Bearing member

Abstract

To provide a high-quality bearing member that allows good air escape from a hole in the bearing member.SOLUTION: In a cylindrical bearing member 10 comprising an inner peripheral surface 11 into which a shaft member 10 can be inserted, an outer peripheral surface 12 opposing the inner peripheral surface 11, and an end face 15 connecting the inner peripheral surface 11 and the outer peripheral surface 12, the outer peripheral surface 12 is provided with at least one groove part 16 having a substantially V-shaped cross section, and an opening angle of the groove part 16 is 135° or more. The groove part 16 is parallel to an axial direction of the bearing member 10, and is formed from one end surface 15 to the other end surface 15, and a plurality of groove parts may be provided.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a bearing member. [Background technology]

[0002] A bearing device that rotatably supports a shaft member has a cylindrical bearing member that supports the shaft member and is fixed in a bottomed hole provided in a housing. In such a bearing device that closes one end of the bearing member, a groove is provided on the outer periphery of the bearing member. The groove in the bearing member is provided for the purpose of discharging air present in the hole to the outside of the bearing member when the shaft member is inserted into the hole of the cylindrical bearing member (see, for example, Patent Document 1 and Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6981900 [Patent Document 2] Patent No. 4481475 Summary of the Invention [Problem to be solved by the invention]

[0004] In a bearing member, differences in thickness between the portion where the groove is formed on the outer periphery and the portion where the groove is not formed can cause local strength differences and density differences in the material constituting the bearing member. In particular, when a bearing member is formed by press molding, the manufacturing process causes uneven pressure distribution in the material constituting the bearing member, which is likely to cause large strength and density differences, and this may lead to a deterioration in the quality of the bearing member. Furthermore, when a bearing member is manufactured by powder molding, which is a type of press molding, local density differences in the bearing member affect the shrinkage rate during sintering, and there is a concern that this may affect the shape quality, such as the roundness of the hole.

[0005] One idea is to make the grooves on the outer periphery smaller in order to reduce these differences in strength and density; however, if the grooves are too small, the groove's original function of expelling air to the outside (air escape) is reduced, making it difficult to smoothly insert the shaft member into the hole.

[0006] In view of the above problems, the present invention aims to provide a high-quality bearing member that allows good air escape from the hole of the bearing member, even when used in a bearing device in which one end of the bearing member is closed. [Means for solving the problem]

[0007] The cylindrical bearing member has an inner peripheral surface into which a shaft can be inserted, an outer peripheral surface facing the inner peripheral surface, and an end surface connecting the inner peripheral surface and the outer peripheral surface, and is characterized in that the outer peripheral surface is provided with at least one substantially V-shaped groove. The opening angle of this groove is preferably 135° or more. In addition, it is preferable that the groove is parallel to the axial direction, and the end of the groove is open to the outside. Furthermore, when a plurality of grooves are provided, it is preferable that they are provided at equal intervals in the circumferential direction of the outer peripheral surface. In addition, the end surface may be provided with an end face groove formed across the inner peripheral surface and the outer peripheral surface, and in this case, it is preferable that the groove end and the end on the outer peripheral side of the end face groove are located at different positions. Furthermore, it is preferable that the opening width of the groove is larger than the opening width of the end face groove. Effect of the Invention

[0008] According to the bearing member of the present invention, air escapes easily from within the hole of the bearing member, making it possible to provide a high-quality bearing member. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a bearing member 10 according to an embodiment of the present disclosure. [Diagram 2] FIG. 1 is a top view of a bearing member 10 according to an embodiment of the present disclosure. [Diagram 3] 1 is an enlarged cross-sectional view of a state in which a shaft 20 is inserted into a bearing member 10 according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the bearing member according to the present invention will be described with reference to the drawings. Fig. 1 shows a perspective view of a bearing member 10 according to an embodiment of the present disclosure. Fig. 2 shows a top view of the bearing member 10 according to an embodiment of the present disclosure. Fig. 3 shows an enlarged partial cross-sectional view of the bearing member 10 according to an embodiment of the present disclosure with a shaft 20 inserted therein.

