Scroll Fluid Machine

Abstract

To successfully supply lubricating oil to a bearing supporting an eccentric bush.SOLUTION: A scroll compressor 100 comprises a fixed scroll 122 fixed to a housing 140, a turning scroll 124 for performing turning motion with respect to the fixed scroll 122, and a conversion mechanism 300 for mutually converting rotating motion of a driving shaft 166 and the turning motion of the turning scroll 124. The conversion mechanism 300 includes: an eccentric shaft 260 provided on an end surface of the driving shaft 166, and eccentric with respect to the driving shaft 166; an eccentric bush 270 comprising a through hole 271 into which the eccentric shaft 260 is inserted; and a bearing 280 press-fitted into a boss part 250 formed in the turning scroll 124, and supporting an outer peripheral surface 272 of the eccentric bush 270. A lubricating oil supply flow passage 350 for supplying lubricating oil to the bearing 280 is formed in the eccentric bush 270 so as to penetrate therethrough. An outflow port 356 of the lubricating oil supply flow passage 350 is arranged in the outer peripheral surface 272 of the eccentric bush 270.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a scroll fluid machine such as a scroll compressor or a scroll expander. [Background technology]

[0002] Patent Document 1 discloses a scroll compressor, which is an example of a scroll fluid machine. In this scroll compressor, a drive shaft is connected to a revolving scroll via a crank mechanism. The crank mechanism has a boss portion formed on the back pressure chamber side end face of the bottom plate of the revolving scroll, and an eccentric bush eccentrically attached to a crank pin provided at the end of the drive shaft. The eccentric bush is rotatably supported on the inner peripheral surface of the boss portion via a bearing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-015188 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, since the above-mentioned bearing is lubricated by splashing lubricating oil from a back pressure chamber formed on the back side of the orbiting scroll, there is a risk that the supply of lubricating oil to the bearing may be insufficient.

[0005] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to efficiently supply lubricating oil to a bearing that supports an eccentric bushing. [Means for solving the problem]

[0006] According to one aspect of the present invention, a scroll fluid machine has a rotating main shaft rotatably provided within a housing, a fixed scroll fixed to the housing, an orbiting scroll that orbits relative to the fixed scroll, and a conversion mechanism that converts between the rotational motion of the rotating main shaft and the orbital motion of the orbiting scroll. The conversion mechanism includes an eccentric shaft provided on an end face of the rotating main shaft and eccentric with respect to the rotating main shaft, an eccentric bush having a through hole into which the eccentric shaft is fitted, and a bearing that is press-fitted into a boss portion formed on the orbiting scroll to support the outer circumferential surface of the eccentric bush. A lubricating oil supply passage for supplying lubricating oil to the bearing is formed through the eccentric bush. . Jun Oil supply passage outlet is biased The core bush is disposed on the outer peripheral surface of the core bush. The scroll fluid machine further includes a back pressure chamber formed on the rear side of the orbiting scroll for generating a back pressure that presses the orbiting scroll against the fixed scroll. The inlet of the lubricating oil supply passage is in communication with the back pressure chamber. Effect of the Invention

[0007] According to one aspect of the present invention, the outlet of the lubricating oil supply passage is disposed on the outer circumferential surface of the eccentric bushing, whereby the lubricating oil can be directly supplied to the bearing from the outlet of the lubricating oil supply passage, thereby enabling the lubricating oil to be efficiently supplied to the bearing. [Brief description of the drawings]

[0008] [Figure 1] 1 is a vertical sectional view of a scroll compressor according to a first embodiment of the present invention. [Diagram 2] FIG. 3 is a block diagram illustrating flows of a gas refrigerant and a lubricating oil in the first embodiment. [Diagram 3] FIG. 3 is an enlarged cross-sectional view of a conversion mechanism in the first embodiment. [Figure 4] FIG. 4 is a perspective view of an eccentric bush in the first embodiment. [Diagram 5] FIG. 4 is a cross-sectional view of an eccentric bush in the first embodiment. [Figure 6] FIG. 11 is an enlarged cross-sectional view of a conversion mechanism according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Here, a case will be described in which the scroll fluid machine according to the present invention is a scroll compressor. However, it goes without saying that the present invention can also be applied to a scroll expander.

[0010] FIG. 1 is a vertical sectional view of a scroll compressor 100 according to a first embodiment of the present invention.

