Sliding member and method for manufacturing sliding member

Abstract

To provide a sliding member capable of easily forming a configuration for suppressing deterioration of sliding performance.SOLUTION: The sliding member 5 includes a first layer 11 serving as a substrate, and a second layer 12 that is made of a material different from that of the first layer 11, is laminated on the first layer 11, and has a sliding surface 13 on which a sliding target slides, the first layer 11 has a plurality of grooves 14 provided on a surface on a side on which the second layer 12 is laminated and extending in a direction orthogonal to a lamination direction, the width of the groove 14 is larger than the width of the groove 14 on the surface of the first layer 11 at least at one position in the depth direction, and a part of the second layer 12 enters the groove 14.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION An embodiment of the present invention relates to a slide member. [Background technology]

[0002] Typically, sliding members for vertical-shaft rotating electric machines are composed of a composite material consisting of a first layer and a second layer made of a different material. However, when the first layer is made of a metal material and the second layer is made of a resin material, it is difficult to bond these materials with sufficient bonding strength. If the bonding strength between the first and second layers is insufficient, the first and second layers may separate due to the large load applied to the sliding member in the lamination direction or perpendicular thereto during operation of the vertical-shaft rotating electric machine. Some sliding members for vertical-shaft rotating electric machines are composed of a metal base material, a resin that forms the sliding portion, and an intermediate layer that connects them. The intermediate layer is made of a mesh-like material or a porous metal material that is filled with resin to provide a grip. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3194866 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-190870 [Patent Document 3] Japanese Patent Application Laid-Open No. 2000-356222 [Patent Document 4] Japanese Patent Publication No. 2022-074899 [Patent Document 5] Japanese Patent Application Publication No. 2019-158083 [Patent Document 6] Japanese Patent Application Publication No. 11-270550 [Patent Document 7] Japanese Patent Application Publication No. 9-210053 Summary of the Invention [Problem to be solved by the invention]

[0004] In the sliding member described above, a time-consuming welding process is required to join the first layer and the intermediate layer. Furthermore, in order to blend the resin material constituting the second layer into the intermediate layer, it is necessary to select an intermediate layer with a complex structure. Therefore, there is a need for a simple method for manufacturing a sliding member having a structure that suppresses the deterioration of sliding performance.

[0005] The embodiments of the present invention have been made in consideration of the above circumstances, and have an object to provide a sliding member that can easily form a configuration for suppressing a decrease in sliding performance. [Means for solving the problem]

[0006] A sliding member according to an embodiment of the present invention comprises a first layer serving as a substrate; and a second layer made of a material different from the first layer, laminated on the first layer, and having a sliding surface on which a sliding part slides. The first layer has a plurality of grooves provided on the surface on which the second layer is laminated and extending in a direction perpendicular to the lamination direction, and the width of the grooves is greater than the width of the grooves on the surface of the first layer at at least one point in the depth direction, and a part of the second layer is embedded in the grooves. [Effects of the Invention]

