Scroll Compressor

Abstract

To provide a scroll-type compressor capable of more effectively suppressing the influences of centrifugal force or the like due to the turning motion of a turning scroll than before.SOLUTION: In a scroll-type compressor, when, in view from the axial direction of a rotary shaft 30, a straight line passing through a center line CL0 of the rotary shaft 30 and a center line CL2 of an eccentric bush 72 is a first straight line VL and a straight line passing through the center line CL0 of the rotary shaft 30 and perpendicular to the first straight line VL is a second straight line HL, a gravity center G1 of a bush balancer 721 provided integrally with the eccentric bush 72 is located on the opposite side to the center line CL2 of the eccentric bush 72 across the second straight line HL and located on the opposite side to a center line CL1 of an eccentric pin 71 across the first straight line VL, and a gravity center G2 of a shaft balancer 31 provided integrally with the rotary shaft 30 is located on the opposite side to the center line CL2 of the eccentric bush 72 across the second straight line HL and located on the same side as the center line CL1 of the eccentric pin 71 with respect to a first straight line VL.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] A scroll compressor has a fixed scroll and an orbiting scroll arranged so that their spiral walls mesh with each other. In a scroll compressor, the orbiting scroll orbits relative to the fixed scroll, changing the volume of the compression chamber formed between the two spiral walls, thereby compressing the fluid taken into the compression chamber. Furthermore, scroll compressors are usually provided with a balancer (also called a balance weight or counterweight) to reduce vibrations caused by the orbiting motion of the orbiting scroll.

[0003] For example, in the scroll compressor described in Patent Document 1, the driving force transmission mechanism that transmits driving force to the orbiting scroll includes a rotating shaft that is driven to rotate, a crank pin provided at one end of the rotating shaft, and an eccentric bushing that is fitted externally onto the crank pin so as to be rotatable relative to the crank pin and is fitted internally into a cylindrical portion provided on the back surface of the orbiting scroll via a bearing so as to be rotatable relative to the crank pin, and a balancer is provided integrally with the eccentric bushing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-100246 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, there has been a demand for scroll compressors with even lower noise (lower vibration). To achieve even lower noise from scroll compressors, it is necessary to more effectively suppress the effects of centrifugal force and other factors caused by the orbiting motion of the orbiting scroll than ever before.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a scroll compressor that can more effectively suppress the influence of centrifugal force and the like caused by the orbiting motion of the orbiting scroll than conventional compressors. [Means for solving the problem]

[0007] As a result of extensive research and experiments, the inventors have discovered a combination of balancers that can more effectively suppress the effects of centrifugal force and other factors caused by the orbiting motion of the orbiting scroll than conventional balancers. The present invention is based on this finding.

[0008] According to one aspect of the present invention, a scroll compressor includes: a fixed scroll having a fixed base plate and a fixed spiral wall erected on the fixed base plate; an orbiting scroll having an orbiting base plate, an orbiting spiral wall erected on one surface of the orbiting base plate and meshing with the fixed spiral wall, and a cylindrical portion erected on the other surface of the orbiting base plate; a compression chamber formed between the fixed scroll and the orbiting scroll; and a driving force transmission mechanism that includes a rotational shaft that is driven to rotate, an eccentric pin provided on one end of the rotational shaft, and an eccentric bushing rotatably attached to the eccentric pin and rotatably inserted inside the cylindrical portion via a bearing, and that transmits driving force to the orbiting scroll. The scroll compressor is configured so that the driving force causes the orbiting scroll to orbit relative to the fixed scroll, thereby changing the volume of the compression chamber, thereby compressing a fluid taken into the compression chamber. The scroll compressor includes: a bush balancer formed integrally with the eccentric bushing and having a first weight portion located radially outward of the eccentric bushing; and a shaft balancer formed integrally with the rotating shaft and having a second weight portion located radially outward of the rotating shaft. When, as viewed axially of the rotating shaft, a line passing through a center line of the rotating shaft and a center line of the eccentric bushing is defined as a first line, and a line passing through the center line of the rotating shaft and perpendicular to the first line is defined as a second line, the center of gravity of the bush balancer is located on the opposite side of the second line from the center line of the eccentric bushing and on the opposite side of the first line from the center line of the eccentric pin. The center of gravity of the shaft balancer is located on the opposite side of the second line from the center line of the eccentric bushing and on the same side of the first line as the center line of the eccentric pin. [Effects of the Invention]

[0009] According to one aspect of the present invention, it is possible to provide a scroll compressor that can more effectively suppress the influence of centrifugal force and the like caused by the orbiting motion of the orbiting scroll than conventional scroll compressors. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of a scroll compressor according to an embodiment. [Figure 2] FIG. 2 is an enlarged view of a main part of FIG. [Figure 3] This is a schematic perspective view showing the rotating shaft, bush balancer, shaft balancer, etc. [Figure 4] This is a schematic perspective view showing the rotating shaft, bush balancer, shaft balancer, etc. [Figure 5] This is a view of the rotating shaft, bush balancer, shaft balancer, etc. as seen from the axial direction of the rotating shaft. [Figure 6] This is a view of the rotating shaft, bush balancer, shaft balancer, etc., as seen from the axial direction of the rotating shaft (the opposite side to Figure 5). DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0012] FIG. 1 is a cross-sectional view showing a schematic configuration of a scroll compressor according to an embodiment of the present invention. The scroll compressor 10 according to the embodiment is incorporated, for example, in a refrigerant circuit of a vehicle air conditioner, and is configured to receive low-pressure gas refrigerant (fluid) from the refrigerant circuit, compress it, increase the pressure, and return it to the refrigerant circuit. The left side of FIG. 1 is the front side of the scroll compressor 10, the right side of FIG. 1 is the rear side of the scroll compressor 10, the upper side of FIG. 1 is the upper side of the scroll compressor 10, and the lower side of FIG. 1 is the lower side of the scroll compressor 10. The front side of the page in FIG. 1 is the left side of the scroll compressor 10, and the back side of the page in FIG. 1 is the right side of the scroll compressor 10.