[0011] The scroll compressor 100 is incorporated, for example, in a refrigerant circuit of a vehicle air conditioner, and compresses and discharges a gaseous refrigerant (fluid) sucked from a low pressure side of the refrigerant circuit. The scroll compressor 100 includes a scroll unit 120, a housing 140 containing a suction chamber H1 and a discharge chamber H2 of the gaseous refrigerant, an electric motor 160 that drives the scroll unit 120, and an inverter 180 that drives and controls the electric motor 160. The scroll unit 120 may be driven by, for example, an engine output instead of the electric motor 160. The inverter 180 may not be incorporated in the scroll compressor 100.

[0012] The scroll unit 120 has a fixed scroll 122 and an orbiting scroll (movable scroll) 124 that mesh with each other. The fixed scroll 122 includes a disk-shaped bottom plate 122A and an involute-shaped (spiral-shaped) wrap 122B standing from one surface of the bottom plate 122A. The orbiting scroll 124, like the fixed scroll 122, includes a disk-shaped bottom plate 124A and an involute-shaped wrap 124B standing from one surface of the bottom plate 124A. Here, the disk shape may be such that it can be recognized as a disk shape by appearance, and for example, a convex portion, a concave portion, a slit, or the like may be formed on the outer surface (the same applies below for the shape).

[0013] The fixed scroll 122 and the orbiting scroll 124 are arranged so that their wraps 122B and 124B mesh with each other. In detail, the tip of the wrap 122B of the fixed scroll 122 is in contact with one surface of the bottom plate 124A of the orbiting scroll 124, and the tip of the wrap 124B of the orbiting scroll 124 is in contact with one surface of the bottom plate 122A of the fixed scroll 122. Tip seals (not shown) are attached to the tip of each of the wraps 122B and 124B.

[0014] The fixed scroll 122 and the orbiting scroll 124 are arranged such that the wraps 122B and 124B are offset from each other in the circumferential direction and the side walls of the wraps 122B and 124B are in partial contact with each other. Therefore, a crescent-shaped sealed space that functions as a compression chamber H3 is formed between the wrap 122B of the fixed scroll 122 and the wrap 124B of the orbiting scroll 124.

[0015] The orbiting scroll 124 orbits relative to the fixed scroll 122. The orbiting scroll 124 is arranged to be able to revolve around the axis of the fixed scroll 122 via a conversion mechanism 300, which will be described later, while being prevented from rotating. Therefore, the scroll unit 120 moves the compression chamber H3, which is defined by the wrap 122B of the fixed scroll 122 and the wrap 124B of the orbiting scroll 124, to the center, and gradually reduces the volume thereof. As a result, the scroll unit 120 compresses the gas refrigerant sucked into the compression chamber H3 from the outer ends of the wraps 122B and 124B.

[0016] The housing 140 has a front housing 142 that houses the electric motor 160 and the inverter 180, a center housing 144 that houses the scroll unit 120, a rear housing 146, and an inverter cover 148. The housing 140 of the scroll compressor 100 is configured by fastening the front housing 142, the center housing 144, the rear housing 146, and the inverter cover 148 together with fasteners (not shown) including, for example, bolts and washers.

[0017] The front housing 142 has a cylindrical peripheral wall portion 142A and a thin plate-shaped partition wall portion 142B. The inner space of the front housing 142 is partitioned by the partition wall portion 142B into a space for accommodating the electric motor 160 and a space for accommodating the inverter 180. One end side of the peripheral wall portion 142A, i.e., an opening of the space for accommodating the inverter 180, is closed by an inverter cover 148. The other end side of the peripheral wall portion 142A, i.e., an opening of the space for accommodating the electric motor 160, is closed by a center housing 144. A cylindrical support portion 142B1 is provided at the radial center of the partition wall portion 142B toward the other end side of the peripheral wall portion 142A, which rotatably supports one end of a drive shaft 166 described later. Here, the drive shaft 166 is an example of the "rotating main shaft" of the present invention, and is provided rotatably within the housing 140.

[0018] In addition, a suction chamber H1 for gaseous refrigerant is defined by the peripheral wall 142A and the partition wall 142B of the front housing 142 and the center housing 144. In the suction chamber H1, gaseous refrigerant is drawn from the low pressure side of the refrigerant circuit through a suction port P1 formed in the peripheral wall 142A. In the suction chamber H1, the gaseous refrigerant flows around the electric motor 160 to cool the electric motor 160, and one suction chamber H1 is formed in which a space on one side of the electric motor 160 communicates with a space on the other side of the electric motor 160. In the suction chamber H1, an appropriate amount of lubricating oil is stored to lubricate sliding parts such as the drive shaft 166 that is rotated. Therefore, in the suction chamber H1, the gaseous refrigerant flows as a mixed fluid with the lubricating oil.

