Eccentric sliding assembly

Abstract

Provided is a sliding member capable of stably reducing the frictional resistance of a sliding surface accompanying eccentric rotation. A sliding member (7) is in the shape of a circular ring in which a high-pressure fluid and a low-pressure fluid exist on the inner and outer surfaces, has a sliding surface (7a) that slides in opposition to each other accompanying eccentric rotation, and in which a plurality of high-pressure grooves (71) that open to a space (50) in which the high-pressure fluid exists and a plurality of low-pressure grooves (72) that open to a space (20) in which the low-pressure fluid exists are respectively provided on the sliding surface (7a) in the circumferential direction.

Description

Technical Field

[0001] The present invention relates to sliding components used in rotating machinery containing eccentric mechanisms. Background Technology

[0002] Rotary machinery used in various industrial sectors includes not only rotating machinery that rotates while its central shaft remains in a fixed position, but also rotating machinery whose central shaft rotates eccentrically. One type of rotating machinery with eccentric rotation includes scroll compressors, which are mechanisms comprising a scroll compression mechanism consisting of a fixed scroll plate with scroll-shaped teeth on the front of its end plate and a movable scroll plate with scroll-shaped teeth on the front of its end plate, and an eccentric mechanism that causes the rotating shaft to rotate eccentrically. By rotating the rotating shaft, the movable scroll plate slides relative to the fixed scroll plate while rotating eccentrically, thereby pressurizing the fluid supplied from the low-pressure chambers on the outer diameter side of the two scroll plates, and ejecting high-pressure fluid from an ejection port formed in the center of the fixed scroll plate.

[0003] These scroll compressors, which utilize a mechanism in which a movable scroll plate slides relative to a fixed scroll plate while rotating eccentrically, not only have high compression efficiency but also low noise, making them suitable for various applications, such as refrigeration cycles. However, they suffer from fluid leakage due to the axial gap between the two scroll plates. In the scroll compressor shown in Patent Document 1, a thrust plate that slides relative to the movable scroll plate is provided on the back side of the movable scroll plate. A portion of the refrigerant compressed by the scroll compression mechanism is supplied to the back pressure chamber formed on the back side of the thrust plate, pressing the movable scroll plate toward the fixed scroll plate. This reduces refrigerant leakage from the axial gap between the two scroll plates during refrigerant compression.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2016-61208 (pages 5-6) Figure 1 ) Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, in the scroll compressor shown in Patent Document 1, a portion of the refrigerant compressed by the scroll compression mechanism presses the movable scroll from the back side toward the fixed scroll via the thrust plate. Therefore, although the leakage of refrigerant from the axial gap between the two scrolls can be reduced, the pressing force acts from both sides of the axial direction between the two scrolls, especially on the sliding surface of the movable scroll and the thrust plate that is accompanied by eccentric rotation. As a result, the frictional resistance increases, the smooth movement of the movable scroll is hindered, and the compression efficiency cannot be improved.

[0009] This invention was made in view of such a problem, and its purpose is to provide a sliding component that can stably reduce the frictional resistance of the sliding surface accompanied by eccentric rotation.

[0010] Methods for solving problems

[0011] To address the aforementioned issues, the sliding component of the present invention is an annular shape with high-pressure fluid and low-pressure fluid facing both the inner and outer surfaces, and has a sliding surface that slides relative to each other with eccentric rotation. A plurality of high-pressure grooves and a plurality of low-pressure grooves are respectively provided on the sliding surface along the circumference. The high-pressure grooves open to the space where the high-pressure fluid exists, and the low-pressure grooves open to the space where the low-pressure fluid exists.

[0012] Therefore, corresponding to the direction of relative movement of the high-pressure and low-pressure grooves that accompany the eccentric rotation, the fluid existing in the inner and outer spaces of the sliding component generates dynamic pressure in any high-pressure and low-pressure grooves arranged circumferentially, causing the sliding surfaces to slightly separate and form a fluid film. This improves lubrication during sliding and stably reduces the frictional resistance of the sliding surfaces.

[0013] Alternatively, the area of ​​the low-pressure groove in the direction parallel to the sliding surface may be larger than the area of ​​the high-pressure groove in the direction parallel to the sliding surface.

[0014] Therefore, it is easy to achieve a balance between the dynamic pressure generated in the low-pressure tank and the dynamic pressure generated in the high-pressure tank, corresponding to the direction of relative movement of the high-pressure tank and the low-pressure tank that accompany the eccentric rotation. Thus, vibration or tilting of the sliding parts caused by the generation of dynamic pressure is suppressed.

[0015] Alternatively, the high-pressure tank and the low-pressure tank can be arranged alternately inside and outside.

[0016] Therefore, regardless of the direction of relative movement of the high-pressure and low-pressure tanks that accompany the eccentric rotation, dynamic pressure is generated in either the high-pressure tank or the low-pressure tank, which are arranged alternately inside and outside. Thus, the dynamic pressure generated in the entire circumferential range of the sliding surface is well balanced.

[0017] Alternatively, the high-pressure tank and the low-pressure tank may be evenly arranged along the circumference.

[0018] Thus, the sliding surfaces can be separated approximately equally in the circumferential direction by the dynamic pressure generated in the high-pressure tank and the low-pressure tank respectively.

[0019] Alternatively, the high-pressure tank and the low-pressure tank may be shaped as a portion of a circle.

[0020] Therefore, stable dynamic pressure can be generated along the arc-shaped walls of the high-pressure and low-pressure tanks respectively, corresponding to the direction of relative movement of the high-pressure and low-pressure tanks that are accompanied by eccentric rotation.

