US20260022700A1

US20260022700A1 - Thrust receiving mechanism

Info

Publication number: US20260022700A1
Application number: US19/106,562
Authority: US
Inventors: Hiroshi Suzuki; Yuichiro Tokunaga
Original assignee: Eagle Industry Co Ltd
Current assignee: Eagle Industry Co Ltd
Priority date: 2022-11-17
Filing date: 2023-11-13
Publication date: 2026-01-22
Also published as: EP4621235A1; KR20250041053A; WO2024106362A1; CN119790228A; JPWO2024106362A1

Abstract

Disclosed is a thrust receiving mechanism that makes it difficult for a fluid in a high-pressure space to leak to a low-pressure space side. A thrust receiving mechanism is provided on a back surface of a movable scroll that slides relative to a fixed scroll while rotating eccentrically, and is configured for generating a dynamic pressure on the back surface of the movable scroll, and the thrust receiving mechanism includes a dynamic pressure generation portion including a first groove communicating with a low-pressure side, and a second groove communicating with a buffer space between a radial inner end and a radial outer end of the thrust receiving mechanism.

Description

TECHNICAL FIELD

The present invention relates to a thrust receiving mechanism, for example, a thrust receiving mechanism used in a rotating machine including an eccentric mechanism.

BACKGROUND ART

Machines that are rotationally driven and that are used in various industrial fields include not only a rotating machine in which a central shaft rotates while being held at a fixed position, but also a rotating machine that a central shaft rotates eccentrically. One example of a rotating machine that rotates eccentrically is a scroll compressor or the like, and this type of compressor includes a scroll compression mechanism composed of a fixed scroll including a scroll wrap on a surface of an end plate and a movable scroll including a scroll wrap on a surface of an end plate, an eccentric mechanism for eccentrically rotating a rotating shaft, and the like, and has a mechanism for pressurizing a fluid supplied from a low-pressure chamber on a radial outer side of both the scrolls and discharging high-pressure fluid from a discharge hole, which is formed at the center of the fixed scroll, by sliding the movable scroll relative to the fixed scroll while eccentrically rotating the movable scroll due to the rotation of the rotating shaft.
Since the scroll compressor using the mechanism for sliding the movable scroll relative to the fixed scroll while eccentrically rotating the movable scroll not only has high compression efficiency, but also is low noise, the scroll compressor is widely used in, for example, a refrigeration cycle and the like; however, leakage of a refrigerant from an axial gap between both scrolls increases, which is a problem.
In a scroll compressor disclosed in Patent Citation 1, a thrust bearing is disposed on a back surface side of a movable scroll, and a ring-shaped plate is disposed in the thrust bearing. A plurality of spiral groove mechanisms are formed independently in a circumferential direction on a surface on a movable scroll side of the ring-shaped plate. A plurality of grooves are provided in a substantially radial shape toward a land at the center of each spiral groove mechanism is provided in the spiral groove mechanism. In detail, each groove extends in a radial direction from the land at the center while inclining in a counterclockwise direction, one end on a land side of the groove is tapered, and the other end on the side opposite to the land is wider than the one end.
The movable scroll moves from the other end of the groove toward the one end during eccentric rotation. Accordingly, a fluid on a radial outer side or a radial inner side of the ring-shaped plate is taken into the groove, and dynamic pressure is generated in the vicinity of the one end of the groove. Accordingly, slidability can be increased by forming a fluid film between sliding surfaces of the movable scroll and the ring-shaped plate while keeping the sliding surfaces apart from each other, and leakage of the refrigerant from an axial gap between both the scrolls can be reduced by pressing the movable scroll against the fixed scroll.