[0019] The center housing 144 has a cylindrical shape with a bottom that is open on the side opposite to the side fastened to the front housing 142, and can accommodate the scroll unit 120 inside. The center housing 144 has a cylindrical portion 144A and a bottom wall portion 144B on one end side thereof. The scroll unit 120 is accommodated in a space defined by the cylindrical portion 144A and the bottom wall portion 144B. A fitting portion 144A1 into which the fixed scroll 122 fits is formed on the other end side of the cylindrical portion 144A. Therefore, the opening of the center housing 144 is closed by the fixed scroll 122. The bottom wall portion 144B is formed such that its radial center portion bulges toward the electric motor 160. A through hole for passing the other end of the drive shaft 166 is formed in the radial center portion of the bulging portion 144B1 of the bottom wall portion 144B. A fitting portion is formed on the scroll unit 120 side of the bulging portion 144B1 into which a bearing 200 that rotatably supports the other end of the drive shaft 166 is fitted.

[0020] A thin, annular thrust plate 210 is disposed between the bottom wall portion 144B of the center housing 144 and the bottom plate 124A of the orbiting scroll 124. The outer periphery of the bottom wall portion 144B receives thrust force from the orbiting scroll 124 via the thrust plate 210. Seal members 220 are embedded in the portions of the bottom wall portion 144B and the bottom plate 124A that come into contact with the thrust plate 210.

[0021] A back pressure chamber H4 is formed between the end face of the bottom plate 124A on the electric motor 160 side and the bottom wall portion 144B, i.e., between the end face of the orbiting scroll 124 opposite the fixed scroll 122 and the center housing 144. A refrigerant introduction passage L1 is formed in the center housing 144 to introduce gaseous refrigerant from the suction chamber H1 to a space H5 near the outer ends of the wraps 122B and 124B of the scroll unit 120. The refrigerant introduction passage L1 communicates between the space H5 and the suction chamber H1, so that the pressure in the space H5 is equal to the pressure in the suction chamber H1 (suction pressure Ps).

[0022] The rear housing 146 is fastened by a fastener to the end of the cylindrical portion 144A of the center housing 144 on the fitting portion 144A1 side. Therefore, the fixed scroll 122 is fixed with its bottom plate 122A sandwiched between the fitting portion 144A1 and the rear housing 146. In other words, the fixed scroll 122 is fixed to the housing 140. The rear housing 146 has a bottomed cylindrical shape with an open side fastened to the center housing 144, and has a cylindrical portion 146A and a bottom wall portion 146B at the other end.

[0023] A discharge chamber H2 for the gaseous refrigerant is defined by the cylindrical portion 146A and the bottom wall portion 146B of the rear housing 146 and the bottom plate 122A of the fixed scroll 122. A discharge passage (discharge hole) L2 for the gaseous refrigerant is formed in the center of the bottom plate 122A. A check valve 230, for example a reed valve, is provided in the discharge passage L2 to regulate the flow of the gaseous refrigerant from the discharge chamber H2 to the scroll unit 120. The gaseous refrigerant compressed in the compression chamber H3 of the scroll unit 120 is discharged into the discharge chamber H2 via the discharge passage L2 and the check valve 230.

[0024] Although not shown, an oil separator that separates lubricating oil from the gaseous refrigerant in the discharge chamber H2 is disposed in the rear housing 146. The gaseous refrigerant from which the lubricating oil has been separated by the oil separator is discharged to the high pressure side of the refrigerant circuit via a discharge port P2 formed in the bottom wall portion 146B of the rear housing 146. Meanwhile, the lubricating oil separated by the oil separator is supplied to the back pressure chamber H4 via a back pressure supply passage L3, which will be described later.

[0025] The electric motor 160 is, for example, a three-phase AC motor, and has a rotor 162 and a stator core unit 164 arranged radially outside the rotor 162. For example, a direct current from an on-board battery (not shown) is converted to an alternating current by an inverter 180 and supplied to the stator core unit 164 of the electric motor 160.

[0026] The rotor 162 is rotatably supported on the radial inside of the stator core unit 164 via a drive shaft 166 that is press-fitted into an axial hole formed in the radial center of the rotor 162. One end of the drive shaft 166 is rotatably supported by a support portion 142B1 of the front housing 142 via a slide bearing 240. The other end of the drive shaft 166 passes through a through hole formed in the center housing 144 and is rotatably supported by a bearing 200. When a magnetic field is generated in the stator core unit 164 by power supply from the inverter 180, a rotational force acts on the rotor 162, and the drive shaft 166 is rotationally driven. The other end of the drive shaft 166 is connected to the orbiting scroll 124 via a conversion mechanism 300.

