bearings

Abstract

To provide a bearing capable of suppressing the breakage of a separator.SOLUTION: A bearing is equipped with a first raceway member that has an annular first raceway surface on an outer peripheral surface, a second raceway member that has an annular second raceway surface opposite the first raceway surface on an inner peripheral surface, a plurality of cylindrical rollers disposed and aligned in a circumferential direction so as to contact with the first raceway surface and the second raceway surface in an annular rolling path along the first raceway surface and the second raceway surface, and a separator that is disposed adjacent to the cylindrical rollers in the circumferential direction. The separator has a cylindrical shape. The separator has an annular groove regulated by a groove wall surface with an arc-shape in a cross-section including a center axis, on an outer peripheral surface. The separator is disposed so that the groove wall surface contacts with an outer peripheral surface of the cylindrical roller adjacent in the circumferential direction. A curvature radius of the groove wall surface is larger than a curvature radius of the outer peripheral surface.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to bearings. [Background technology]

[0002] Conventionally, there has been known a bearing that includes an inner ring having an inner raceway surface on its outer peripheral surface, an outer ring having an outer raceway surface facing the inner raceway surface on its inner peripheral surface, a plurality of rolling elements arranged circumferentially in annular rolling paths along the inner raceway surface and the outer raceway surface, and separators arranged between adjacent rolling elements in the circumferential direction. This type of technology is disclosed, for example, in Patent Document 1 and Patent Document 2.

[0003] Patent Document 1 discloses a cross roller bearing in which rollers and separators, which are rolling elements, are arranged alternately in the circumferential direction in the rolling path. Patent Document 2 discloses a ball bearing in which balls and cylindrical separators, which are rolling elements, are arranged alternately in the circumferential direction in the rolling path. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-287587 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-22864 Summary of the Invention [Problem to be solved by the invention]

[0005] In the bearings disclosed in Patent Documents 1 and 2, damage such as indentations may occur on the surface of the separator due to contact with the rolling elements. Therefore, conventional bearings have room for improvement in terms of suppressing damage to the separator due to contact with the rolling elements.

[0006] An object of the present disclosure is to provide a bearing that can suppress damage to the separator. [Means for solving the problem]

[0007] A bearing according to the present disclosure includes a first raceway member having an annular first raceway surface on its outer peripheral surface, a second raceway member having an annular second raceway surface on its inner peripheral surface that faces the first raceway surface, a plurality of cylindrical rollers arranged circumferentially in contact with the first raceway surface and the second raceway surface in an annular rolling path along the first raceway surface and the second raceway surface, and a separator arranged circumferentially adjacent to the cylindrical rollers. The separator has a cylindrical shape. The separator has an annular groove formed on its outer peripheral surface, the groove groove being defined by a groove wall surface that has an arc-shaped cross section including the central axis. The separator is arranged so that the groove wall surface contacts the outer peripheral surface of a circumferentially adjacent cylindrical roller. The radius of curvature of the groove wall surface is greater than the radius of curvature of the outer peripheral surface. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a bearing that can suppress damage to the separator. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing the overall configuration of a bearing according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along the radial direction of the bearing according to the embodiment. [Figure 3] FIG. 3 is a perspective view showing a state in which a second raceway member is removed from the bearing according to the embodiment. [Figure 4] FIG. 4 is a perspective view showing the overall configuration of the separator according to the embodiment. [Figure 5] FIG. 5 is a cross-sectional view including the central axis of the separator according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Outline of the embodiment] A bearing according to the present disclosure includes a first raceway member having an annular first raceway surface on its outer peripheral surface, a second raceway member having an annular second raceway surface on its inner peripheral surface that faces the first raceway surface, a plurality of cylindrical rollers arranged circumferentially in contact with the first raceway surface and the second raceway surface in an annular rolling path along the first raceway surface and the second raceway surface, and a separator arranged circumferentially adjacent to the cylindrical rollers. The separator has a cylindrical shape. The separator has an annular groove formed on its outer peripheral surface, the groove groove being defined by a groove wall surface that has an arc-shaped cross section including the central axis. The separator is arranged so that the groove wall surface contacts the outer peripheral surface of a circumferentially adjacent cylindrical roller. The radius of curvature of the groove wall surface is greater than the radius of curvature of the outer peripheral surface.