[0021] Alternatively, the space where the low-pressure fluid exists may be the space on the outer diameter side of the sliding surface.

[0022] Therefore, since a low-pressure groove is formed on the outer diameter side of the sliding surface, it is easy to ensure that the opening of the low-pressure groove and the area in the direction parallel to the sliding surface are large. Attached Figure Description

[0023] Figure 1 This is a schematic structural diagram of a scroll compressor that uses a side seal as a sliding component, according to Embodiment 1 of the present invention.

[0024] Figure 2 This is a diagram showing the sliding surface of the side seal of Embodiment 1 of the present invention.

[0025] Figure 3 This is a partially enlarged view showing the high-pressure groove and low-pressure groove on the sliding surface.

[0026] Figure 4 This is a diagram illustrating the relative sliding of the sliding surface of the side seal and the sliding surface of the thrust plate in Embodiment 1 of the present invention. Additionally, with... Figure 4 (a) is taken as the starting position. Figure 4 (b) shows the positional relationship between the sliding surface of the side seal and the sliding surface of the thrust plate when the rotating shaft is eccentrically rotated to 90 degrees. Figure 4 (c) shows the positional relationship between the sliding surface of the side seal and the sliding surface of the thrust plate when the rotating shaft is eccentrically rotated to 180 degrees. Figure 4 (d) shows the positional relationship between the sliding surface of the side seal and the sliding surface of the thrust plate when the rotating shaft is eccentrically rotated to 270 degrees.

[0027] Figure 5 It is shown in Figure 4 The diagram (a) shows the distribution of pressure generated in multiple grooves in the sliding surface of the side seal due to the relative movement of the grooves accompanied by the eccentric rotation of the rotating shaft.

[0028] Figure 6 It is shown in Figure 4(b) is a diagram showing the distribution of pressure generated in multiple grooves in the sliding surface of the side seal due to the relative movement of the grooves accompanied by the eccentric rotation of the rotating shaft.

[0029] Figure 7 It is shown in Figure 4 The diagram shown in (c) illustrates the distribution of pressure generated in multiple grooves in the sliding surface of the side seal due to the relative movement of the grooves accompanied by the eccentric rotation of the rotating shaft.

[0030] Figure 8 It is shown in Figure 4 The diagram (d) shows the distribution of pressure generated in multiple grooves in the sliding surface of the side seal due to the relative movement of the grooves accompanied by the eccentric rotation of the rotating shaft.

[0031] Figure 9 This is a diagram showing the sliding surface of the side seal of Embodiment 2 of the present invention.

[0032] Figure 10 This is a diagram showing the sliding surface of the side seal of Embodiment 3 of the present invention.

[0033] Figure 11 This is a diagram showing the sliding surface of the side seal of Embodiment 4 of the present invention. Detailed Implementation

[0034] Hereinafter, the method of implementing the sliding component of the present invention will be described based on embodiments.

[0035] Example 1

[0036] Reference Figures 1 to 8 The sliding component of Embodiment 1 will be described. For ease of explanation, the grooves and the like formed on the sliding surface of the sliding component are marked with points in the accompanying drawings.

[0037] The sliding component of the present invention is applicable to rotating machinery containing an eccentric mechanism, such as a scroll compressor C used in air conditioning systems of automobiles to draw in, compress, and eject a refrigerant as a fluid. Furthermore, in this embodiment, the refrigerant is a gas mixed with a mist of lubricating oil.

[0038] First, let's explain the scroll compressor C. For example... Figure 1 As shown, the scroll compressor C mainly comprises a housing 1, a rotating shaft 2, an inner shell 3, a scroll compression mechanism 4, a side seal 7 as a sliding component, a thrust plate 8, and a drive motor M.

[0039] The housing 1 has a cylindrical outer shell 11 and a cover 12 that closes an opening in the outer shell 11. Inside the outer shell 11 are a low-pressure chamber 20, a high-pressure chamber 30, and a back-pressure chamber 50. A refrigerant circuit (not shown) supplies low-pressure refrigerant to the low-pressure chamber 20 through a suction port 10. High-pressure refrigerant, compressed by a scroll compressor 4, is injected into the high-pressure chamber 30. A portion of the refrigerant compressed by the scroll compressor 4, along with lubricating oil, is supplied to the back-pressure chamber 50. The back-pressure chamber 50 is formed inside a cylindrical inner shell 3, which is housed within the outer shell 11.

[0040] An ejection passage 13 is formed on the cover 12. The ejection passage 13 connects the high-pressure chamber 30 and a refrigerant circuit (not shown). Additionally, a portion of a back pressure passage 14, branching from the ejection passage 13, connecting the high-pressure chamber 30 and the back pressure chamber 50, is formed on the cover 12. Furthermore, an oil separator 6 is provided on the ejection passage 13 to separate lubricating oil from the refrigerant.

[0041] The inner shell 3 is fixed in such a state that one end abuts against the end plate 41a of the fixed scroll disk 41 constituting the scroll compressor mechanism 4. Furthermore, a radially penetrating suction passage 15 is formed at one end of the inner shell 3. That is, the low-pressure chamber 20 is formed from the outside of the inner shell 3 to the inside of the inner shell 3 via the suction passage 15. Refrigerant supplied to the inside of the inner shell 3 through the suction passage 15 is drawn into the scroll compressor mechanism 4.

[0042] The scroll compression mechanism 4 mainly consists of a fixed scroll plate 41 and a movable scroll plate 42. The fixed scroll plate 41 is fixed to the cover 12 in a generally sealed manner. The movable scroll plate 42 is housed inside the inner shell 3.

