sliding member

Abstract

Provided is a sliding member capable of reducing frictional resistance of a sliding surface accompanying eccentric rotation. A sliding member (7) is in a circular ring shape, has a sliding surface (7a) that slides in opposition to each other accompanying eccentric rotation, and in the sliding surface (7a), a plurality of grooves (70) that open to a fluid-containing space (50) on an inner diameter side are provided in a circumferential direction, and the grooves (70) are composed of a wall surface (70a) that is continuous in a circular arc shape.

Description

TECHNICAL FIELD

[0001] The present application relates to a sliding member for a rotary machine including an eccentric mechanism. BACKGROUND

[0002] In the past, as a rotary machine including an eccentric mechanism, for example, a scroll compressor for an air conditioning system of an automobile is a mechanism that has a scroll compression mechanism composed of a fixed scroll having a scroll-like scroll wrap on the surface of an end plate and a movable scroll having a scroll-like scroll wrap on the surface of an end plate, and an eccentric mechanism that rotates a rotating shaft eccentrically, and that relatively slides the movable scroll with respect to the fixed scroll in conjunction with eccentric rotation by the rotation of the rotating shaft, thereby pressurizing a refrigerant supplied from a low-pressure chamber on the outer diameter side of the two scrolls, and discharging a high-pressure refrigerant from a discharge hole formed in the center of the fixed scroll (see Patent Literature 1).

[0003] In addition, the scroll compressor shown in Patent Literature 1 has a back pressure supply mechanism that supplies a part of the refrigerant compressed by the scroll compression mechanism to a back pressure chamber formed on the back surface side of a thrust plate that receives an axial load of the movable scroll. By the back pressure acting on the back surface of the movable scroll, the movable scroll is pressed toward the fixed scroll. Thereby, the refrigerant leakage in the axial direction between the two scrolls is reduced, and the compression efficiency of the scroll compressor is improved.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Laid-Open No. 2016-61208 (pages 5 to 6, FIG. 1) Figure 1 ) SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] In the scroll compressor shown in Patent Literature 1, by sandwiching a seal ring between the thrust plate and the housing, it is possible to move the thrust plate in the axial direction while preventing the back pressure from leaking from the back pressure chamber, and thereby press the movable scroll toward the fixed scroll via the thrust plate. However, the sliding surface of the thrust plate is pushed against the back surface of the movable scroll, and therefore the frictional resistance of the sliding surface is large, and it is possible to affect the operation of the movable scroll.

[0009] The present application is completed in view of such a problem point, and aims to provide a sliding member capable of reducing the frictional resistance of the sliding surface in conjunction with eccentric rotation.

[0010] MEANS FOR SOLVING THE PROBLEMS

[0011] To solve the above problems, a sliding member of the present application,

[0012] which has sliding surfaces that slide relative to each other with eccentric rotation, wherein

[0013] a plurality of grooves that open to a space in at least either the inner diameter side or the outer diameter side of the sliding surfaces are provided in the circumferential direction,

[0014] the grooves are formed by a wall surface that is continuous in a circular arc shape.

[0015] Thus, fluid can flow into the sliding surfaces from the openings of the grooves provided in the sliding surfaces that slide relative to each other with eccentric rotation, and dynamic pressure can be generated along the wall surface that forms the grooves in accordance with the direction of the relative movement of the grooves with eccentric rotation, and the dynamic pressure is generated differently in each groove, and the sliding member moves, so that vibration, tilting, and the like of the sliding member caused by the dynamic pressure can be suppressed, the sliding surfaces can be slightly separated from each other and a fluid film can be formed, and thus the lubricity between the sliding surfaces can be improved and the frictional resistance of the sliding surfaces can be reduced. Thus, dynamic pressure can be generated constantly in the grooves in a range that is continuous in the circumferential direction of the sliding surfaces.

[0016] Also, the grooves can be formed in a semicircular shape having a center at the innermost diameter or the outermost diameter of the sliding surfaces.

[0017] Thus, stable dynamic pressure can be generated in accordance with any of the directions of the relative movement corresponding to the wall surface of the substantially semicircular arc shape of the grooves. Thus, dynamic pressure can be generated constantly in the grooves in a range that is substantially 180 degrees in the circumferential direction of the sliding surfaces.