[0011] The bearing member (hereinafter, simply referred to as "bearing") 10 is a tubular member having a hollow portion 18, and includes a cylindrical inner peripheral surface 11 forming the hollow portion 18, a cylindrical outer peripheral surface 12 facing the inner peripheral surface 11, and an end surface 15 connecting the respective ends of the inner peripheral surface 11 and the outer peripheral surface 12. Note that the bearing device can be an open type in which the lower part of the bearing 10 in the axial direction is sealed and the upper part is open to the outside, and a shaft 20 is inserted into the hollow portion 18 of the bearing 10, and the bearing 10 supports the shaft 20 relatively rotatably in a predetermined rotational direction. Here, the bearing device can fix the bearing 10 to a housing of the bearing device or the like and rotate the shaft 20. However, the present invention is not limited to such an example, and the shaft 20 may be fixed and the bearing 10 may be rotated.

[0012] At one end of the inner circumferential surface 11 of the bearing 10, there are formed a step portion 19 that is connected to the inner circumferential surface 11 and is parallel to the end face 15, and a first inclined portion 13 that is connected to the step portion 19 and the end face 15 and increases in diameter toward the end face (see FIG. 3). The first inclined portion 13 and the step portion 19 are provided at both one end and the other end of the inner circumferential surface 11, but may be provided at only one of the ends.

[0013] Further, at the end of the outer peripheral surface 12, a second inclined portion 14 is formed which is connected to the end face 15 and expands in diameter from the end face 15 toward the outer peripheral surface 12 (see Figs. 1 and 2). This second inclined portion 14 is provided at both one end and the other end of the outer peripheral surface 12, but may be provided at only one of the ends.

[0014] Furthermore, an outer peripheral groove 16 is formed in the outer peripheral surface 12 from one end face 15 to the other end face 15 in parallel with the central axis of the hollow portion 18. The outer peripheral grooves 16 are arranged at four locations at equal intervals in the circumferential direction of the outer peripheral surface 12, and one end of the outer peripheral groove 16 opens into the second inclined portion 14 formed on one end face side, and the other end opens into the second inclined portion 14 formed on the other end face side, so that the ends of the outer peripheral groove 16 are open to the outside. The cross section of the outer peripheral groove 16 is substantially V-shaped with the opening gradually widening from the bottom of the groove toward the surface of the outer peripheral surface 12, and the opening angle θ is 135°.

[0015] The end face grooves 17 are formed on the end face 15, extending from the first inclined portion 13 to the second inclined portion 14. The end face grooves 17 are arranged at four locations at equal intervals in the circumferential direction of the end face 15 on a straight line passing through the central axis of the hollow portion 18 in a plane parallel to the end face 15. One end of the end face groove 17 opens to the first inclined portion 13, and the other end opens to the second inclined portion 14, so that the end of the end face groove 17 is open to the outside. The cross section of the end face groove 17 is substantially V-shaped, with a bottom portion parallel to the end face 15 and side walls whose opening gradually widens from the bottom toward the surface of the end face 15, and the opening angle between the side walls is 90°. The end face grooves 17 are arranged so as to be located in the center between the adjacent outer circumferential grooves 16 when viewed from a plane perpendicular to the axis of the bearing member 10. The end face grooves 17 formed in the end faces 15 are provided on one end face 15 of the bearing 10 and on the other end face 15 , but may be provided on only one of the end faces 15 .

[0016] Here, when the bearing member 10 according to one embodiment of the present disclosure is used in an open-type bearing device in which the lower side of the bearing 10 is sealed, when the shaft 20 is inserted into the hollow portion 18, the air present in the hollow portion 18 is pushed out to the lower side as the shaft 20 is inserted, and can escape to the outside of the bearing 10 by using the step portion 19, the first inclined portion 13, the end face groove 17, the second inclined portion 14, and the outer peripheral groove 16 formed in the bearing 10 on the lower side of the bearing 10 as flow paths, in that order.

[0017] In the bearing member 10 according to an embodiment of the present disclosure, the V-shaped opening angle θ of the outer peripheral groove 16 is set to 135°. By setting the opening angle θ large in this way, the volume of the outer peripheral groove 16 through which air escapes can be increased even if the groove depth of the outer peripheral groove 16 is made shallow. In other words, the volume of the outer peripheral groove 16 can be increased while ensuring the thickness in the diameter direction of the bearing 10, and the strength of the bearing 10 can be maintained high while adequately ensuring the function of air escape. Similarly, by setting the depth of the outer peripheral groove 16 shallow, when the outer peripheral groove 16 is formed by powder molding, it is also possible to suppress density differences during molding. By setting the opening angle θ of the outer peripheral groove 16 in the range of 135° or more and less than 180°, it is possible to significantly suppress partial strength differences and density differences of the bearing 10.