CITATION LIST

Patent Literature

Patent Citation 1: JP H9-317666 A (Page 4, FIG. 4 )

SUMMARY OF INVENTION

Technical Problem

However, in the scroll compressor of Patent Citation 1, since the grooves disposed on a low-pressure side of the spiral groove mechanism take in the fluid in a low-pressure chamber, and generate dynamic pressure toward a high-pressure chamber side to push the fluid back, but the grooves disposed on a high-pressure side of the spiral groove mechanism take in the fluid in a high-pressure chamber, and generates dynamic pressure toward a low-pressure chamber side, a large amount of the fluid in the high-pressure chamber which tends to easily flow toward the low-pressure side flows from the gap between the sliding surfaces of the movable scroll and the ring-shaped plate toward the low-pressure chamber side, which is a risk.
The present invention has been made in view of such problems, and an object of the present invention is to provide a thrust receiving mechanism that makes it difficult for a fluid in a high-pressure space to leak to a low-pressure space side.

Solution to Problem

In order to solve the foregoing problems, a thrust receiving mechanism according to the present invention is a thrust receiving mechanism provided on a back surface of a movable scroll that slides relative to a fixed scroll while rotating eccentrically, and configured for generating a dynamic pressure on the back surface of the movable scroll, the thrust receiving mechanism including: a dynamic pressure generation portion including a first groove communicating with a low-pressure side, and a second groove communicating with a buffer space between a radial inner end and a radial outer end of the thrust receiving mechanism. According to the aforesaid feature of the present invention, a fluid on the low-pressure side is directed toward the high-pressure side by each groove, and a fluid on the high-pressure side outside the sliding surfaces is less likely to enter a gap between the sliding surfaces. For that reason, leakage of the fluid on the high-pressure side to the low-pressure side can be suppressed. In addition, the fluid that has flowed out from the first groove into the gap between the sliding surfaces can be stored in the buffer space, and the fluid can be supplied from the buffer space to the second groove.
It may be preferable that the buffer space is a depression. According to this preferable configuration, the fluid in the buffer space can more reliably generate dynamic pressure in the second groove without being affected by the axial positions of the thrust receiving mechanism and the movable scroll.
It may be preferable that the depression communicatees with the low-pressure side. According to this preferable configuration, the fluid in the depression does not run out, and stable slidability can be achieved.
It may be preferable that each of the dynamic pressure generation portions has a diameter smaller than a diameter of the thrust receiving mechanism, and the dynamic pressure generation portions are disposed at equal spacings in a circumferential direction of the thrust receiving mechanism. According to this preferable configuration, leakage of the fluid on the high-pressure side to the low-pressure side in the circumferential direction can be suppressed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic configuration view illustrating a scroll compressor to which a thrust plate serving as a thrust receiving mechanism according to a first embodiment of the present invention is applied.

FIG. 2 is a schematic view illustrating a sliding surface of the thrust plate in the first embodiment of the present invention.

FIG. 3 is a view illustrating relative sliding between a sliding surface of a side seal and the sliding surface of the thrust plate in the first embodiment of the present invention. Incidentally, FIGS. 3B, 3C, and 3D illustrate positional relationships between the sliding surface of the side seal and the sliding surface of the thrust plate that slide relative to each other when a rotating shaft has eccentrically rotated by 90 degrees, 180 degrees, and 270 degrees with FIG. 3A as a starting position, respectively.

FIG. 4 is a schematic view illustrating a sliding state between one dynamic pressure generation portion and the side seal in a state illustrated in FIG. 3A.

FIG. 5 is a schematic view illustrating a sliding state between one dynamic pressure generation portion and the side seal in a state illustrated in FIG. 3C.

FIG. 6 is a schematic view illustrating a thrust plate serving as a thrust receiving mechanism according to a second embodiment of to the present invention.

DESCRIPTION OF EMBODIMENTS

Modes for implementing a thrust receiving mechanism according to the present invention will be described below based on embodiments.