[0027] The conversion mechanism 300 has a function of converting between the rotational motion of the above-mentioned rotating main shaft (the drive shaft 166 in this embodiment) and the orbiting motion of the orbiting scroll 124. The details of the conversion mechanism 300 will be described later with reference to Figs. 3 to 5. In this embodiment, the orbiting scroll 124 is capable of revolving around the axis of the fixed scroll 122 via the conversion mechanism 300 while its rotation is prevented. A balancer weight (counterweight) 290 that counters the centrifugal force of the orbiting scroll 124 is attached to the other end of the drive shaft 166.

[0028] FIG. 2 is a block diagram for explaining the flows of gaseous refrigerant and lubricating oil in the scroll compressor 100. As shown in FIG.

[0029] As shown in Figures 1 and 2, low-temperature, low-pressure gas refrigerant from the low-pressure side of the refrigerant circuit is introduced into the suction chamber H1 through the suction port P1, and then guided to the space H5 near the outer end of the scroll unit 120 through the refrigerant introduction passage L1. The gas refrigerant in the space H5 is then taken into the compression chamber H3 of the scroll unit 120 and compressed. The gas refrigerant compressed in the compression chamber H3 is discharged into the discharge chamber H2 through the discharge passage L2 and the check valve 230, and then discharged to the high-pressure side of the refrigerant circuit through the discharge port P2. In this way, the scroll unit 120 is configured to compress the gas refrigerant flowing in through the suction chamber H1 in the compression chamber H3 and discharge the gas refrigerant through the discharge chamber H2.

[0030] 1, the scroll compressor 100 further includes a back pressure control valve 400 for controlling the back pressure Pm of the back pressure chamber H4. The back pressure control valve 400 is a mechanical (autonomous) pressure regulating valve that operates in response to the pressure difference between the discharge pressure Pd of the discharge chamber H2 and the back pressure Pm of the back pressure chamber H4 and automatically adjusts the valve opening degree so that the back pressure Pm of the back pressure chamber H4 approaches a target back pressure Pc. The back pressure control valve 400 is accommodated in an accommodation chamber 146C formed in the bottom wall portion 146B of the rear housing 146 so as to extend from the outer circumferential surface of the bottom wall portion 146B in a direction perpendicular to the central axis of the drive shaft 166 of the electric motor 160.

[0031] As shown in FIGS. 1 and 2, the scroll compressor 100 further includes a back pressure supply passage L3, a pressure release passage L4, and a suction pressure sensing passage L5 in addition to the refrigerant introduction passage L1 and the discharge passage L2.

[0032] The back pressure supply passage L3 is formed in the rear housing 146 and the center housing 144 so as to communicate between the discharge chamber H2 and the back pressure chamber H4. Here, the back pressure supply passage L3 in the rear housing 146 passes through the accommodation chamber 146C in which the back pressure control valve 400 is accommodated. Then, the lubricating oil separated from the gas refrigerant in the discharge chamber H2 by the oil separator is guided to the back pressure chamber H4 via the back pressure control valve 400 and the back pressure supply passage L3, where it is used to lubricate each sliding portion and increase the back pressure Pm in the back pressure chamber H4.

[0033] The back pressure control valve 400 is disposed in the back pressure supply passage L3 so as to form a part of the back pressure supply passage L3. Therefore, the lubricant oil separated from the gas refrigerant in the discharge chamber H2 is supplied to the back pressure chamber H4 through the back pressure supply passage L3 located downstream thereof while being appropriately depressurized by the back pressure control valve 400. In other words, the back pressure Pm is adjusted by adjusting the opening of the back pressure supply passage L3 connected to the inlet side (upstream side) of the back pressure chamber H4, thereby increasing or decreasing the flow rate of the lubricant oil flowing into the back pressure chamber H4.

[0034] The pressure release passage L4 is formed to penetrate the drive shaft 166 in the axial direction so as to communicate between the back pressure chamber H4 and the suction chamber H1. An orifice OL is disposed midway through the pressure release passage L4, for example, at the end of the drive shaft 166 on the suction chamber H1 side. Therefore, the lubricating oil in the back pressure chamber H4 is returned to the suction chamber H1 while the flow rate is restricted by the orifice OL.

[0035] The suction pressure sensing passage L5 communicates between a space H5 near the outer end of the scroll unit 120 and the accommodation chamber 146C so that the suction pressure Ps of the suction chamber H1 can be sensed by the back pressure control valve 400. Specifically, the suction pressure sensing passage L5 is formed in the bottom plate 122A of the fixed scroll 122 and the rear housing 146. Although the suction pressure sensing passage L5 indirectly senses the suction pressure Ps of the suction chamber H1 via the space H5, it is also possible to directly sense the suction pressure Ps of the suction chamber H1.