[0013] The scroll compressor 10 includes a housing 20, a rotating shaft 30, an electric motor 40 that rotates the rotating shaft 30, a scroll unit 50 that is driven via the rotating shaft 30 and compresses a (low-pressure) gaseous refrigerant, and an inverter 60 that controls the driving of the electric motor 40. The rotating shaft 30, the electric motor 40, the scroll unit 50, and the inverter 60 are accommodated in the housing 20. The scroll unit 50 also includes a fixed scroll 51 and an orbiting scroll 52 that orbits relative to the fixed scroll 51.

[0014] The housing 20 includes a front housing 21, a cover member 22, a center housing 23, and a rear housing 24. These are fastened together by fasteners (not shown) or the like to form the housing 20 of the scroll compressor 10.

[0015] The front housing 21 has a cylindrical peripheral wall portion (hereinafter referred to as the "first peripheral wall portion") 211 that extends in the front-to-rear direction, and a partition portion (hereinafter referred to as the "first partition portion") 212 that divides the interior of the first peripheral wall portion 211 into front and rear portions. The front end surface of the first peripheral wall portion 211 forms the front end surface of the front housing 21, and the rear end surface of the first peripheral wall portion 211 forms the rear end surface of the front housing 21. The interior of the first peripheral wall portion 211 (i.e., the internal space of the front housing 21) is divided by the first partition portion 212 into a front inverter accommodating space in which the inverter 60 is accommodated, and a rear motor accommodating space in which the electric motor 40 is accommodated. In other words, the electric motor 40 and the inverter 60 are accommodated in the front housing 21.

[0016] The first partition wall 212 is provided with a support portion 213 that supports the front end portion of the rotating shaft 30. The support portion 213 is formed so as to protrude cylindrically from the rear surface of the first partition wall 212 into the motor accommodating space, and is configured to rotatably support the front end portion of the rotating shaft 30 via a first bearing 214 installed inside.

[0017] A cover member 22 is joined to the front end surface of the front housing 21, thereby closing off the inverter accommodating space (forming an inverter accommodating chamber). The front end surface of the center housing 23 is joined to the rear end surface of the front housing 21. Note that seal members may be arranged between the front housing 21 and the cover member 22 and between the front housing 21 and the center housing 23, as necessary.

[0018] The center housing 23 has a cylindrical circumferential wall portion (hereinafter referred to as the "second circumferential wall portion") 231 that extends in the front-to-rear direction, and a partition portion (hereinafter referred to as the "second partition portion") 232 that divides the interior of the second circumferential wall portion 231 into front and rear portions. The front end surface of the second circumferential wall portion 231 forms the front end surface of the center housing 23, and the rear end surface of the second circumferential wall portion 231 forms the rear end surface of the center housing 23. The interior of the second circumferential wall portion 231 (i.e., the internal space of the center housing 23) is divided by the second partition portion 232 into a front connection space that connects to the motor accommodating space of the front housing 21, and a rear scroll accommodating space that accommodates the scroll unit 50. In other words, the scroll unit 50 is accommodated in the center housing 23.

[0019] The second partition wall 232 has a hollow protruding portion 233 that protrudes toward the front housing 21 (motor accommodating space). The hollow protruding portion 233 is provided in the radial center of the second partition wall 232 so as to face the support portion 213 provided in the first partition wall 212 of the front housing 21. A shaft insertion hole 234 is formed in the top (front end) of the hollow protruding portion 233, which communicates between the inside and outside of the hollow protruding portion 233 and through which the rotating shaft 30 is inserted. A second bearing 235 that rotatably supports a portion of the rear end of the rotating shaft 30 is mounted inside the hollow protruding portion 233. That is, in this embodiment, the rotating shaft 30 extends in the front-rear direction within the housing 20 and is rotatably supported by the first bearing 214 provided on the front housing 21 side and the second bearing 235 provided on the center housing 23 side.

[0020] The front end surface of the rear housing 24 is joined to the rear end surface of the center housing 23. Here, in this embodiment, a recess 236 is formed in the rear end surface of the center housing 23, i.e., the rear end surface of the second circumferential wall portion 231, to accommodate the outer edge portion of a fixed base plate 511 (described later) of a fixed scroll 51 that constitutes the scroll unit 50. The outer edge portion of the fixed base plate 511 is accommodated in the recess 236 and is sandwiched between the center housing 23 and the rear housing 24. This fixes the fixed scroll 51, and also closes the rear opening of the second circumferential wall portion 231 by the fixed base plate 511 of the fixed scroll 51. Note that a seal member can be arranged between the center housing 23 and the rear housing 24 as needed.

[0021] The rear housing 24 is formed in a cylindrical shape with a bottom, and has a cylindrical circumferential wall portion (hereinafter referred to as the "third circumferential wall portion") 241 extending in the front-rear direction, and a bottom wall portion 242 that closes a rear opening of the third circumferential wall portion 241. The front end surface of the third circumferential wall portion 241 that constitutes the front end surface of the rear housing 24 is joined to the rear end surface of the second circumferential wall portion 231 that is the rear end surface of the center housing 23, so that the front opening of the third circumferential wall portion 241 is closed by the fixed base plate 511 of the fixed scroll 51.