[0018] Also, the grooves can open to the space on the inner diameter side.

[0019] Thus, fluid that flows into the grooves from the openings of the grooves is easily held in the grooves by centrifugal force.

[0020] Also, the grooves can open to the space on the high pressure side.

[0021] Thus, fluid is easily caused to flow into the grooves from the openings of the grooves by the pressure of the fluid, and thus higher dynamic pressure can be generated.

[0022] Also, the sliding member can be a sliding member that is narrower in the radial direction among a pair of sliding members that slide relative to each other.

[0023] Thus, dynamic pressure can be reliably generated by the grooves between the sliding surfaces that slide relative to each other with eccentric rotation. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a schematic configuration view of a scroll compressor that applies a side seal that is a sliding member of an embodiment of the present application.

[0025] Figure 2 FIG. 1 is a view showing a sliding surface of a side seal of an embodiment of the present application;

[0026] Figure 3 FIG. 2 is a view showing relative sliding of the sliding surface of the side seal and a sliding surface of a thrust plate of the embodiment of the present application. Further, the positional relationship of the sliding surface of the side seal and the sliding surface of the thrust plate is shown when the rotation shaft is eccentrically rotated to 90 degrees in (b), 180 degrees in (c), and 270 degrees in (d) from the start position in (a);

[0027] Figure 4 FIG. 3 is a view showing a distribution of pressure generated in a plurality of grooves on the sliding surface of the side seal shown in (a) by relative movement of the grooves accompanying eccentric rotation of the rotation shaft; Figure 3

[0028] FIG. 4 is a view showing a distribution of pressure generated in a plurality of grooves on the sliding surface of the side seal shown in (b) by relative movement of the grooves accompanying eccentric rotation of the rotation shaft; Figure 5 Figure 3 FIG. 5 is a view showing a distribution of pressure generated in a plurality of grooves on the sliding surface of the side seal shown in (c) by relative movement of the grooves accompanying eccentric rotation of the rotation shaft;

[0029] Figure 6 Figure 3 FIG. 6 is a view showing a distribution of pressure generated in a plurality of grooves on the sliding surface of the side seal shown in (d) by relative movement of the grooves accompanying eccentric rotation of the rotation shaft;

[0030] Figure 7 FIG. 7 is a view showing a modification example 1 of the grooves formed on the sliding surface of the side seal; Figure 3

[0031] FIG. 8 is a view showing a modification example 2 of the grooves formed on the sliding surface of the side seal; Figure 8

[0032] FIG. 9 is a view showing modification examples 3 to 5 of the grooves formed on the sliding surface of the side seal. Figure 9 DETAILED DESCRIPTION

[0033] Hereinafter, the manner of the sliding member for embodying the present application will be described based on an embodiment. Figure 10 EMBODIMENT

[0034] Referring to FIG. 1, a side seal 1 is provided with a sliding surface 2 and a thrust plate 3. The sliding surface 2 is formed on a side surface of a seal housing 4. The thrust plate 3 is formed on a side surface of a rotor 5. The sliding surface 2 is provided with a plurality of grooves 6. The thrust plate 3 is provided with a plurality of grooves 7. The grooves 6 and 7 are formed in a spiral shape. The grooves 6 and 7 are formed in a spiral shape so as to be inclined with respect to the rotation axis of the rotor 5.

[0035] EMBODIMENT

[0036] Referring to FIG. 1, a side seal 1 is provided with a sliding surface 2 and a thrust plate 3. The sliding surface 2 is formed on a side surface of a seal housing 4. The thrust plate 3 is formed on a side surface of a rotor 5. The sliding surface 2 is provided with a plurality of grooves 6. The thrust plate 3 is provided with a plurality of grooves 7. The grooves 6 and 7 are formed in a spiral shape. The grooves 6 and 7 are formed in a spiral shape so as to be inclined with respect to the rotation axis of the rotor 5. Figures 1 to 7 ​​The sliding member of the embodiment will be described. For ease of description, in the drawings, dots are added to grooves and the like formed on the sliding surface of the sliding member.