[0007] According to the embodiment of the present invention, it is possible to provide a sliding member that can easily form a configuration for suppressing a decrease in sliding performance. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing a thrust bearing device according to a first embodiment. [Figure 2] FIG. 2 is a plan view showing the sliding member of the first embodiment. [Figure 3] FIG. 2 is a perspective view showing a sliding member of the first embodiment. [Figure 4] FIG. 2 is a cross-sectional view showing the sliding member of the first embodiment. [Figure 5]FIG. 3 is an enlarged cross-sectional view showing a groove portion of the first embodiment. [Figure 6] 3A to 3C are plan views showing a manufacturing method of the slide member of the first embodiment. [Figure 7] 10A to 10C are cross-sectional views showing a manufacturing method of a sliding member according to a modified example. [Figure 8] FIG. 10 is a cross-sectional view showing a sliding member according to a second embodiment. [Figure 9] FIG. 10 is a cross-sectional view showing a sliding member according to a third embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing a sliding member according to a fourth embodiment. [Figure 11] FIG. 10 is a cross-sectional view showing a sliding member according to a fifth embodiment. [Figure 12] FIG. 13 is an enlarged cross-sectional view showing a groove portion of the sixth embodiment. [Figure 13] FIG. 13 is an enlarged cross-sectional view showing a groove portion of the seventh embodiment. [Figure 14] FIG. 13 is an enlarged cross-sectional view showing a groove portion of the eighth embodiment. [Figure 15] FIG. 13 is an enlarged cross-sectional view showing a groove portion of the ninth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] (First embodiment) Hereinafter, embodiments of a sliding member and a method for manufacturing a sliding member will be described in detail with reference to the drawings. First, a first embodiment will be described with reference to Figs. 1 to 7. In Figs. 1, 4, and 5, the upper side of the paper is the upper side of the device and each member. The horizontal direction is the X-axis direction and the Y-axis direction, and the vertical direction is the Z-axis direction. In addition, the scale of each illustrated configuration may be changed as appropriate to facilitate understanding.

[0010] Reference numeral 1 in Fig. 1 denotes a thrust bearing device of the first embodiment. The thrust bearing device 1 is a device that supports a rotor shaft 2 (rotor) of a vertical shaft rotating electric machine. An example of the vertical shaft rotating electric machine is a hydroelectric generator. Note that the vertical shaft rotating electric machine may also be a predetermined motor.

[0011] As shown in Fig. 1, a generator (not shown) is connected to the upper side of the rotor shaft 2, and a water turbine (not shown) is connected to the lower side. The rotor shaft 2 extends vertically and rotates around its axis. The direction in which the rotor shaft 2 rotates is along a horizontal plane.

[0012] The thrust bearing device 1 comprises a support portion 3, a base 4, a sliding member 5, and a runner 6. The support portion 3, the base 4, the sliding member 5, and the runner 6 are housed in a predetermined housing (not shown). These members are immersed in lubricating oil inside the housing.

[0013] The support part 3 is an immovable member fixed to the housing. The base 4 is fixed to the upper surface of the support part 3. The sliding member 5 is fixed to the upper surface of the base 4.

[0014] The runner 6 is a member that is fixed to the rotor shaft 2 and rotates together with the rotor shaft 2. The lower end of the runner 6 has a smooth surface that is in sliding contact with the upper surface of the sliding member 5. The rotor shaft 2 is rotatably supported by the runner 6.

[0015] 2, a plurality of fan-shaped, plate-like sliding members 5 are arranged in a ring shape to form a sliding surface 13 on which a runner 6 (FIG. 1) slides. For example, in a plan view, the runner 6 rotates on the upper surface of the sliding member 5 in a clockwise direction (sliding direction H).

[0016] As shown in FIG. 3, the sliding member 5 includes a first layer 11 and a second layer 12. The first layer 11 is a metal substrate (base material, metal material). The second layer 12 is made of a different material from the first layer 11, is laminated on the first layer 11, and has a sliding surface 13 (upper surface) on which the sliding part slides. The sliding part is the lower end of a runner 6 attached to a rotor shaft 2 of a vertical shaft rotating electric machine. The second layer 12 is made of resin. Therefore, the lower end of the runner 6 slides smoothly on the sliding surface 13 of the second layer 12.

[0017] As shown in FIG. 4, the first layer 11 has a plurality of grooves 14 provided on the surface on which the second layer 12 is stacked, and extending in a direction perpendicular to the stacking direction (Z-axis direction). The plurality of grooves 14 are formed to extend linearly along the Y-axis direction. In other words, the grooves 14 are dug perpendicular to the stacking direction (Y-axis direction) and are open at the top. A portion of the second layer 12 extends into the grooves 14. The plurality of grooves 14 are aligned parallel to one another in the X-axis direction.

