Sliding parts

Abstract

To provide a sliding part capable of more surely preventing contact of sliding faces with each other.SOLUTION: A sliding part 100 has: a sliding portion including one sliding portion 1 and the other sliding portion 2 slid to each other via an oil B; and a V-shaped groove 3 formed on a sliding face 11 of the one sliding portion 1. The V-shaped groove 3 is formed in a state that both end portions 3b, 3c of the V-shaped groove 3 are positioned at a tip side in a sliding direction to relatively slide the one sliding portion 1 provided with the V-shaped groove 3 to the opposed other sliding portion 2. In the V-shaped groove 3, a groove depth D is reduced toward a tip portion 3a side so as to generate oil film pressure F.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a sliding component, and more particularly to a sliding component having a sliding portion that slides via oil. [Background technology]

[0002] BACKGROUND ART Conventionally, sliding components that include a sliding portion that slides via oil are known (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses a sliding component including a first member (sliding part) and a second member (sliding part) that slide via a lubricant. The first member includes a first sliding surface that faces the second member. The second member includes a second sliding surface that faces the first member. Dimples are formed on the first sliding surface. The first member is configured to rotate in a sliding direction relative to the stationary second member. Furthermore, lubricant is filled between the first member and the second member. As a result, in the sliding component, lubricant is sucked into the dimples from the edge portion of the dimple on the sliding direction side, and the sucked lubricant is expelled from the edge portion of the dimple on the opposite side to the sliding direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-50768 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the sliding component of Patent Document 1, the depth of the edge portion of the dimple that sucks in lubricating oil on the sliding direction side is approximately the same as the depth of the edge portion of the dimple that discharges lubricating oil on the opposite side of the sliding direction, so the amount of lubricating oil that is sucked in and discharged by the dimple is approximately the same. As a result, the lubricating oil is discharged smoothly from the dimple without clogging. Therefore, in the sliding component of Patent Document 1, pressure (oil film pressure) is not easily generated when the lubricating oil is discharged from the dimple, which makes it difficult to avoid contact between the first sliding surface and the second sliding surface (the sliding surfaces).

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a sliding component that can more reliably avoid contact between sliding surfaces. [Means for solving the problem]

[0007] In order to achieve the above object, a sliding component according to one aspect of the present invention comprises: Contains oil film The sliding section includes a sliding section including one sliding section and another sliding section that slide against each other via oil, and a V-shaped groove provided on the sliding surface of the one sliding section, and the two ends of the V-shaped groove are arranged so as to be at the leading end side in the sliding direction in which the one sliding section provided with the V-shaped groove slides relative to the other sliding section that faces it, and in the V-shaped groove: From both ends of the V-shaped groove on the tip side in the sliding direction to the corner of the V-shaped groove located on the tip side in the opposite direction to the sliding direction and where the grooves extending from both ends intersect By reducing the groove depth, In the direction in which one sliding part and another sliding part are arranged, the configured to generate oil film pressure The V-shaped grooves include a plurality of inner V-shaped grooves provided circumferentially on the inner side of the sliding surface of one sliding part, and a plurality of outer V-shaped grooves provided circumferentially on the outer side of the sliding surface of one sliding part. .

[0008] In one aspect of the present invention, the sliding component is configured such that the V-shaped groove is disposed such that both ends of the V-shaped groove are located at the leading end in the sliding direction in which one sliding part provided with the V-shaped groove slides relative to the other opposing sliding part, and the V-shaped groove is configured to generate oil film pressure by decreasing the groove depth toward the leading end. The V-shaped groove is configured such that the groove depth decreases toward the leading end. This reduces the amount of oil discharged from the leading end of the V-shaped groove compared to the amount of oil sucked into the V-shaped groove, thereby preventing oil from clogging the leading end of the V-shaped groove. This increases the oil film pressure when oil is discharged from the leading end of the V-shaped groove, thereby more reliably avoiding contact between the sliding surfaces.

[0009] In the sliding component according to the above aspect, preferably, in the V-shaped groove, Corners The groove depth at the center is made smaller than the groove depth at both ends, thereby generating oil film pressure.

[0010] With this configuration, oil flowing from both ends of the V-shaped groove toward the tip can be clogged at the tip of the V-shaped groove, thereby increasing the oil film pressure when oil is discharged from the tip of the V-shaped groove.

[0011] In the sliding component according to the above aspect, preferably, Corners The groove depth is continuously reduced toward the groove edge to generate oil film pressure.

[0012] With this configuration, the oil flowing from both ends of the V-shaped groove toward the tip end can be gradually blocked, thereby effectively increasing the oil film pressure.

[0013] In the sliding component according to the above aspect, preferably, the groove width at both ends of the V-shaped groove in the sliding direction is Corners The groove width is equal to or greater than that.

[0014] With this configuration, compared to when the groove width at both ends of the V-shaped groove is less than the groove width at the tip of the V-shaped groove, oil can be clogged at the tip of the V-shaped groove not only in the depth direction of the V-shaped groove but also in the groove width direction of the V-shaped groove, so the oil film pressure can be effectively increased when oil is discharged from the tip of the V-shaped groove.

[0015] In the sliding component according to the above aspect, preferably, the sliding part includes a stationary-side sliding part as the other sliding part and an actuating-side sliding part as the one sliding part, and the V-shaped groove is disposed so that both ends of the V-shaped groove are on the tip side in the sliding direction, and is provided on the surface of the actuating-side sliding part.

[0016] With this configuration, a V-shaped groove is provided on the surface of the operating side sliding part that moves in the sliding direction, so that oil can be directly sucked into the V-shaped groove as it moves in the sliding direction, allowing a larger amount of oil to be sucked into the V-shaped groove.

[0017] In the sliding component according to the aforementioned aspect, preferably, a plurality of V-shaped grooves are provided at predetermined intervals along the sliding direction.

[0018] With this configuration, the oil film pressure can be increased at a plurality of locations in the sliding component, so that contact between the sliding surfaces can be avoided more reliably.

[0019] In the sliding component according to the above aspect, preferably, the sliding portion includes at least one of a drive rotor, a driven rotor, and a shaft that constitute the oil pump, and the V-shaped groove is provided in at least one of the drive rotor, the driven rotor, and the shaft that constitute the oil pump along the rotational direction as the sliding direction.

[0020] With this configuration, contact between the sliding surfaces within the oil pump can be more reliably avoided, allowing the oil pump to operate efficiently.

[0021] In the sliding component according to the aforementioned aspect, at least one of both end portions of the V-shaped groove preferably has an open structure exposed laterally on the sliding surface of the sliding part.

[0022] This configuration allows a larger amount of oil to be sucked into the V-shaped groove, increasing the difference between the amount of oil sucked into the V-shaped groove and the amount of oil discharged, thereby further increasing the oil film pressure when oil is discharged from the tip of the V-shaped groove. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 2 is a side view of the sliding element of the first embodiment. [Figure 2] FIG. 2 is a view taken along the line II-II in FIG. [Figure 3] FIG. 3 is an enlarged view of the Zm portion of FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] 5A to 5C are schematic diagrams illustrating a radial wedge effect in a V-shaped groove of the sliding element of the first embodiment. [Figure 6] 5A to 5C are schematic diagrams illustrating a wedge effect in the depth direction in a V-shaped groove of the sliding element of the first embodiment. [Figure 7] 3 is a plan view showing a state in which oil film pressure is generated in a plurality of V-shaped grooves on an operating side sliding surface of the sliding element of the first embodiment. FIG. [Figure 8] 4 is an enlarged view showing the intervals between V-shaped grooves in an outer circumferential groove group and an inner circumferential groove group of the sliding element of the first embodiment. FIG. [Figure 9] FIG. 10 is a side view of the sliding element of the second embodiment. [Figure 10] 10 is a view taken along the line XX in FIG. 9. [Figure 11]FIG. 10 is a schematic diagram showing the internal structure of an oil pump as a sliding part of a third embodiment. [Figure 12] 10 is an enlarged view showing a V-shaped groove provided in a drive rotor of an oil pump as a sliding component of a third embodiment. FIG. [Figure 13] FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. 12. [Figure 14] 10 is an enlarged view showing a V-shaped groove on the outer periphery provided in a driven rotor of an oil pump as a sliding component of a third embodiment. FIG. [Figure 15] 10 is an enlarged view showing an inner peripheral V-shaped groove provided in a driven rotor of an oil pump as a sliding component of a third embodiment. FIG. [Figure 16] FIG. 16 is a cross-sectional view taken along line XVI-XVI in FIG. [Figure 17] FIG. 17 is a cross-sectional view taken along line XVII-XVII in FIG. [Figure 18] FIG. 10 is an enlarged view showing a shaft of an oil pump as a sliding component of a third embodiment. [Figure 19] 10 is an enlarged view showing a V-shaped groove provided in a shaft of an oil pump as a sliding component of a third embodiment. FIG. [Figure 20] FIG. 20 is a cross-sectional view taken along line XX-XX in FIG. 19. [Figure 21] FIG. 10 is an enlarged view showing a V-shaped groove provided in an operating side sliding portion of a sliding element according to a fourth embodiment. [Figure 22] FIG. 13 is a cross-sectional view taken along line XXII-XXII in FIG. [Figure 23] 10 is a graph showing an example of the relationship between the central angle of the sliding element and the average oil film pressure of the first modified example. [Figure 24] 10 is a graph showing an example of the relationship between the difference in groove depth between the tip end side and the end side of the sliding element of the second modified example and the average oil film pressure. [Figure 25] 10 is a graph showing an example of the relationship between the groove width on the end side of the sliding element of the third modified example and the average oil film pressure. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0025] [First embodiment] The configuration of the sliding element 100 will be described with reference to FIGS.