[0036] Here, the back pressure chamber H4 (a machine chamber in which revolution drive elements such as the drive shaft 166 are provided) is formed on the back side of the orbiting scroll 124 (i.e., the end face side of the orbiting scroll 124 opposite the fixed scroll 122). The back pressure chamber H4 generates a back pressure Pm that presses the orbiting scroll 124 toward the fixed scroll 122. Therefore, the orbiting scroll 124 is pressed against the fixed scroll 122 by the back pressure Pm of the back pressure chamber H4. During compression operation of the scroll unit 120, if the resultant force of the back pressure Pm acting on the back pressure chamber H4 side end face of the bottom plate 124A of the orbiting scroll 124 is lower than the compression reaction force acting on the compression chamber H3 side end face of the bottom plate 124A, that is, if the back pressure is insufficient, a gap will be generated between the tip of the wrap 124B of the orbiting scroll 124 and the bottom plate 122A of the fixed scroll 122, and a gap will be generated between the bottom plate 124A of the orbiting scroll 124 and the tip of the wrap 122B of the fixed scroll 122, decreasing the volumetric efficiency of the compressor. When the back pressure Pm falls below the target back pressure Pc, the back pressure control valve 400 increases the back pressure Pm to approach the target back pressure Pc so as to avoid an insufficient back pressure state.

[0037] On the other hand, when the resultant force of the back pressure Pm in the back pressure chamber H4 is higher than the compression reaction force, that is, when an excessive back pressure state occurs, the frictional force between the fixed scroll 122 and the orbiting scroll 124 increases, and the mechanical efficiency of the compressor decreases. When the back pressure Pm exceeds the target back pressure Pc, the back pressure control valve 400 reduces the back pressure Pm to approach the target back pressure Pc so as to prevent an excessive back pressure state.

[0038] Next, details of the conversion mechanism 300 will be described with reference to Figs. 3 to 5 in addition to Fig. 1. Fig. 3 is an enlarged cross-sectional view of the conversion mechanism 300. Fig. 4 is a perspective view of the eccentric bush 270. Fig. 5 is a cross-sectional view of the eccentric bush 270.

[0039] The conversion mechanism 300 has an eccentric shaft (crank pin) 260, an eccentric bush 270, and a bearing 280. The eccentric shaft 260 is provided on the other end surface of the drive shaft 166, and is eccentric (offset) with respect to the drive shaft 166. The eccentric bush 270 is cylindrical, and has a through hole 271 into which the eccentric shaft 260 is fitted at a position eccentric from the central axis BS. Therefore, the eccentric bush 270 is attached in an eccentric state to the eccentric shaft 260 via the through hole 271.

[0040] The bearing 280 is press-fitted into a cylindrical boss portion 250 formed on the end surface of the bottom plate 124A of the orbiting scroll 124 on the back pressure chamber H4 side to support an outer circumferential surface 272 of the eccentric bush 270. In this embodiment, a sliding bearing is used as the bearing 280. Therefore, the eccentric bush 270 is rotatably supported on the inner circumferential surface of the boss portion 250 via the bearing 280. In this manner, the orbiting scroll 124 is capable of revolving around the axis of the fixed scroll 122 via the conversion mechanism 300 while its rotation is prevented.

[0041] A lubricant supply passage 350 for supplying lubricant to the bearing 280 is formed through the eccentric bush 270. The lubricant supply passage 350 includes an axial passage portion 351 extending in the axial direction of the eccentric bush 270 and a radial passage portion 352 extending in the radial direction of the eccentric bush 270.

[0042] The axial flow passage portion 351 extends approximately parallel to the central axis BS of the eccentric bushing 270 and the central axis RS of the drive shaft 166, and penetrates the eccentric bushing 270. The radial flow passage portion 352 branches off from the middle of the axial flow passage portion 351, extends in the radial direction of the eccentric bushing 270, and reaches an outer circumferential surface 272 of the eccentric bushing 270.

[0043] On the end face of the eccentric bush 270 adjacent to the other end face of the drive shaft 166, a recess 273 extending in the radial direction of the eccentric bush 270 is formed, and an opening at one end side of the axial flow path portion 351 is located on the bottom surface of this recess 273. This opening can function as an inlet 355 of the lubricating oil supply passage 350. That is, the axial flow path portion 351 has the inlet 355 of the lubricating oil supply passage 350.