[0037] The sliding member of the present application is applied to a scroll compressor C that sucks, compresses, and discharges a refrigerant as a fluid in an air conditioning system of a vehicle or the like including an eccentric mechanism. Further, in the present embodiment, the refrigerant is a gas in a state mixed with misty lubricating oil.

[0038] First, the scroll compressor C will be described. As shown in FIG. 1, the scroll compressor C is mainly composed of a housing 1, a rotation shaft 2, an inner housing 3, a scroll compression mechanism 4, a side seal 7 as a sliding member, a thrust plate 8, and a drive motor M. Figure 1

[0039] The housing 1 is composed of a cylindrical outer shell 11 and a lid 12 that closes one opening of the outer shell 11. In the inside of the outer shell 11, a low-pressure chamber 20 to which a low-pressure refrigerant is supplied from a refrigerant circuit not shown through a suction port 10, a high-pressure chamber 30 to which a high-pressure refrigerant compressed by the scroll compression mechanism 4 is discharged, and a back-pressure chamber 50 to which a part of the refrigerant compressed by the scroll compression mechanism 4 is supplied together with lubricating oil are formed. Further, the back-pressure chamber 50 is formed in the inside of the cylindrical inner housing 3 housed in the inside of the outer shell 11.

[0040] The lid 12 is formed with a discharge communication path 13 that communicates the refrigerant circuit not shown and the high-pressure chamber 30. In addition, on the lid 12, a part of a back-pressure communication path 14 that communicates the high-pressure chamber 30 and the back-pressure chamber 50 is formed branching from the discharge communication path 13. Further, on the discharge communication path 13, an oil separator 6 that separates the lubricating oil from the refrigerant is provided.

[0041] The inner housing 3 is fixed in a state where one end thereof abuts against an end plate 41a of a fixed scroll plate 41 that constitutes the scroll compression mechanism 4. In addition, on one end portion of the inner housing 3, a suction communication path 15 that penetrates in the radial direction is formed. That is, the low-pressure chamber 20 is formed from the outside of the inner housing 3 to the inside of the inner housing 3 via the suction communication path 15. The refrigerant supplied to the inside of the inner housing 3 through the suction communication path 15 is sucked into the scroll compression mechanism 4.

[0042] The scroll compression mechanism 4 is mainly composed of the fixed scroll plate 41 fixed in a substantially sealed state with respect to the lid 12 and a movable scroll plate 42 housed in the inside of the inner housing 3.

[0043] ​The fixed scroll 41 is made of metal and has a scroll-like scroll 41b provided to protrude from the surface of a circular plate-like end plate 41a, i.e., one end surface of the end plate 41a. Further, a recessed portion 41c recessed toward the inner diameter side of the other end surface of the end plate 41a is formed in the fixed scroll 41, and the high-pressure chamber 30 is defined by the recessed portion 41c and the end surface of the cover 12.

[0044] The movable scroll 42 is made of metal and has a scroll-like scroll 42b provided to protrude from the surface of a circular plate-like end plate 42a, i.e., one end surface of the end plate 42a. Further, a protrusion 42c protruding from the center of the other end surface of the end plate 42a is formed in the movable scroll 42. The eccentric portion 2a formed in one end portion of the rotation shaft 2 is relatively rotatably fitted in the protrusion 42c. In addition, in the present embodiment, the eccentric mechanism that eccentrically rotates the rotation shaft 2 is constituted by the eccentric portion 2a of the rotation shaft 2 and a counterweight portion 2b protruding outward in the radial direction from the one end portion of the rotation shaft 2.

[0045] When the rotation shaft 2 is rotationally driven by the drive motor M, the eccentric portion 2a is eccentrically rotated, and the movable scroll 42 is relatively slid with respect to the fixed scroll 41 in conjunction with the eccentric rotation. At this time, the movable scroll 42 is eccentrically rotated with respect to the fixed scroll 41, and in conjunction with the rotation, the contact positions of the scrolls 41b, 42b are sequentially moved in the rotation direction, and the compression chambers 40 formed between the scrolls 41b, 42b are gradually reduced while moving toward the center. Thus, the refrigerant sucked into the compression chambers 40 from the low-pressure chamber 20 formed on the outer diameter side of the scroll compression mechanism 4 is compressed, and finally, high-pressure refrigerant is discharged to the high-pressure chamber 30 through the discharge hole 41d provided in the center of the fixed scroll 41.