[0022] The electric motor 40 is configured as, for example, a three-phase AC motor, and includes a stator core unit 41 and a rotor 42.

[0023] The stator core unit 41 is fixed to the inner circumferential surface of the first circumferential wall portion 211 of the front housing 21. Direct current from an on-board battery (not shown) or the like is converted into alternating current by an inverter 60 and supplied to the stator core unit 41.

[0024] The rotor 42 is disposed radially inside the stator core unit 41 with a predetermined gap therebetween. A permanent magnet is incorporated into the rotor 42. The rotor 42 is formed in a cylindrical shape, and the rotating shaft 30 is inserted into its hollow portion and fixed to the rotating shaft 30. In other words, the rotor 42 is integrated with the rotating shaft 30 and rotates integrally therewith.

[0025] When a magnetic field is generated in the stator core unit 41 by power supply from the inverter 60, a rotational force acts on the permanent magnet of the rotor 42, causing the rotor 42 to rotate, thereby rotating (rotatingly driving) the rotating shaft 30.

[0026] As described above, the scroll unit 50 includes the fixed scroll 51 and the orbiting scroll 52 that orbits relative to the fixed scroll 51.

[0027] The fixed scroll 51 has a disk-shaped fixed base plate 511 and a fixed spiral wall 512 erected on one surface of the fixed base plate 511. The fixed spiral wall 512 extends in a spiral shape (involute curve) on the one surface of the fixed base plate 511 from an inner end (a winding start portion) on the radially inner side to an outer end (a winding end portion) on the radially outer side. The fixed scroll 51 is sandwiched and fixed between the center housing 23 and the rear housing 24 with the one surface of the fixed base plate 511 (the surface on which the fixed spiral wall 512 erects) facing forward and the outer edge portion of the fixed base plate 511 housed in the recess 236.

[0028] The orbiting scroll 52 has a disk-shaped orbiting base plate 521, an orbiting spiral wall 522 erected on one surface of the orbiting base plate 521, and a cylindrical portion 523 formed to protrude from the other surface of the orbiting base plate 521. The orbiting spiral wall 522 extends in a spiral shape (involute curve) on the one surface of the orbiting base plate 521 from an inner end (winding start portion) on the radially inner side to an outer end (winding end portion) on the radially outer side. The cylindrical portion 523 protrudes from approximately the center of the other surface of the orbiting base plate 521. The orbiting scroll 52 is arranged so that the orbiting spiral wall 522 meshes with the fixed spiral wall 512 of the fixed scroll 51. That is, the orbiting scroll 52 is disposed between the second partition wall portion 232 of the center housing 23 and the fixed scroll 51 with the one surface of the orbiting base plate 521 (the surface on which the orbiting spiral wall 522 is erected) facing backward. Note that the other surface of the orbiting base plate 521 may also be referred to as the back surface of the orbiting base plate 521.

[0029] The orbiting scroll 52 is driven by a driving force transmitted via the rotating shaft 30 and the crank mechanism 70. The driven orbiting scroll 52 is configured to orbit relative to the fixed scroll 51, in other words, to orbit around the axis of the fixed scroll 51, while its rotation is prevented by the rotation-preventing mechanism 80. Therefore, in this embodiment, the rotating shaft 30 and the crank mechanism 70 constitute the "driving force transmission mechanism" of the present invention.

[0030] The scroll unit 50 is configured so that the orbiting scroll 52 orbits relative to the fixed scroll 51, thereby taking in and compressing a low-pressure gaseous refrigerant. An annular thrust plate 90 is disposed between the orbiting base plate 521 of the orbiting scroll 52 and the second partition wall portion 232 of the center housing 23, and the rear surface of the second partition wall portion 232 receives the thrust force from the orbiting scroll 52 via the thrust plate 90.

[0031] FIG. 2 is an enlarged view of the main part of FIG. 1, and mainly shows the crank mechanism 70 and the rotation-preventing mechanism 80. As shown in FIG.

[0032] The crank mechanism 70 is configured to connect the rotary shaft 30 and the orbiting scroll 52 and to convert the rotational motion of the rotary shaft 30 into the orbiting motion of the orbiting scroll 52. As shown in FIG. 2 , the crank mechanism 70 includes an eccentric pin 71 provided at the rear end of the rotary shaft 30 and an eccentric bushing 72 attached to the eccentric pin 71.

[0033] The eccentric pin 71 extends in the axial direction of the rotary shaft 30 from the rear end surface of the rotary shaft 30. The eccentric pin 71 is eccentric with respect to the rotary shaft 30. That is, the center line CL1 of the eccentric pin 71 is deviated from the center line CL0 of the rotary shaft 30.

[0034] The eccentric bushing 72 is rotatably attached to the eccentric pin 71 and is rotatably inserted inside the cylindrical portion 523 of the orbiting scroll 52 via a bearing 73. Specifically, the eccentric bushing 72 is formed in a cylindrical (cylindrical) shape. The eccentric bushing 72 is formed with a pin insertion hole 72a, through which the eccentric pin 71 is rotatably inserted. The pin insertion hole 72a is formed at a position eccentric from a center line CL2 of the eccentric bushing 72 and passes through the eccentric bushing 72 in the axial direction. The eccentric bushing 72 is rotatably attached to the eccentric pin 71 by inserting the eccentric pin 71 into the pin insertion hole 72a, i.e., via the pin insertion hole 72a. Therefore, the center line of the pin insertion hole 72a coincides with the center line CL1 of the eccentric pin 71.