[0043] The fixed scroll plate 41 is made of metal and has scroll-shaped teeth 41b. The scroll-shaped teeth 41b protrude from the front side of the circular end plate 41a, i.e., one end face of the end plate 41a. In addition, a recess 41c is formed on the fixed scroll plate 41, which is recessed on the inner diameter side of the back side of the end plate 41a, i.e., the other end face of the end plate 41a. The high-pressure chamber 30 is divided by this recess 41c and the end face of the cover 12.

[0044] The movable scroll plate 42 is made of metal and has scroll-shaped teeth 42b. The scroll-shaped teeth 42b protrude from the front side of the circular end plate 42a, i.e., one end face of the end plate 42a. In addition, a protrusion 42c is formed on the movable scroll plate 42, protruding from the center of the back side of the end plate 42a, i.e., the other end face of the end plate 42a. An eccentric portion 2a formed at one end of the rotating shaft 2 is rotatably inserted into the protrusion 42c. Furthermore, in this embodiment, the eccentric portion 2a of the rotating shaft 2 and the counterweight portion 2b protruding from one end of the rotating shaft 2 in the outward diameter direction constitute an eccentric mechanism for causing the rotating shaft 2 to rotate eccentrically.

[0045] When the rotating shaft 2 is driven to rotate by the drive motor M, the eccentric part 2a rotates eccentrically, and the movable scroll plate 42 slides relative to the fixed scroll plate 41 while maintaining its posture during the eccentric rotation. At this time, the movable scroll plate 42 rotates eccentrically relative to the fixed scroll plate 41, and with this rotation, the contact position of the scroll teeth 41b and 42b moves sequentially in the direction of rotation, and the compression chamber 40 formed between the scroll teeth 41b and 42b gradually shrinks while moving towards the center. As a result, the refrigerant drawn into the compression chamber 40 from the low-pressure chamber 20 formed on the outer diameter side of the scroll compressor mechanism 4 is compressed and finally ejected into the high-pressure chamber 30 through the ejection hole 41d provided in the center of the fixed scroll plate 41.

[0046] Next, the side seal 7, which serves as a sliding component in this embodiment, will be described. Figure 2 and Figure 3 As shown, the side seal 7 is made of resin, has a rectangular cross-section, and appears annular when viewed axially. Furthermore, the side seal 7 is fixed to the back of the end plate 42a of the movable scroll plate 42 (see reference). Figure 1 Additionally, in Figure 2 , Figure 3 The sliding surface 7a of the side seal 7 is shown in the figure.

[0047] A sliding surface 7a is formed on one side of the side seal 7, which abuts against the sliding surface 8a of the thrust plate 8.

[0048] like Figure 2 As shown, the sliding surface 7a of the side seal 7 has a land portion 79, a plurality of high-pressure grooves 71, and a plurality of low-pressure grooves 72. The high-pressure grooves 71 are formed to be recessed from the flat surface 79a of the land portion 79, and the back pressure chamber 50 (see reference) is located laterally to the inner diameter of the high-pressure groove 71 as a space where high-pressure fluid exists. Figure 1 The low-pressure groove 72 is formed as a depression in the surface 79a of the land portion 79, and is located laterally to the outer diameter of the sliding surface 7a in the low-pressure chamber 20, which is the space where the low-pressure fluid exists (see reference). Figure 1 The high-pressure groove 71 and the low-pressure groove 72 are arranged alternately inside and outside the sliding surface 7a in a roughly equal manner.

[0049] like Figure 3 As shown, the high-pressure groove 71 is formed as a roughly semicircle with a center P1 at the innermost diameter of the sliding surface 7a. Similarly, the low-pressure groove 72 is formed as a roughly semicircle with a center P2 at the outermost diameter of the sliding surface 7a. In other words, when viewed axially from a direction parallel to the sliding surface 7a, both the high-pressure groove 71 and the low-pressure groove 72 are formed from a portion of a circle.

[0050] In detail, the high-pressure tank 71 is formed by a wall surface 71a and a bottom surface 71b. The wall surface 71a extends substantially perpendicular to the surface 79a of the land portion 79, has a constant radius of curvature, and its continuous topography forms a substantially semi-circular arc shape. The bottom surface 71b extends substantially perpendicular to the end of the wall surface 71a and substantially parallel to the surface 79a of the land portion 79, forming a planar shape. Furthermore, although each high-pressure tank 71 is the same size, the sizes of each high-pressure tank 71 can also be different.

[0051] The low-pressure trough 72 is formed by a wall surface 72a and a bottom surface 72b. The wall surface 72a extends substantially perpendicular to the surface 79a of the land portion 79, has a constant radius of curvature, and is continuously formed in a substantially semi-circular arc shape. The bottom surface 72b extends substantially perpendicular to the end of the wall surface 72a and substantially parallel to the surface 79a of the land portion 79, and is formed in a planar shape. Furthermore, although all low-pressure troughs 72 are the same size, their individual sizes may differ.

[0052] Furthermore, the bottom surface 71b of the high-pressure tank 71 and the bottom surface 72b of the low-pressure tank 72 are not limited to being formed as a planar shape extending substantially parallel to the sliding surface 7a; for example, they may also be formed as inclined surfaces or curved surfaces.

