating shaft 15. At this time, as viewed from the axial direction of the rotating shaft 15, a portion of the shaft balancer 60 located on the same side of the second line L12 as the center of gravity W1 of the bush balancer 50 has lower rigidity than a portion of the shaft balancer 60 located on the opposite side of the center of gravity W1 of the bush balancer 50. Therefore, when centrifugal force Fc acts on the shaft balancer 60, as viewed from the axial direction of the rotating shaft 15, the shaft balancer 60 deforms from the portion located on the same side of the second line L12 as the center of gravity W1 of the bush balancer 50 toward the portion located on the opposite side of the center of gravity W1 of the bush balancer 50. Therefore, as viewed from the axial direction of the rotating shaft 15, the position of the center of gravity W2 of the shaft balancer 60 moves in a direction away from the center of gravity W1 of the bush balancer 50. Therefore, the position of the center of gravity W2 of the shaft balancer 60 moves in the opposite direction to the direction in which the position of the center of gravity W1 of the bush balancer 50 shifts. As a result, it is possible to prevent the moment Ma due to the orbiting scroll 26 from becoming unbalanced, and therefore vibration of the rotary shaft 15 can be suppressed.

[0074] (1-2) A notch 66 is formed on the side edge of a portion of the shaft balancer 60 that is located on the same side of the second straight line L12 as the center of gravity W1 of the bush balancer 50 when viewed from the axial direction of the rotating shaft 15. This allows the rigidity of the portion of the shaft balancer 60 that is located on the same side of the second straight line L12 as the center of gravity W1 of the bush balancer 50 when viewed from the axial direction of the rotating shaft 15 to be lower than the rigidity of the portion of the shaft balancer 60 that is located on the opposite side of the second straight line L12 from the center of gravity W1 of the bush balancer 50.

[0075] [Second embodiment] A second embodiment of a scroll compressor will be described below with reference to Fig. 5. In the embodiment described below, the same components as those in the first embodiment will be denoted by the same reference numerals, and redundant description will be omitted or simplified.

[0076] 5, the insertion hole 44 is formed in the cylindrical portion 43 so that the axis of the insertion hole 44 is located on the leading side of the first straight line L11 in the rotation direction R1 of the rotating shaft 15, as viewed from the axial direction of the rotating shaft 15, and is located farther than the axis L3 of the cylindrical portion 43 with respect to the axis L1 of the rotating shaft 15. Therefore, the axis L2 of the eccentric shaft 41 is located on the leading side of the first straight line L11 in the rotation direction R1 of the rotating shaft 15, as viewed from the axial direction of the rotating shaft 15, and is located farther than the axis L3 of the cylindrical portion 43 with respect to the axis L1 of the rotating shaft 15.

[0077] When a centrifugal force Fa acts on the orbiting scroll 26, a moment Ma is generated around the eccentric shaft 41 in the orbiting scroll 26. When a centrifugal force Fb acts on the bush balancer 50, a moment Mb is generated around the eccentric shaft 41 in the bush balancer 50. Here, when viewed from the axial direction of the rotation shaft 15, the axis L2 of the eccentric shaft 41 is located on the leading side of the first straight line L11 in the rotation direction R1 of the rotation shaft 15 and is located farther from the axis L1 of the rotation shaft 15 than the axis L3 of the cylindrical portion 43. Therefore, the moment Ma around the eccentric shaft 41 in the orbiting scroll 26 is directed in the same direction as the rotation direction R1 of the rotation shaft 15, while the moment Mb around the eccentric shaft 41 in the bush balancer 50 is directed in the opposite direction to the rotation direction R1 of the rotation shaft 15. Therefore, the moment Ma around the eccentric shaft 41 in the orbiting scroll 26 and the moment Mb around the eccentric shaft 41 in the bush balancer 50 are in opposite directions to each other.

[0078] Specifically, when viewed in the axial direction of the rotary shaft 15, the center of gravity W1 of the bush balancer 50 is located on the opposite side of the center of gravity of the orbiting scroll 26 with respect to a line Lb connecting the axis L1 of the rotary shaft 15 and the axis L2 of the eccentric shaft 41. Therefore, the moment Ma around the eccentric shaft 41 generated by the centrifugal force Fa acting on the orbiting scroll 26 and the moment Mb around the eccentric shaft 41 generated by the centrifugal force Fb acting on the bush balancer 50 are directed in opposite directions. In this way, the moment Mb around the eccentric shaft 41 generated by the centrifugal force Fb acting on the bush balancer 50 as the rotary shaft 15 rotates is directed in the opposite direction to the moment Ma around the eccentric shaft 41 generated by the centrifugal force Fa acting on the orbiting scroll 26 as the orbiting scroll 26 revolves. As a result, the moment Ma around the eccentric shaft 41 in the orbiting scroll 26 is offset by the moment Mb around the eccentric shaft 41 in the bush balancer 50 .