[0018] 5, groove portion 14 is dug so that at least a portion thereof forms a circle C in a cross-sectional view, and a part of circle C overlaps interface 15 between first layer 11 and second layer 12. This part of circle C has a size that is less than half the diameter of circle C (diameter dimension D).

[0019] For example, if we imagine an imaginary circle C representing the shape of groove portion 14, the upper edge of this circle C is above interface 15. The dimension of the region above interface 15 (upper region R1) is less than half the diameter (diameter dimension D) of circle C. The dimension of the region below interface 15 (lower region R2) is more than half the diameter (diameter dimension D) of circle C.

[0020] The circle C showing the cross-sectional shape of the groove 14 may be a perfect circle, an ellipse, or a circle with a slightly distorted shape.

[0021] Furthermore, the width of groove 14 is larger than the width of groove 14 on the surface of first layer 11 at at least one point midway in the depth direction.

[0022] For example, the width of the opening of the groove 14 on the surface of the first layer 11 (opening width W1) is used as a reference. Here, the width of the center portion of the circle C of the groove 14 (center width W2) is larger than the width of the opening of the groove 14 (opening width W1). Therefore, the resin (part of the second layer 12) that has entered the groove 14 will not fall out, and a decrease in sliding performance that would occur when the second layer 12 peels off from the first layer 11 can be suppressed.

[0023] If the bottoms of the grooves 14 are considered to be a reference plane, the portions between the plurality of grooves 14 can be considered as convex portions protruding upward from the reference plane. If the cross-sectional shape of the grooves 14 were rectangular or trapezoidal, stress could be concentrated at the bases of the convex portions, which could cause the bases to break. However, in this embodiment, the width of the grooves 14 increases partway along the depth direction, so stress does not concentrate at the bases of the convex portions, eliminating the risk of breakage. Furthermore, because the cross-sectional shape of the grooves 14 is a circle C, there are no areas where stress concentrates near the grooves 14, and the first layer 11 is also free from the risk of breakage.

[0024] As shown in FIG. 6, at least some of the grooves 14 extend in a direction (Y-axis direction) perpendicular to the direction (sliding direction H) in which the runner 6 (FIG. 1) slides.

[0025] The "orthogonal direction" means a direction that is approximately orthogonal. When the runner 6 rotates, the direction may be "orthogonal" to the tangent of an imaginary circle that indicates the rotation direction. The "orthogonal direction" may be slightly inclined relative to the true orthogonal direction as long as the effect of this embodiment is achieved.

[0026] Next, a method for manufacturing the slide member 5 will be described. As shown in Fig. 6, when manufacturing the slide member 5, an operator forms the groove portion 14 using a drilling device 20 that drills (machines) holes from the side surface of the first layer 11, which is the substrate.

[0027] For example, the drilling device 20 includes a drill bit 21 that is longer than the width of the first layer 11 in the Y-axis direction. This drill bit 21 drills a hole from the side surface of the first layer 11 to form the groove portion 14. By drilling with the upper surface side of the drill bit 21 protruding from the upper surface of the first layer 11, it is possible to form the groove portion 14 that is open at the top and has a circular cross section C (FIG. 5).

[0028] After the grooves 14 are formed in the first layer 11, the second layer 12 made of resin is pressed against the first layer 11 while being heated. The lower part of the second layer 12 then melts and flows into the grooves 14. When the second layer 12 is cooled in this state, it solidifies and is fixed in place with a portion of the second layer 12 embedded in the grooves 14.

[0029] The first layer 11 has a rectangular plate shape. After the second layer 12 is formed, the first layer 11 is cut into a sector F, whereby the sliding member 5 is completed.

[0030] 7 shows a modified example of the method for manufacturing the sliding member 5. In this modified example, when manufacturing the sliding member 5, an operator forms the grooves 14 using a cutter 22 whose tip has a shape that forms the cross-sectional shape of the grooves 14.