[0053] Furthermore, the dimension from the surface 79a of the land portion 79 to the bottom surface 71b of the high-pressure groove 71 (i.e., the depth dimension of the high-pressure groove 71) and the dimension from the surface 79a of the land portion 79 to the bottom surface 72b of the low-pressure groove 72 (i.e., the depth dimension of the low-pressure groove 72) are approximately the same, forming a depth that can generate dynamic pressure that separates the sliding surfaces 7a and 8a from each other as they slide relative to the sliding surface 8a of the thrust plate 8. However, the depth dimensions of the high-pressure groove 71 and the low-pressure groove 72 are not limited to being approximately the same.

[0054] Furthermore, the low-pressure groove 72 is formed such that its area in the direction parallel to the sliding surface 7a (i.e., the area when viewed axially) is larger than the area of ​​the high-pressure groove 71 in the direction parallel to the sliding surface 7a. Specifically, the dimension of the low-pressure groove 72 from its center P2 to its wall surface 72a, i.e., its radius R2, is longer than the dimension of the high-pressure groove 71 from its center P1 to its wall surface 71a, i.e., its radius R1 (R1...). <R2)。

[0055] Furthermore, the circumferential dimension L2 of the low-pressure trough 72 is longer than the circumferential dimension L4 of the land portion between adjacent low-pressure troughs 72 (L2>L4). That is, multiple low-pressure troughs 72 are densely formed over the entire circumferential range of the sliding surface 7a, and the opening area for the supply fluid of the low-pressure trough 72 to flow in from the space on the outer diameter side of the sliding surface 7a is large.

[0056] Furthermore, the wall surface 72a of the low-pressure tank 72 extends to a position closer to the inner diameter than the radial center of the sliding surface 7a. This results in a larger capacity for holding fluid within the low-pressure tank 72.

[0057] In addition, the circumferential dimension L2 of the low-pressure groove 72 is shorter than the circumferential dimension L3 of the land portion between adjacent high-pressure grooves 71 (L2 < L3), and the circumferential dimension L1 of the high-pressure groove 71 is shorter than the circumferential dimension L4 of the land portion between adjacent low-pressure grooves 72 (L1 < L4).

[0058] Refer to Figure 1 , the thrust plate 8 is made of metal and is in an annular shape. A sealing ring 43 is fixed to one end face of the thrust plate 8. In addition, the sealing ring 43 abuts against the inner side surface of the inner shell 3. Thus, the thrust plate 8 functions as a thrust bearing and bears the axial load of the movable scroll 42 via the side seal 7.

[0059] In addition, the side seal 7 and the sealing ring 43 divide the inside of the inner shell 3 into a low-pressure chamber 20 formed on the outer diameter side of the movable scroll 42 and a back-pressure chamber 50 formed on the back side of the movable scroll 42. The back-pressure chamber 50 is a closed section formed between the inner shell 3 and the rotating shaft 2. A sealing ring 44 is fixed to the inner periphery of a through-hole 3a formed in the center of the other end of the inner shell 3 and is in sealing sliding contact with the rotating shaft 2 inserted through the through-hole 3a. In addition, a back-pressure communication path 14 connecting the high-pressure chamber 30 and the back-pressure chamber 50 is formed through the cover 12, the fixed scroll 41, and the inner shell 3. In addition, a throttle hole (not shown) is provided on the back-pressure communication path 14, and the refrigerant in the high-pressure chamber 30 after being decompressed and adjusted by the throttle hole and the lubricating oil separated by the oil separator 6 are supplied to the back-pressure chamber 50 together. Thus, the pressure in the back-pressure chamber 50 is adjusted to be higher than the pressure in the low-pressure chamber 20. In addition, a pressure release hole 16 penetrating radially and connecting the low-pressure chamber 20 and the back-pressure chamber 50 is formed in the inner shell 3. In addition, a pressure regulating valve 45 is provided in the pressure release hole 16. When the pressure in the back-pressure chamber 50 exceeds the set value, the pressure regulating valve 45 opens.

[0060] In addition, a convex portion 42c of the movable scroll 42 is inserted through a through-hole 8b in the center of the thrust plate 8. The through-hole 8b is formed to have a diameter size that can allow eccentric rotation caused by the eccentric portion 2a of the rotating shaft 2 inserted into the convex portion 42c. That is, the sliding surface 7a of the side seal 7 can relatively slide along with the eccentric rotation with respect to the sliding surface 8a of the thrust plate 8 through the eccentric rotation of the rotating shaft 2 (refer to Figure 4 ).

[0061] In addition, in Figure 4 , Figure 4 (a) to (d) show the rotation locus of the convex portion 42c as indicated by the black arrow when viewed from the side of the fixed scroll 41 (refer to Figure 1 ), and the convex portion 42c rotates at Figure 4(a) shows the states after rotating 90 degrees, 180 degrees, and 270 degrees clockwise, respectively. Additionally, 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 with dots. Furthermore, for ease of explanation, only the eccentric portion 2a inserted into the protrusion 42c is shown for the rotating shaft 2; the illustrations of the counterweight portion 2b, etc., constituting the eccentric mechanism, are omitted.

[0062] 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 with eccentric rotation.

[0063] Next, refer to Figures 5-8 The generation of dynamic pressure when the side seal 7 slides relative to the thrust plate 8 will be explained. Furthermore, even when rotation stops, fluids containing refrigerant and lubricating oil flow into the high-pressure tank 71 and the low-pressure tank 72. Additionally, in Figures 5-8 The diagrams show the effects from the drive motor M side (refer to...). Figure 1 Under observation, the circular markings on the wall surface 71a of the high-pressure groove 71 and the wall surface 72a of the low-pressure groove 72 indicate the locations with the highest pressure in each of the high-pressure grooves 71 and low-pressure grooves 72.