[0079] The second side edge 64 of the weight portion 62 is located on the same side as the center of gravity W1 of the bush balancer 50 with respect to a second straight line L12, which is a line passing through the center of gravity W2 of the shaft balancer 60 and the axis L1 of the rotating shaft 15, when viewed in the axial direction of the rotating shaft 15. Therefore, the second side edge 64 of the weight portion 62 is the side edge of the portion of the shaft balancer 60 that is located on the same side as the center of gravity W1 of the bush balancer 50 with respect to the second straight line L12, when viewed in the axial direction of the rotating shaft 15.

[0080] A notch 66 is formed in the shaft balancer 60. The notch 66 is formed in the second side edge 64 of the weight portion 62. Therefore, when viewed in the axial direction of the rotating shaft 15, the notch 66 is formed in the side edge of a portion of the shaft balancer 60 located on the same side as the center of gravity W1 of the bush balancer 50 with respect to the second straight line L12. The notch 66 is formed by cutting out a portion of the second side edge 64 in an arc shape toward the first side edge 63. In this way, when viewed in the axial direction of the rotating shaft 15, the portion of the shaft balancer 60 located on the same side as the center of gravity W1 of the bush balancer 50 with respect to the second straight line L12 has lower rigidity than the portion of the shaft balancer 60 located on the opposite side of the center of gravity W1 of the bush balancer 50 with respect to the second straight line L12. This provides the same effects as those of the first embodiment.

[0081] [Effects of the second embodiment] In the second embodiment, the following effects can be obtained. (2-1) When viewed from the axial direction of the rotating shaft 15, the axis L2 of the eccentric shaft 41 is located on the leading side of the first straight line L11 in the rotation direction R1 of the rotating shaft 15, and is located farther from the axis L1 of the rotating shaft 15 than the axis L3 of the cylindrical portion 43. Even with this configuration, it is possible to suppress vibration of the rotating shaft 15 when the rotating shaft 15 is rotating at a high rotation speed.

[0082] [Example of change] The above-described embodiments can be modified as follows: The above-described embodiments and the following modifications can be combined with each other within the scope of technical compatibility.

[0083] As shown in FIGS. 6 and 7 , the weight portion 62 may have a thin portion 67 and a thick portion 68. The thin portion 67 is provided in a portion of the weight portion 62 located on the same side of the second line L12 as the center of gravity W1 of the bush balancer 50 when viewed in the axial direction of the rotating shaft 15. Therefore, the thin portion 67 is provided in a portion of the shaft balancer 60 located on the same side of the second line L12 as the center of gravity W1 of the bush balancer 50 when viewed in the axial direction of the rotating shaft 15. The portion of the weight portion 62 located on the opposite side of the second line L12 from the center of gravity W1 of the bush balancer 50 when viewed in the axial direction of the rotating shaft 15 is a thick portion 68 that is thicker than the thin portion 67. The first surface 62a of the weight portion 62 has a step at the boundary between the thin portion 67 and the thick portion 68. This allows the rigidity of the portion of the shaft balancer 60 located on the same side of the second straight line L12 as the center of gravity W1 of the bush balancer 50 when viewed from the axial direction of the rotating shaft 15 to be lower than the rigidity of the portion of the shaft balancer 60 located on the opposite side of the center of gravity W1 of the bush balancer 50. The shaft balancer 60 having the thick portion 68 and the thin portion 67 in this manner is easy to manufacture.

[0084] As shown in FIG. 8 , a through hole 69 may be formed in the shaft balancer 60 in the axial direction of the rotating shaft 15 at a portion of the shaft balancer 60 located on the same side of the second line L12 as the center of gravity W1 of the bush balancer 50, as viewed in the axial direction of the rotating shaft 15. Two through holes 69 are formed in the weight portion 62. Each through hole 69 penetrates the weight portion 62 in the thickness direction of the weight portion 62. The number of through holes 69 formed in the shaft balancer 60 is not particularly limited. This allows the rigidity of the portion of the shaft balancer 60 located on the same side of the second line L12 as the center of gravity W1 of the bush balancer 50, as viewed in the axial direction of the rotating shaft 15, to be lower than the rigidity of the portion of the shaft balancer 60 located on the opposite side of the center of gravity W1 of the bush balancer 50. A shaft balancer 60 having through holes 69 formed in this manner is easy to process.

[0085] 9, for example, a notch 66 may be formed in the shaft balancer 60, cutting from the first side edge 63 to the connecting edge 65. In short, the shape of the notch 66 formed in the portion of the shaft balancer 60 located on the same side of the second straight line L12 as the center of gravity W1 of the bush balancer 50 when viewed in the axial direction of the rotating shaft 15 is not particularly limited.