[0026] As shown in Figures 1 and 2, the following describes the configuration of a sliding element 100 that slides while rotating in a fixed direction (direction R) in an environment where oil B is abundantly supplied. Oil B is a liquid oil such as engine oil. Oil B may be either low-viscosity oil or high-viscosity oil. Sliding element 100 includes, for example, an oil pump, bearings, a variable valve timing mechanism, and gears.

[0027] Specifically, as shown in FIG. 2, the sliding element 100 includes an operating side sliding portion 1 (an example of the "sliding portion" and "one sliding portion" in the claims), a stationary side sliding portion 2 (an example of the "sliding portion" and "another sliding portion" in the claims), a V-shaped groove 3, and a V-shaped groove 4.

[0028] Here, the direction in which the operating side sliding part 1 and the stationary side sliding part 2 are aligned is defined as the Z direction, the stationary side sliding part 2 side of the Z direction is defined as the Z1 direction, and the operating side sliding part 1 side of the Z direction is defined as the Z2 direction. The R direction (an example of the "relative sliding direction" in the claims) is the circumferential direction around the center line C extending parallel to the Z direction. The direction perpendicular to the direction in which the center line C extends is defined as the K direction (radial direction).

[0029] The actuating side sliding part 1 is slid in the R direction relative to the stationary side sliding part 2 via oil B by a driving force from a driving source (not shown). The actuating side sliding part 1 has a circular shape when viewed from the Z1 direction side. The actuating side sliding part 1 has an actuating side sliding surface 11 (an example of the "sliding surface" and "one sliding surface" in the claims). The actuating side sliding surface 11 is the surface of the actuating side sliding part 1 on the Z1 direction side. The actuating side sliding surface 11 is a curved surface. The actuating side sliding part 1 is made of a metal such as iron or aluminum.

[0030] The stationary-side sliding part 2 is stationary relative to the operating-side sliding part 1. The stationary-side sliding part 2 has a circular shape when viewed from the Z2 direction side. The stationary-side sliding part 2 has a stationary-side sliding surface 21 (one example of the "sliding surface" and "other sliding surface" in the claims). The stationary-side sliding surface 21 is the surface on the Z2 direction side of the stationary-side sliding part 2. The stationary-side sliding surface 21 is a curved surface. The stationary-side sliding part 2 is made of a metal such as iron or aluminum.

[0031] The operating side sliding part 1 and the stationary side sliding part 2 face each other in the Z direction. A minute gap 5 is formed between the operating side sliding part 1 and the stationary side sliding part 2. The minute gap 5 is filled with oil B.

[0032] A plurality (30) of V-shaped grooves 3 are provided on the actuation side sliding surface 11. The plurality of V-shaped grooves 3 are arranged on the outer side of the actuation side sliding surface 11 in the K direction. The plurality of V-shaped grooves 3 are arranged at equal angular intervals at a predetermined angle θ1. The predetermined angle θ1 is, for example, approximately 12 degrees. Note that the predetermined angle θ1 may be an angle other than approximately 12 degrees. The number of V-shaped grooves 3 may be 2 to 29, or 31 or more.

[0033] A plurality (30) of V-shaped grooves 4 are provided on the actuation side sliding surface 11. The V-shaped grooves 4 are arranged on the inner side of the actuation side sliding surface 11 in the K direction. The V-shaped grooves 4 are arranged at equal angular intervals at a predetermined angle θ1. The number of V-shaped grooves 4 may be 2 to 29, or 31 or more.

[0034] Hereinafter, we will explain the V-shaped groove 3 and the V-shaped groove 4, but since the V-shaped groove 3 and the V-shaped groove 4 have the same structure, we will only explain the V-shaped groove 3 arranged in the Zm portion of Figure 2.

[0035] (V-shaped groove) As shown in Fig. 3, the V-shaped groove 3 of the first embodiment has a structure that locally increases the oil film pressure F (see Fig. 7). Here, the oil film pressure F refers to the pressure generated in the oil B in the minute gap 5.

[0036] The V-shaped groove 3 has a substantially V-shape when viewed from the Z1 direction side. The V-shaped groove 3 is formed by recessing the operating side sliding surface 11 toward the Z2 direction side.

[0037] The V-shaped groove 3 is arranged on the actuating-side sliding part 1 so as to be at the tip side of the R direction, which is the sliding direction in which the actuating-side sliding part 1 in which the V-shaped groove 3 is provided slides relatively to the opposing stationary-side sliding part 2. In this way, the R direction, which is the sliding direction in which the actuating-side sliding part 1 slides relatively to the stationary-side sliding part 2, indicates the sliding direction when the "stationary-side sliding part 2 in which the V-shaped groove 3 is not provided" is used as the reference, not the "actuating-side sliding part 1 in which the V-shaped groove 3 is provided," and therefore the "sliding direction in which the relative sliding occurs" is the "R direction."

[0038] That is, the V-shaped groove 3 is arranged so that both end portions 3b, 3c of the V-shaped groove 3 are on the tip side in the R direction. The end portion 3b of the V-shaped groove 3 is an outer end portion provided on the outer side in the K direction. The end portion 3c of the V-shaped groove 3 is an inner end portion provided on the inner side in the K direction. The V-shaped groove 3 is arranged so that the tip portion 3a of the V-shaped groove 3 is on the tip side in the direction opposite to the R direction.

[0039] The V-shaped groove 3 has a first oil flow passage 31 and a second oil flow passage 32. The first oil flow passage 31 extends from the tip end 3a toward the end 3b in the V-shaped groove 3. The first oil flow passage 31 is inclined outward in the K direction as it extends in the R direction. The second oil flow passage 32 extends from the tip end 3a toward the end 3c in the V-shaped groove 3. The second oil flow passage 32 is inclined inward in the K direction as it extends in the R direction.

[0040] <Central corner> The V-shaped groove 3 has a central angle θ2. The central angle θ2 is the angle between the first oil flow passage 31 and the second oil flow passage 32. The central angle θ2 is approximately 90 degrees. The V-shaped groove 3 has a length L in the R direction. In the K direction, the V-shaped groove 3 has a lateral width W1. The lateral width W1 is greater than the length L.

[0041] <Groove width> In the R direction, the tip 3a of the V-shaped groove 3 has a groove width W2. In the R direction, the end 3b of the V-shaped groove 3 has a groove width W3. In the R direction, the end 3c of the V-shaped groove 3 has a groove width W4. The groove width W3 is approximately the same length as the groove width W4. In the R direction, the groove width W3 and the groove width W4 of the end 3b of the V-shaped groove 3 are larger than the groove width W2 of the tip 3a of the V-shaped groove 3.