[0011] In the above-described bearing, the radius of curvature of the separator groove wall surface is larger than the radius of curvature of the cylindrical roller outer peripheral surface. Therefore, compared to when the radius of curvature of the groove wall surface is the same as the radius of curvature of the outer peripheral surface, damage such as indentations to the separator groove wall surface due to contact with the cylindrical roller can be suppressed. Therefore, with the above-described bearing, it is possible to suppress breakage of the separator compared to conventional bearings.

[0012] In the bearing, the separator may include, in a cross section including the central axis, a first corner and a second corner located on a diagonal line of the separator relative to the first corner. In the cross section of the separator including the central axis, the length of the diagonal line may be equal to or greater than the outer diameter of the separator. With this configuration, the separator can be prevented from tipping over, compared to when the length of the diagonal line is less than the outer diameter of the separator.

[0013] In the above-described bearing, the first raceway surface may include a first contact surface with which the outer peripheral surface of the cylindrical roller contacts, and a second contact surface with which the end face of the cylindrical roller contacts, continuing to the first contact surface at the inner diameter end of the first contact surface, and perpendicular to the first contact surface. The second raceway surface may include a third contact surface with which the outer peripheral surface of the cylindrical roller contacts, and a fourth contact surface with which the end face of the cylindrical roller contacts, continuing to the third contact surface at the inner diameter end of the third contact surface, and perpendicular to the third contact surface. Cylindrical rollers may be arranged on both circumferential sides of the separator. The separator may be sandwiched between the cylindrical rollers arranged on both circumferential sides so as to contact the groove wall surfaces, so that the outer peripheral surface faces the fourth contact surface and is spaced apart from the second contact surface, and a first end face in the direction of extension of the central axis faces the first contact surface, and a second end face opposite the first end face faces the third contact surface. This configuration can suppress wear of the separator due to contact with the raceway surface.

[0014] In the above bearing, the plurality of cylindrical rollers may be arranged to form a plurality of rows spaced apart in the width direction.

[0015] [Specific example of embodiment] Next, specific embodiments of the bearing of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and the description thereof will not be repeated.

[0016] First, the configuration of a bearing 1 according to this embodiment will be described with reference to Figs. 1 to 5. Fig. 1 is a perspective view showing the overall configuration of the bearing 1. Fig. 2 is a cross-sectional view of the bearing 1 taken along the radial direction D2. Fig. 3 is a perspective view showing the bearing 1 with the second raceway member 20 (outer ring) removed. Fig. 4 is a perspective view showing the overall configuration of the separator 40. Fig. 5 is a cross-sectional view including the central axis of the separator 40.

[0017] The bearing 1 is a rolling bearing that includes a plurality of cylindrical rollers 30 as rolling elements. As shown in Fig. 1, the bearing 1 according to this embodiment mainly includes a first raceway member 10 (inner ring) having an annular shape, and a second raceway member 20 (outer ring) that has an annular shape with a larger diameter than the first raceway member 10 and surrounds the first raceway member 10. The length of the first raceway member 10 in the width direction D1 is approximately the same as the length of the second raceway member 20 in the width direction D1.

[0018] As shown in Fig. 2, the first raceway member 10 has an annular first inner peripheral surface 11 and an annular first outer peripheral surface 12 facing away from the first inner peripheral surface 11 in the radial direction D2. The first raceway member 10 has an annular first raceway surface 13 on the first outer peripheral surface 12. In this embodiment, a plurality (two) of the first raceway surfaces 13 are formed spaced apart from each other in the width direction D1, but this is not limiting. The first raceway surfaces 13 may be formed in a single row.

[0019] The first raceway surface 13 includes a first contact surface 13A and a second contact surface 13B that is continuous with the first contact surface 13A at the inner diameter end of the first contact surface 13A. As shown in FIG. 2, the second contact surface 13B is perpendicular to the first contact surface 13A in a cross section taken along the radial direction D2 of the bearing 1, and together with the first contact surface 13A, defines a V-shaped groove. The first contact surface 13A and the second contact surface 13B are connected at the bottom of the groove. As shown in FIG. 2, the first contact surface 13A and the second contact surface 13B in this embodiment are inclined at an angle of approximately 45° with respect to both the width direction D1 and the radial direction D2 in a cross section taken along the radial direction D2 of the bearing 1. The outer peripheral surface of the cylindrical roller 30 contacts the first contact surface 13A. The second contact surface 13B is in contact with a first end face of the cylindrical roller 30 in the direction in which the first center axis A1 (rolling axis) extends.