[0035] The eccentric bushing 72 has an outer peripheral surface 72b supported by a bearing 73 attached to the inside of the cylindrical portion 523 of the orbiting scroll 52, and is rotatably inserted inside the cylindrical portion 523 of the orbiting scroll 52 via the bearing 73. The center of gravity of the orbiting scroll 52 is located approximately on the center line CL2 of the eccentric bushing 72.

[0036] The rotation-preventing mechanism 80 is configured as a pin-ring type rotation-preventing mechanism and includes a plurality of rotation-preventing portions 81. As shown in FIG. 2, each of the rotation-preventing portions 81 of the rotation-preventing mechanism 80 includes a ring 82 press-fitted into a circular hole formed in the other surface (back surface) of the swivel base plate 521, and a pin 83 fixed to the second partition wall portion 232 of the center housing 23 and extending through the thrust plate 90 to the inside of the ring 82. In this embodiment, six circular holes are formed in the other surface (back surface) of the swivel base plate 521 at equal intervals to surround the cylindrical portion 523, and a ring 82 is press-fitted into each circular hole (see FIG. 3). In addition, six pins 83 corresponding to the six rings 82 are fixed to the second partition wall portion 232 of the center housing 23. That is, in this embodiment, the rotation-preventing mechanism 80 includes six rotation-preventing portions 81 arranged at equal intervals in the circumferential direction. However, this is not limited to this. The number of rotation-preventing portions 81 may be three or more, and the number of rotation-preventing portions 81 may be set arbitrarily.

[0037] Returning to Figure 1, the scroll compressor 10 has a suction chamber H1 into which low-pressure gas refrigerant flows, a compression chamber H2 that compresses the low-pressure gas refrigerant, a discharge chamber H3 from which the gas refrigerant compressed in the compression chamber H2 is discharged, a gas-liquid separation chamber H4 that separates lubricating oil from the gas refrigerant compressed in the compression chamber H2, and a back pressure chamber H5 provided on the other surface side (back side) of the orbiting base plate 521 of the orbiting scroll 52.

[0038] The suction chamber H1 is defined by a first peripheral wall portion 211 of the front housing 21, a first partition wall portion 212 of the front housing 21, a second peripheral wall portion 231 of the center housing 23, and a second partition wall portion 232 of the center housing 23. That is, in this embodiment, the suction chamber H1 is defined by the motor accommodating space of the front housing 21 and the connecting section of the center housing 23. A suction port P1 is formed in the first peripheral wall portion 211. The suction port P1 is connected to the refrigerant circuit (the low-pressure side) via a connecting pipe (not shown) or the like. Therefore, low-pressure refrigerant from the refrigerant circuit flows into the suction chamber H1 through the suction port P1. In addition, a refrigerant passage L1 is formed in the center housing 23 to guide the low-pressure gas refrigerant in the suction chamber H1 to a space H6 near the outer end of the scroll unit 50.

[0039] Compression chamber H2 is formed between the fixed scroll 51 and the orbiting scroll 52. Specifically, in the scroll unit 50, when the orbiting scroll 52 orbits relative to the fixed scroll 51, the orbiting spiral wall 522 comes into contact with the fixed spiral wall 512, and a crescent-shaped sealed space is formed radially outward by the fixed base plate 511, the fixed spiral wall 512, the orbiting base plate 521, and the orbiting spiral wall 522. The formed crescent-shaped sealed space moves radially inward while gradually decreasing in volume. This crescent-shaped sealed space formed between the fixed scroll 51 and the orbiting scroll 52 constitutes compression chamber H2. The scroll unit 50 is configured to compress the low-pressure gas refrigerant by taking in low-pressure gas refrigerant from space H6 when the crescent-shaped sealed space (i.e., compression chamber H2) is formed.

[0040] The discharge chamber H3 is defined by the third circumferential wall portion 241 of the rear housing 24, the bottom wall portion 242 of the rear housing 24, and the fixed base plate 511 of the fixed scroll 51. That is, the interior of the third circumferential wall portion 241 of the rear housing 24 constitutes the discharge chamber H3. A discharge hole L2 is formed in the radial center of the fixed base plate 511 of the fixed scroll 51, connecting the compression chamber H2, which has moved to the innermost position, with the discharge chamber H3. Therefore, gaseous refrigerant compressed in the compression chamber H2 of the scroll unit 50 is discharged into the discharge chamber H3 through the discharge hole L2. A check valve (reed valve) 95 is attached to the discharge hole L2, which allows the gaseous refrigerant to flow from the compression chamber H2 to the discharge chamber H3 but restricts the flow of gaseous refrigerant from the discharge chamber H3 to the compression chamber H2.

[0041] The gas-liquid separation chamber H4 is provided in the rear housing 24. Specifically, in this embodiment, the gas-liquid separation chamber H4 is formed as a cylindrical space extending downward from the outer peripheral surface toward the inside of the bottom wall portion 242 of the rear housing 24. The discharge chamber H3 and the gas-liquid separation chamber H4 are in communication with each other via a communication hole L3. An oil separator 100 that separates lubricating oil contained in the gas refrigerant is disposed in the gas-liquid separation chamber H4. Although a centrifugal oil separator is used here, this is not limiting, and other types of oil separators may also be used. A discharge port P2 is provided in the gas-liquid separation chamber H4 above the oil separator 100. The discharge port P2 is connected to the refrigerant circuit (the high-pressure side thereof) via a connecting pipe or the like (not shown).