First Embodiment

A thrust receiving mechanism according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 5 .
The thrust receiving mechanism according to the first embodiment of the present invention is applied to a rotating machine including an eccentric mechanism, for example, a scroll compressor C that suctions, compresses, and discharges a refrigerant serving as a fluid used in an air conditioning system of an automobile or the like. Incidentally, in the present embodiment, the refrigerant is a gas, and is mixed with lubricating oil in the form of mist.
First, the scroll compressor C will be described. As illustrated in FIG. 1 , the scroll compressor C is mainly composed of a housing 1; a rotating shaft 2; an inner casing 3; a scroll compression mechanism 4; a side seal 7; a thrust plate 8 serving as the thrust receiving mechanism; and a drive motor M.
The housing 1 is composed of a casing 11 having a cylindrical shape, and a cover 12 that closes an opening of the casing 11. An opening of the casing 11 on the side axially opposite to the opening closed by the cover 12 is closed by the drive motor M.
Inside the casing 11, a low-pressure chamber 20 serving as an external space on a low-pressure side to which low-pressure refrigerant is supplied from a refrigerant circuit (not illustrated) through a suction port 10, a high-pressure chamber 30 from which high-pressure refrigerant compressed by the scroll compression mechanism 4 is discharged, and a back pressure chamber 50 serving as an external space on a high-pressure side to which some of the refrigerant compressed by the scroll compression mechanism 4 is supplied together with the lubricating oil are formed. Incidentally, the back pressure chamber 50 is formed inside the inner casing 3 having a cylindrical shape that is accommodated inside the casing 11.
A discharge communication passage 13 communicating between the refrigerant circuit (not illustrated) and the high-pressure chamber 30 is formed in the cover 12. In addition, a part of a back pressure communication passage 14 communicating between the high-pressure chamber 30 and the back pressure chamber 50 is formed in the cover 12 by branching off from the discharge communication passage 13. Incidentally, an oil separator 6 that separates the lubricating oil from the refrigerant is provided in the discharge communication passage 13.
The inner casing 3 is fixed in a state where an axial end portion of the inner casing 3 abuts against an end plate 41 a of a fixed scroll 41 constituting the scroll compression mechanism 4. In addition, a suction communication passage 15 is formed in a side wall of the inner casing 3 so as to penetrate therethrough in a radial direction. Namely, the low-pressure chamber 20 is formed from the outside of the inner casing 3 to the inside of the inner casing 3 via the suction communication passage 15. The refrigerant supplied to the inside of the inner casing 3 through the suction communication passage 15 is suctioned into the scroll compression mechanism 4.
The scroll compression mechanism 4 is mainly composed of the fixed scroll 41 fixed to the cover 12 in a sealed manner, and the movable scroll 42 accommodated inside the inner casing 3.
The fixed scroll 41 is made of metal, and includes a scroll wrap 41 b protruding from a surface of the end plate 41 a having a disk shape, namely, from the end plate 41 a toward the movable scroll 42. In addition, a recess 41 c formed by recessing a radial inner side of a back surface of the end plate 41 a, namely, an end surface of the end plate 41 a in a direction opposite to the cover 12, the end surface abutting against the cover 12, is formed in the fixed scroll 41, and the high-pressure chamber 30 is defined by the recess 41 c and the cover 12.
The movable scroll 42 is made of metal, and includes a scroll wrap 42 b protruding from a surface of an end plate 42 a having a disk shape, namely, from the end plate 42 a toward the fixed scroll 41. In addition, a boss 42 c protruding from the center of a back surface of the end plate 42 a is formed on the movable scroll 42. An eccentric portion 2 a formed on the rotating shaft 2 is inserted into the boss 42 c so as to be capable of relative rotation. Incidentally, in the present embodiment, the eccentric portion 2 a of the rotating shaft 2 and a counterweight portion 2 b protruding from the rotating shaft 2 in a radially outward direction constitute an eccentric mechanism that eccentrically rotates the rotating shaft 2.