[0042] As a result, the groove width W of the first oil flow passage 31 in the R direction continuously decreases from the end 3b toward the tip 3a of the V-shaped groove 3. The groove width W of the second oil flow passage 32 in the R direction continuously decreases from the end 3c toward the tip 3a of the V-shaped groove 3.

[0043] Here, groove width W2 is preferably 1.1 mm, for example. Groove width W3 and groove width W4 are preferably greater than groove width W2 but not greater than twice groove width W2, for example. Groove width W3 and groove width W4 are more preferably greater than 1.1 mm but not greater than 1.7 mm, for example, when groove width W2 is 1.1 mm. In other words, the ratio of groove width W3 and groove width W4 to groove width W2 is more preferably 1:1 to 1.5, for example.

[0044] <Open structure> An end 3b of the V-shaped groove 3 has an open structure 3d exposed to the outside (lateral side) in the K direction of the actuation-side sliding surface 11. The open structure 3d connects the internal space of the V-shaped groove 3 with the space on the outside in the K direction of the actuation-side sliding part 1. The open structure 3d is provided to suck oil B, which is filled in the space on the outside in the K direction of the actuation-side sliding part 1, into the internal space of the V-shaped groove 3.

[0045] <Groove depth> As shown in FIG. 4, the groove depth D of the V-shaped groove 3 decreases toward the tip 3a. In the V-shaped groove 3, the groove depth D2 at the tip 3a is smaller than the groove depth D1 at both end portions 3b and 3c. In the V-shaped groove 3, the groove depth D continuously decreases from both end portions 3b and 3c of the V-shaped groove 3 toward the tip 3a. Therefore, although not shown, the bottom surface of the first oil flow passage 31 on the Z2 side is an inclined surface that slopes toward the Z1 direction from the end portion 3b toward the tip 3a. The bottom surface of the first oil flow passage 31 on the Z2 side is smooth. Furthermore, the bottom surface 32a of the second oil flow passage 32 on the Z2 side is an inclined surface that slopes toward the Z1 direction from the end portion 3c toward the tip 3a. The bottom surface 32a of the second oil flow passage 32 on the Z2 side is smooth. Although only the second oil flow passage 32 is shown in FIG. 4, the first oil flow passage 31 has the same structure as the second oil flow passage 32.

[0046] Here, the groove depth D1 is preferably, for example, 6 μm or more and 20 μm or less, and more preferably, for example, 9 μm, and the groove depth D2 is preferably, for example, 1 μm.

[0047] <Oil film pressure> As shown in Figures 5 and 6, the location in the V-shaped groove 3 where the oil film pressure F (see Figure 7) is locally increased is the tip 3a of the V-shaped groove 3. At the tip 3a of the V-shaped groove 3, the oil film pressure F (see Figure 7) is increased due to a wedge effect. The wedge effect refers to the effect of increasing the oil film pressure F (see Figure 7) of oil B at the tip 3a of the V-shaped groove 3 by making the amount of oil B sucked in smaller than the amount of oil B discharged, thereby clogging the flow of oil B at the tip 3a of the V-shaped groove 3.

[0048] The amount of oil suction is the amount of oil B sucked into both end portions 3b, 3c of the V-shaped groove 3. At end portion 3b, not only the oil B filled in the minute gap 5 but also the oil B filled outside the sliding component 100 is sucked in through the open structure 3d. At end portion 3c, the oil B filled in the minute gap 5 is sucked in. As a result, the amount of oil suction at end portion 3b is greater than the amount of oil suction at end portion 3c. The amount of oil discharged is the amount of oil B discharged from the linear end portion 31a of the V-shaped groove 3 into the minute gap 5.

[0049] Here, in the V-shaped groove 3, oil film pressure F is generated by a wedge effect caused by a change in the groove depth D of the V-shaped groove 3 shown in Figure 5. In addition, oil film pressure F increases due to a change in the groove width W of the V-shaped groove 3 shown in Figure 6. The oil film pressure F is a pressure acting in the direction along the Z1 direction.

[0050] As shown in Figures 5 and 6, the V-shaped groove 3 is configured to generate oil film pressure F by decreasing the groove depth D toward the tip end 3a. That is, the V-shaped groove 3 is configured to generate oil film pressure F by continuously decreasing the groove depth D from both end portions 3c (3b) toward the tip end 3a. Also, the V-shaped groove 3 is configured to generate oil film pressure F by making the groove depth D2 at the tip end 3a smaller than the groove depth D1 at the end portions 3c (3b). Note that while Figure 6 shows only the second oil flow passage 32, the first oil flow passage 31 has a similar structure to the second oil flow passage 32.

[0051] Here, the V-shaped groove 3 has a cavitation region Cb where cavitation occurs when oil B is sucked into the end 3c (3b) of the groove depth D1 from the minute gap 5. Cavitation is a phenomenon in which bubbles dissolved in the high-pressure minute gap 5 are generated when oil B is sucked from the high-pressure minute gap 5 into the space at the end 3c (3b) where the pressure is lower than that of the minute gap 5.

[0052] As described above, it is preferable that the groove depth D1 of the V-shaped groove 3 is deep enough to generate a small amount of cavitation (bubbles) near the R-direction side of the end 3c (3b). As a result of investigations by the present inventors, it has been found that this makes the oil film pressure F relatively large.

[0053] The V-shaped groove 3 is configured so that the oil film pressure F increases by reducing the groove width W toward the tip 3a. That is, the groove width W continuously decreases from both end portions 3b and 3c of the V-shaped groove 3 toward the tip 3a. Also, in the V-shaped groove 3, the groove width W2 at the tip 3a is smaller than both the groove width W3 at the end 3b and the groove width W4 at the end 3c.

[0054] 7, oil film pressure F is generated in all V-shaped grooves 3 provided on the operating side sliding surface 11 of the operating side sliding part 1. Here, since oil film pressure F is generated at the tip end 3a of the V-shaped grooves 3, the V-shaped grooves 3 need to be evenly (well-balanced) arranged on the operating side sliding surface 11 of the operating side sliding part 1 in order to prevent the operating side sliding part 1 and the stationary side sliding part 2 from tilting.

[0055] That is, the multiple V-shaped grooves 3 are arranged point-symmetrically with respect to the center line C when viewed from the Z1 direction side. As described above, the multiple V-shaped grooves 3 are arranged at equal angular intervals at the predetermined angle θ1. The multiple V-shaped grooves 4 are arranged point-symmetrically with respect to the center line C when viewed from the Z1 direction side. As described above, the multiple V-shaped grooves 4 are arranged at equal angular intervals at the predetermined angle θ1.

[0056] <interval> As shown in Figure 8, the multiple V-shaped grooves 3 aligned in the R direction have a sufficient predetermined spacing (pitch) M1 so that the oil film pressure F generated in the V-shaped groove 3 on the R direction side of the multiple V-shaped grooves 3 does not escape to the V-shaped groove 3 on the opposite side of the R direction of the multiple V-shaped grooves 3.

[0057] A plurality of V-shaped grooves 3 are provided at predetermined intervals M1 along the R direction. The plurality of V-shaped grooves 3 are arranged so as not to overlap each other in the K direction when viewed from the Z1 direction side.

[0058] The multiple V-shaped grooves 4 arranged in the R direction have a sufficient predetermined spacing (pitch) M2 so that the oil film pressure F generated in the V-shaped groove 4 on the R direction side of the multiple V-shaped grooves 4 does not escape to the V-shaped groove 4 on the opposite side of the R direction of the multiple V-shaped grooves 4.

[0059] A plurality of V-shaped grooves 4 are provided at predetermined intervals M2 along the R direction. The V-shaped grooves 4 are arranged so as not to overlap each other in the K direction when viewed from the Z1 direction side.

[0060] Here, the predetermined interval M1 and the predetermined interval M2 are each six times or more the groove width W2 of the V-shaped groove 3. Furthermore, the predetermined interval M1 is longer than the predetermined interval M2.

[0061] (Effects of the first embodiment) In the first embodiment, the following effects can be obtained.