[0064] Although the illustrations are omitted for clarity, the side seal 7 relative to the thrust plate 8 (see reference) Figure 1 When sliding relative to each other, as the side seal 7 moves, the fluid in the high-pressure groove 71 and the low-pressure groove 72 is subjected to shear force in a direction approximately opposite to the direction of movement of the side seal 7 and moves in that direction.

[0065] As a result, the fluid pressure increases at the wall surface 71a of the high-pressure tank 71 and the wall surface 72a of the low-pressure tank 72, generating dynamic pressure as positive pressure. Furthermore, in the following description, dynamic pressure as positive pressure will sometimes be simply referred to as dynamic pressure.

[0066] By generating dynamic pressure, the sliding surfaces 7a and 8a are slightly separated from each other, and a fluid film is formed by the fluid flowing into the space between the sliding surfaces 7a and 8a. As a result, the lubrication of the sliding surfaces 7a and 8a improves, and thus the frictional resistance between the sliding surfaces 7a and 8a is reduced.

[0067] Next, the generation of dynamic pressure throughout the entire area of ​​the side seal 7 will be explained. (Refer to...) Figure 5 As shown by the white arrow, when the side seal 7 wants to... Figure 4 The rotational state of (a) towards Figure 4When moving in the rotational state of (b), the fluid moves relative to the direction opposite to the white arrow. Within each high-pressure tank 71, the fluid moves towards the upper right side of the wall 71a, generating dynamic pressure; similarly, within each low-pressure tank 72, the fluid moves towards the upper right side of the wall 72a, generating dynamic pressure. That is, dynamic pressure is generated within each high-pressure tank 71 within a range of approximately 180 degrees on the inner diameter side of the sliding surface 7a formed from the right side to the top of the paper, and within each low-pressure tank 72 within a range of approximately 180 degrees on the outer diameter side of the sliding surface 7a formed from the left side to the bottom of the paper.

[0068] Additionally, refer to Figure 6 As shown by the white arrow, when the side seal 7 wants to... Figure 4 The rotational state of (b) towards Figure 4 When (c) rotates, the fluid moves relative to the direction opposite to the white arrow. Within each high-pressure tank 71, the fluid moves towards the upper left side of the wall 71a, generating dynamic pressure; similarly, within each low-pressure tank 72, the fluid moves towards the upper left side of the wall 72a, generating dynamic pressure. That is, dynamic pressure is generated within each high-pressure tank 71 within a range of approximately 180 degrees on the inner diameter side of the sliding surface 7a formed above the paper surface to the left side of the paper surface, and within each low-pressure tank 72 within a range of approximately 180 degrees on the outer diameter side of the sliding surface 7a formed below the paper surface to the right side of the paper surface.

[0069] Additionally, refer to Figure 7 As shown by the white arrow, when the side seal 7 wants to... Figure 4 The rotational state of (c) towards Figure 4 When the (d) rotates, the fluid moves relative to the direction opposite to the white arrow. Within each high-pressure tank 71, the fluid moves towards the lower left side of the wall 71a, generating dynamic pressure; similarly, within each low-pressure tank 72, the fluid moves towards the lower left side of the wall 72a, generating dynamic pressure. That is, dynamic pressure is generated within each high-pressure tank 71 within a range of approximately 180 degrees on the inner diameter side of the sliding surface 7a formed from the left side of the paper to below the paper surface, and within each low-pressure tank 72 within a range of approximately 180 degrees on the outer diameter side of the sliding surface 7a formed from the right side of the paper to above the paper surface.

[0070] Additionally, refer to Figure 8 As shown by the white arrow, when the side seal 7 wants to... Figure 4 The rotational state of (d) towards Figure 4When moving in the rotational state of (a), the fluid moves relative to the direction opposite to the white arrow. Within each high-pressure tank 71, the fluid moves towards the lower right side of the wall 71a, generating dynamic pressure, and within each low-pressure tank 72, the fluid moves towards the lower right side of the wall 72a, generating dynamic pressure. That is, dynamic pressure is generated within each high-pressure tank 71 within a range of approximately 180 degrees on the inner diameter side of the sliding surface 7a formed below the paper surface to the right side of the paper surface, and dynamic pressure is generated within each low-pressure tank 72 within a range of approximately 180 degrees on the outer diameter side of the sliding surface 7a formed above the paper surface to the left side of the paper surface.

[0071] Furthermore, the side seal 7, on which high-pressure groove 71 and low-pressure groove 72 are formed on the sliding surface 7a, has a narrower radial width compared to the relatively sliding thrust plate 8 (see reference). Figure 1 and Figure 4 Therefore, between the sliding surfaces 7a and 8a that slide relative to each other during eccentric rotation, the sliding surface 7a of the side seal 7 is always located within the sliding area with the sliding surface 8a of the thrust plate 8 (see reference). Figure 4 Therefore, the high-pressure tank 71 and the low-pressure tank 72 can reliably generate dynamic pressure.

[0072] Furthermore, in the high-pressure tank 71 and the low-pressure tank 72, the wall surfaces 71a and 72a are formed into a roughly semi-circular arc shape when viewed axially. Therefore, in each high-pressure tank 71 and each low-pressure tank 72, the location where pressure is generated on the wall surfaces 71a and 72a gradually moves along the wall surfaces 71a and 72a within a range of approximately 180 degrees depending on the rotation angle of the protrusion 42c (see reference). Figures 5-8 ).