[0044] An opening at one end side of the radial flow path portion 352 located on the outer peripheral surface 272 of the eccentric bush 270 can function as an outlet 356 of the lubricating oil supply passage 350. That is, the radial flow path portion 352 has the outlet 356 of the lubricating oil supply passage 350. The outlet 356 of the lubricating oil supply passage 350 faces the inner peripheral surface (support surface) 281 of the bearing 280. Incidentally, the outlet 356 of the lubricating oil supply passage 350 is preferably arranged so as to face the axial center portion of the inner peripheral surface 281 of the bearing 280.

[0045] As shown in FIG. 5, in the present embodiment, when the eccentric bush 270 is divided into a first region T1 and a second region T2 by a first virtual plane PL1 including the central axis RS of the drive shaft 166, within the first region T1, the central axis BS of the eccentric bush 270, the lubricating oil supply passage 350, and the through hole 271 are located. This first virtual plane PL1 is a virtual plane orthogonal to a second virtual plane PL2 including both the central axis RS of the drive shaft 166 and the central axis BS of the eccentric bush 270.

[0046] In the present embodiment, when the distance between the first virtual plane PL1 and the central axis BS of the eccentric bush 270 is N1, and the distance between the first virtual plane PL1 and the central axis WS of the axial flow path portion 351 is N2, the relationship N1 < N2 is satisfied. That is, when viewed from the first virtual plane PL1, the central axis WS of the axial flow path portion 351 is farther away from the central axis BS of the eccentric bush 270. Also, when viewed from the first virtual plane PL1, the lubricating oil supply passage 350 is farther away from the central axis BS of the eccentric bush 270.

[0047] In this embodiment, assuming that the distance between the central axis RS of the drive shaft 166 and the central axis BS of the eccentric bush 270 is N3, and the distance between the central axis RS of the drive shaft 166 and the central axis WS of the axial flow path portion 351 is N4, the relationship N3 < N4 is satisfied. That is, when viewed from the central axis RS of the drive shaft 166, the central axis WS of the axial flow path portion 351 is farther away from the central axis BS of the eccentric bush 270. Also, when viewed from the central axis RS of the drive shaft 166, the lubricating oil supply flow path 350 is farther away from the central axis BS of the eccentric bush 270.

[0048] Here, the supply of lubricating oil to the bearing 280 will be described with reference to FIGS. 1 and 3 to 5.

[0049] A part of the lubricating oil in the back pressure chamber H4 enters the axial flow path portion 351 from the inlet 355 through the concave portion 273 of the eccentric bush 270. Then, due to the centrifugal force generated by the rotational movement of the drive shaft 166 with the central axis RS of the drive shaft 166 as the rotation center, most of the lubricating oil in the axial flow path portion 351 reaches the radial flow path portion 352 and is supplied from the outlet 356 to the inner peripheral surface 281 of the bearing 280. In order to sufficiently obtain the action of this centrifugal force, in this embodiment, the layout of the lubricating oil supply flow path 350 as described above is adopted.

[0050] According to this embodiment, the scroll compressor 100, which is an example of a scroll fluid machine, includes a drive shaft 166 (rotation main shaft) rotatably provided in a housing 140, a fixed scroll 122 fixed to the housing 140, an orbiting scroll 124 that orbits with respect to the fixed scroll 122, and a conversion mechanism 300 that converts between the rotational motion of the drive shaft 166 (rotation main shaft) and the orbital motion of the orbiting scroll 124. The conversion mechanism 300 includes an eccentric shaft 260 provided on an end face of the drive shaft 166 (rotation main shaft) and eccentric with respect to the drive shaft 166 (rotation main shaft), an eccentric bush 270 having a through hole 271 into which the eccentric shaft 260 is fitted, and a bearing 280 that is press-fitted into a boss portion 250 formed on the orbiting scroll 124 and supports an outer circumferential surface 272 of the eccentric bush 270. A lubricant supply passage 350 for supplying lubricant to the bearing 280 is formed through the eccentric bush 270. The outlet 356 of the lubricating oil supply passage 350 is disposed on the outer circumferential surface 272 of the eccentric bush 270. This allows the lubricating oil to be directly supplied to the bearing 280 from the outlet 356 of the lubricating oil supply passage 350, so that the lubricating oil can be supplied to the bearing 280 satisfactorily.

[0051] Furthermore, according to this embodiment, the outlet 356 of the lubricant oil supply passage 350 faces the inner circumferential surface 281 of the bearing 280. This allows the lubricant oil to be supplied to the inner circumferential surface 281 of the bearing 280 in an excellent manner.