[0086] As shown in FIG. 10 , the weight portion 62 may include a first part 71 and a second part 72. The first part 71 and the second part 72 are joined via a joint 73 on the opposite side of the center of gravity W1 of the bush balancer 50 with respect to the second line L12 as viewed in the axial direction of the rotating shaft 15. The joint 73 may be, for example, a joint portion where the first part 71 and the second part 72 are joined using different materials, or a welded portion where the first part 71 and the second part 72 are joined by welding. With this configuration, the rigidity of the portion of the shaft balancer 60 located on the same side of the second line L12 as the center of gravity W1 of the bush balancer 50 as viewed in the axial direction of the rotating shaft 15 may be lower than that of the portion of the shaft balancer 60 located on the opposite side of the center of gravity W1 of the bush balancer 50.

[0087] 11 , the weight portion 62 may have a first part 71 and a second part 72. The first part 71 and the second part 72 are connected by a bolt 74 on the opposite side of the center of gravity W1 of the bush balancer 50 with respect to the second line L12 as viewed in the axial direction of the rotating shaft 15. With this configuration, the rigidity of the portion of the shaft balancer 60 located on the same side of the second line L12 as the center of gravity W1 of the bush balancer 50 as viewed in the axial direction of the rotating shaft 15 may be lower than the rigidity of the portion of the shaft balancer 60 located on the opposite side of the center of gravity W1 of the bush balancer 50.

[0088] In each of the above-described embodiments, the eccentric shaft 41 may be integrally formed with the rotary shaft 15 . In each of the above-described embodiments, the bearing 46 is not limited to a sliding bearing, and may be, for example, a rolling bearing.

[0089] In each of the above-described embodiments, the scroll compressor 10 does not have to be a type that is driven by the motor 22, and may be a type that is driven by, for example, a vehicle engine.

[0090] In the above-described embodiments, the scroll compressor 10 is used in a vehicle air conditioner. However, the present invention is not limited to this. The scroll compressor 10 may be used in any application as long as it compresses a refrigerant, and the application of the scroll compressor 10 may be changed as appropriate.

[0091] In each of the above-described embodiments, the object to be compressed by the scroll compressor 10 is not limited to a refrigerant, and may be a fluid such as air. [Explanation of symbols]

[0092] 10...Scroll compressor, 15...Rotating shaft, 25...Fixed scroll, 25a...Fixed base plate, 25b...Fixed spiral wall, 26...Orbiting scroll, 26a...Orbiting base plate, 26b...Orbiting spiral wall, 41...Eccentric shaft, 42...Bush, 43...Cylindrical portion, 44...Insertion hole, 50...Bush balancer, 60...Shaft balancer, 66...Notch, 67...Thin-walled portion, 69...Through hole.

Claims

1. A rotation axis; an eccentric shaft that protrudes from the tip of the rotary shaft and extends parallel to the rotary shaft at a position eccentric with respect to the axis of the rotary shaft; a fixed scroll having a fixed base plate and a fixed spiral wall standing upright from the fixed base plate; an orbiting scroll having an orbiting base plate facing the fixed base plate and an orbiting spiral wall rising from the orbiting base plate toward the fixed base plate and engaging with the fixed spiral wall; a bushing having an insertion hole into which the eccentric shaft is inserted and swingable around the eccentric shaft, The bushing is a cylindrical portion having the insertion hole formed therein and inserted into the swivel base plate so as to be rotatable relative to the swivel base plate; a bush balancer protruding from the cylindrical portion radially outward of the cylindrical portion, a center of gravity of the bush balancer is located on the same side as the axis of the eccentric shaft with respect to a first line that is a line passing through the axis of the cylindrical portion and the axis of the rotation shaft, as viewed in the axial direction of the rotation shaft; a shaft balancer that protrudes from the rotary shaft toward an outer side in a radial direction of the rotary shaft and rotates integrally with the rotary shaft; a center of gravity of the shaft balancer is located on the opposite side of the eccentric shaft across a line that passes through the axis of the rotation shaft and is perpendicular to the first line, as viewed in the axial direction of the rotation shaft; a moment around the eccentric shaft generated by a centrifugal force acting on the bush balancer is directed away from a center of gravity of the shaft balancer when viewed from an axial direction of the rotation shaft; A scroll compressor characterized in that, when viewed from the axial direction of the rotating shaft, a portion of the shaft balancer located on the same side as the center of gravity of the bush balancer with respect to a second line, which is a line passing through the center of gravity of the shaft balancer and the axis of the rotating shaft, has lower rigidity than a portion of the shaft balancer located on the opposite side of the center of gravity of the bush balancer.

2. 2. The scroll compressor according to claim 1, wherein a notch is formed in a side edge of a portion of the shaft balancer that is located on the same side as the center of gravity of the bush balancer with respect to the second straight line when viewed in the axial direction of the rotating shaft.

3. 2. The scroll compressor according to claim 1, wherein a thin-walled portion is provided in a portion of the shaft balancer that is located on the same side of the center of gravity of the bush balancer with respect to the second line when viewed in the axial direction of the rotating shaft.

4. 2. The scroll compressor according to claim 1, wherein a through hole penetrating in the axial direction is formed in a portion of the shaft balancer that is located on the same side of the second line as the center of gravity of the bush balancer when viewed in the axial direction of the rotating shaft.

Images