[0020] 2, the second raceway member 20 has an annular second inner peripheral surface 21 and an annular second outer peripheral surface 22 that faces away from the second inner peripheral surface 21 in the radial direction D2. The second raceway member 20 has an annular second raceway surface 23 on the second inner peripheral surface 21. The second raceway surface 23 surrounds the first raceway surface 13 and faces the first raceway surface 13 in the radial direction D2.

[0021] The second raceway surface 23 has a third contact surface 23A and a third contact surface 23A. outside and a fourth contact surface 23B that is continuous with the third contact surface 23A at the radial end. As shown in FIG. 2, the fourth contact surface 23B is perpendicular to the third contact surface 23A in a cross section taken along the radial direction D2 of the bearing 1, and together with the third contact surface 23A, defines a V-shaped groove. The third contact surface 23A and the fourth contact surface 23B are connected at the bottom of the groove. As shown in FIG. 2, the third contact surface 23A and the fourth contact surface 23B in this embodiment are inclined at an angle of approximately 45° with respect to both the width direction D1 and the radial direction D2 in a cross section taken along the radial direction D2 of the bearing 1. The third contact surface 23A is in contact with the outer circumferential surface of the cylindrical roller 30. The fourth contact surface 23B is in contact with a second end face (an end face opposite to the first end face) of the cylindrical roller 30 in the direction in which the first center axis A1 extends.

[0022] 2, the third contact surface 23A in this embodiment is parallel to the first contact surface 13A in a cross section taken along the radial direction D2 of the bearing 1. On the other hand, the fourth contact surface 23B in this embodiment is parallel to the second contact surface 13B in a cross section taken along the radial direction D2 of the bearing 1.

[0023] Between the first raceway member 10 and the second raceway member 20, an annular rolling path (space) is formed along the first raceway surface 13 and the second raceway surface 23. As shown in Fig. 2, the bearing 1 is provided with a plurality of cylindrical rollers 30 arranged in the circumferential direction so as to come into contact with the first raceway surface 13 and the second raceway surface 23 in the rolling path.

[0024] Cylindrical roller 30 includes an imaginary first center axis A1, and includes an annular outer peripheral surface 30A that surrounds first center axis A1. As shown in Fig. 2, first center axis A1 of cylindrical roller 30 in this embodiment is inclined at an angle of approximately 45° with respect to both width direction D1 and radial direction D2 in a cross section taken along radial direction D2 of bearing 1.

[0025] In this embodiment, the multiple cylindrical rollers 30 are arranged to form multiple rows (first annular row and second annular row) spaced apart in the width direction D1. In each annular row, the first central axes A1 of the multiple cylindrical rollers 30 face the same direction. Meanwhile, as shown in FIG. 2, in a cross section taken along the radial direction D2 of the bearing 1, the first central axes A1 of the cylindrical rollers 30 constituting the first annular row (the cylindrical rollers 30 on the left side in FIG. 2, hereinafter also referred to as "first cylindrical rollers") are perpendicular to the first central axes A1 of the cylindrical rollers 30 constituting the second annular row (the cylindrical rollers 30 on the right side in FIG. 2, hereinafter also referred to as "second cylindrical rollers"). More specifically, the first contact surface 13A with which the outer circumferential surface of the first cylindrical roller comes into contact (the first contact surface 13A on the left side in FIG. 2) is perpendicular to the first contact surface 13A with which the outer circumferential surface of the second cylindrical roller comes into contact (the first contact surface 13A on the right side in FIG. 2).

[0026] The bearing 1 further comprises a plurality of separators 40 arranged adjacent to the cylindrical rollers 30 in the circumferential direction (Fig. 3). As shown in Fig. 3, the cylindrical rollers 30 and separators 40 in this embodiment are arranged alternately over the entire circumferential direction of the first outer peripheral surface 12. In other words, a cylindrical roller 30 is arranged on each side of a separator 40 in the circumferential direction. As shown in Fig. 3, the cylindrical rollers 30 and separators 40 that are adjacent in the circumferential direction are arranged with their central axes perpendicular to each other and in contact with each other.