When the rotating shaft 2 is rotationally driven by the drive motor M, the eccentric portion 2 a rotates eccentrically, and the movable scroll 42 slides relative to the fixed scroll 41 in a state where the movable scroll 42 maintains the posture with respect to the fixed scroll 41 while rotating eccentrically. At this time, the movable scroll 42 rotates eccentrically with respect to the fixed scroll 41, and the contact position between the wraps 41 b and 42 b moves sequentially in a rotation direction along with this rotation, and a compression chamber 40 formed between the wraps 41 b and 42 b is gradually reduced while moving toward the center. Accordingly, the refrigerant suctioned into the compression chamber 40 from the low-pressure chamber 20 formed on the radial outer side of the scroll compression mechanism 4 is compressed, and finally, the high-pressure refrigerant is discharged into the high-pressure chamber 30 through a discharge hole 41 d provided at the center of the fixed scroll 41.
Next, the side seal 7 will be described. The side seal 7 is made of resin, has a rectangular cross section and an annular shape when viewed in an axial direction, and is fixed to the back surface of the end plate 42 a of the movable scroll 42.
A sliding surface 7 a that abuts against a sliding surface 8 a (refer to FIG. 1 ) formed on the thrust plate 8 is formed on the side seal 7. The sliding surface 7 a is a flat surface, and constitutes a back surface-side sliding surface of the movable scroll 42.
Next, the thrust plate 8 will be described. As illustrated in FIGS. 1 and 2 , the thrust plate 8 is made of metal, and has an annular shape. The thrust plate 8 is composed of a plurality of dynamic pressure generation portions 81 (16 pieces in the present embodiment) and a plurality of connecting portions 82 (16 pieces in the present embodiment).
The dynamic pressure generation portions 81 adjacent to each other in a circumferential direction are connected by the connecting portions 82. Each connecting portion 82 has the same thickness as a base portion 83 of each dynamic pressure generation portion 81, and has a smaller radial width than the base portion 83. Namely, the dynamic pressure generation portion 81 bulges further toward the radial inner side and the radial outer side of the thrust plate 8 than the connecting portion 82. In other words, when viewed in the axial direction, the dynamic pressure generation portion 81 and the connecting portion 82 form a step portion on each of the radial inner side and the radial outer side. Hereinafter, these step portions will be simply referred to as “step portions between the dynamic pressure generation portion 81 and the connecting portion 82”.
The dynamic pressure generation portion 81 includes the base portion 83; a depression 84 serving as a buffer space; a first inclined groove group 85 serving as first grooves; and a second inclined groove group 86 severing as second grooves. Incidentally, since the sizes of the depression 84, the first inclined groove group 85, and the second inclined groove group 86 are small, in FIG. 1 , the illustration thereof is omitted for convenience of description. Furthermore, in order to clearly illustrate that the depression 84 is a bottomed hole, in an enlarged portion of FIG. 2 , the depression 84 is marked with dots for convenience of description.
The base portion 83 has a circular shape when viewed in the axial direction.
The depression 84 is formed at a central portion of the base portion 83, namely, between a radial inner end and a radial outer end of the thrust plate 8 to be open toward a sliding surface 8 a side. The depression 84 is a bottomed recess having a circular shape when viewed in the axial direction.
