Rolling bearing

Abstract

To provide a rolling bearing that achieves both suppression of noise and improvement in productivity.SOLUTION: A rolling bearing comprises a cage 5. The cage 5 comprises an annular ring part 51 and a plurality of column parts 52. The plurality of column parts 52 protrude to one axial side from the ring part 51 and are formed so as to be aligned along a circumferential direction. A pocket 53 in which rolling bodies are arranged is formed between the adjacent column parts 52. An inner surface 530 of the pocket 53 includes a first region 531 and a second region 532. The second region 532 is located inside the first region 531 in a radial direction. The first region 531 exhibits a curved shape which is curved in a concave shape when viewed from the radial direction, and also exhibits a curved shape which is curved in a concave shape when viewed from the axial direction. The second region 532 protrudes to the inner side from the first region 531 at least in the circumferential direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] There is known a rolling bearing including a cage that holds rolling elements (see, for example, Patent Document 1). The cage of such a rolling bearing has a cylindrical surface having a central axis extending along the radial direction, and a pocket including a protrusion protruding from the cylindrical surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-158951 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the pocket as described above, by holding the rotating rolling elements by the protrusions, it is possible to suppress abnormal noise caused by vibration of the cage. However, if the pocket includes a cylindrical surface having a central axis parallel to the radial direction, it is difficult to realize a so-called axial draw during the manufacture of the cage, so there are cases where an improvement in productivity of the cage is required.

[0005] An object of the present invention is to provide a rolling bearing that can achieve both suppression of abnormal noise and improvement of productivity. [Means for solving the problem]

[0006] The rolling bearing of the present invention is, [1] "a rolling bearing comprising: an inner ring, an outer ring, a plurality of rolling elements arranged between the inner ring and the outer ring; and a retainer for holding the plurality of rolling elements, the retainer including an annular ring portion and a plurality of column portions protruding from the ring portion to one side in the axial direction and formed to be aligned along the circumferential direction, a pocket in which one of the plurality of rolling elements is disposed is formed between adjacent column portions of the plurality of column portions, an inner surface of the pocket includes a first region and a second region located at least on the radially inner side or outer side relative to the first region, the first region presents a concavely curved curved shape when viewed in the radial direction and a concavely curved curved shape when viewed in the axial direction, and the second region protrudes inward from the first region at least in the circumferential direction."

[0007] In this rolling bearing, the inner surface of the pocket includes a second region that protrudes inward from the first region at least in the circumferential direction. This allows the rotating rolling elements to be held by the second region, and noise caused by vibration of the cage can be suppressed. Moreover, the inner surface of the pocket includes a first region that has a concavely curved shape when viewed from the radial direction and also has a concavely curved shape when viewed from the axial direction. This makes it easier to manufacture the cage by axial draw, compared to when the inner surface of the pocket has a straight shape when viewed from the axial direction. Therefore, this rolling bearing can achieve both suppression of noise and improvement of productivity.

[0008] The rolling bearing of the present invention may be [2] "the rolling bearing according to the above [1], in which the first region is a part of a spherical surface." This makes it even easier to manufacture the cage by axial draw.

[0009] The rolling bearing of the present invention may be [3] "the rolling bearing according to the above [1] or [2], in which the second region is located radially inward relative to the first region, and the first region widens radially outward." This makes it easier to manufacture the cage by axial draw.

[0010] The rolling bearing of the present invention may be [4] "the rolling bearing according to any one of the above [1] to [3], wherein the second region has a concavely curved shape when viewed from the radial direction and a straight shape when viewed from the axial direction." This makes it possible to appropriately hold the rotating rolling elements by the second region, while appropriately suppressing abnormal noise caused by vibration of the cage.

[0011] The rolling bearing of the present invention may be [5] "the rolling bearing according to any one of the above [1] to [3], wherein the second region includes a convexly curved surface." This makes it possible to suppress abnormal noise caused by vibration of the cage and to promote the inflow of lubricant between the rolling elements and the inner surface of the pocket. Effect of the Invention

[0012] According to the present invention, it is possible to provide a rolling bearing that can realize both suppression of abnormal noise and improvement of productivity. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a front view of a rolling bearing according to an embodiment. [Diagram 2] FIG. 2 is a perspective view of the retainer shown in FIG. [Diagram 3] 2 is a cross-sectional view of a portion of the retainer shown in FIG. 1. [Figure 4] FIG. 11 is a cross-sectional view of a portion of a modified retainer. [Diagram 5] FIG. 11 is a cross-sectional view of a portion of a modified retainer. [Figure 6] FIG. 11 is a cross-sectional view of a portion of a modified retainer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and duplicated explanations will be omitted.