[0073] Furthermore, in the high-pressure tank 71 and the low-pressure tank 72, the approximately semi-circular arc-shaped wall surfaces 71a and 72a are continuous with the same radius of curvature. Therefore, in each of the high-pressure tanks 71 and the low-pressure tank 72, the pressure generated is approximately the same regardless of the eccentric rotation angle. As a result, the dynamic pressure generated in each of the high-pressure tanks 71 and the low-pressure tank 72 between the sliding surfaces 7a and 8a is not prone to drastic changes, and the generated dynamic pressure is stable.

[0074] Furthermore, in this embodiment, the low-pressure tank 72 is formed such that its area when viewed along the axial direction is larger than that of the high-pressure tank 71 when viewed along the axial direction, so that the pressure generated in the high-pressure tank 71 and the pressure generated in the low-pressure tank 72 are approximately the same, thus achieving a balance.

[0075] Furthermore, the high-pressure groove 71 and the low-pressure groove 72 are arranged alternately and approximately equally in the circumferential direction of the sliding surface 7a. Therefore, corresponding to the direction of relative movement of the high-pressure groove 71 and the low-pressure groove 72 accompanying eccentric rotation, dynamic pressure is generated in each of the high-pressure grooves 71 within a range of approximately 180 degrees on the inner diameter side of the sliding surface 7a, and dynamic pressure is generated in each of the low-pressure grooves 72 within a range of approximately 180 degrees on the outer diameter side of the sliding surface 7a, which is offset circumferentially by half a circumference from that range (see reference). Figures 5-8 That is, between the sliding surfaces 7a and 8a, approximately the same dynamic pressure is generated throughout the circumferential range through each high-pressure groove 71 and each low-pressure groove 72.

[0076] As explained above, in the side seal 7, corresponding to the direction of relative movement of the high-pressure groove 71 and the low-pressure groove 72 that are eccentrically rotated, the fluid present in the inner and outer spaces of the side seal 7 generates dynamic pressure in any of the high-pressure grooves 71 and the low-pressure grooves 72 arranged along the circumferential direction. This causes the sliding surfaces 7a and 8a to slightly separate from each other and form a fluid film, thereby improving the lubricity between the sliding surfaces 7a and 8a and stably reducing the frictional resistance of the sliding surfaces 7a and 8a.

[0077] Furthermore, the low-pressure groove 72 is formed such that its area when viewed along the axial direction is larger than that of the high-pressure groove 71 when viewed along the axial direction. This allows the dynamic pressure generated in the low-pressure groove 72 to be balanced in a manner that corresponds to the direction of relative movement of the sliding surface 7a with eccentric rotation, so that the dynamic pressure generated in the low-pressure groove 72 is approximately the same as that generated in the high-pressure groove 71. Therefore, the sliding surfaces 7a and 8a can be separated from each other approximately equally in the circumferential direction, and the vibration or tilting of the side seal 7 caused by the generation of dynamic pressure can be suppressed.

[0078] Furthermore, the high-pressure groove 71 and the low-pressure groove 72 are alternately arranged inside and outside the sliding surface 7a. This ensures that regardless of the direction of relative movement of the high-pressure groove 71 and the low-pressure groove 72 accompanying the eccentric rotation, dynamic pressure will be generated in either the high-pressure groove 71 or the low-pressure groove 72. Therefore, the dynamic pressure generated throughout the entire circumferential range of the sliding surface 7a is well balanced. Additionally, the areas where the high-pressure groove 71 and the low-pressure groove 72 are formed on the sliding surface 7a are less likely to interfere with each other, thus allowing for the efficient formation of the high-pressure groove 71 and the low-pressure groove 72 on the sliding surface 7a.

[0079] In addition, the low-pressure chamber 20, which is the space where the low-pressure fluid exists, is the space on the outer diameter side of the sliding surface 7a. The low-pressure groove 72 is formed on the outer diameter side of the sliding surface 7a, so it is easy to ensure that the opening of the low-pressure groove 72 and the area when viewed along the axial direction are large.

[0080] Example 2

[0081] Next, refer to Figure 9The high-pressure groove 171 and the low-pressure groove 172 of the side seal 107 of Embodiment 2 will be described. In addition, the description of the structures that are the same as those in the above Embodiment 1 will be omitted.

[0082] As Figure 9 shown, the high-pressure groove 171 and the low-pressure groove 172 are formed in a substantially rectangular shape.

[0083] Specifically, the high-pressure groove 171 is formed by a wall surface 171a, side wall surfaces 171c, 171d, and a bottom surface 171b. The wall surface 171a extends substantially perpendicular to the surface 179a of the land portion 179 and extends linearly in the circumferential direction. The side wall surfaces 171c, 171d extend substantially perpendicular to the surface 179a of the land portion 179 and extend linearly in the radial direction. The bottom surface 171b is substantially perpendicular to the end portions of the wall surface 171a and the side wall surfaces 171c, 171d, respectively, and extends substantially parallel to the surface 179a of the land portion 179, forming a planar shape.

[0084] The low-pressure groove 172 is formed by a wall surface 172a, side wall surfaces 172c, 172d, and a bottom surface 172b. The wall surface 172a extends substantially perpendicular to the surface 179a of the land portion 179 and extends linearly in the circumferential direction. The side wall surfaces 172c, 172d extend substantially perpendicular to the surface 179a of the land portion 179 and extend linearly in the radial direction. The bottom surface 172b is substantially perpendicular to the end portions of the wall surface 172a and the side wall surfaces 172c, 172d, respectively, and extends substantially parallel to the surface 179a of the land portion 179, forming a planar shape.

[0085] In addition, the circumferential dimension L12 of the low-pressure groove 172 is a dimension substantially the same as the circumferential dimension L11 of the high-pressure groove 171 (L11 = L12). Thus, the opening area for fluid to flow into the inner and outer spaces of the sliding surface 107a of the high-pressure groove 171 and the low-pressure groove 172 is large.