[0062] In the first embodiment, as described above, the V-shaped groove 3(4) is disposed on the tip side in the R direction of the actuating-side sliding part 1 having the actuating-side sliding surface 11 on which both ends 3b, 3c of the V-shaped groove 3(4) are provided. The groove depth D of the V-shaped groove 3(4) is reduced toward the tip end 3a. This makes it possible to clog the tip end 3a of the V-shaped groove 3(4) with oil B, since the amount of oil B discharged from the V-shaped groove 3(4) at the tip end 3a is less than the amount of oil B sucked into the V-shaped groove 3(4). This increases the oil film pressure F when the oil B is discharged from the tip end 3a of the V-shaped groove 3(4), thereby more reliably avoiding contact between the actuating-side sliding surface 11 and the stationary-side sliding surface 21.

[0063] Furthermore, in the first embodiment, as described above, the V-shaped groove 3(4) is configured to generate oil film pressure F by making the groove depth D2 of the tip end 3a smaller than the groove depth D1 of both end portions 3b, 3c. This allows the oil B flowing from each of both end portions 3b, 3c of the V-shaped groove 3(4) toward the tip end 3a to be clogged at the tip end 3a of the V-shaped groove 3(4), thereby increasing the oil film pressure F when the oil B is discharged from the tip end 3a of the V-shaped groove 3(4).

[0064] Furthermore, in the first embodiment, as described above, the groove depth D is continuously reduced from both end portions 3b, 3c of the V-shaped groove 3(4) toward the tip end portion 3a, thereby generating the oil film pressure F. This allows the oil B flowing from each of the both end portions 3b, 3c of the V-shaped groove 3(4) toward the tip end portion 3a to be gradually blocked, thereby effectively increasing the oil film pressure F.

[0065] In the first embodiment, as described above, the groove widths W3 and W4 of the both end portions 3b and 3c of the V-shaped groove 3(4) in the R direction are equal to or greater than the groove width W2 of the tip end portion 3a of the V-shaped groove 3(4). This makes it possible to clog the oil B at the tip end portion 3a of the V-shaped groove 3(4) not only in the Z direction (depth direction) of the V-shaped groove 3(4) but also in the R direction (groove width direction) of the V-shaped groove 3(4), compared to when the groove widths W3 and W4 of the both end portions 3b and 3c of the V-shaped groove 3(4) are less than the groove width W2 of the tip end portion 3a of the V-shaped groove 3(4). This makes it possible to effectively increase the oil film pressure F when the oil B is discharged from the tip end portion 3a of the V-shaped groove 3(4).

[0066] Moreover, in the first embodiment, as described above, the sliding part includes the stationary-side sliding part 2 and the actuating-side sliding part 1. The V-shaped groove 3 is arranged so that both end portions 3b, 3c of the V-shaped groove 3 are on the tip side in the R direction, and is provided on the actuating-side sliding surface 11 of the actuating-side sliding part 1. As a result, by providing the V-shaped groove 3 on the actuating-side sliding surface 11 of the actuating-side sliding part 1 that moves in the R direction, oil B can be directly sucked into the V-shaped groove 3 as it moves in the R direction, and therefore a larger amount of oil B can be sucked into the V-shaped groove 3.

[0067] In the first embodiment, as described above, a plurality of V-shaped grooves 3 (4) are provided along the direction R at predetermined intervals M1 (M2). This allows the oil film pressure F to be increased at a plurality of locations in the sliding element 100, thereby more reliably preventing contact between the operating-side sliding surface 11 and the stationary-side sliding surface 21.

[0068] Furthermore, in the first embodiment, as described above, the end 3b of the V-shaped groove 3(4) has an open structure 3d that is exposed laterally from the operating-side sliding surface 11 of the operating-side sliding part 1. This allows a larger amount of oil B to be sucked into the V-shaped groove 3(4), thereby increasing the difference between the amount of oil B sucked into the V-shaped groove 3(4) and the amount of oil B discharged. This allows the oil film pressure F to be further increased when the oil B is discharged from the tip end 3a of the V-shaped groove 3(4).

[0069] [Second embodiment] Next, a sliding element 200 according to a second embodiment will be described with reference to Fig. 9 and Fig. 10. Specifically, unlike the sliding element 100 according to the first embodiment, the sliding element 200 according to the second embodiment has a V-shaped groove 203 formed in the stationary-side sliding portion 202. Note that in the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

[0070] 9 and 10, the sliding element 200 of the second embodiment includes an operating-side sliding part 201 (an example of the "sliding part" and "another sliding part" in the claims), a stationary-side sliding part 202 (an example of the "sliding part" and "one sliding part" in the claims), a plurality (30) of V-shaped grooves 203, and a plurality (30) of V-shaped grooves 204. The number of the V-shaped grooves 203 and the number of the V-shaped grooves 204 may be 2 to 29, or 31 or more.

[0071] Here, the direction in which the operating side sliding part 201 and the stationary side sliding part 202 are aligned is defined as the Z direction, the operating side sliding part 201 side of the Z direction is defined as the Z1 direction, and the stationary side sliding part 202 side of the Z direction is defined as the Z2 direction. The R direction is the circumferential direction around the center line C extending parallel to the Z direction. The direction perpendicular to the direction in which the center line C extends is defined as the K direction (radial direction).

[0072] The actuation-side sliding part 201 is slid in the R direction relative to the stationary-side sliding part 202 via oil B by a driving force from a driving source (not shown). The actuation-side sliding part 201 has an actuation-side sliding surface 211 (an example of the "sliding surface" and "one sliding surface" in the claims). The actuation-side sliding surface 211 is the surface of the actuation-side sliding part 201 on the Z2 direction side.

[0073] The stationary-side sliding part 202 is stationary relative to the operating-side sliding part 201. The stationary-side sliding part 202 has a circular shape when viewed from the Z1 direction side. The stationary-side sliding part 202 has a stationary-side sliding surface 221 (an example of the "sliding surface" and "other sliding surface" in the claims). The stationary-side sliding surface 221 is the surface of the stationary-side sliding part 202 on the Z1 direction side.

[0074] (V-shaped groove) As shown in FIG. 10, the V-shaped groove 203 of the second embodiment has a structure that locally increases the oil film pressure F (see FIG. 7).

[0075] The V-shaped groove 203 has a substantially V-shape when viewed from the Z1 direction side. The V-shaped groove 203 is provided on the stationary-side sliding surface 221 of the stationary-side sliding part 202. The V-shaped groove 203 is formed by recessing the stationary-side sliding surface 221 toward the Z2 direction side.

[0076] The V-shaped groove 203 is arranged so as to be on the tip side in the direction opposite to the R direction (an example of the "relative sliding direction" in the claims) with respect to the operating-side sliding part 201 that faces the stationary-side sliding part 202 in which the V-shaped groove 203 is provided. In this way, the direction opposite to the R direction, which is the sliding direction of relative sliding with respect to the operating-side sliding part 201, indicates the sliding direction when the "operating-side sliding part 201 in which the V-shaped groove 203 is not provided" is used as the reference, not the "stationary-side sliding part 202 in which the V-shaped groove 203 is provided," and therefore the "sliding direction of relative sliding" becomes the "direction opposite to the R direction."

[0077] That is, the V-shaped groove 203 is arranged so that both end portions 203b, 203c of the V-shaped groove 203 are on the tip side in the direction opposite to the R direction. The end portion 203b of the V-shaped groove 203 is an outer end portion provided on the outer side in the K direction. The end portion 203c of the V-shaped groove 203 is an inner end portion provided on the inner side in the K direction. The V-shaped groove 203 is arranged so that the tip portion 203a of the V-shaped groove 203 is on the R direction side.

[0078] Here, the V-shaped groove 204 has the same structure as the V-shaped groove 203, and therefore a description thereof will be omitted. The other configurations of the second embodiment are the same as those of the first embodiment, and therefore a description thereof will be omitted.

[0079] (Effects of the second embodiment) In the second embodiment, the following effects can be obtained.

[0080] In the second embodiment, similarly to the first embodiment, the V-shaped groove 203 (204) is arranged such that both end portions 203b, 203c of the V-shaped groove 203 (204) are located on the tip side in the direction opposite to the R direction with respect to the actuation-side sliding part 201 that faces the stationary-side sliding part 202 in which the V-shaped groove 203 is provided. In the V-shaped groove 3 (4), the groove depth D is made smaller toward the tip portion 203a. This makes it possible to more reliably avoid contact between the actuation-side sliding surface 211 and the stationary-side sliding surface 221. Note that other effects of the second embodiment are similar to those of the first embodiment, and therefore description thereof will be omitted.