[0052] Further, according to this embodiment, the lubricant oil supply passage 350 includes an axial passage portion 351 extending in the axial direction of the eccentric bushing 270, and a radial passage portion 352 extending in the radial direction of the eccentric bushing 270. The axial passage portion 351 has an inlet 355 of the lubricant oil supply passage 350. The radial passage portion 352 has an outlet 356 of the lubricant oil supply passage 350. This makes it possible to easily form the lubricant oil supply passage 350.

[0053] According to this embodiment, the lubricant supply passage 350 is located farther from the central axis RS of the drive shaft 166 (main rotating shaft) than the central axis BS of the eccentric bush 270. This makes it possible to actively supply lubricant to the bearing 280 by utilizing the centrifugal force generated by the rotational motion of the drive shaft 166.

[0054] Furthermore, according to this embodiment, when the eccentric bushing 270 is divided into a first region T1 and a second region T2 by a first imaginary plane PL1 including a central axis RS of the drive shaft 166 (main rotation shaft), the central axis BS of the eccentric bushing 270, the lubricant supply passage 350, and the through hole 271 are located in the first region T1. When viewed from the first imaginary plane PL1, the lubricant supply passage 350 is farther away than the central axis BS of the eccentric bushing 270. This makes it possible to actively supply lubricant to the bearing 280 by utilizing the centrifugal force generated by the rotational motion of the drive shaft 166.

[0055] According to this embodiment, the scroll compressor 100, which is an example of a scroll fluid machine, further includes a back pressure chamber H4 that is formed on the back side of the orbiting scroll 124 and generates a back pressure that presses and urges the orbiting scroll 124 toward the fixed scroll 122. The inlet 355 of the lubricating oil supply passage 350 communicates with the back pressure chamber H4. Therefore, the lubricating oil in the back pressure chamber H4 can be smoothly supplied to the bearing 280.

[0056] According to this embodiment, the inlet 355 of the lubricant supply passage 350 is disposed in the recess 273 formed in the end face of the eccentric bush 270. This allows the lubricant to be smoothly guided from the back pressure chamber H4 to the lubricant supply passage 350.

[0057] Furthermore, according to this embodiment, a sliding bearing is used as the bearing 280. This makes it possible to rotatably support the eccentric bush 270 with a simple configuration.

[0058] Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 6 is an enlarged cross-sectional view of the conversion mechanism 300 in this embodiment. The points that differ from the first embodiment will be described.

[0059] A balancer weight (counterweight) 290' is provided integrally with the eccentric bush 270. The balancer weight 290' is provided on the opposite side of the through hole 271 across the central axis RS of the drive shaft 166. It is preferable that the lubricant oil supply passage 350 similar to that described above is also formed in such an eccentric bush 270 integrally provided with the balancer weight 290'.

[0060] In the first and second embodiments described above, the balancer weights 290, 290' may be omitted.

[0061] In the above-described first and second embodiments, the scroll fluid machine according to the present invention is described as a scroll compressor, but it goes without saying that the present invention can also be applied to a scroll expander. When applied to a scroll expander, the scroll expander may be incorporated, for example, in a refrigerant circuit of a vehicle Rankine cycle device, and configured to expand the refrigerant introduced from the refrigerant circuit to generate power (recover power from the refrigerant). When applied to a scroll expander, the drive shaft 166 described above becomes the output shaft. That is, if the scroll fluid machine according to the present invention is a scroll compressor, the "rotating main shaft" of the present invention functions as a drive shaft, and if the scroll fluid machine according to the present invention is a scroll expander, the "rotating main shaft" of the present invention functions as an output shaft.