[0086] In addition, the radial dimension L14 of the low-pressure groove 172 is longer than the radial dimension L13 of the high-pressure groove 171 (L13 < L14). That is, the low-pressure groove 172 is formed such that the area when viewed in the axial direction is larger than the area of the high-pressure groove 171 when viewed in the axial direction.

[0087] In addition, the low-pressure groove 172 extends to a position closer to the inner diameter side than the radial center of the sliding surface 107a. Thus, the capacity for holding fluid in the low-pressure groove 172 is large.

[0088] Thus, corresponding to the direction of relative movement of the high-pressure groove 171 and the low-pressure groove 172 accompanying eccentric rotation, the fluid in the high-pressure groove 171 and the low-pressure groove 172 concentrates at the corner formed by any one of the wall surface 171a and the side wall surfaces 171c, 171d constituting the high-pressure groove 171, and the corner formed by any one of the wall surface 172a and the side wall surfaces 172c, 172d constituting the low-pressure groove 172. Therefore, a high dynamic pressure is generated in the high-pressure groove 171 and the low-pressure groove 172.

[0089] Example 3

[0090] Next, refer to Figure 10 The high-pressure groove 271 and the low-pressure groove 272 of the side seal 207 of Example 3 will be described. In addition, the description of the repeated structure identical to that of the above Example 1 will be omitted.

[0091] As Figure 10 shown, the high-pressure groove 271 and the low-pressure groove 272 are formed in a substantially rectangular shape.

[0092] In addition, the circumferential dimension L22 of the low-pressure groove 272 is longer than the circumferential dimension L21 of the high-pressure groove 271 (L21 < L22). Thus, the opening area for the fluid to flow into the space on the outer diameter side of the sliding surface 207a of the low-pressure groove 172 is large.

[0093] In addition, the radial dimension L24 of the low-pressure groove 272 is substantially the same as the radial dimension L23 of the high-pressure groove 271 (L23 = L24). That is, the low-pressure groove 272 is formed such that the area when viewed in the axial direction is larger than the area of the high-pressure groove 271 when viewed in the axial direction.

[0094] In addition, the high-pressure groove 271 extends to a position on the outer diameter side with respect to the radial center of the sliding surface 207a, and the low-pressure groove 272 extends to a position on the inner diameter side with respect to the radial center of the sliding surface 207a. That is, the high-pressure groove 271 and the low-pressure groove 272 are formed such that they mostly overlap in the circumferential direction.

[0095] Thus, the fluid flowing out from the high-pressure groove 271 or the low-pressure groove 272 on the circumferential upstream side to between the sliding surfaces 207a, 8a due to the generation of dynamic pressure is easily introduced into the high-pressure groove 271 or the low-pressure groove 272 adjacent on the downstream side at that moment. It is not only easy to form a fluid film composed of fluid over the entire circumferential range between the sliding surfaces 207a, 8a, but also easy to supply the fluid on the land portion 279 into the high-pressure groove 271 or the low-pressure groove 272.

[0096] Example 4

[0097] Next, refer to Figure 11The high-pressure groove 371 and low-pressure groove 372 of the side seal 307 in Embodiment 4 will be described. Furthermore, repeated structural descriptions identical to those in Embodiment 1 described above are omitted.

[0098] like Figure 11 As shown, the high-pressure tank 371 and the low-pressure tank 372 are formed into approximately isosceles trapezoids, and the low-pressure tank 372 has a larger area when viewed along the axial direction than the high-pressure tank 371.

[0099] In detail, the high-pressure groove 371 and the low-pressure groove 372 are each formed as approximately isosceles trapezoids with the largest circumferential dimension and both inner and outer openings. This ensures a large axial area for the land portion between the circumferentially adjacent high-pressure grooves 371 and low-pressure grooves 372. This allows fluid flowing from the high-pressure groove 371 or low-pressure groove 372 to the sliding surfaces 307a and 8a, which is generated with dynamic pressure, to easily remain in the land portion. Therefore, lubrication between the sliding surfaces 307a and 8a can be ensured during sliding, and sealing performance is improved.

[0100] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the specific structure is not limited to these embodiments, and changes and additions that do not depart from the spirit of the present invention are also included in the present invention.

[0101] In the above embodiments, the application of a side seal, which serves as a sliding component, to a scroll compressor used in an air conditioning system such as an automobile has been described, but it is not limited thereto. Any rotating machinery that includes an eccentric mechanism is acceptable, such as a scroll expander compressor that integrates an expander and a compressor.

[0102] In addition, the fluid existing in the inner and outer spaces of the sliding surface of the sliding component can be any of the following states: gas, liquid, or a mixture of gas and liquid.

[0103] Furthermore, in the above embodiment 1, the high-pressure groove 71 was described as being formed as a circle with a center P1 at the innermost diameter of the sliding surface 7a, and the wall surface 71a being formed as a roughly semi-circular arc shape. However, it is not limited to this. The high-pressure groove can be formed as long as the wall surface is continuous in an arc shape. For example, the high-pressure groove can also be formed as a semi-ellipse with an arc-shaped wall surface. The low-pressure groove 72 is the same.

[0104] Furthermore, in the above embodiments, the case where the area of ​​the low-pressure groove is larger when viewed axially than that of the high-pressure groove has been described, but this is not a limitation. The area of ​​the low-pressure groove when viewed axially may be the same as that of the high-pressure groove, or it may be smaller than that of the high-pressure groove. Additionally, in this case, the number of low-pressure grooves may be greater than the number of high-pressure grooves, thereby achieving a balance by generating approximately the same dynamic pressure across the entire circumferential 360-degree range between the sliding surfaces.