[0046] Next, the side seal 7 as a sliding member in the present embodiment will be described. As shown in Figs. 1 and 2, the side seal 7 is made of resin, has a cross-sectional rectangular shape and a circular ring shape when viewed in the axial direction, and is fixed to the back surface of the end plate 42a of the movable scroll 42. A sliding surface 7a that abuts against the sliding surface 8a of the thrust plate 8 is formed on one side surface of the side seal 7. Figure 1 Figure 2 As shown in Figs. 1 and 2, the side seal 7 is made of resin, has a cross-sectional rectangular shape and a circular ring shape when viewed in the axial direction, and is fixed to the back surface of the end plate 42a of the movable scroll 42. A sliding surface 7a that abuts against the sliding surface 8a of the thrust plate 8 is formed on one side surface of the side seal 7.

[0047] As shown in Figs. 1 and 2, the side seal 7 is made of resin, has a cross-sectional rectangular shape and a circular ring shape when viewed in the axial direction, and is fixed to the back surface of the end plate 42a of the movable scroll 42. A sliding surface 7a that abuts against the sliding surface 8a of the thrust plate 8 is formed on one side surface of the side seal 7. Figure 2

[0048] ​​The groove 70 is formed as a generally semi-circular shape with a center P at the innermost diameter of the sliding surface 7a. In detail, the groove 70 is composed of the following parts: a generally semi-circular arc-shaped wall surface 70a that extends axially in a manner orthogonal to the flat sliding surface 7a, having the same radius of curvature and being continuous; and a planar bottom surface 70b that extends parallel to the sliding surface 7a.

[0049] Furthermore, the bottom surface 70b of the groove 70 is not limited to being formed as a planar shape extending parallel to the sliding surface 7a; for example, it can also be formed as an inclined surface or a curved surface.

[0050] Furthermore, the circumferential dimension L1 of the groove 70 is larger than the circumferential dimension L2 of the boss portion between adjacent grooves 70 (L1 > L2). That is, multiple grooves 70 are densely formed throughout the entire circumference of the sliding surface 7a, and the opening area of ​​the grooves 70 that allow fluid to flow in from the space on the inner diameter side of the sliding surface 7a becomes larger.

[0051] Furthermore, the wall surface 70a of the channel 70 extends to a position further outward than the radial center of the sliding surface 7a. This increases the capacity for holding fluid within the channel 70.

[0052] like Figure 1 As shown, the thrust plate 8 is made of metal and is annular in shape. A sealing ring 43 is fixed to one end face of the thrust plate 8, which abuts against the inner circumferential surface of the inner shell 3. Thus, the thrust plate 8 functions as a thrust bearing that bears the axial load of the movable scroll plate 42 via the side seal 7.

[0053] Furthermore, the side seal 7 and the sealing ring 43 divide the interior of the inner shell 3 into a low-pressure chamber 20 formed on the outer diameter side of the movable scroll plate 42 and a back-pressure chamber 50 formed on the back side of the movable scroll plate 42. The back-pressure chamber 50 is sealed to the rotating shaft 2 inserted through the through hole 3a by a sealing ring 44 fixed to the inner circumference of the through hole 3a located at the center of the other end of the inner shell 3, thus forming a sealed space. In addition, a throttling orifice (not shown) is provided on the back-pressure communication path 14, which spans the cover 12, the fixed scroll plate 41, and the inner shell 3 and connects the high-pressure chamber 30 and the back-pressure chamber 50. The refrigerant in the high-pressure chamber 30, after being depressurized and adjusted by the throttling 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. Additionally, a pressure relief hole 16 is formed on the inner shell 3, which extends radially and connects the low-pressure chamber 20 and the back-pressure chamber 50. A pressure regulating valve 45 is installed in the pressure relief hole 16. The pressure regulating valve 45 opens when the pressure in the back-pressure chamber 50 exceeds a set value.