[0042] The back pressure chamber H5 is formed between the orbiting base plate 521 of the orbiting scroll 52 and the second partition wall portion 232 of the center housing 23. In this embodiment, the back pressure chamber H5 includes the internal space of the hollow protrusion portion 233 of the second partition wall portion 232. A lubricating oil passage L4 is formed in the center housing 23 and the rear housing 24, connecting the discharge chamber H3 and the back pressure chamber H5 and connecting the gas-liquid separation chamber H4 and the back pressure chamber H5. An orifice (throttle portion) OL is disposed in the lubricating oil passage L4. The back pressure chamber H5 is also connected to the suction chamber H1 via a small gap between the inner circumferential surface of the shaft insertion hole 234 and the outer circumferential surface of the rotary shaft 30. However, this is not limiting. The back pressure chamber H5 may be configured to communicate with the suction chamber H1 via a pressure release passage provided with an orifice or a back pressure control valve, or may be configured to communicate with the compression chamber H2 via a pressure release passage provided with a throttle valve or a check valve.

[0043] Here, the operation of the scroll compressor 10 will be briefly described.

[0044] When the electric motor 40 rotates the rotating shaft 30 by power supplied from the inverter 60, the rotation of the rotating shaft 30 is transmitted to the orbiting scroll 52 via the crank mechanism 70, causing the orbiting scroll 52 to orbit relative to the fixed scroll 51. Then, low-pressure gaseous refrigerant from the refrigerant circuit flows into the suction chamber H1 via the suction port P1, passes through the refrigerant passage L1, and reaches the space H6. It is then taken into the compression chamber H2 formed between the fixed scroll 51 and the orbiting scroll 52 and compressed. The gaseous refrigerant (high-pressure gaseous refrigerant) compressed in the compression chamber H2 is discharged into the discharge chamber H3 via the discharge hole L2 (and the check valve 95), and then flows into the gas-liquid separation chamber H4 via the communication hole L3. The lubricating oil contained in the gaseous refrigerant that flows into the gas-liquid separation chamber H4 is separated by the oil separator 100. The gaseous refrigerant from which the lubricating oil has been separated by the oil separator 100 is discharged to the refrigerant circuit from the discharge port P2. Meanwhile, the lubricating oil separated from the gaseous refrigerant by the oil separator 100 is stored at the bottom of the gas-liquid separation chamber H4. Note that a portion of the lubricating oil contained in the gaseous refrigerant discharged to the discharge chamber H3 is stored at the bottom of the discharge chamber H3.

[0045] The back pressure chamber H5 communicates with the discharge chamber H3 and the gas-liquid separation chamber H4 via the lubricating oil passage L4 and also communicates with the suction chamber H1 via a small gap between the inner circumferential surface of the shaft insertion hole 234 and the outer circumferential surface of the rotary shaft 30. Therefore, lubricating oil stored in the bottom of the discharge chamber H3 and / or the bottom of the gas-liquid separation chamber H4 is supplied to the back pressure chamber H5 via the lubricating oil passage L4 and is depressurized by the orifice OL. The back pressure chamber H5 and the suction chamber H1 communicate with each other via the small gap, restricting the amount of lubricating oil (and / or gaseous refrigerant) flowing from the back pressure chamber H5 to the suction chamber H1. Therefore, the pressure in the back pressure chamber H5 is maintained at an intermediate pressure Pm between the pressure Ps in the suction chamber H1 and the pressure Pd in ​​the discharge chamber H3 (= the pressure in the gas-liquid separation chamber H4). This intermediate pressure Pm presses the orbiting scroll 52 against the fixed scroll 51. That is, the back pressure chamber H5 applies a pressure (back pressure) Pm to the orbiting scroll 52, pressing it against the fixed scroll 51.

[0046] Next, a configuration for suppressing the influence of centrifugal force and the like caused by the orbiting motion of the orbiting scroll 52 in the scroll compressor 10 will be described.

[0047] The scroll compressor 10 has such a configuration mainly to suppress noise caused by vibration of the first bearing 214 and the second bearing 235 that support the rotating shaft 30. Also, this is to prevent an increase in the pressing force of the orbiting spiral wall 522 against the fixed spiral wall 512, which would increase wear of the fixed spiral wall 512 and / or the orbiting spiral wall 522, or damage to the fixed spiral wall 512 and / or the orbiting spiral wall 522.

[0048] The scroll compressor 10 has a configuration for suppressing the effects of centrifugal force and the like caused by the orbiting motion of the orbiting scroll 52, and is mainly provided with a balancer (hereinafter referred to as the "bush balancer") 721 integrally formed with the eccentric bush 72 and a balancer (hereinafter referred to as the "shaft balancer") 31 integrally formed with the rotating shaft 30.

[0049] 3 and 4 are schematic perspective views showing the rotating shaft 30, bush balancer 721, and shaft balancer 31, Fig. 5 is a view showing the rotating shaft 30, bush balancer 721, and shaft balancer 31 as viewed from the axial direction of the rotating shaft 30, and Fig. 6 is a view showing the rotating shaft 30, bush balancer 721, and shaft balancer 31 as viewed from the axial direction of the rotating shaft 30 (the opposite side to Fig. 5). In the following description, the dimension in the front-to-rear direction, in other words, the dimension corresponding to the axial direction of the rotating shaft 30, will be referred to as "thickness," and the dimension corresponding to the left-to-right direction will be referred to as "width."

[0050] The bushing balancer 721 is fixed to the outer peripheral surface near the front end of the eccentric bushing 72 (i.e., near the end on the rotary shaft 30 side). The bushing balancer 721 rotates integrally with the eccentric bushing 72. The bushing balancer 721 is disposed in the back pressure chamber H5 (see FIGS. 1 and 2). Note that reference numeral 74 in FIG. 4 denotes a snap ring that fixes the eccentric bushing 72 attached to the eccentric pin 71.