The first inclined groove group 85 is provided on the sliding surface 8 a side of the base portion 83 to be closer to a low-pressure chamber 20 side than the depression 84. The first inclined groove group 85 is composed of a plurality of first inclined grooves 851 (eight pieces in the present embodiment).
Each first inclined groove 851 extends from one end 851 a on the low-pressure chamber 20 side toward the other end 851 b on a back pressure chamber 50 side while inclining toward one side in the circumferential direction (in the present embodiment, a counterclockwise direction in FIG. 2 ). The one end 851 a communicates with the low-pressure chamber 20, and the other end 851 b is a closed end portion. In other words, the other end 851 b of the first inclined groove 851 and the depression 84 are partitioned off from each other by a land.
The second inclined groove group 86 is provided on the sliding surface 8 a side of the base portion 83 to be closer to the back pressure chamber 50 side than the depression 84. The second inclined groove group 86 is composed of a plurality of second inclined grooves 861 (eight pieces in the present embodiment).
Each second inclined groove 861 extends from one end 861 a on the low-pressure chamber 20 side toward the other end 861 b on the back pressure chamber 50 side while inclining toward the one side in the circumferential direction (in the present embodiment, the counterclockwise direction in FIG. 2 ). The one end 861 a communicates with the depression 84, and the other end 861 b is a closed end portion. In other words, the other end 861 b of the second inclined groove 861 is partitioned off from the back pressure chamber 50 or the second inclined grooves 861 by the land. Namely, each second inclined groove 861 does not communicate with the back pressure chamber 50.
The thrust plate 8 is fitted into an installation groove 3 b provided in the inner casing 3. An inner wall constituting the installation groove 3 b has a shape that is substantially similar to and slightly larger than the outer shape of the thrust plate 8, and by engaging the step portions between the dynamic pressure generation portions 81 and the connecting portions 82 with the inner wall, the rotation of the thrust plate 8 in the circumferential direction is restricted.
In addition, a seal ring 43 (refer to FIG. 1 ) is fixed to a back surface of the thrust plate 8. The seal ring 43 abuts against a bottom surface of the installation groove 3 b of the inner casing 3. Accordingly, the thrust plate 8 functions as a thrust receiving mechanism that receives an axial load of the movable scroll 42 via the side seal 7.
In addition, the side seal 7 and the seal ring 43 partition the low-pressure chamber 20 formed on the radial outer side of the movable scroll 42 and the back pressure chamber 50 formed on a back surface side of the movable scroll 42 off from each other inside the inner casing 3. The back pressure chamber 50 is formed as a sealed space by sealing a gap between a through-hole 3 a and the rotating shaft 2 inserted into the through-hole 3 a with a seal ring 44 fixed to an inner periphery of the through-hole 3 a provided at the center of the inner casing 3.
In addition, an orifice (not illustrated) is provided in the back pressure communication passage 14 that is formed through the cover 12, the fixed scroll 41, and the inner casing 3, and that communicates between the high-pressure chamber 30 and the back pressure chamber 50, and the refrigerant in the high-pressure chamber 30, of which the pressure is adjusted to be reduced by the orifice, is supplied to the back pressure chamber 50, together with the lubricating oil separated by the oil separator 6. At this time, the pressure in the back pressure chamber 50 is adjusted to be higher than the pressure in the low-pressure chamber 20. Incidentally, a pressure relief hole 16 penetrating through the inner casing 3 in the radial direction and communicating between the low-pressure chamber 20 and the back pressure chamber 50 is formed in the inner casing 3, and a pressure adjustment valve 45 is provided in the pressure relief hole 16. The pressure adjustment valve 45 opens when the pressure in the back pressure chamber 50 becomes higher than a set value.