[0031] This cutter 22 includes a shaft 23 and a plurality of semicircular blades 24 provided at the tip of the shaft 23. By rotating the cutter 22 around its axis, it is possible to form grooves 14 that are open at the top and have a circular cross section C (FIG. 5). The cutter 22 starts grinding from the side surface of the first layer 11 and moves along the Y-axis direction, thereby forming grooves 14 that extend linearly in the Y-axis direction.

[0032] The shape of the tip of the cutter 22 may be changed as appropriate to suit the cross-sectional shape of the groove 14 to be manufactured.

[0033] Alternatively, the worker may weld a rod-shaped member to the surface of the first layer 11 to form multiple protrusions, and then insert a drill bit 21 or a cutter 22 between these protrusions to form a groove 14 that is circular C in cross section.

[0034] According to the first embodiment, it is possible to omit the intermediate layer process that complicates the manufacturing process as in the conventional technology, and therefore it is possible to manufacture the sliding member 5 for a vertical shaft rotating electric machine, which has a sufficient configuration, through a simple process.

[0035] (Second embodiment) Next, a second embodiment will be described with reference to Fig. 8. Note that the same components as those shown in the above-described embodiment will be assigned the same reference numerals and redundant description will be omitted.

[0036] In the second embodiment, at least a portion of the groove portion 14 forms a plurality of circles C in a cross-sectional view. The groove portion 14 is made up of a first circle C1 dug so as to overlap a portion of the interface 15 between the first layer 11 and the second layer 12, and a second circle C2 dug so as to overlap a portion of the first circle C1. Here, the second circle C2 is formed larger than the first circle C1.

[0037] The first circle C1 and the second circle C2 are aligned in the stacking direction (Z-axis direction). More than half of the diameter of the first circle C1 is located above the interface 15. The first circle C1 is also carved so that a portion of the second circle C2 overlaps with the first circle C1. This portion of the second circle C2 has a dimension less than half the diameter of the second circle C2.

[0038] According to the second embodiment, the presence of the first circular portion C1 in the groove portion 14 prevents the edges of the opening of the groove portion 14 from chipping and prevents concentrated stress from being applied to the second layer 12 from these edges.

[0039] (Third embodiment) Next, a third embodiment will be described with reference to Fig. 9. Note that the same components as those shown in the above-described embodiments will be assigned the same reference numerals and redundant description will be omitted.

[0040] The groove 14 of the third embodiment is dug so that at least a part thereof forms a circle C in a cross-sectional view, and the circle C does not overlap with the interface 15 between the first layer 11 and the second layer 12.

[0041] Furthermore, the groove 14 has a neck 30 which is an opening that extends from the interface 15 to the circle C and is narrower than the circle C.

[0042] The neck portion 30 is a hole that is rectangular in cross section and is dug in the stacking direction (Z-axis direction), and extends linearly along the Y-axis direction. The circular C portion of the groove portion 14 is connected to the interface 15 via the neck portion 30.

[0043] According to the third embodiment, the presence of the neck portion 30 can prevent the edges of the openings of the grooves 14 from chipping and prevent concentrated application of stress to the second layer 12 from these edges.

[0044] (Fourth embodiment) Next, a fourth embodiment will be described with reference to Fig. 10. Note that the same components as those shown in the above-described embodiments will be assigned the same reference numerals and redundant description will be omitted.

[0045] In the fourth embodiment, the first layer 11 is provided with passages 40 for releasing at least the air present in the grooves 14 when resin is forced into the grooves 14 during manufacturing.

[0046] The passages 40 are made up of first passages 41 extending from the groove portion 14 in the stacking direction (Z-axis direction) and second passages 42 connecting the first passages 41 and the side surface of the first layer 11. The second passages 42 are open at the side surface. The first passages 41 are holes extending in the Z-axis direction, and the second passages 42 are holes extending in the X-axis direction. The first passages 41 open at multiple locations in one groove portion 14. In other words, multiple first passages 41 are lined up in the Y-axis direction. Furthermore, multiple second passages 42 are lined up in the Y-axis direction corresponding to these first passages 41.