[0051] The bush balancer 721 has an annular fixed portion (hereinafter referred to as the "first fixed portion") 722 that is fitted onto and fixed to the outer peripheral surface 72b of the eccentric bush 72, a weight portion (hereinafter referred to as the "first weight portion") 723 that is provided radially outside the first fixed portion 722 (in other words, the eccentric bush 72) and spaced apart from the first fixed portion 722 (eccentric bush 72), and a connecting portion (hereinafter referred to as the "first connecting portion") 724 that connects the first fixed portion 722 and the first weight portion 723.

[0052] The first weight portion 723 is formed in a block shape. On the other hand, the first connecting portion 724 is formed in a plate shape. In other words, the first weight portion 723 is formed to be thicker than the first connecting portion 724. Furthermore, when the bush balancer 721 is viewed from the axial direction of the rotating shaft 30, the first weight portion 723 and the first connecting portion 724 are formed in a semicircular or approximately fan shape as a whole.

[0053] The first weight portion 723 has a rearward protruding portion 723a that protrudes rearward (i.e., toward the orbiting scroll 52) relative to the first connecting portion 724, and a first forward protruding portion 723b and a second forward protruding portion 723c that protrude forward (i.e., toward the rotary shaft 30) relative to the first connecting portion 724. In other words, the rearward protruding portion 723a, the first forward protruding portion 723b, and the second forward protruding portion 723c each constitute a part of the first weight portion 723. The first forward protruding portion 723b and the second forward protruding portion 723c are spaced apart from each other in the left-right direction, in other words, in the rotational direction R of the rotary shaft 30. In this embodiment, the first forward protruding portion 723b is formed smaller than the rearward protruding portion 723a, and the second forward protruding portion 723c is formed smaller than the rearward protruding portion 723a and the first forward protruding portion 723b.

[0054] The shaft balancer 31 is fixed to the outer peripheral surface near the rear end of the rotating shaft 30 (i.e., near the end on the eccentric pin 71 side). The shaft balancer 31 rotates integrally with the rotating shaft 30. The shaft balancer 31, like the bush balancer 721, is disposed in the back pressure chamber H5. The shaft balancer 31 is located in front of the bush balancer 721 within the back pressure chamber H5 (see Figures 1 and 2).

[0055] The shaft balancer 31 has an annular fixed portion (hereinafter referred to as the "second fixed portion") 32 that is fitted onto and fixed to the outer peripheral surface of the rotating shaft 30, a weight portion (hereinafter referred to as the "second weight portion") 33 that is provided radially outside the second fixed portion 32 (in other words, the rotating shaft 30) and spaced apart from the second fixed portion 32 (the rotating shaft 30), and a connecting portion (hereinafter referred to as the "second connecting portion") 34 that connects the second fixed portion 32 and the second weight portion 33.

[0056] The shaft balancer 31 is formed to have a generally constant thickness. The second connecting portion 34 is formed to be narrower than the second fixing portion 32 and the second weight portion 33.

[0057] Furthermore, in this embodiment, the distance between the first forward protrusion 723b and the second forward protrusion 723c of the bushing balancer 721 in the rotation direction R of the rotating shaft 30 is set to be larger than the width of the second connecting portion 34 of the shaft balancer 31. The second connecting portion 34 of the shaft balancer 31 is disposed between the first forward protrusion 723b and the second forward protrusion 723c of the bushing balancer 721 (see FIG. 5). Therefore, the bushing balancer 721 rotates integrally with the shaft balancer 31, and is allowed to be slightly displaced relative to the shaft balancer 31.

[0058] In this embodiment, as shown in FIGS. 5 and 6 , when viewed in the axial direction of the rotating shaft 30, a line passing through the center line CL0 of the rotating shaft 30 and the center line CL2 of the eccentric bushing 72 is defined as a first line VL, and a line passing through the center line CL0 of the rotating shaft 30 and perpendicular to the first line VL is defined as a second line HL. The first weight portion 723 of the bushing balancer 721 is located on the opposite side of the second line HL from the center line of the pin insertion hole 72a (= the center line CL1 of the eccentric pin 71). Furthermore, the center of gravity G1 of the bushing balancer 721 is located on the opposite side of the second line HL from the center line CL2 of the eccentric bushing 72. As described above, the center of gravity of the orbiting scroll 52 is located approximately on the center line CL2 of the eccentric bushing 72. Therefore, when viewed in the axial direction of the rotating shaft 30, the center of gravity G1 of the bushing balancer 721 is located on the opposite side of the second line HL from the center of gravity of the orbiting scroll 52. Furthermore, the center of gravity G1 of the bush balancer 721 is located on the opposite side of the first straight line VL from the center line CL1 of the eccentric pin 71.

[0059] When viewed from the axial direction of the rotating shaft 30, the second weight portion 33 of the shaft balancer 31 is located on the opposite side of the second straight line HL from the eccentric pin 71, and the second connecting portion 34 of the shaft balancer 31 extends from the second fixed portion 32 toward the second weight portion 33 at an incline with respect to the first straight line VL, i.e., at a predetermined angle θ (approximately 20° in this case). The center of gravity G2 of the shaft balancer 31 is located on the opposite side of the second straight line HL from the center line CL2 of the eccentric bushing 72. In other words, like the center of gravity G1 of the bush balancer 721, the center of gravity G2 of the shaft balancer 31 is located on the opposite side of the second straight line HL from the center of gravity of the orbiting scroll 52. Furthermore, the center of gravity G2 of the shaft balancer 31 is located on the same side of the first straight line VL as the center line CL1 of the eccentric pin 71.

[0060] The scroll compressor 10 according to the embodiment provides the following effects.