[0015] 1, rolling bearing 1 includes an inner ring 2, an outer ring 3, multiple rolling elements 4, and a cage 5. Hereinafter, the direction parallel to center line A of rolling bearing 1 will be referred to as the axial direction, the direction perpendicular to center line A will be referred to as the radial direction, and the direction along the circumference centered on center line A when viewed from a direction parallel to center line A will be referred to as the circumferential direction.

[0016] The inner ring 2 has a raceway surface 2a. The raceway surface 2a is a surface facing outward in the radial direction and extends in an annular shape along the circumferential direction. As an example, the inner surface of the inner ring 2 in the radial direction is fitted with a shaft (not shown). In this embodiment, the inner ring 2 rotates in accordance with the rotation of the shaft.

[0017] The outer ring 3 is disposed radially outward of the inner ring 2. The outer ring 3 has a raceway surface 3a. The raceway surface 3a is a surface facing inward in the radial direction and extends annularly along the circumferential direction. As an example, the outer surface of the outer ring 3 in the radial direction is fitted into a housing (not shown).

[0018] The multiple rolling elements 4 are disposed between the inner ring 2 and the outer ring 3. More specifically, the multiple rolling elements 4 are disposed between the raceway surface 2a of the inner ring 2 and the raceway surface 3a of the outer ring 3. In this embodiment, each rolling element 4 is a ball (spherical body).

[0019] The cage 5 holds the multiple rolling elements 4. More specifically, the cage 5 holds the multiple rolling elements 4 so that each rolling element 4 can freely roll between the raceway surface 2a of the inner ring 2 and the raceway surface 3a of the outer ring 3. The material of the cage 5 is a resin such as PA66 or PA46.

[0020] As shown in FIG. 2, the cage 5 is a so-called crown cage. The cage 5 has a circular ring shape. The cage 5 includes an inner surface 5a, an outer surface 5b, a first side surface 5c, and a second side surface 5d. The inner surface 5a is a cylindrical surface having a central axis parallel to the axial direction. The outer surface 5b faces the opposite side to the inner surface 5a. The outer surface 5b is a cylindrical surface having the same central axis as the inner surface 5a.

[0021] The first side surface 5c faces one side in the axial direction (upper side in FIG. 2). The first side surface 5c is a flat surface perpendicular to the axial direction. The second side surface 5d faces the other side in the axial direction (lower side in FIG. 2). In other words, the second side surface 5d faces the opposite side to the first side surface 5c. The second side surface 5d is a flat surface perpendicular to the axial direction.

[0022] The cage 5 includes a ring portion 51 and a plurality of pillar portions 52. The ring portion 51 has an annular shape. The ring portion 51 is a partial area of ​​the cage 5 that includes the second side surface 5d. Each pillar portion 52 protrudes from the ring portion 51 to one side in the axial direction (the side opposite to the second side surface 5d). The pillar portions 52 are arranged at predetermined intervals along the circumferential direction. The plurality of pillar portions 52 are a partial area of ​​the cage 5 that includes the first side surface 5c.

[0023] The ring portion 51 and the plurality of column portions 52 are integrally formed from the same material. In this embodiment, the cage 5 is formed by, for example, injection molding. In the manufacturing process of the cage 5, the inserts corresponding to the respective pockets 53 are extracted from the pockets 53 along the axial direction. In other words, the cage 5 is manufactured by a so-called axial draw. The axial draw is a method in which a mold used for injection molding of the cage 5 is released along the axial direction.

[0024] A pocket 53 is formed between each of the multiple column portions 52. The pocket 53 is defined by a pair of adjacent column portions 52 and a region of the ring portion 51 located between the pair of column portions 52. The pocket 53 is open to each of the inner surface 5a, the outer surface 5b, and the first side surface 5c. The pocket 53 is not open to the second side surface 5d. One rolling element 4 is arranged in one pocket 53.

[0025] Fig. 3 is a cross-sectional view of the cage 5 cut along a plane perpendicular to the axial direction. As shown in Fig. 3, the inner surface 530 of the pocket 53 includes a first region 531 and a second region 532. The first region 531 is a radially outer region of the inner surface 530 of the pocket 53, and the second region 532 is a radially inner region of the inner surface 530 of the pocket 53. In other words, the second region 532 is located radially inner with respect to the first region 531. The first region 531 and the second region 532 are connected to each other.

[0026] The first region 531 is open to each of the outer surface 5b and the first side surface 5c (see FIG. 2). The first region 531 has a concavely curved curved shape when viewed from the radial direction and a concavely curved curved shape when viewed from the axial direction. That is, the first region 531 has a concavely curved curved shape in both a cross section parallel to the circumferential direction and a cross section perpendicular to the axial direction. The first region 531 is formed by a three-dimensional curved surface. In this embodiment, the first region 531 is a three-dimensional curved surface with the axis L as the center line.