[0054] Furthermore, a protrusion 42c of a movable scroll plate 42 is inserted into a through hole 8b in the center of the thrust plate 8. The through hole 8b is formed to allow eccentric rotation by the eccentric portion 2a of the rotating shaft 2, which is inserted into the protrusion 42c. That is, the sliding surface 7a of the side seal 7 can slide relative to the sliding surface 8a of the thrust plate 8 as the rotating shaft 2 rotates eccentrically (see reference). Figure 3 ).

[0055] In addition, Figure 3 middle, Figure 3 (a) to (d) show the movement from the fixed scroll plate 41 (refer to) Figure 1 In the rotation trajectory of protrusion 42c under the condition of side observation, protrusion 42c is... Figure 3 (a) The reference points were rotated 90 degrees, 180 degrees, and 270 degrees clockwise, respectively. The sliding areas of the sliding surface 7a of the side seal 7 and the sliding surface 8a of the thrust plate 8 are schematically shown using dots. For ease of explanation, only the eccentric portion 2a inserted into the protrusion 42c is shown regarding the rotating shaft 2; the balancing counterweight 2b and other components constituting the eccentric mechanism are omitted.

[0056] Thus, the side seal 7 is a sliding component having a sliding surface 7a that slides relative to the sliding surface 8a of the thrust plate 8 as it rotates eccentrically.

[0057] Next, refer to Figures 4 to 7 The generation of dynamic pressure on the side seal 7 as a whole when it slides relative to the thrust plate 8 will be explained. Furthermore, fluid containing refrigerant and lubricating oil is stored in the groove 70 even when rotation stops. Figures 4 to 7 The diagrams show the drive motor M (reference) and its components. Figure 1 When viewed from the side, the circular mark shown on the wall 70a of the groove 70 indicates the location of the highest pressure in each groove 70.

[0058] Reference Figure 4 As shown by the white arrow, when the side seal 7 is to be removed from... Figure 3 (a) Rotation state towards Figure 3 When (b) moves in a rotating state, the fluid moves relative to the white arrow in the opposite direction, so the fluid in each groove 70 moves toward the area on the upper right side of the paper surface of the wall 70a, generating dynamic pressure.

[0059] Additionally, refer to Figure 5 As shown by the white arrow, when the side seal 7 is to be removed from... Figure 3 (b) rotational state towards Figure 3When the rotation state of (c) is moved to the rotation state of (d), the fluid relatively moves in the opposite direction with respect to the white arrow, and thus the fluid in each groove 70 moves toward the area on the left lower side of the paper with respect to the wall surface 70a, and dynamic pressure is generated.

[0060] Further, referring to Figure 6 As shown by the white arrow, when the side seal 7 is to be moved from the rotation state of (c) to the rotation state of (d), the fluid relatively moves in the opposite direction with respect to the white arrow, and thus the fluid in each groove 70 moves toward the area on the left lower side of the paper with respect to the wall surface 70a, and dynamic pressure is generated. Figure 3 When the rotation state of (c) is moved to the rotation state of (d), the fluid relatively moves in the opposite direction with respect to the white arrow, and thus the fluid in each groove 70 moves toward the area on the left lower side of the paper with respect to the wall surface 70a, and dynamic pressure is generated. Figure 3 When the rotation state of (c) is moved to the rotation state of (d), the fluid relatively moves in the opposite direction with respect to the white arrow, and thus the fluid in each groove 70 moves toward the area on the left lower side of the paper with respect to the wall surface 70a, and dynamic pressure is generated.

[0061] Further, referring to Figure 7 As shown by the white arrow, when the side seal 7 is to be moved from the rotation state of (c) to the rotation state of (d), the fluid relatively moves in the opposite direction with respect to the white arrow, and thus the fluid in each groove 70 moves toward the area on the left lower side of the paper with respect to the wall surface 70a, and dynamic pressure is generated. Figure 3 When the rotation state of (c) is moved to the rotation state of (d), the fluid relatively moves in the opposite direction with respect to the white arrow, and thus the fluid in each groove 70 moves toward the area on the left lower side of the paper with respect to the wall surface 70a, and dynamic pressure is generated. Figure 3 When the rotation state of (c) is moved to the rotation state of (d), the fluid relatively moves in the opposite direction with respect to the white arrow, and thus the fluid in each groove 70 moves toward the area on the left lower side of the paper with respect to the wall surface 70a, and dynamic pressure is generated.