[0061] The scroll compressor 10 has a bush balancer 721 provided integrally with the eccentric bush 72, and the bush balancer 721 has a first weight portion 723 positioned radially outward of the eccentric bush 72.

[0062] As a result, the centrifugal force caused by the orbiting scroll 52 is offset by the centrifugal force generated in the bush balancer 721, and the pressing force of the orbiting spiral wall 522 against the fixed spiral wall 512 can be appropriately maintained. This prevents increased wear of the fixed spiral wall 512 and / or the orbiting spiral wall 522 and prevents damage to the fixed spiral wall 512 and / or the orbiting spiral wall 522. Furthermore, good sealing (hermetic sealing) of the compression chamber H2 formed between the fixed scroll 51 and the orbiting scroll 52 can be ensured.

[0063] The scroll compressor 10 further includes a shaft balancer 31 that is integral with the rotating shaft 30, and the shaft balancer 31 includes a second weight portion 33 that is located radially outward of the rotating shaft 30. When viewed from the axial direction of the rotating shaft 30, the center of gravity G1 of the bushing balancer 721 is located on the opposite side of the second straight line HL from the center line CL2 of the eccentric bushing 72 and on the opposite side of the first straight line VL from the center line CL1 of the eccentric pin 71. The center of gravity G2 of the shaft balancer 31 is located on the opposite side of the second straight line HL from the center line CL2 of the eccentric bushing 72 and on the same side of the first straight line VL as the center line CL1 of the eccentric pin 71.

[0064] With this configuration, the scroll compressor 10 according to this embodiment can achieve weight balance in the vertical direction, which is the direction along the first line VL, and weight balance in the horizontal direction, which is the direction along the second line HL perpendicular to the first line VL, with respect to the rotating shaft 30. Furthermore, the shaft balancer 31 can mainly suppress the influence of the moment generated by the centrifugal force of the orbiting scroll 52 and the bush balancer 721. Therefore, vibration / noise of the first bearing 214 and the second bearing 235 that support the rotating shaft 30 is suppressed, improving noise reduction (low vibration).

[0065] In addition, the bush balancer 721 has a first forward protruding portion 723b and a second forward protruding portion 723c that protrude forward (i.e., toward the shaft balancer 31) and are spaced apart from each other in the rotational direction of the rotating shaft 30, and the second connecting portion 34 of the shaft balancer 31 is arranged between the first forward protruding portion 723b and the second forward protruding portion 723c.

[0066] Therefore, the second connecting portion 34 of the shaft balancer 31 functions as a stopper that limits the swing range of the bush balancer 721, preventing the bush balancer 721 from swinging more than necessary due to inertia, etc. Furthermore, the space required for arranging the shaft balancer 31 and the bush balancer 721 in the axial direction of the rotating shaft 30 can also be reduced.

[0067] Furthermore, the combination of the bush balancer 721 and the shaft balancer 31 as described above can also address issues that may arise due to increased speed and weight reduction (particularly thinning of the volute wall) of the scroll compressor 10, such as increased vibration and noise during high-speed operation. An example of this will be described below.

[0068] When the shaft balancer 31 and the bush balancer 721 are used as a configuration for suppressing the effects of centrifugal force and the like caused by the orbiting motion of the orbiting scroll 52, the imbalance caused by the orbiting motion of the orbiting scroll 52 (hereinafter referred to as "imbalance (A)"), the imbalance caused by the bush balancer 721 (hereinafter referred to as "imbalance (B)") and the imbalance caused by the shaft balancer 31 (hereinafter referred to as "imbalance (C)") are configured to cancel each other out.

[0069] Normally, the orbiting scroll 52, the bush balancer 721, and the shaft balancer 31 are dynamically balanced. In other words, "unbalance (A) = unbalance (B) + unbalance (C)." However, as the speed and weight of the scroll compressor 10 increase, the pressing force of the orbiting scroll wall 522 against the fixed scroll wall 512 during high-speed operation increases, which can cause the fixed scroll wall 512 to bend outward (elastically).

[0070] When the fixed spiral wall 512 tilts outward, the orbiting radius AOR of the orbiting scroll 52, which is determined by the contact between the orbiting spiral wall 522 and the fixed spiral wall 512, increases. As the orbiting radius AOR of the orbiting scroll 52 increases, the dynamic unbalance of the orbiting scroll 52 increases (unbalance (A) ⇒ unbalance (A') > unbalance (A)). Also, as the orbiting radius AOR of the orbiting scroll 52 increases, the eccentric bushing 72 (i.e., the bush balancer 721) swings about the eccentric pin 71, and the dynamic unbalance of the bush balancer 721 decreases (unbalance (B) ⇒ unbalance (B') < unbalance (B)).

[0071] As a result, even if the orbiting scroll 52, bush balancer 721, and shaft balancer 31 are dynamically balanced during low- to medium-speed operation, the orbiting scroll 52, bush balancer 721, and shaft balancer 31 are no longer dynamically balanced during high-speed operation, meaning that "unbalance (A') > unbalance (B') + unbalance (C)" occurs, resulting in increased vibration and noise.

[0072] Here, vibration / noise during low- to medium-speed operation is usually smaller than vibration / noise during high-speed operation. Therefore, even if the vibration / noise during low- to medium-speed operation increases slightly, if the vibration / noise during high-speed operation decreases, it is possible to reduce the vibration / noise of the scroll compressor 10 as a whole.

[0073] In order to reduce the vibration / noise during high-speed operation as described above, for example, the unbalance (B) of the shaft balancer 31 can be set to be greater than the unbalance (B) that can achieve dynamic balance among the orbiting scroll 52, bush balancer 721, and shaft balancer 31 when the orbiting radius AOR of the orbiting scroll 52 is the design value, thereby achieving dynamic balance among the orbiting scroll 52, bush balancer 721, and shaft balancer 31 during high-speed operation, that is, ``unbalance (A') = unbalance (B') + unbalance (C).''