[0062] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that further modifications and variations are possible based on the technical concept of the present invention. The claims as originally filed were as follows: [Claim 1] A scroll fluid machine having a rotating main shaft rotatably provided in a housing, a fixed scroll fixed to the housing, an orbiting scroll that performs an orbital motion relative to the fixed scroll, and a conversion mechanism that converts between the rotational motion of the rotating main shaft and the orbital motion of the orbiting scroll, The conversion mechanism is an eccentric shaft provided on an end surface of the main rotating shaft and eccentric with respect to the main rotating shaft; an eccentric bushing having a through hole into which the eccentric shaft is fitted; a bearing that is press-fitted into a boss portion formed on the orbiting scroll to support an outer peripheral surface of the eccentric bush; Including, a lubricating oil supply passage for supplying lubricating oil to the bearing is formed through the eccentric bush; A scroll fluid machine, wherein an outlet of the lubricating oil supply passage is disposed on an outer circumferential surface of the eccentric bush. [Claim 2] 2. The scroll fluid machine according to claim 1, wherein an outlet of the lubricating oil supply passage faces an inner circumferential surface of the bearing. [Claim 3] the lubricating oil supply passage includes an axial passage portion extending in an axial direction of the eccentric bushing and a radial passage portion extending in a radial direction of the eccentric bushing, The axial flow passage portion has an inlet of the lubricant oil supply passage, 3. The scroll fluid machine according to claim 1, wherein the radial flow passage portion has an outlet of the lubricating oil supply passage. [Claim 4] 4. The scroll fluid machine according to claim 1, wherein the lubricant oil supply passage is located away from a central axis of the eccentric bush as viewed from the central axis of the main rotating shaft. [Claim 5] 5. A scroll fluid machine according to claim 1, wherein when the eccentric bushing is divided into a first region and a second region by a virtual plane including a central axis of the rotating main shaft, the central axis of the eccentric bushing, the lubricating oil supply passage, and the through hole are located within the first region. [Claim 6] 6. The scroll fluid machine according to claim 5, wherein the lubricating oil supply passage is located away from a central axis of the eccentric bush as viewed from the imaginary plane. [Claim 7] The rotary scroll further includes a back pressure chamber formed on a rear side of the rotary scroll to generate a back pressure that presses the rotary scroll toward the fixed scroll. 7. The scroll fluid machine according to claim 1, wherein an inlet of the lubricating oil supply passage communicates with the back pressure chamber. [Claim 8] 8. The scroll fluid machine according to claim 1, wherein an inlet of the lubricating oil supply passage is disposed in a recess formed in an end face of the eccentric bush. [Claim 9] 9. The scroll fluid machine according to claim 1, wherein a slide bearing is used as the bearing. [Explanation of symbols]

[0063] 100 Scroll compressor (scroll fluid machine) 122 Fixed Scroll 124 Swivel Scroll 140 Housing 166 Drive shaft (rotating shaft) 250 Boss 260 eccentric shaft 270 Eccentric Bush 271 Through hole 272 Outer surface 273 Recess 280 Bearings 290,290' Balancer Weight 281 Inner surface 300 Conversion Mechanism 350 Lubricant supply passage 351 Axial flow passage section 352 Radial flow passage 355 Inlet 356 Outlet BS,RS,WS center axis H4 Back pressure chamber PL1 First virtual plane PL2 Second virtual plane T1 1st area T2 2nd area

Claims

1. A scroll fluid machine having a rotating main shaft rotatably provided in a housing, a fixed scroll fixed to the housing, an orbiting scroll that performs an orbital motion relative to the fixed scroll, and a conversion mechanism that converts between the rotational motion of the rotating main shaft and the orbital motion of the orbiting scroll, The conversion mechanism is an eccentric shaft provided on an end surface of the main rotating shaft and eccentric with respect to the main rotating shaft; an eccentric bushing having a through hole into which the eccentric shaft is fitted; a bearing that is press-fitted into a boss portion formed on the orbiting scroll to support an outer peripheral surface of the eccentric bush; Including, a lubricating oil supply passage for supplying lubricating oil to the bearing is formed through the eccentric bush; an outlet of the lubricating oil supply passage is disposed on an outer circumferential surface of the eccentric bush; The scroll fluid machine further includes a back pressure chamber formed on a rear side of the orbiting scroll to generate a back pressure that presses the orbiting scroll toward the fixed scroll, a lubricating oil supply passage having an inlet communicating with the back pressure chamber;

2. 2. The scroll fluid machine according to claim 1, wherein an outlet of the lubricating oil supply passage faces an inner circumferential surface of the bearing.

3. the lubricating oil supply passage includes an axial passage portion extending in an axial direction of the eccentric bushing and a radial passage portion extending in a radial direction of the eccentric bushing, The axial flow passage portion has an inlet of the lubricant oil supply passage, The scroll fluid machine according to claim 1 or 2, wherein the radial flow passage portion has an outlet of the lubricating oil supply passage.

4. 4. The scroll fluid machine according to claim 1, wherein the lubricating oil supply passage is located away from a central axis of the eccentric bush as viewed from the central axis of the main rotating shaft.

5. A scroll fluid machine according to any one of claims 1 to 4, wherein when the eccentric bushing is divided into a first region and a second region by a virtual plane including a central axis of the main rotating shaft, the central axis of the eccentric bushing, the lubricating oil supply passage, and the through hole are located within the first region.

6. The scroll fluid machine according to claim 5 , wherein the lubricating oil supply passage is located away from a central axis of the eccentric bush when viewed from the imaginary plane.

7. 7. The scroll fluid machine according to claim 1, wherein an inlet of the lubricating oil supply passage is disposed in a recess formed in an end face of the eccentric bush.

8. The scroll fluid machine according to any one of claims 1 to 7, wherein a sliding bearing is used as the bearing.

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