[0027] As shown in FIGS. 4 and 5, the separator 40 has a cylindrical shape and includes an imaginary second center axis A2 and an annular outer peripheral surface 43 that surrounds the second center axis A2. The separator 40 in this embodiment is smaller than the cylindrical rollers 30 in both the radial and axial directions. As shown in FIG. 5, a first recess 41 and a second recess 42 are formed on both end surfaces of the separator 40 in the axial direction D3. The first recess 41 and the second recess 42 in this embodiment have a circular shape when viewed in the axial direction D3. As shown in FIG. 5, the bottoms of the first recess 41 and the second recess 42 in this embodiment are located closer to the end faces than the center of the separator 40 in the axial direction D3, but this is not limited to this. As shown in FIG. 3, the separator 40 contacts the outer peripheral surface 30A of the cylindrical roller 30 that is adjacent in the circumferential direction, and is arranged so that the second center axis A2 (FIG. 4) is perpendicular to the first center axis A1 (FIG. 2) of the cylindrical roller 30 that is adjacent in the circumferential direction. The "cylindrical shape" of the separator may have recesses formed on the end surfaces as in the present embodiment, or may have no recesses. The wall surfaces of the first recess 41 and the second recess 42 may be tapered, and the bottom surfaces of the first recess 41 and the second recess 42 may be hemispherical. The first recess 41 and the second recess 42 may be connected to each other in the axial direction D3.

[0028] 4 and 5, separator 40 has an annular groove 47 formed in its outer peripheral surface 43. The groove wall surface 46 defines an arc-shaped groove that bulges inward in the radial direction D4 in a cross section including second center axis A2. In this embodiment, groove wall surface 46 is a toroidal surface. Separator 40's outer peripheral surface 43 includes a first annular surface 44, a second annular surface 45, and groove wall surface 46 located between first annular surface 44 and second annular surface 45 in the axial direction D3.

[0029] The first annular surface 44 and the second annular surface 45 are annular surfaces surrounding the second central axis A2. As shown in FIG. 5, in a cross section including the second central axis A2, the first annular surface 44 and the second annular surface 45 are parallel to the axial direction D3. In a cross section including the second central axis A2, the bottom of the groove wall surface 46 is located more inward in the radial direction D4 than the first annular surface 44 and the second annular surface 45. The groove wall surface 46 is formed over the entire circumferential direction of the separator 40. As shown in FIG. 3, the separator 40 is arranged such that the outer peripheral surface 43 faces the outer peripheral surface 30A of the cylindrical roller 30 and the groove wall surface 46 contacts the outer peripheral surface 30A of the cylindrical roller 30 adjacent in the circumferential direction.

[0030] 5 shows an imaginary circle C1, of which the groove wall surface 46 forms a portion of the circumference. The radius of curvature r1 of the groove wall surface 46 in a cross section of the separator 40 including the second center axis A2 is larger than the radius of curvature r2 (FIG. 3) of the outer peripheral surface 30A of the cylindrical roller 30. The radius of curvature r1 of the groove wall surface 46 is approximately constant over the entire circumferential direction of the separator 40. For this reason, the outer peripheral surface 30A of the cylindrical roller 30 does not contact the entire groove wall surface 46 of the separator 40, but only partially.

[0031] As shown in FIG. 5, the separator 40 includes a first corner 40A and a second corner 40B located on a diagonal line L1 of the separator 40 relative to the first corner 40A in a cross section including the second center axis A2. In this embodiment, in a cross section of the separator 40 including the second center axis A2, the length of the diagonal line L1 is equal to or greater than the outer diameter L2 of the separator 40. Here, the "outer diameter L2" refers to the maximum diameter of the separator 40, i.e., the outer diameter of the first annular surface 44 or the second annular surface 45. From another perspective, the separator 40 has a size larger than the tumbling size (the size at which the separator 40 can rotate 90° or more in the cross section of FIG. 2) when disposed between two cylindrical rollers 30. Furthermore, the separator 40 may have a size that is 1.1 times or less in both the radial and axial directions of the tumbling size between the two cylindrical rollers 30. As shown in FIG. 5, in a cross section of the separator 40 including the second central axis A2, the diagonal line L1 does not pass through either the first recess 41 or the second recess .