[0105] Furthermore, the sliding component of the present invention only needs to have a sliding surface that slides relative to the sliding surface with eccentric rotation, and is not limited to use in environments where there is a pressure difference between the inside and outside of the sliding surface, but can also be used in environments where the pressures inside and outside the sliding surface are approximately the same. Additionally, the sliding component of the present invention does not need to function as a sealing element; it is sufficient that it can stably reduce the frictional resistance of the sliding surface.

[0106] Furthermore, in the above embodiments, the side seal with the relatively sliding sliding surface is made of resin and the thrust plate is made of metal, but the material of the sliding component can be freely selected according to the usage environment, etc.

[0107] Furthermore, in the above embodiments, the method of forming high-pressure grooves and low-pressure grooves on the sliding surface of the side seal has been described, but it is not limited to this. It is also possible to form high-pressure grooves and low-pressure grooves on the sliding area of ​​the sliding surface of the thrust plate, which is a sliding member having a sliding surface that slides relative to each other with eccentric rotation (see the sliding area of ​​the thrust plate). Figure 4 Grooves can be formed. Alternatively, grooves can be formed on both the sliding surface of the side seal and the sliding surface of the thrust plate.

[0108] Furthermore, in the above embodiments, a structure was described in which the sliding surface of the side seal, which serves as a sliding member, and the sliding surface of the thrust plate slide relative to each other during eccentric rotation. However, this is not a limitation; either the side seal or the thrust plate may be used, and a groove may be formed on the sliding surface that slides relative to each other during eccentric rotation. For example, in the case of only having a thrust plate, a groove may be formed on either or both of the sliding surface of the thrust plate, which serves as a sliding member, and the back surface of the end plate of the movable scroll. In addition, in the case of only having a side seal, a groove may be formed on the sliding surface of the side seal as a sliding member. In this case, the side seal also functions as a thrust bearing, abutting against the inner circumferential surface of the inner shell to bear the axial load of the movable scroll.

[0109] In addition, when the side seal and thrust plate are not provided, and the back of the end plate of the movable scroll plate abuts against the inner circumferential surface of the inner shell to function as a thrust bearing to bear the axial load of the movable scroll plate, a groove may be formed on the sliding surface formed on the back of the end plate of the movable scroll plate.

[0110] Furthermore, in the above embodiments, the side seal has been described as having an annular structure when viewed axially, but it is not limited thereto and may also be formed as a circular plate when viewed axially.

[0111] Label Explanation

[0112] 1: Housing; 2: Rotating shaft; 2a: Eccentric part; 3: Inner shell; 4: Scroll compressor mechanism; 6: Oil separator; 7: Side seal (sliding component); 7a: Sliding surface; 8: Thrust plate; 8a: Sliding surface; 10: Inlet; 13: Ejection passage; 14: Back pressure passage; 15: Inlet passage; 20: Low-pressure chamber; 30: High-pressure chamber; 40: Compression chamber; 41: Fixed scroll plate; 42: Movable scroll plate; 50: Back pressure Chamber; 71: High-pressure tank; 72: Low-pressure tank; 79: Land section; 107: Side seal (sliding component); 171: High-pressure tank; 172: Low-pressure tank; 207: Side seal (sliding component); 271: High-pressure tank; 272: Low-pressure tank; 307: Side seal (sliding component); 371: High-pressure tank; 372: Low-pressure tank; C: Scroll compressor; M: Drive motor; P1: Center of high-pressure tank; P2: Center of low-pressure tank.

Claims

1. An eccentric sliding assembly for use in rotating machinery, The eccentric sliding component has: The first sliding component is annular in shape and has a sliding surface; The second sliding component has a sliding surface; and An eccentric drive mechanism causes the sliding surface of the first sliding member to slide relative to the sliding surface of the second sliding member during eccentric rotation, or causes the sliding surface of the second sliding member to slide relative to the sliding surface of the first sliding member during eccentric rotation. in, The radial width of the sliding surface of the first sliding component is smaller than the radial width of the sliding surface of the second sliding component. At least one high-pressure groove and one low-pressure groove are respectively provided circumferentially on the sliding surface of the first sliding member. The high-pressure groove opens into one of the spaces on the outer diameter side and the inner diameter side of the sliding surface of the first sliding member, where a high-pressure fluid exists during the operation of the rotating machinery. The low-pressure groove opens into the other of the spaces on the outer diameter side and the inner diameter side of the sliding surface of the first sliding member, where a low-pressure fluid exists during the operation of the rotating machinery. The area of ​​the low-pressure groove in the direction parallel to the sliding surface is larger than the area of ​​the high-pressure groove in the direction parallel to the sliding surface.

2. The eccentric sliding assembly according to claim 1, wherein, The high-pressure groove and the low-pressure groove are alternately arranged on the inner diameter side and the outer diameter side of the sliding surface of the first sliding member.

3. The eccentric sliding assembly according to claim 1 or 2, wherein, The high-pressure tank and the low-pressure tank are equally arranged along the circumference.

4. The eccentric sliding assembly according to claim 1 or 2, wherein, The high-pressure trough and the low-pressure trough are shaped as a portion of a circle.

5. The eccentric sliding assembly according to claim 1 or 2, wherein, The space in which the low-pressure fluid exists during the operation of the rotating machinery is the space on the outer diameter side of the sliding surface of the first sliding member.

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