[0062] Thus, since the grooves 70 are constituted by the continuous wall surface 70a of the same radius of curvature, in each groove 70, the position of the pressure generated on the wall surface 70a gradually moves along the wall surface 70a in accordance with the rotation angle of the protrusion 42c (refer to Figures 4 to 7 ).

[0063] At this time, in each groove 70, the number of grooves 70 in which dynamic pressure is generated is equal regardless of the eccentric rotation angle, in other words, the eccentric rotation phase, and the positions of the highest pressure in these grooves 70 in which dynamic pressure is generated are substantially the same in terms of the angle with respect to the center of the circular arc of the groove 70, and thus the positions in which dynamic pressure is generated are dispersed in a range of about 180 degrees in the circumferential direction of the sliding surface 7a of the side seal 7.

[0064] Thus, since the grooves 70 are constituted by the continuous wall surface 70a of the same radius of curvature, in each groove 70, the position of the pressure generated on the wall surface 70a gradually moves along the wall surface 70a in accordance with the rotation angle of the protrusion 42c (refer to Figure 3 ). Thus, by suppressing the vibration, tilting, and the like of the side seal 7 caused by the dynamic pressure, the sliding surfaces 7a, 8a are slightly separated from each other and a liquid film of lubricating oil is formed, the lubricity between the sliding surfaces 7a, 8a can be improved, and the frictional resistance of the sliding surface 7a can be reduced. Thus, dynamic pressure can be generated in the grooves 70 in a range that is continuous in the circumferential direction of the sliding surface 7a.

[0065] Furthermore, multiple grooves 70 are provided circumferentially along the sliding surface 7a, thus dynamic pressure can be generated through the multiple grooves 70 in accordance with the direction of relative movement of the grooves 70 accompanying eccentric rotation. Additionally, the distribution of pressure generated within the multiple grooves 70 due to the relative movement of the grooves 70 accompanying the eccentric rotation of the rotating shaft 2 (see reference) Figures 4 to 7 It moves approximately circumferentially along with eccentric rotation. Therefore, the fluid flowing from the upstream groove 70 to the sliding surfaces 7a and 8a with the generation of dynamic pressure easily flows into the adjacent downstream groove 70, and easily forms a lubricating oil film in the entire circumferential direction between the sliding surfaces 7a and 8a.

[0066] Furthermore, through the relative movement of the eccentrically rotating grooves 70, the fluid within the grooves 70 collides with the wall surface 70a, thereby generating dynamic pressure as the fluid flows out between the sliding surfaces 7a and 8a. However, within each groove 70, the position with the highest pressure corresponds to... Figure 3 The pressure varies with the rotation angle of the protrusion 42c shown. That is, the position of the highest pressure in each groove 70 is different depending on the rotation angle of the protrusion 42c. However, by arranging multiple grooves 70 at equal intervals along the circumference of the sliding surface 7a, the deviation of the dynamic pressure generated in the circumference between the sliding surfaces 7a and 8a can be suppressed.

[0067] Furthermore, the wall surface 70a of the groove 70 is a continuous shape with the same radius of curvature. Therefore, dynamic pressure is generated in different ways within each groove 70. Corresponding to the rotation angle of the protrusion 42c, the location of the pressure generated on the wall surface 70a gradually moves along the wall surface 70a. Thus, the dynamic pressure generated circumferentially between the sliding surfaces 7a and 8a is less prone to abrupt changes, and the generated dynamic pressure can be stabilized. Furthermore, "way" refers to the location and pressure of the dynamic pressure generation in the groove 70.

[0068] Furthermore, the groove 70 is formed to have a center P at the innermost diameter of the sliding surface 7a (see reference). Figure 2 The groove 70 is approximately semi-circular. Therefore, the groove 70 has a generally semi-circular arc shape, enabling the generation of stable dynamic pressure relative to any direction of relative movement corresponding to a continuous wall 70a with the same radius of curvature. Specifically, since the groove 70 is formed approximately semi-circular, it can generate stable dynamic pressure relative to a direction of relative movement of approximately 180 degrees relative to the wall 70a.