[0081] [Third embodiment] Next, a sliding element 300 according to a third embodiment will be described with reference to Figures 11 to 20. Specifically, unlike the sliding element 100 according to the first embodiment, the sliding element 300 according to the third embodiment has V-shaped grooves 342, 343, 352, 353, 362a, and 363a provided in an oil pump 301. Note that in the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

[0082] As shown in Fig. 11, the following describes the configuration of an oil pump 301, which serves as a sliding component 300 that slides while rotating in a fixed direction (direction R) in an environment where oil B is abundantly supplied. The oil pump 301 is an internal gear pump (trochoid pump). The oil pump 301 is an electric oil pump.

[0083] Specifically, as shown in FIG. 11, oil pump 301 includes a pump housing 311 (an example of the "sliding part," "stationary side sliding part," and "another sliding part" in the claims), an intake port 312, a discharge port 313, a drive rotor 314 (an example of the "sliding part," "operating side sliding part," and "one sliding part" in the claims), a driven rotor 315 (an example of the "sliding part," "operating side sliding part," and "one sliding part" in the claims), and a shaft 316 (an example of the "sliding part," "operating side sliding part," and "one sliding part" in the claims).

[0084] Here, the direction in which the center line C1 of the shaft 316 extends is defined as the A direction (axial direction), one side of the A direction is defined as the A1 direction, and the other side of the A direction is defined as the A2 direction. The rotation direction of the shaft 316 around the center line C1 is defined as the R direction (circumferential direction, an example of the "relative sliding direction" in the claims). The direction perpendicular to the A direction in which the center line C1 of the shaft 316 extends is defined as the K direction (radial direction).

[0085] 11, pump housing 311 is configured to accommodate drive rotor 314 and driven rotor 315. Suction port 312 is formed in pump housing 311 and configured to guide oil B into pump chamber S formed by drive rotor 314 and driven rotor 315 inside pump housing 311. Discharge port 313 is formed in pump housing 311 and configured to guide oil B out of pump chamber S.

[0086] The drive rotor 314 and the driven rotor 315 are housed in a rotor housing space. The drive rotor 314 has a center line C1 that is eccentric with respect to a center line C2 of the driven rotor 315.

[0087] (drive rotor) The drive rotor 314 includes a sliding surface 341, a plurality of V-shaped grooves 342, and a plurality of V-shaped grooves 343.

[0088] The sliding surface 341 is the surface on the A1 direction side of the drive rotor 314. The sliding surface 341 faces the pump housing 311 in the A direction.

[0089] A plurality of V-shaped grooves 342 are provided on the sliding surface 341. The plurality of V-shaped grooves 342 are arranged on the outer side in the K direction of the sliding surface 341. The plurality of V-shaped grooves 342 are arranged at equal angular intervals at a predetermined angle θ31.

[0090] A plurality of V-shaped grooves 343 are provided on the sliding surface 341. The plurality of V-shaped grooves 343 are arranged on the inner side in the K direction of the sliding surface 341. The plurality of V-shaped grooves 343 are arranged at equal angular intervals at a predetermined angle θ31.

[0091] Hereinafter, we will explain V-shaped groove 342 and V-shaped groove 343, but since V-shaped groove 342 and V-shaped groove 343 have the same structure, we will only explain V-shaped groove 342 in Figure 11.

[0092] <V-shaped groove> As shown in FIG. 12, the V-shaped groove 342 of the third embodiment has a structure that locally increases the oil film pressure Pr (see FIG. 7).

[0093] The V-shaped groove 342 has a substantially V-shape when viewed from the Z1 direction side. The V-shaped groove 342 is provided on the sliding surface 341 of the drive rotor 314. The V-shaped groove 342 is formed by recessing the sliding surface 341 toward the A2 direction side.

[0094] V-shaped groove 342 is arranged so that both ends 3422, 3423 of V-shaped groove 342 are at the leading end side in the R direction in which it slides relative to pump housing 311, which faces drive rotor 314 in which V-shaped groove 342 is provided. In this way, the R direction in which it slides relative to pump housing 311 indicates the sliding direction when "pump housing 311 in which V-shaped groove 342 is not provided" is used as the reference, rather than "drive rotor 314 in which V-shaped groove 342 is provided," and therefore the "relative sliding direction" is the "R direction."

[0095] That is, the V-shaped groove 342 is arranged so that both end portions 3422, 3423 of the V-shaped groove 342 are on the tip side in the R direction. The end portion 3422 of the V-shaped groove 342 is an outer end portion provided on the outer side in the K direction. The end portion 3423 of the V-shaped groove 342 is an inner end portion provided on the inner side in the K direction. The V-shaped groove 342 is arranged so that the tip portion 3421 of the V-shaped groove 342 is on the tip side in the direction opposite to the R direction.

[0096] The V-shaped groove 342 has a central angle θ33. The central angle θ33 is approximately 90 degrees. The V-shaped groove 342 has a lateral width W301 in the K direction. The lateral width W301 is, for example, 2.2 mm.

[0097] In the R direction, the tip end 3421 of the V-shaped groove 342 has a groove width W302. In the R direction, the end 3422 of the V-shaped groove 342 has a groove width W303. In the R direction, the end 3423 of the V-shaped groove 342 has a groove width W304. The groove width W303 is approximately the same length as the groove width W304. The groove widths W303 and W304 are approximately the same length as the groove width W302 of the tip end 3421 of the V-shaped groove 342. Here, the groove widths W302, W303, and W304 are, for example, 0.3 mm.

[0098] An end 3422 of the V-shaped groove 342 has an open structure 3424 exposed to the outside (side) of the sliding surface 341 in the K direction.

[0099] <Groove depth> 13, in the V-shaped groove 342, the groove depth D decreases toward the tip 3421. In the V-shaped groove 342, the groove depth D32 at the tip 3421 is smaller than the groove depth D31 at both end portions 3422, 3423. In the V-shaped groove 342, the groove depth D continuously decreases from both end portions 3422, 3423 of the V-shaped groove 342 toward the tip 3421.

[0100] Here, the groove depth D31 is, for example, 9 μm, and the groove depth D32 is, for example, 1 μm.

[0101] <interval> 12, a plurality of V-shaped grooves 342 on the outer periphery are provided along the R direction at predetermined intervals M31. Similar to the V-shaped grooves 342 on the outer periphery, a plurality of V-shaped grooves 343 on the inner periphery are provided along the R direction at predetermined intervals M31. Here, the predetermined intervals M31 are, for example, 1.5 mm. Here, the predetermined intervals M31 are five or more times the groove width W302 of the V-shaped grooves 342.

[0102] (Driven rotor) As shown in FIG. 11, the driven rotor 315 includes a sliding surface 351, a plurality of V-shaped grooves 352, a plurality of V-shaped grooves 353, and a sliding surface 354.

[0103] The sliding surface 351 is the surface on the A1 direction side of the driven rotor 315. The sliding surface 351 faces the pump housing 311 in the A direction.

[0104] A plurality of V-shaped grooves 352 are provided on the sliding surface 351. The plurality of V-shaped grooves 352 are arranged on the outer side in the K direction of the sliding surface 351. The plurality of V-shaped grooves 352 are arranged at equal angular intervals at a predetermined angle θ32.

[0105] A plurality of V-shaped grooves 353 are provided on the sliding surface 351. The plurality of V-shaped grooves 353 are arranged on the inner side in the K direction of the sliding surface 351. The plurality of V-shaped grooves 353 are arranged at equal angular intervals at a predetermined angle θ32.

[0106] Hereinafter, the V-shaped groove 352 and the V-shaped groove 353 will be described.

[0107] <V-shaped groove> As shown in FIGS. 14 and 15, the V-shaped grooves 352 and 353 of the third embodiment have a structure that locally increases the oil film pressure Pr (see FIG. 7).

[0108] 14, the V-shaped groove 352 has a substantially V-shape when viewed from the A1 direction side. The V-shaped groove 352 is provided on the sliding surface 351 of the driven rotor 315. The V-shaped groove 352 is formed by recessing the sliding surface 351 toward the A2 direction side.