[0027] In this embodiment, the first region 531 is formed by a concavely curved ellipsoid. The first region 531 is a part of the ellipsoid. The ellipticity of the first region 531 is, for example, 1. In other words, the first region 531 is a part of a sphere. In this embodiment, the first region 531 widens and then narrows as it moves from the inner side in the radial direction to the outer side in the radial direction.

[0028] The second region 532 is open to each of the inner surface 5a and the first side surface 5c (see FIG. 2). The second region 532 has a concavely curved shape when viewed in the radial direction and a straight line when viewed in the axial direction. That is, the second region 532 has a concavely curved shape in a cross section parallel to the circumferential direction and a straight line in a cross section perpendicular to the axial direction. The second region 532 is, for example, a part of a conical surface.

[0029] The second region 532 protrudes inward from the first region 531 at least in the circumferential direction. In this embodiment, the second region 532 extends continuously around the entire circumference of the first region 531 when viewed in the radial direction. The second region 532 protrudes from the first region 531 so as to approach the axis L as it moves inward in the radial direction. The second region 532 narrows from the outer side in the radial direction to the inner side in the radial direction.

[0030] The second region 532 is located inside the extension plane of the first region 531. The second region 532 intersects with the first region 531. An intersection line 533 between the first region 531 and the second region 532 has a circular shape centered on the axis L. The radius of curvature of the boundary between the first region 531 and the second region 532 is infinitesimal.

[0031] The second region 532 intersects with the inner surface 5a. An intersection line 534 between the second region 532 and the inner surface 5a has a circular shape centered on the axis L. The diameter of the intersection line 534 is smaller than the diameter of the intersection line 533. The diameter of the intersection line 534 is smaller than the diameter of a virtual intersection line 535 when the first region 531 intersects with the inner surface 5a.

[0032] In a cross section perpendicular to the axial direction, the angle between the contact point between the rolling element 4 and the second region 532 and the line passing through the center of the rolling element 4, and the line perpendicular to the axis L is larger than the friction angle corresponding to the friction coefficient between the rolling element 4 and the second region 532. This reduces the frictional force between the rotating rolling element 4 and the second region 532, thereby suppressing deformation of the column portion 52 caused by the frictional force. Therefore, abnormal noise caused by vibration of the column portion 52 is suppressed.

[0033] As described above, in the rolling bearing 1, the inner surface 530 of the pocket 53 includes the second region 532 that protrudes inward from the first region 531 at least in the circumferential direction. This allows the rotating rolling elements 4 to be held by the second region 532, and noise caused by vibration of the cage 5 can be suppressed. Moreover, the inner surface 530 of the pocket 53 includes the first region 531 that has a concavely curved curved shape when viewed from the radial direction and also has a concavely curved curved shape when viewed from the axial direction. This makes it easier to manufacture the cage 5 by axial draw, compared to when the inner surface 530 of the pocket 53 has a straight shape when viewed from the axial direction. Therefore, the rolling bearing 1 can achieve both suppression of noise and improvement of productivity. According to the axial draw, multiple inserts can be efficiently extracted along the axial direction from multiple pockets 53 in a single extraction operation. Therefore, compared to, for example, a radial draw in which multiple inserts are extracted one by one along the radial direction from multiple pockets 53, it is possible to realize both improved production efficiency of the cage 5 and reduced production costs of the cage 5.

[0034] The first region 531 is a part of a spherical surface. The axial draw tends to be easier as the inner surface 530 of the pocket 53 becomes closer to a spherical surface. In this embodiment, since the first region 531 is a part of a spherical surface, it becomes even easier to manufacture the cage 5 by the axial draw.

[0035] The second region 532 has a concavely curved shape when viewed in the radial direction and a straight shape when viewed in the axial direction, so that the rotating rolling elements are appropriately held by the second region 532 and abnormal noise caused by vibration of the cage 5 can be appropriately suppressed.

[0036] Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment.

[0037] In the embodiment, an example has been shown in which the first region 531 widens and then narrows as it moves from the radially inner side to the radially outer side, but as shown in Fig. 4, the first region 531 may widen as it moves toward the radially outer side. The first region 531 may be formed by an elliptical surface having an ellipticity greater than 1. The first region 531 may be a part of a region located radially inward of a minor axis perpendicular to the axis L, of an elliptical surface having the axis L as its major axis. The first region 531 may be a part of a paraboloid. In these cases as well, the cage 5 can be easily manufactured by axial draw.