In addition, the boss 42 c of the movable scroll 42 is inserted into a through-hole 8 b at the center of the thrust plate 8. The through-hole 8 b is formed with a diameter large enough to allow eccentric rotation of the eccentric portion 2 a of the rotating shaft 2 that is inserted into the boss 42 c. Namely, the sliding surface 7 a of the side seal 7 is slidable relative to the sliding surface 8 a of the thrust plate 8 while rotating eccentrically due to the eccentric rotation of the rotating shaft 2 (refer to FIG. 3 ).
Incidentally, in FIG. 3 , FIGS. 3B to 3D illustrate states where the boss 42 c has rotated by 90 degrees, 180 degrees, and 270 degrees, respectively, with FIG. 3A as a reference for the counterclockwise direction, along a rotation trajectory of the boss 42 c indicated by a black arrow when viewed from a fixed scroll 41 side. In addition, a sliding region between the sliding surface 7 a of the side seal 7 and the sliding surface 8 a of the thrust plate 8 is schematically illustrated by dots. In addition, for convenience of description, regarding the rotating shaft 2, only the eccentric portion 2 a inserted into the boss 42 c is illustrated, and the illustration of the counterweight portion 2 b and the like constituting the eccentric mechanism is omitted.
In such a manner, the thrust plate 8 has the sliding surface 8 a that slides relative to the sliding surface 7 a of the side seal 7 that rotates eccentrically.
In addition, an elastic member 9 (refer to FIG. 1 ) is inserted between the side seal 7 and the scroll compression mechanism 4, in detail, between the side seal 7 and the movable scroll 42, and dynamic pressure generated between the side seal 7 and the thrust plate 8 absorbs a difference in axial position in the circumferential phase, namely, prevents the movable scroll 42 from tilting. Incidentally, the elastic member 9 may be made of a deformable material, such as an O-ring, or may be deformable in shape, such as a spring.
Next, the generation of dynamic pressure when the side seal 7 slides relative to the thrust plate 8 will be described with reference to FIGS. 4 and 5 .
Incidentally, in FIGS. 4 and 5 , a sliding state between one dynamic pressure generation portion 81A of the thrust plate 8 located at 12 o′clock in FIG. 3 and the side seal 7 will be described as an example. FIG. 4 illustrates a mode when the side seal 7 moves with respect to the one dynamic pressure generation portion 81A from the state illustrated in FIG. 3A toward the state illustrated in FIG. 3B. FIG. 5 illustrates a mode when the side seal 7 moves with respect to the one dynamic pressure generation portion 81A from the state illustrated in FIG. 3C toward the state illustrated in FIG. 3D.
In the state illustrated in FIG. 4 , the side seal 7 overlaps the first inclined groove group 85 of the one dynamic pressure generation portion 81A in the axial direction. At this time, the side seal 7 slides counterclockwise relative to the dynamic pressure generation portion 81A.
According to this configuration, a fluid F1 in the low-pressure chamber 20 that is present in each first inclined groove 851 of the first inclined groove group 85 moves from the one end 851 a toward the other end 851 b (refer to black arrows in FIG. 4 ).
Accordingly, dynamic pressure is generated at the other end 851 b, the sliding surfaces 7 a and 8 a are slightly separated from each other, and a fluid film is formed by the fluid F1. In addition, the fluid F1 in the low-pressure chamber 20 is constantly supplied into each first inclined groove 851 from the one end 851 a.
The fluid F1 that has flowed out from the other end 851 b into a gap between the sliding surfaces 7 a and 8 a moves toward the back pressure chamber 50 side. Accordingly, a fluid F2 in the back pressure chamber 50 is pushed back toward the back pressure chamber 50 side, and is less likely to flow into the gap between the sliding surfaces 7 a and 8 a (refer to white arrows in FIG. 4 ). In addition, some of the fluid F1 and some of the fluid F2 are stored in the depression 84.