[0047] During the manufacture of the sliding member 5, an operator heats and presses the resin that will become the second layer 12 against the substrate of the first layer 11, on which the grooves 14 have been formed, to cause the resin to fill the grooves 14. During this process, an increase in air pressure inside the grooves 14 may prevent the resin that will become the second layer 12 from filling the grooves 14 sufficiently. Therefore, a passage 40 is formed in the first layer 11 of the fourth embodiment.

[0048] The first passages 41 are formed by drilling (machining) holes from the interface 15 of the first layer 11. The depth of the first passages 41 may be determined arbitrarily by the worker. The first passages 41 may also penetrate to the bottom surface of the first layer 11. In that case, the second passages 42 are not necessary.

[0049] The second passages 42 are formed by drilling (machining) holes from the side surfaces of the first layer 11. The second passages 42 are formed so as to open to at least one side surface of the first layer 11.

[0050] According to the fourth embodiment, an escape route for air can be secured so that the entire groove 14 is filled with resin during manufacturing. In other words, the passage 40 does not create a pressure difference inside the groove 14, allowing the resin to easily enter the groove 14. In this way, the impregnation of the second layer 12 into the groove 14 can be improved, and the bonding strength between the first layer 11 and the second layer 12 can be increased.

[0051] (Fifth embodiment) Next, a fifth embodiment will be described with reference to Fig. 11. Note that the same components as those shown in the above-described embodiments will be assigned the same reference numerals and redundant description will be omitted.

[0052] The groove portion 14 of the fifth embodiment has at least a portion that forms a circle C in a cross-sectional view, and is composed of a first circle C1 that is dug so as to overlap a portion of the interface 15 between the first layer 11 and the second layer 12, and a second circle C2 that is dug so as not to overlap the first circle C1. Here, the first circle C1 and the second circle C2 are formed to be approximately the same size.

[0053] The first circle C1 and the second circle C2 are aligned in the stacking direction (Z-axis direction). Less than half of the diameter of the first circle C1 is above the interface 15. Note that more than half of the diameter of the first circle C1 may be above the interface 15.

[0054] Furthermore, the groove 14 has a neck 31 which is an opening that extends from the first circle C1 to the second circle C2 and is narrower than the first circle C1 and the second circle C2.

[0055] The neck portion 31 is a hole that is rectangular in cross section and is dug in the stacking direction (Z-axis direction), and extends linearly along the Y-axis direction. The first circle C1 and the second circle C2 are connected to each other by the neck portion 31.

[0056] According to the fifth embodiment, during manufacturing, the second circle C2 ensures an escape route for air from the first circle C1. At least the first circle C1 is filled with resin. In other words, the second circle C2 prevents a pressure difference from occurring inside the first circle C1, allowing the resin to easily enter the first circle C1.

[0057] (Sixth embodiment) Next, a sixth embodiment will be described with reference to Fig. 12. Note that the same components as those shown in the above-described embodiments will be assigned the same reference numerals and redundant description will be omitted.

[0058] The configuration of the groove portion 14 in the sixth embodiment is based on the configuration in the first embodiment (FIG. 5). In this sixth embodiment, a chamfered portion 50 is formed on the edge of the groove portion 14 on the surface of the first layer 11. The chamfered portion 50 has a curved shape (arcuate shape) that bulges out at a predetermined curvature.

[0059] The provision of the groove 14 may result in sharp edges being formed on the edges of the groove 14, but the chamfered portion 50 is formed by grinding off the sharp edges and providing a notch.

[0060] For example, the interface 15 between the first layer 11 and the second layer 12 is the main surface, and both edges of the groove 14 formed on this main surface are the peripheral surfaces. Here, the chamfered portion 50 is a surface having a curvature that changes in the direction in which the two peripheral surfaces approach each other as they move away from the main surface.