[0038] As shown in FIG. 5, the second region 532 may include a base surface 532a and a curved surface 532b that is curved convexly. The base surface 532a may be, for example, a part of a cone surface. The curved surface 532b protrudes from the first region 531 and the base surface 532a when viewed from the radial direction. The curved surface 532b has, for example, a curved convex shape in a cross section perpendicular to the axial direction. The curved surface 532b has an annular shape with the axis L as the center line. The curved surface 532b is, for example, a part of a torus surface. In this case, too, since the second region 532 protrudes from the first region 531 when viewed from the radial direction, abnormal noise caused by vibration of the cage 5 is suppressed. In addition, when the rolling element 4 is arranged in the pocket 53, a gap exists between the rolling element 4 and the base surface 532a, so that the inflow of a lubricant (for example, grease, etc.) between the rolling element 4 and the inner surface 530 of the pocket 53 is promoted. Furthermore, the position in the pocket 53 with which the rolling element 4 comes into contact is stabilized. When the curved surface 532b protrudes from the first region 531 when viewed in the radial direction, the base surface 532a may be an extension of the first region 531.

[0039] In a cross section perpendicular to the axial direction, the angle between the contact point between the rolling element 4 and the curved surface 532b and the line passing through the center of the rolling element 4 and the line perpendicular to the axis L is larger than the friction angle corresponding to the friction coefficient between the rolling element 4 and the curved surface 532b. In this case as well, the friction force between the rotating rolling element 4 and the curved surface 532b is reduced, so that deformation of the column portion 52 caused by the friction force is suppressed. Therefore, abnormal noise caused by vibration of the column portion 52 is suppressed.

[0040] As shown in FIG. 6, the first region 531 may include a base surface 531a and a convexly curved curved surface 532b, similar to the second region 532. The base surface 531a has a concavely curved curved shape when viewed from the radial direction, and has a concavely curved curved shape when viewed from the axial direction. The curved surface 531b protrudes from the base surface 531a when viewed from the radial direction. The curved surface 531b has, for example, a convexly curved curved shape in a cross section perpendicular to the axial direction. The curved surface 531b has a circular ring shape with the axis L as the center line. The curved surface 531b is, for example, a part of a torus surface.

[0041] In the embodiment, an example in which the second region 532 is a part of a conical surface has been shown, but the second region 532 may be, for example, a part of an elliptical surface that is concavely curved. The ellipticity of the second region 532 may be greater than 1. In this case, the second region 532 has an axis L that is parallel to the radial direction and passes through the center of the first region 531 as its minor axis or major axis. In such a case, not only the first region 531 but also the second region 532 presents a concavely curved curved shape when viewed from the radial direction and a concavely curved curved shape when viewed from the axial direction, which facilitates the manufacture of the cage 5 by axial draw.

[0042] In the embodiment, an example has been shown in which the second region 532 is located radially inward relative to the first region 531, but the second region 532 may be located radially outward relative to the first region 531. The second region 532 may be located both radially inward and outward relative to the first region 531. It is sufficient that the second region 532 is located at least on the radial inner side or the radial outer side relative to the first region 531.

[0043] In the embodiment, an example has been shown in which the second region 532 extends continuously around the entire circumference of the first region 531 when viewed in the radial direction, but the second region 532 only needs to protrude inward from the first region 531 at least in the circumferential direction. The second region 532 does not have to protrude inward from the first region 531 in, for example, the axial direction. [Explanation of symbols]

[0044] 4... rolling element, 5... cage, 51... ring portion, 52... column portion, 53... pocket, 530... inner surface, 531... first region, 532... second region, 532b... curved surface.

Claims

1. With the inner circle, The outer ring and A plurality of rolling elements disposed between the inner ring and the outer ring; a cage that holds the plurality of rolling elements, The cage includes an annular ring portion and a plurality of pillar portions protruding from the ring portion to one side in the axial direction and arranged along a circumferential direction, A pocket is formed between adjacent ones of the plurality of column portions, in which one rolling element of the plurality of rolling elements is disposed, The inner surface of the pocket includes a first region and a second region located at least one of a radial inner side and an radial outer side of the first region, The first region has a curved shape that is concavely curved when viewed in a radial direction and has a curved shape that is concavely curved when viewed in an axial direction, The second region protrudes inward from the first region at least in the circumferential direction.

2. The rolling bearing according to claim 1 , wherein the first region is a part of a spherical surface.

3. The second region is located radially inward relative to the first region, The rolling bearing according to claim 1 , wherein the first region widens radially outward.

4. 2. The rolling bearing according to claim 1, wherein the second region has a concavely curved shape when viewed in the radial direction and a straight shape when viewed in the axial direction.

5. The rolling bearing according to claim 1 , wherein the second region includes a convexly curved surface.

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