[0109] The V-shaped groove 352 is arranged so that both ends 3522, 3523 of the V-shaped groove 352 are at the leading end side in the R direction in which the pump housing 311 slides relatively to the pump housing 311 that faces the driven rotor 315 in which the V-shaped groove 352 is provided. In this way, the R direction in which the pump housing 311 slides relatively to the pump housing 311 indicates the sliding direction when the pump housing 311 is based on the "pump housing 311 in which the V-shaped groove 352 is not provided" and not on the "driven rotor 315 in which the V-shaped groove 352 is provided," and therefore the "sliding direction in which the pump housing 311 slides relatively to the pump housing 311" is the "R direction."

[0110] That is, the V-shaped groove 352 is arranged so that both end portions 3522, 3523 of the V-shaped groove 352 are on the tip side in the R direction. The end portion 3522 of the V-shaped groove 352 is an outer end portion provided on the outer side in the K direction. The end portion 3523 of the V-shaped groove 352 is an inner end portion provided on the inner side in the K direction. The V-shaped groove 352 is arranged so that the tip portion 3521 of the V-shaped groove 352 is on the tip side in the direction opposite to the R direction.

[0111] The V-shaped groove 352 has a central angle θ34. The central angle θ34 is approximately 90 degrees. The V-shaped groove 352 has a lateral width W305 in the K direction. The lateral width W305 is, for example, 2.2 mm.

[0112] In the R direction, the tip 3521 of the V-shaped groove 352 has a groove width W306. In the R direction, the end 3522 of the V-shaped groove 352 has a groove width W307. In the R direction, the end 3523 of the V-shaped groove 352 has a groove width W308. The groove width W307 is approximately the same length as the groove width W308. The groove widths W307 and W308 are approximately the same length as the groove width W306 of the tip 3521 of the V-shaped groove 352. Here, the groove widths W306, W307, and W308 are, for example, 0.3 mm.

[0113] An end 3522 of the V-shaped groove 352 has an open structure 3524 exposed to the outside (side) of the sliding surface 351 in the K direction.

[0114] 15, the V-shaped groove 353 has a substantially V-shape when viewed from the A1 direction side. The V-shaped groove 353 is provided on the sliding surface 351 of the driven rotor 315. The V-shaped groove 353 is formed by recessing the sliding surface 351 toward the A2 direction side.

[0115] The V-shaped groove 353 is disposed on the driven rotor 315 so as to be on the leading end side in the R direction, which is the sliding direction relative to the pump housing 311 that faces the driven rotor 315 having the sliding surface 351 on which the V-shaped groove 353 is disposed. That is, the V-shaped groove 353 is disposed so that both end portions 3532, 3533 of the V-shaped groove 353 are on the leading end side in the R direction. The end portion 3532 of the V-shaped groove 353 is an outer end portion that is disposed on the outer side in the K direction. The end portion 3533 of the V-shaped groove 353 is an inner end portion that is disposed on the inner side in the K direction. The V-shaped groove 353 is disposed so that the leading end portion 3531 of the V-shaped groove 353 is on the leading end side in the direction opposite to the R direction.

[0116] The V-shaped groove 353 has a central angle θ35. The central angle θ35 is approximately 90 degrees. The V-shaped groove 353 has a lateral width W309 in the K direction. The lateral width W309 is, for example, 2.2 mm.

[0117] In the R direction, the tip 3531 of the V-shaped groove 353 has a groove width W310. In the R direction, the end 3532 of the V-shaped groove 353 has a groove width W311. In the R direction, the end 3533 of the V-shaped groove 353 has a groove width W312. The groove width W311 is approximately the same length as the groove width W312. The groove width W311 and the groove width W312 are approximately the same length as the groove width W310 of the tip 3531 of the V-shaped groove 353. Here, the groove width W310, the groove width W311, and the groove width W312 are, for example, 0.3 mm.

[0118] An end 3532 of the V-shaped groove 353 has an open structure 3534 exposed to the outside (side) of the sliding surface 351 in the K direction.

[0119] <Groove depth> 16 , in the V-shaped groove 352, the groove depth D decreases toward the tip 3521. In the V-shaped groove 352, the groove depth D34 at the tip 3521 is smaller than the groove depth D33 at both end portions 3522, 3523. In the V-shaped groove 352, the groove depth D continuously decreases from both end portions 3522, 3523 of the V-shaped groove 352 toward the tip 3521.

[0120] Here, the groove depth D33 is, for example, 9 μm, and the groove depth D34 is, for example, 1 μm.

[0121] 17, in the V-shaped groove 353, the groove depth D decreases toward the tip 3531. In the V-shaped groove 353, the groove depth D36 at the tip 3531 is smaller than the groove depth D35 at both end portions 3532, 3533. In the V-shaped groove 352, the groove depth D continuously decreases from both end portions 3532, 3533 of the V-shaped groove 353 toward the tip 3531.

[0122] Here, the groove depth D35 is, for example, 9 μm, and the groove depth D36 is, for example, 1 μm.

[0123] <interval> As shown in FIGS. 14 and 15 , the V-shaped grooves 352 are provided in a plurality of positions along the R direction, spaced apart at a predetermined interval M32. The V-shaped grooves 353 are provided in a plurality of positions along the R direction, spaced apart at a predetermined interval M33. Here, the predetermined interval M32 is, for example, 1.5 mm. The predetermined interval M32 is at least five times the groove width W306 of the V-shaped groove 352. The predetermined interval M33 is, for example, 1.5 mm. The predetermined interval M33 is at least five times the groove width W310 of the V-shaped groove 353.

[0124] Furthermore, sliding surface 354 is the outer peripheral surface of drive rotor 314 in the K direction. Sliding surface 354 faces pump housing 311 in the K direction. A plurality of V-shaped grooves (not shown) are formed in sliding surface 354. These V-shaped grooves have the same configuration as V-shaped grooves 352 and V-shaped grooves 353, and are structured to locally increase oil film pressure Pr (see FIG. 7). The V-shaped grooves are formed by recessing sliding surface 354 inward in the K direction.

[0125] The V-shaped groove is arranged so that both ends of the V-shaped groove are on the leading edge side in the R direction that slides relatively with respect to the pump housing 311 that faces the driven rotor 315 on which the V-shaped groove is provided. In other words, the V-shaped groove is arranged so that both ends of the V-shaped groove are on the leading edge side in the R direction. The V-shaped groove is arranged so that the leading edge of the V-shaped groove is on the leading edge side in the direction opposite to the R direction.

[0126] (shaft) As shown in FIG. 18, the shaft 316 includes a sliding surface 361, a first groove group 362, and an second groove group 363.

[0127] The sliding surface 361 is a surface along the R direction of the shaft 316. The sliding surface 361 faces the pump housing 311 in the K direction.

[0128] Each of the first groove groups 362 is an assembly having a plurality (two) of V-shaped grooves 362a. The first groove groups 362 are provided on the sliding surface 361. The first groove groups 362 are arranged on the A1 direction side of the sliding surface 361. In the first groove group 362, the plurality (two) of V-shaped grooves 362a are arranged at equal angular intervals. Note that the first groove group 362 may be an assembly having three or more V-shaped grooves 362a.

[0129] Each of the second groove groups 363 is an assembly having a plurality (two) of V-shaped grooves 363a. The second groove groups 363 are provided on the sliding surface 361. The second groove groups 363 are arranged on the A2 direction side of the sliding surface 361. In the second groove groups 363, the plurality (two) of V-shaped grooves 363a are arranged at equal angular intervals. Furthermore, each of the second groove groups 363 may be an assembly having three or more V-shaped grooves 363a.

[0130] Hereinafter, the V-shaped groove 362a and the V-shaped groove 363a will be described, but since the V-shaped groove 362a and the V-shaped groove 363a have the same structure, only the V-shaped groove 362a in Figure 18 will be described.

[0131] <V-shaped groove> As shown in FIGS. 19 and 20, the V-shaped groove 362a of the third embodiment has a structure that locally increases the oil film pressure Pr (see FIG. 7).