[0018] It should be noted that, although the greater the opening angle θ, the greater the reduction in strength and density differences, the smaller the surface area of ​​the outer peripheral face 12 excluding the outer peripheral groove 16, and therefore the fixing of the bearing 10 will be less stable when, for example, the bearing 10 is installed in a bearing device by press fitting. For this reason, it is more preferable to set the opening angle θ of the outer peripheral groove 16 to 135° or more and 160° or less.

[0019] In the bearing member 10 according to an embodiment of the present disclosure, the opening width of the outer peripheral groove 16 is set to be larger than the opening width of the end face groove 17. This is because the quality of the portion between the inner peripheral surface 11 and the opposing outer peripheral surface 12 that receives the radial load of the shaft 20 is particularly important, and it is particularly important to suppress the occurrence of differences in strength and density caused by the formation of the outer peripheral groove 16, and such quality is not required for the differences in strength and density caused by the formation of the end face groove 17. Note that, when the thickness of the bearing 10 in the height direction (axial direction of the bearing 10) is thin and it is particularly desired to obtain strength against the load acting in that direction, the opening width of the end face groove 17 may be set to be the same as or larger than the opening width of the outer peripheral groove 16.

[0020] Here, the bearing 10 can be formed by, for example, molding ceramic powder. When molding the bearing 10 from ceramic, it can be formed by forming the punch and die into shapes that correspond to the peripheral groove 16 and the end face groove 17. Also, after molding and sintering a cylindrical member without the peripheral groove 16 and the end face groove 17, the peripheral groove 16 and the end face groove 17 may be formed by cutting, laser processing, or other means.

[0021] The bearing member of the present invention has been described above using the bearing member 10 of one embodiment of the present disclosure as an example, but it should be noted that the technical scope of the present invention is not limited to those embodiments, but extends to the invention described in the claims and their equivalents. For example, the outer circumferential groove 16 and the end face groove 17 are provided in four locations on the outer circumferential surface 12 and one end face 15, respectively, but they may be provided in one location or multiple locations other than four. Also, the number of outer circumferential grooves 16 and the end face grooves 17 do not have to be the same.

[0022] In addition, the cross section of the outer peripheral groove 16 is V-shaped with the opening expanding from the bottom of the groove toward the surface of the outer peripheral surface 12, but like the end face groove 17, the bottom of the groove may have a flat surface, and the side wall portion may have an approximately V-shaped opening expanding from the bottom toward the surface of the outer peripheral surface 12. In this case, the opening angle θ of the outer peripheral groove 16 is the angle formed by the side wall portion. In addition, the side wall portion of the outer peripheral groove 16 is not limited to a straight line, and may be a surface having a curvature. In this case, the opening angle θ of the outer peripheral groove 16 is the angle formed by the straight line connecting the opening end of one side wall portion on the outer peripheral surface 12 and the end portion on the central axis side of the bearing 10, and the straight line connecting the opening end of the other side wall portion on the outer peripheral surface 12 and the end portion on the central axis side of the bearing 10. In one embodiment of the present disclosure, the terms V-shaped and approximately V-shaped are used to describe the cross-sectional shape of the groove, but in the present invention, the cross-sectional shape of a groove in which the opening width increases from the bottom of the groove toward the opening, including V-shaped and grooves with curvature in the side wall, is collectively referred to as approximately V-shaped. [Explanation of symbols]

[0023] 10. Bearings 11 Inner surface 12 Outer surface 13 1st slope part 14 2nd slope part 15 End face 16 Outer Circumferential Groove 17 End groove 18 Hollow part 19 Step section 20 Axis

Claims

1. A cylindrical bearing member having an inner circumferential surface into which an axial member can be inserted, an outer circumferential surface opposite the inner circumferential surface, and an end surface connecting the inner circumferential surface and the outer circumferential surface, wherein the outer circumferential surface is provided with at least one groove portion having a substantially V-shaped cross section, and the opening angle of the groove portion is 135° or more.

2. 2. The bearing member according to claim 1, wherein the groove is parallel to an axial direction of the bearing member, and an end of the groove is open to the outside.

3. 3. The bearing member according to claim 1, wherein the grooves are provided in a plurality at equal intervals in the circumferential direction of the outer circumferential surface.

4. 2. The bearing member according to claim 1, wherein the end face is provided with an end face groove formed across the inner circumferential surface and the outer circumferential surface.

5. The bearing member according to claim 4, characterized in that the outer peripheral end of the end face groove provided on one of the end faces and the end of the groove portion located on the one of the end faces are located at different positions.

6. 6. A bearing member according to claim 4, wherein an opening width of the groove portion is larger than an opening width of the end face groove.

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