[0069] Furthermore, the groove 70 has an opening on the inner diameter side, which allows fluid flowing into the groove 70 from the opening to be easily retained within the groove 70 due to centrifugal force. Therefore, the sliding surfaces 7a and 8a are less likely to be in a poor lubrication state, and a lubricating oil film is easily formed.

[0070] Further, the groove 70 is opened toward the back pressure chamber 50 which is higher in pressure than the low pressure chamber 20, whereby fluid is easily caused to flow into the groove 70 from the opening of the groove 70 due to the pressure of the fluid. Therefore, a higher dynamic pressure can be generated in the groove 70.

[0071] Further, the side seal 7 in which the groove 70 is formed on the sliding surface 7a is narrower in radial width than the thrust plate 8 which relatively slides (refer to Figure 1 and Figure 3 ). Due to this, the entire sliding surface 7a of the side seal 7 is always located in the sliding region of the sliding surface 8a of the thrust plate 8 between the sliding surfaces 7a, 8a which relatively slide along with eccentric rotation (refer to Figure 3 ), and a dynamic pressure can be reliably generated by the groove 70.

[0072] The above describes embodiments of the present application according to the drawings, but the specific structure is not limited to these embodiments, and even if there are modifications, additions, etc. within the scope of the gist of the present application, they are included in the present application.

[0073] In the above embodiments, the manner in which the side seal 7 which is applied as a sliding member in the scroll compressor C used in an air conditioning system of an automobile, etc. is described, but this is not limiting, and can be applied to, for example, a scroll expansion compressor which integrally has an expander and a compressor, etc. as long as it is a rotary machine including an eccentric mechanism.

[0074] Further, the fluid which exists in the space inside and outside the sliding surface of the sliding member can be any one of a gas, a liquid, or a mixed state of a gas and a liquid.

[0075] Further, in the above embodiments, the manner in which the groove 70 formed on the sliding surface 7a of the side seal 7 is opened toward the space on the inner diameter side is described, but this is not limiting, and can be, for example, as with the side seal 107 of Modification Example 1 shown in Figure 8 , the groove 170 is formed in a circular shape having a center at the outermost diameter of the sliding surface 107a and is opened toward the space on the outer diameter side.

[0076] Further, it can be, for example, as with the side seal 207 of Modification Example 2 shown in Figure 9 , the groove 270A which is opened toward the space on the inner diameter side and the groove 270B which is opened toward the space on the outer diameter side are alternately formed in the circumferential direction of the sliding surface 207a.

[0077] Further, in the above embodiments, the case in which the groove 70 is formed in a circular shape having a center at the innermost diameter of the sliding surface 7a and the wall surface 70a is formed in a substantially semicircular arc shape is described, but this is not limiting, and as long as the wall surface of the groove is continuous in a circular arc shape, for example, it can be, for example, as with Modification Example 3 shown in Figure 10 (a), the groove is formed in a semicircular shape and the wall surface is in a circular arc shape.

[0078] Alternatively, as shown in Modification Example 4 of (b), the groove can be formed so as to be continuous in a circular arc shape, and the groove can be formed in a wavy shape along the inner periphery of the sliding surface. Figure 10

[0079] Alternatively, as shown in Modification Example 5 of (c), in addition to the groove that is open to the space on the inner diameter side, another groove that is not communicated with either of the spaces on the inner and outer sides can be formed. Further, the grooves of Modification Examples 3 to 5 can be open to the space on the outer diameter side as in Modification Example 1, or can be alternately open to the space on the inner diameter side and the space on the outer diameter side as in Modification Example 2. Figure 10

[0080] Further, in the above-described embodiment, the manner in which the groove 70 formed on the sliding surface 7a of the side seal 7 is open to the back pressure chamber 50 having a higher pressure than the low pressure chamber 20 has been described, but the groove can be open to the low pressure chamber 20. Further, the sliding member of the present application can be used in an environment in which the pressure on the inner and outer sides of the sliding surface is substantially the same, as long as the sliding member has a sliding surface that relatively slides in conjunction with eccentric rotation, and is not limited to an environment in which there is a pressure difference between the inner and outer sides of the sliding surface. Further, in the sliding member of the present application, it is not necessary to function as a seal, and it is only necessary to be able to reduce the friction of the sliding surface.