[0061] According to the sixth embodiment, the stress applied to the resin forming the second layer 12 from the substrate forming the first layer 11 can be alleviated.

[0062] During operation, a sliding member 5 for a vertical shaft rotating electric machine is subjected to load and friction in the rotational direction of a runner 6 (FIG. 1). In this case, a shear force on the sliding member 5 generates a load at an interface 15 (joint surface) between the first layer 11 and the second layer 12. At this time, the sharp portions of the first layer 11 concentrate stress on the second layer 12, leading to damage to the second layer 12. Therefore, in the sixth embodiment, the sharp portions of the first layer 11 are removed, thereby dispersing the stress on the second layer 12. Furthermore, damage to the second layer 12 can be prevented, thereby providing a sliding member 5 for a vertical shaft rotating electric machine whose quality can be maintained for a long period of time.

[0063] The first circular portion C1 of the second embodiment (FIG. 8) described above is also one of other forms of the chamfered portion 50.

[0064] (Seventh embodiment) Next, a seventh embodiment will be described with reference to Fig. 13. Note that the same components as those shown in the above-described embodiments will be assigned the same reference numerals and redundant description will be omitted.

[0065] The configuration of the grooves 14 in the seventh embodiment is based on the configuration in the first embodiment (FIG. 5). In this seventh embodiment, chamfered portions 51 are formed on the edges of the grooves 14 on the surface of the first layer 11. The chamfered portions 51 are flat and inclined at a predetermined angle.

[0066] For example, the interface 15 between the first layer 11 and the second layer 12 is the main surface, and both edges of the groove 14 formed on this main surface are the peripheral surfaces. Here, the chamfered portion 51 is a surface inclined in such a way that the two peripheral surfaces approach each other as they move away from the main surface.

[0067] According to the seventh embodiment, it is possible to relieve stress applied from the substrate forming the first layer 11 to the resin forming the second layer 12. Furthermore, since the chamfered portion 51 can be formed simply by cutting both edges of the groove portion 14, manufacturing is easy.

[0068] (Eighth embodiment) Next, an eighth embodiment will be described with reference to Fig. 14. Note that the same components as those shown in the above-described embodiments will be given the same reference numerals and redundant description will be omitted.

[0069] The configuration of the groove portion 14 in the eighth embodiment is based on the configuration in the third embodiment (FIG. 9). In this eighth embodiment, a chamfered portion 52 is formed on the edge of the groove portion 14 (neck portion 30) on the surface of the first layer 11. The chamfered portion 52 has a curved shape (arcuate shape) that bulges out at a predetermined curvature.

[0070] According to the eighth embodiment, the stress applied to the resin forming the second layer 12 from the substrate forming the first layer 11 can be alleviated.

[0071] (Ninth embodiment) Next, a ninth embodiment will be described with reference to Fig. 15. Note that the same components as those shown in the above-described embodiments will be assigned the same reference numerals and redundant description will be omitted.

[0072] The configuration of the groove 14 in the ninth embodiment is based on the configuration in the third embodiment (FIG. 9). In this ninth embodiment, a chamfered portion 53 is formed on the edge of the groove 14 (neck portion 30) on the surface of the first layer 11. The chamfered portion 53 is a flat surface inclined at a predetermined angle.

[0073] According to the ninth embodiment, it is possible to relieve stress applied from the substrate forming the first layer 11 to the resin forming the second layer 12. Furthermore, since the chamfered portion 53 can be formed simply by cutting both edges of the groove portion 14 (neck portion 30), manufacturing is easy.

[0074] The present invention has been described above based on the first to ninth embodiments, but the configuration applied in any of the embodiments may be applied to other embodiments, and the configurations applied in each embodiment may be combined.

[0075] In the above-described embodiment, the cross-sectional shape of the groove 14 is a circle C, but other shapes are also possible. For example, the cross-sectional shape of the groove 14 may be a trapezoid. The groove 14 may be a so-called dovetail groove.