[0074] As an example, the orbiting radius AOR of the orbiting scroll 52 increases by approximately 0.5 to 2% from the reference value (design value) during high-speed operation, and the unbalance (B) of the bush balancer 721 can be set so that the dynamic unbalance (unbalance (A')) of the orbiting scroll 52 is offset by the unbalance (C) of the shaft balancer 31 and the dynamic unbalance (unbalance (B')) of the bush balancer 721 after the eccentric bush 72 oscillates due to the increase in the orbiting radius AOR.

[0075] In this case, vibration / noise can be reduced during high-speed operation, but dynamic balance between the orbiting scroll 52, the bush balancer 721, and the shaft balancer 31 cannot be achieved during low- to medium-speed operation. In other words, "unbalance (A) < unbalance (B) + unbalance (C)" occurs, raising concerns about increased vibration / noise during low- to medium-speed operation. However, experiments conducted by the inventors have confirmed that, although vibration / noise increases during low- to medium-speed operation by adopting the above-described combination of the bush balancer 721 and the shaft balancer 31, the impact is small, and it is possible to reduce the vibration / noise of the entire scroll compressor 10. Therefore, it is possible to effectively address the increase in vibration / noise during high-speed operation that occurs due to the increased speed and weight of the scroll compressor 10.

[0076] In the above-described embodiment, the bush balancer 721 is formed separately from the eccentric bush 72 and fixed to the outer peripheral surface of the eccentric bush 72. However, this is not limitative. The eccentric bush 72 and the bush balancer 721 may be formed integrally, that is, as a single component (for example, an eccentric bush with a balancer).

[0077] The above describes the embodiments and modifications of the present invention, but the present invention is not limited to the above-described embodiments and modifications, and it goes without saying that further modifications and changes are possible based on the technical concept of the present invention. [Explanation of symbols]

[0078] 10...Scroll compressor, 30...Rotating shaft, 31...Shaft balancer, 32...Second fixed portion, 33...Second weight portion, 34...Second connecting portion, 51...Fixed scroll, 52...Orbiting scroll, 71...Eccentric pin, 72...Eccentric bushing, 73...Bearing, 511...Fixed base plate, 512...Fixed spiral wall, 521...Orbiting base plate, 522...Orbiting spiral wall, 523...Cylindrical portion, 721...Bush balancer, 722 ...first fixed portion, 723...first weight portion, 723a...rear protruding portion, 723b...first forward protruding portion, 723c...second forward protruding portion, G1...center of gravity of bush balancer, G2...center of gravity of shaft balancer, CL0...center line of rotating shaft, CL1...center line of eccentric pin, CL2...center line of eccentric bush, H1...suction chamber, H2...compression chamber, H3...discharge chamber, H5...back pressure chamber, HL...second straight line, VL...first straight line,

Claims

1. a fixed scroll having a fixed base plate and a fixed spiral wall erected on the fixed base plate; an orbiting scroll having a rotating base plate, an orbiting scroll wall provided on one surface of the orbiting base plate and engaging with the fixed spiral wall, and a cylindrical portion formed on the other surface of the orbiting base plate to protrude therefrom; a compression chamber formed between the fixed scroll and the orbiting scroll; a driving force transmission mechanism including a rotating shaft that is driven to rotate, an eccentric pin provided at one end of the rotating shaft, and an eccentric bushing that is rotatably attached to the eccentric pin and rotatably inserted inside the cylindrical portion via a bearing, and that transmits driving force to the orbiting scroll; and The scroll compressor is configured such that the driving force causes the orbiting scroll to orbit relative to the fixed scroll, thereby changing the volume of the compression chamber, thereby compressing a fluid taken into the compression chamber, a bush balancer provided integrally with the eccentric bushing and having a first weight portion located radially outward of the eccentric bushing; a shaft balancer provided integrally with the rotary shaft and having a second weight portion located radially outward of the rotary shaft; and When viewed from the axial direction of the rotating shaft, a line passing through the center line of the rotating shaft and the center line of the eccentric bushing is defined as a first line, and a line passing through the center line of the rotating shaft and perpendicular to the first line is defined as a second line, the center of gravity of the bush balancer is located on the opposite side of the second line to the center line of the eccentric bushing and on the opposite side of the first line to the center line of the eccentric pin, and the center of gravity of the shaft balancer is located on the opposite side of the second line to the center line of the eccentric bushing and on the same side of the first line as the center line of the eccentric pin, The bush balancer has a first protruding portion and a second protruding portion that protrude toward the shaft balancer and are spaced apart from each other in the rotational direction of the rotary shaft, and a part of the shaft balancer is disposed between the first protruding portion and the second protruding portion. Scroll type compressor.

2. the bush balancer further includes a first fixed portion fixed to an outer peripheral surface of the eccentric bushing, and a first connecting portion connecting the first fixed portion and the first weight portion, The scroll compressor according to claim 1 , wherein the first protrusion and the second protrusion are provided on the first weight portion.

3. 2. The scroll compressor according to claim 1, wherein the shaft balancer further includes a second fixed portion fixed to an outer circumferential surface of the rotating shaft and a second connecting portion connecting the second fixed portion and the second weight portion, the second connecting portion being disposed between the first protruding portion and the second protruding portion.

4. The scroll compressor according to claim 3 , wherein the second connecting portion extends at an angle with respect to the first straight line when viewed in the axial direction of the rotary shaft.

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