[0132] The V-shaped groove 362a has a substantially V-shape when viewed from the outside in the K direction. The V-shaped groove 362a is provided on the sliding surface 361 of the shaft 316. The V-shaped groove 362a is formed by recessing the sliding surface 361 inward in the K direction.

[0133] V-shaped groove 362a is arranged so that both ends 3622, 3623 of V-shaped groove 362a are at the tip side in the R direction in which it slides relatively to pump housing 311 that faces shaft 316 in which V-shaped groove 362a is provided. In this way, the R direction in which it slides relatively to pump housing 311 indicates the sliding direction when "pump housing 311 in which V-shaped groove 362a is not provided" is used as the reference, not "shaft 316 in which V-shaped groove 362a is provided," and therefore the "sliding direction in which it slides relatively" is the "R direction."

[0134] That is, the V-shaped groove 362a is arranged so that both end portions 3622, 3623 of the V-shaped groove 362a are at the tip side in the R direction. The end portion 3622 of the V-shaped groove 362a is one end portion provided in the A1 direction. The end portion 3623 of the V-shaped groove 362a is the other end portion provided in the A2 direction. The V-shaped groove 362a is arranged so that the tip portion 3621 of the V-shaped groove 362a is at the tip side in the direction opposite to the R direction.

[0135] The V-shaped groove 362a has a central angle θ36. The central angle θ36 is approximately 90 degrees. The V-shaped groove 362a has a lateral width W313 in the R direction. The lateral width W313 is, for example, 8 mm.

[0136] In the R direction, a tip end 3621 of the V-shaped groove 362a has a groove width W314. In the R direction, an end 3622 of the V-shaped groove 362a has a groove width W315. In the R direction, an end 3623 of the V-shaped groove 362a has a groove width W316. The groove width W315 is approximately the same length as the groove width W316. The groove width W315 and the groove width W316 are approximately the same length as the groove width W314 of the tip end 3621 of the V-shaped groove 362a. Here, the groove width W314, the groove width W315, and the groove width W316 are, for example, 1.1 mm.

[0137] <Groove depth> 20, in the V-shaped groove 362a, the groove depth D decreases toward the tip 3621. In the V-shaped groove 362a, the groove depth D38 at the tip 3621 is smaller than the groove depth D37 at both end portions 3622, 3623. In the V-shaped groove 362a, the groove depth D continuously decreases from both end portions 3622, 3623 of the V-shaped groove 362a toward the tip 3621.

[0138] Here, the groove depth D37 is, for example, 15 μm, and the groove depth D38 is, for example, 1 μm.

[0139] <interval> 19, in one side groove group 362, a plurality of (two) V-shaped grooves 362a are provided along the R direction, spaced apart at a predetermined interval M34. Here, the predetermined interval M34 is, for example, 5.5 mm. Here, the predetermined interval M34 is five times or more the groove width W314 of the V-shaped groove 362a. Note that other configurations of the third embodiment are similar to those of the first embodiment, and therefore description thereof will be omitted.

[0140] (Effects of the third embodiment) In the third embodiment, the following effects can be obtained.

[0141] In the third embodiment, as in the first embodiment, the V-shaped groove 342a (343a, 352a, 353a, 362a, 363a) is positioned so that both end portions 3422, 3423 (3522, 3523, 3532, 3533, 3622, 3623) of the V-shaped groove 342a (343a, 352a, 353a, 362a, 363a) are at the tip side in the R direction, sliding relative to the pump housing 311 facing the drive rotor 314 (315, 316) in which the V-shaped groove 342a (343a, 352a, 353a, 362a, 363a) is provided. In the V-shaped grooves 342a (343a, 352a, 353a, 362a, 363a), the groove depth D is reduced toward the tip end 3421 (3521, 3531, 3621) side, thereby generating an oil film pressure Pr. This makes it possible to more reliably avoid contact between the sliding surfaces 341 (351, 354, 361).

[0142] In the third embodiment, as described above, the sliding portion includes the drive rotor 314, the driven rotor 315, and the shaft 316 that constitute the oil pump 301. The V-shaped grooves 342a (343a, 352a, 353a, 362a, 363a) are provided along the R direction in the drive rotor 314, the driven rotor 315, and the shaft 316 that constitute the oil pump 301. This more reliably prevents contact between the sliding surfaces 341 (351, 354, 361) within the oil pump 301, allowing the oil pump 301 to operate efficiently. Note that other effects of the third embodiment are similar to those of the first embodiment, and therefore description thereof will be omitted.

[0143] [Fourth embodiment] Next, a sliding element 400 according to a fourth embodiment will be described with reference to Fig. 21 and Fig. 22. Specifically, unlike the sliding element 100 according to the first embodiment, the sliding element 400 according to the fourth embodiment has a V-shaped groove 403 with a stepped shape in which the groove depth D becomes shallower in the direction opposite to the R direction. Note that in the fourth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

[0144] 21 and 22, the V-shaped groove 403 of the sliding element 400 of the fourth embodiment is provided in the operating-side sliding portion 401 (an example of the "sliding portion" and "one sliding portion" in the claims). Note that the stationary-side sliding portion is not shown in the drawings.

[0145] Here, the direction in which the operating-side sliding part 401 and the stationary-side sliding part 2 (see FIG. 1) are aligned is defined as the Z direction, the stationary-side sliding part side of the Z direction is defined as the Z1 direction, and the operating-side sliding part 401 side of the Z direction is defined as the Z2 direction. The R direction (an example of the "relative sliding direction" in the claims) is the circumferential direction around a center line C (see FIG. 1) extending parallel to the Z direction. The direction perpendicular to the extending direction of the center line C is defined as the K direction (radial direction).

[0146] (V-shaped groove) As shown in FIGS. 21 and 22, the V-shaped groove 403 of the fourth embodiment has a structure that locally increases the oil film pressure F (see FIG. 7).

[0147] The V-shaped groove 403 has a substantially V-shape when viewed from the Z1 direction side. The V-shaped groove 403 is formed by recessing the operating side sliding surface 411 toward the Z2 direction side.

[0148] The V-shaped groove 403 has a first groove portion 431 and a second groove portion 432. The first groove portion 431 and the second groove portion 432 have a substantially V-shape when viewed from the Z1 direction side. When viewed from the Z1 direction side, the first groove portion 431 is adjacent to the second groove portion 432 on the opposite side from the R direction. The first groove portion 431 and the second groove portion 432 are connected in the R direction. In the R direction, the first groove portion 431 is larger than the second groove portion 432.

[0149] The V-shaped groove 403 is arranged so that both end portions 403b, 403c of the V-shaped groove 403 are at the tip end side in the R direction in which the V-shaped groove 403 slides relatively to the stationary-side sliding part that faces the actuation-side sliding part 401 in which the V-shaped groove 403 is provided. In this way, the R direction in which the V-shaped groove 403 slides relatively to the stationary-side sliding part indicates the sliding direction when the "stationary-side sliding part in which the V-shaped groove 403 is not provided" is used as the reference, not the "actuation-side sliding part 401 in which the V-shaped groove 403 is provided," and therefore the "sliding direction in which the V-shaped groove 403 slides relatively" is the "R direction."

[0150] That is, the V-shaped first groove 431 is arranged so that both end portions 431b, 431c of the V-shaped first groove 431 are on the tip side in the R direction. The V-shaped first groove 431 is arranged so that the tip portion 431a of the V-shaped first groove 431 is on the tip side in the direction opposite to the R direction. The V-shaped second groove 432 is arranged so that both end portions 432b, 432c of the V-shaped second groove 432 are on the tip side in the R direction. The V-shaped second groove 432 is arranged so that the tip portion 432a of the V-shaped second groove 432 is on the tip side in the direction opposite to the R direction.

[0151] <Central corner> The first groove portion 431 has a central angle θ41. The central angle θ41 is approximately 90 degrees. The second groove portion 432 has a central angle θ42. The central angle θ42 is approximately 90 degrees.

[0152] <Groove width> In the R direction, the tip end 431a of the first groove portion 431 has a groove width W41. In the R direction, the end portion 431b of the first groove portion 431 has a groove width W42. In the R direction, the end portion 431c of the first groove portion 431 has a groove width W43. The groove width W41, the groove width W42, and the groove width W43 are all approximately the same length.