[0076] According to at least one of the embodiments described above, the width of the groove portion 14 is larger at at least one location in the depth direction than the width of the groove portion 14 on the surface of the first layer 11. This makes it possible to provide a sliding member 5 that can easily be configured to suppress a decrease in sliding performance.

[0077] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations can be made without departing from the spirit of the invention. These embodiments and modifications thereof are intended to be included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents. [Explanation of symbols]

[0078] 1...thrust bearing device, 2...rotor shaft, 3...support portion, 4...base, 5...sliding member, 6...runner, 11...first layer, 12...second layer, 13...sliding surface, 14...groove portion, 15...interface, 20...drilling device, 21...drill bit, 22...cutter, 23...shank portion, 24...blade portion, 30, 31...neck portion, 40...passage, 41...first passage, 42...second passage, 50, 51, 52, 53...chamfered portion, C...circle, C1...first circle, C2...second circle, D...diameter dimension, F...fan shape, H...sliding direction, R1...upper region, R2...lower region, W1...opening width, W2...central width.

Claims

1. a first layer that serves as a substrate; a second layer made of a material different from the first layer, laminated on the first layer, and having a sliding surface on which a sliding part slides; Equipped with the first layer has a plurality of grooves provided on a surface on which the second layer is laminated and extending in a direction perpendicular to the lamination direction; a width of the groove portion is larger than a width of the groove portion on the surface of the first layer at at least one point in a depth direction; a part of the second layer is embedded in the groove; Sliding member.

2. the groove portion is dug so that at least a portion thereof has a circular shape in a cross-sectional view and a portion of the circular shape overlaps with an interface between the first layer and the second layer, The portion of the circle is less than half the diameter of the circle. The sliding member according to claim 1 .

3. the groove portion has at least a portion that is circular in cross section, and includes a first circle that is dug so as to overlap a portion of the interface between the first layer and the second layer, and a second circle that is dug so as to overlap a portion of the first circle, The second circle is formed larger than the first circle. The sliding member according to claim 1 .

4. the groove portion has at least a portion that is circular in cross section, and includes a first circle that is dug so as to overlap a portion of the interface between the first layer and the second layer, and a second circle that is dug so as not to overlap the first circle; The groove portion extends from the first circular portion to the second circular portion and has a neck portion which is an opening having a width narrower than the first circular portion and the second circular portion. The second circle is formed larger than the first circle. The sliding member according to claim 1 .

5. the groove portion has at least a portion that is circular in cross section, and is dug so that the circle does not overlap with the interface between the first layer and the second layer; The groove portion extends from the interface to the circle and has a neck portion that is an opening having a width narrower than the circle. The sliding member according to claim 1 .

6. the second layer is made of resin, and a passage is formed in the first layer for releasing at least air present in the groove portion when the second layer is pressed into the resin in the groove portion during manufacturing; The sliding member according to any one of claims 1 to 5.

7. a chamfered portion is formed on the edge of the groove portion on the surface of the first layer; The sliding member according to any one of claims 1 to 5.

8. the sliding portion is a lower end portion of a runner attached to a rotor shaft of a vertical shaft rotating electric machine, The groove portion extends in a direction perpendicular to a direction in which the runner slides. The sliding member according to any one of claims 1 to 5.

9. a first layer that serves as a substrate; a second layer made of a material different from the first layer, laminated on the first layer, and having a sliding surface on which a sliding part slides; Equipped with the first layer has a plurality of grooves provided on a surface on which the second layer is laminated and extending in a direction perpendicular to the lamination direction; a width of the groove portion is larger than a width of the groove portion on the surface of the first layer at at least one point in a depth direction; a part of the second layer is embedded in the groove; A method for manufacturing a slide member, During manufacturing, the groove is formed using at least one of a cutter whose tip shape forms the cross-sectional shape of the groove and a drill that drills a hole from the side surface of the substrate. A method for manufacturing a sliding member.

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