In the state illustrated in FIG. 5 , the side seal 7 overlaps the second inclined groove group 86 of the one dynamic pressure generation portion 81A in the axial direction. At this time, the side seal 7 slides counterclockwise relative to the dynamic pressure generation portion 81A.
According to this configuration, the fluid present in each second inclined groove 861 of the second inclined groove group 86 moves from the one end 861 a toward the other end 861 b (refer to black arrows in FIG. 5 ).
Accordingly, dynamic pressure is generated at the other end 861 b, the sliding surfaces 7 a and 8 a are slightly separated from each other, and a fluid film is formed by the fluid. In addition, the fluid in the depression 84 is constantly supplied into each second inclined groove 861 from the one end 861 a.
Incidentally, during transitioning from the state illustrated in FIG. 4 to the state illustrated in FIG. 5 , the depression 84 gradually ceases to communicate with the back pressure chamber 50 side, and begins to communicate with the low-pressure chamber 20 side, so that the amount of the fluid F1 in the low-pressure chamber 20 in the fluid supplied from the depression 84 to the second inclined grooves 861 gradually increases, and in the state illustrated in FIG. 5 , almost all of the supplied fluid is the fluid F1.
The fluid F1 that has flowed out from the other end 861 b into the gap between the sliding surfaces 7 a and 8 a moves toward the back pressure chamber 50 side. Accordingly, the fluid F2 in the back pressure chamber 50 is pushed back toward the back pressure chamber 50 side, and is less likely to flow into the gap between the sliding surfaces 7 a and 8 a (refer to white arrows in FIG. 5 ).
As described above, the thrust plate 8 includes the dynamic pressure generation portions 81, each including the first inclined groove group 85 located on the low-pressure chamber 20 side and the second inclined groove group 86 located on the back pressure chamber 50 side, and the second inclined grooves 861 of the second inclined groove group 86 do not communicate with the back pressure chamber 50 side. According to this configuration, since the fluid F2 in the back pressure chamber 50 that has higher pressure than the fluid F1 in the low-pressure chamber 20 is restricted from entering the gap between the sliding surfaces 7 a and 8 a, leakage of the fluid F2 into the low-pressure chamber 20 can be suppressed.
In addition, since the depression 84 serving as a buffer space is formed between the first inclined groove group 85 and the second inclined groove group 86, the fluid F1 that has flowed out from the first inclined groove group 85 into the gap between the sliding surfaces 7 a and 8 a can be stored in the depression 84, and the fluid F1 can be supplied from the depression 84 to the second inclined groove group 86.
In addition, since the depression 84 is provided in the dynamic pressure generation portion 81, the depression 84 can store the fluid F1 without being affected by a separation distance between the sliding surfaces 7 a and 8 a, namely, the axial positions of the thrust plate 8 and the side seal 7, so that dynamic pressure can be generated in the second inclined groove group 86 by the fluid F1 in the depression 84.
In addition, the one ends 861 a of the second inclined grooves 861 of the second inclined groove group 86 communicate with the depression 84. According to this configuration, the fluid F1 can be smoothly supplied from the depression 84 to the second inclined grooves 861 of the second inclined groove group 86.
In addition, since the one ends 851 a of the first inclined grooves 851 of the first inclined groove group 85 communicate with the low-pressure chamber 20, the fluid F1 can be smoothly supplied from the low-pressure chamber 20 to the first inclined grooves 851.
In addition, the thrust plate 8 is configured such that the plurality of dynamic pressure generation portions 81 are connected in an annular shape such that each second inclined groove group 86 is located on the back pressure chamber 50 side. According to this configuration, leakage of the fluid F2 in the back pressure chamber 50 to the low-pressure chamber 20 side in the circumferential direction can be suppressed.