[0153] In the R direction, the tip end 4032a of the second groove portion 432 has a groove width W44. In the R direction, the end 403b of the second groove portion 432 has a groove width W45. In the R direction, the end 403c of the second groove portion 432 has a groove width W46. The groove width W44, the groove width W45, and the groove width W46 are all approximately the same length.

[0154] <Groove depth> As shown in Figure 22, the V-shaped groove 403 has a stepped shape in which the groove depth D decreases in the direction opposite to the R direction. The first groove portion 431 has a groove depth D41 in the Z direction. The second groove portion 432 has a groove depth D42 in the Z direction. The groove depth D41 is smaller than the groove depth D42. Note that the other configurations of the fourth embodiment are similar to those of the first embodiment, and therefore description thereof will be omitted.

[0155] (Effects of the fourth embodiment) In the fourth embodiment, the following effects can be obtained.

[0156] In the fourth embodiment, similarly to the first embodiment, the V-shaped groove 403 is arranged so that both end portions 403b, 403c of the V-shaped groove 403 are at the tip side in the R direction of relative sliding with respect to the stationary-side sliding part that faces the actuation-side sliding part 401 on which the V-shaped groove 403 is provided. In the V-shaped groove 403, the groove depth D is made smaller toward the tip portion 431a side. This makes it possible to more reliably avoid contact with the actuation-side sliding surface 411. Note that other effects of the fourth embodiment are similar to those of the first embodiment, and therefore description thereof will be omitted.

[0157] [Variations] The above-described embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the description of the above-described embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0158] For example, in the first, second, and fourth embodiments, the actuation side sliding portion 1 (201, 401) is made of a metal such as iron or aluminum, but the present invention is not limited to this. In the present invention, the actuation side sliding portion may be made of a resin or the like.

[0159] In the first, second and fourth embodiments, the stationary sliding portion 2 (202) is made of a metal such as iron or aluminum, but the present invention is not limited to this. In the present invention, the stationary sliding portion may be made of a resin or the like.

[0160] In the first and third embodiments, the open structures 31d (3424, 3524, 3534) are exposed on the outer side (lateral side) in the K direction (radial direction) of the actuating-side sliding surface 11 (341, 351), but the present invention is not limited to this. In the present invention, the open structures may be exposed on the inner side or both sides in the radial direction of the actuating-side sliding surface, or on the inner side, outer side, or both sides in the radial direction of the stationary-side sliding surface.

[0161] In the first embodiment, the V-shaped grooves 3 are arranged so as not to overlap each other in the K direction (radial direction) when viewed from the Z1 direction, but the present invention is not limited to this. In the present invention, the V-shaped grooves may overlap each other when viewed from the Z1 direction.

[0162] In the first, second, and fourth embodiments, the actuation-side sliding surface 11 (211, 411) and the stationary-side sliding surface 21 (221) are curved surfaces, but the present invention is not limited to this. In the present invention, the actuation-side sliding surface and the stationary-side sliding surface may be flat surfaces that are not curved.

[0163] Furthermore, in the first to fourth embodiments, examples were shown in which the central angles θ2, θ33 to θ36, θ41, and θ42 were approximately 90 degrees, but the present invention is not limited to this. In the present invention, the central angle may be any angle greater than 0 degrees and less than 180 degrees. For example, in the sliding component of the first example shown in Figure 23, the relationship between the average oil film pressure, which is the average of the oil film pressure generated in the oil in the V-shaped groove, and the central angle is shown, and it can be seen that the average oil film pressure is maximum when the central angle is approximately 90 degrees.

[0164] In the first and second embodiments, the groove depth D1 is, for example, 9 μm, and the groove depth D2 is, for example, 1 μm, but the present invention is not limited to this. In the present invention, for example, the depth on the tip side may be set to 1 μm and the groove depth on the end side may be set to 10 μm, based on the graph showing the relationship between the average oil film pressure and the difference between the groove depth on the tip side and the groove depth on the end side in the sliding component of the second example shown in FIG.

[0165] Furthermore, in the first and second embodiments, an example was shown in which groove width W3 and groove width W4 are preferably greater than groove width W2 but not greater than twice groove width W2, but the present invention is not limited to this. In the present invention, the groove width at the end portion and the groove width at the tip portion may be the same. Here, the groove width at the end portion and the groove width at the tip portion may be determined based on, for example, the graph shown in FIG. 25, which shows the relationship between the average oil film pressure and the groove width at the end portion in the sliding component of the third embodiment. Note that in the graph of the third embodiment shown in FIG. 25, the groove width at the tip portion is constant. [Explanation of symbols]

[0166] 1, 201, 401 Operating side sliding part (sliding part) 2, 202 Stationary side sliding part (sliding part) 11, 211, 411 Operating side sliding surface (sliding surface, one sliding surface) 21, 221 Stationary sliding surface (sliding surface, other sliding surface) 31, 41, 231, 241, 342a, 343a, 352a, 353a, 362a, 363a, 431 groove 31a, 231a, 3421, 3521, 3531, 3621, 4311a Tip 31b, 31c, 231b, 231c, 3422, 3423, 3522, 3523, 3532, 3533, 3622, 3623, 4312b, 4312c End 100, 200, 300, 400 Sliding parts 301 Oil pump 314 Drive rotor (sliding part, operating side sliding part) 315 Driven rotor (sliding part, operating side sliding part) 316 Shaft (sliding part, operating side sliding part) 341, 351, 354, 361 sliding surface B Oil D Groove depth D1, D32, D33, D35, D37, D42 (end) groove depth D2, D32, D34, D36, D38, D41 (tip) groove depth Pr Oil film pressure W2, W41, W302, W306, W310, W314 (tip side) groove width W3, W4, W45, W46, W303, W304, W307, W308, W311, W312, W315, W316 (end side) groove width

Claims

1. A sliding unit including one sliding part and another sliding part that slide against each other via oil containing an oil film; a V-shaped groove provided on the sliding surface of the one sliding part, the V-shaped groove is disposed such that both end portions thereof are located at leading end sides in a sliding direction in which the one sliding portion provided with the V-shaped groove slides relatively to the other sliding portion opposed thereto, the V-shaped groove is configured such that a groove depth decreases from both end portions of the V-shaped groove on the tip side in the sliding direction toward corner portions of the V-shaped groove that are located on the tip side in the direction opposite to the sliding direction and where the grooves extending from the both end portions intersect, thereby generating an oil film pressure that acts from the one sliding part side to the other sliding part side in the direction in which the one sliding part and the other sliding part are arranged, the V-shaped groove includes a plurality of inner V-shaped grooves circumferentially provided on the inner side of the sliding surface of the one sliding part, and a plurality of outer V-shaped grooves circumferentially provided on the outer side of the sliding surface of the one sliding part.

2. 2. The sliding component according to claim 1, wherein the V-shaped groove is configured to generate an oil film pressure by making the groove depth at the corners smaller than the groove depth at both ends.

3. 3. The sliding component according to claim 1, wherein the V-shaped groove has a depth that continuously decreases from the both ends toward the corners, thereby generating an oil film pressure.

4. 4. The sliding component according to claim 1, wherein a groove width at each of the two end portions of the V-shaped groove in the sliding direction is equal to or greater than a groove width at each of the corner portions of the V-shaped groove.

5. The sliding portion is a stationary-side sliding portion as the other sliding portion; an operating side sliding portion as the one sliding portion, The sliding component according to any one of claims 1 to 4, wherein the V-shaped groove is disposed so that both end portions of the V-shaped groove are on tip sides in the sliding direction, and is provided on a surface of the operating-side sliding part.

6. 6. The sliding component according to claim 1, wherein a plurality of the V-shaped grooves are provided at predetermined intervals along the sliding direction.

7. the sliding portion includes at least one of a drive rotor, a driven rotor, and a shaft that constitute an oil pump, 7. The sliding component according to claim 1, wherein the V-shaped groove is provided in at least one of a drive rotor, a driven rotor, and a shaft that configure the oil pump, along a rotational direction as the sliding direction.

8. 8. The sliding component according to claim 1, wherein at least one of both end portions of the V-shaped groove has an open structure exposed laterally on the sliding surface of the sliding part.

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