[0081] Further, in the above-described embodiment, the case in which the side seal 7 having the sliding surface 7a that relatively slides is made of resin and the thrust plate 8 is made of metal has been described, but the material of the sliding member can be freely selected depending on the use environment or the like.

[0082] Further, in the above-described embodiment, the manner in which the groove 70 is formed on the sliding surface 7a of the side seal 7 has been described, but this is not limiting, and a groove can be formed in the sliding region of the sliding surface 8a of the thrust plate 8 that is a sliding member having a sliding surface that relatively slides in conjunction with eccentric rotation (see FIG. 10). Figure 3 Further, a groove can be formed on both the sliding surface 7a of the side seal 7 and the sliding surface 8a of the thrust plate 8.

[0083] ​​In the above embodiment, the structure in which the sliding surface 7a of the side seal 7 as the sliding member and the sliding surface 8a of the thrust plate 8 slide against each other in conjunction with eccentric rotation is described, but the present application is not limited to this. For example, in the case where only the thrust plate is provided, a groove can be formed in either or both of the sliding surface of the thrust plate as the sliding member and the back surface of the end plate of the movable scroll. In the case where only the side seal is provided, a groove can be formed in the sliding surface of the side seal as the sliding member. In this case, the side seal also functions as a thrust bearing that receives the axial load of the movable scroll by abutting against the inner peripheral surface of the inner case.

[0084] In the case where the back surface of the end plate of the movable scroll abuts against the inner peripheral surface of the inner case to function as a thrust bearing that receives the axial load of the movable scroll without the side seal and the thrust plate, a groove can be formed in the sliding surface formed in the back surface of the end plate of the movable scroll.

[0085] Symbol Explanation

[0086] 1: housing; 2: rotation shaft; 2a: eccentric portion; 3: inner case; 4: scroll compression mechanism; 6: oil separator; 7: side seal (sliding member); 7a: sliding surface; 8: thrust plate; 8a: sliding surface; 10: suction port; 13: discharge communication passage; 14: back pressure communication passage; 15: suction communication passage; 20: low pressure chamber; 30: high pressure chamber; 40: compression chamber; 41: fixed scroll; 42: movable scroll; 50: back pressure chamber; 70: groove; 70a: wall surface; 70b: bottom surface; 107: side seal (sliding member); 107a: sliding surface; 170: groove; 207: side seal (sliding member); 207a: sliding surface; 270A: groove; 270B: groove; C: scroll compressor; M: drive motor; P: center of groove; Q: center of sliding surface.

Claims

1. An eccentric sliding assembly comprising: a first sliding member having a sliding surface, a second sliding member having a sliding surface, an eccentric drive configured to slide the surface of the first sliding member with the sliding surface of the second sliding surface such that a center of the first sliding assembly virtually draws a circle eccentric to a center of the second sliding member, wherein the sliding surface of the first sliding member has: a plurality of inner diameter side grooves each having a space opening for fluid on an inner diameter side of the sliding surface, and a plurality of outer diameter side grooves each having a space opening for fluid on an outer diameter side of the sliding surface, disposed circumferentially on the sliding surface; each of the inner diameter side grooves and each of the outer diameter side grooves is defined by a side wall surface that is circular arc-shaped in a plan view; at least an outermost diameter side portion of each of the inner diameter side grooves and an innermost diameter side portion of each of the outer diameter side grooves overlap in a circumferential view.

2. The eccentric sliding assembly according to claim 1, wherein: each of the inner diameter side grooves is semicircular with a center of a circle located at an innermost diameter side edge of the sliding surface of the first sliding member; each of the outer diameter side grooves is semicircular with a center of a circle located at an outermost diameter side edge of the sliding surface of the first sliding member.

3. The eccentric sliding assembly according to claim 1 or 2, wherein: each of the inner diameter side grooves has a space opening on a high pressure side.

4. The eccentric sliding assembly according to claim 1 or 2, wherein: a radial width of the first sliding member is smaller than a radial width of the second sliding member.

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