Second Embodiment

Next, a thrust receiving mechanism according to a second embodiment of the present invention will be described with reference to FIG. 6 . Incidentally, the description of configurations that are the same as and overlap with the configurations of the first embodiment will be omitted.
As illustrated in FIG. 6 , a thrust plate 28 of the second embodiment is provided with a communication groove 287 that communicates between a depression 284 and the low-pressure chamber 20. The communication groove 287 is a recessed groove that is open to a sliding surface 28 a side.
According to this configuration, since the fluid F1 in the low-pressure chamber 20 can be constantly taken into the depression 284 through the communication groove 287, the fluid F1 in the depression 284 does not run out, and stable slidability can be achieved.
Incidentally, in the second embodiment, the mode in which the communication groove 287 is a recessed groove that is open to the sliding surface 28 a side has been provided as an example; however, the present invention is not limited to this mode, and a hole that communicates between a side surface on the low-pressure chamber 20 side of the depression 284 and a side surface on the low-pressure chamber 20 side of the thrust plate 28 may be provided.
The embodiments of the present invention have been described above with reference to the drawings; however, specific configurations are not limited to these embodiments, and modifications or additions that are made without departing from the scope of the present invention are also included in the present invention.
For example, in the first and second embodiments, the mode in which all the second inclined grooves 861 of the second inclined groove group 86 do not communicate with the back pressure chamber 50 side has been provided as an example; however, some of the second inclined grooves 861 may communicate with the back pressure chamber. Preferably, the number of the inclined grooves not communicating with the back pressure chamber is larger than the number of the inclined grooves communicating with the back pressure chamber.
In addition, in the first and second embodiments, the mode in which the first grooves and the second grooves are inclined grooves has been provided as an example; however, the first grooves and the second grooves may not be inclined grooves. Namely, any groove may be implemented as long as the groove can generate dynamic pressure, and a known structure capable of generating dynamic pressure, such as a groove extending parallel to the circumferential direction or a groove of which the bottom surface is inclined, may be used.
In addition, the mode in which the thrust plate of the first and second embodiments is configured such that the plurality of dynamic pressure generation portions are connected in the circumferential direction to form an annular shape has been provided as an example; however, at least one dynamic pressure generation portion may be provided. Incidentally, the thrust plate is not limited to having an annular shape.
In addition, in the first and second embodiments, the mode in which the depression serving as a buffer space is formed in the thrust plate has been provided as an example; however, a buffer space such as a depression may be formed on a side seal side. Incidentally, the buffer space may not be provided between the first inclined groove group and the second inclined groove group.
In addition, in the first and second embodiments, the mode in which the inclined grooves of the second inclined groove group communicate with the depression has been provided as an example; however, dimples or the like not communicating with the depression may be implemented.
In addition, in the first and second embodiments, the mode in which the inclined grooves of the first inclined groove group communicate with the low-pressure chamber has been provided as an example; however, dimples or the like not communicating with the low-pressure chamber may be implemented.
In addition, in the first and second embodiments, the mode in which the thrust plate serving as a thrust receiving mechanism is applied to the scroll compressor C used in an air conditioning system of an automobile or the like has been described; however, the present invention is not limited to this mode, and may be applied to, for example, a scroll expander-compressor or the like in which an expander and a compressor are integrally provided as long as the scroll expander-compressor is a rotating machine including an eccentric mechanism.
In addition, in the first and second embodiments, the radial outer side and the radial inner side of the thrust plate have been described as the low-pressure side and the high-pressure side, respectively; however, the radial outer side and the radial inner side of the thrust plate may be the high-pressure side and the low-pressure side, respectively.
In addition, the fluid present in the spaces inside and outside the sliding surface of the thrust receiving mechanism may be any of gas, liquid, and a mixture of gas and liquid.
In addition, in the first and second embodiments, the side seal and the thrust plate having the sliding surfaces that slide relative to each other have been described as being made of resin and metal, respectively; however, the material of the thrust receiving mechanism may be freely selected depending on the usage environment or the like.
In addition, in the first and second embodiments, the mode in which the side seal slides relative to the thrust plate has been provided as an example; however, the back surface of the movable scroll may directly slide relative to the thrust plate.
In addition, in the first and second embodiments, the mode in which the thrust plate is disposed in a state where the thrust plate is restricted from rotating by being fitted to the installation groove provided in the inner casing has been provided as an example; however, the present invention is not limited to this mode, and for example, the thrust plate may be non-rotatably fixed to the inner casing by bolts or the like.

REFERENCE SIGNS LIST

- 4 Scroll compression mechanism
- 7 Side seal
- 7 a Sliding surface (back surface-side sliding surface)
- 8 Thrust plate (thrust receiving mechanism)
- 8 a Sliding surface
- 20 Low-pressure chamber (low-pressure side)
- 28 Thrust plate
- 28 a Sliding surface
- 41 Fixed scroll
- 42 Movable scroll
- 50 Back pressure chamber (high-pressure side)
- 81, 81A Dynamic pressure generation portion
- 84 Depression (Buffer space)
- 85 First inclined groove group
- 86 Second inclined groove group
- 284 Depression (Buffer space)
- 287 Communication groove
- 851 First inclined groove
- 861 Second inclined groove
- C Scroll compressor
- F1, F2 Fluid

Claims

1. A thrust receiving mechanism provided on a back surface of a movable scroll that is configured to slide relative to a fixed scroll while rotating eccentrically, and configured for generating a dynamic pressure on the back surface of the movable scroll, comprising:

a dynamic pressure generation portion including a first groove communicating with a low-pressure side, and a second groove communicating with a buffer space between a radial inner end and a radial outer end of the thrust receiving mechanism.

2. The thrust receiving mechanism according to claim 1,

wherein the buffer space is a depression.

3. The thrust receiving mechanism according to claim 2,

wherein the depression communicates with the low-pressure side.

4. The thrust receiving mechanism according to claim 1,

wherein each of the dynamic pressure generation portions has a diameter smaller than a diameter of the thrust receiving mechanism, and the dynamic pressure generation portions are disposed at equal spacings in a circumferential direction of the thrust receiving mechanism.

5. The thrust receiving mechanism according to claim 2,

6. The thrust receiving mechanism according to claim 3,