[0032] 3, separator 40 is sandwiched between cylindrical rollers 30 arranged on both sides in the circumferential direction so as to be in contact with groove wall surfaces 46. As a result, as shown in FIG. 2, separator 40 has an outer peripheral surface facing fourth contact surface 23B and spaced apart from second contact surface 13B, a first end face in the direction in which the central axis (cylinder axis) extends facing first contact surface 13A, and a second end face opposite to the first end face facing third contact surface 23A.

[0033] As described above, in the bearing 1 according to this embodiment, the radius of curvature r1 of the groove wall surface 46 of the separator 40 is larger than the radius of curvature r2 of the outer peripheral surface 30A of the cylindrical roller 30. Therefore, compared to when the radius of curvature r1 of the groove wall surface 46 is the same as the radius of curvature r2 of the outer peripheral surface 30A of the cylindrical roller 30, it is possible to prevent damage such as indentations from occurring on the groove wall surface 46 of the separator 40 due to contact with the cylindrical roller 30. Therefore, the bearing 1 according to this embodiment can prevent breakage of the separator 40. Moreover, by employing separators 40 that are smaller in size than the cylindrical rollers 30, the bearing 1 according to this embodiment can increase the number of cylindrical rollers 30. This also makes it possible to improve the load-bearing performance of the bearing 1.

[0034] Here, other embodiments will be described.

[0035] In the above embodiment, the first raceway member 10 has an annular shape, but this is not limiting. For example, the first raceway member may be a stud. In other words, the bearing of the present disclosure can also be applied to a cam follower.

[0036] In the bearing 1 according to the above embodiment, an insertion port for inserting the cylindrical rollers 30 into the rolling paths formed between the first raceway surface 13 and the second raceway surface 23 may be formed to penetrate the second raceway member 20 in the radial direction D2. In this case, this insertion port is closed by a cover member (not shown). This cover member may also be fixed to the second raceway member 20 by a fixing member such as a pin.

[0037] In the above embodiment, the case where the cylindrical rollers 30 and the separators 40 are alternately arranged around the entire circumference of the raceway has been described as an example, but the present invention is not limited to this. For example, a plurality of separators 40 may be arranged between two cylindrical rollers 30 lined up in the circumferential direction.

[0038] In the above embodiment, the case where the outer peripheral surface 43 of the separator 40 includes not only the groove wall surface 46 but also the first annular surface 44 and the second annular surface 45 has been described as an example, but the present invention is not limited to this. For example, the entire outer peripheral surface 43 of the separator 40 may be the groove wall surface 46.

[0039] In the above embodiment, the case where the length of the diagonal line L1 of the separator 40 is equal to or greater than the outer diameter L2 of the separator 40 has been described as an example, but this is not limiting. The length of the diagonal line L1 may be equal to or less than the outer diameter L2. Furthermore, in the separator 40, one or both of the first recess 41 and the second recess 42 may be omitted.

[0040] The embodiments disclosed herein are illustrative in all respects and should not be construed as limiting. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0041] 1 bearing, 10 first raceway member, 11 first inner peripheral surface, 12 first outer peripheral surface, 13 first raceway surface, 13A first contact surface, 13B second contact surface, 20 second raceway member, 21 second inner peripheral surface, 22 second outer peripheral surface, 23 second raceway surface, 23A third contact surface, 23B fourth contact surface, 30 cylindrical rollers, 30A, 43 Outer surface, 40 Separator, 40A First corner portion, 40B Second corner portion, 41 First recess portion, 42 Second recess portion, 44 First annular surface, 45 Second annular surface, 46 Groove wall surface, 47 Groove, A1 First central axis, A2 Second central axis, C1 Circle, D1 Width direction, D2, D4 Radial direction, D3 Axial direction, L1 Diagonal line, L2 Outer diameter, r1, r2 Radius of curvature.

Claims

1. a first raceway member having an annular first raceway surface on its outer circumferential surface; a second raceway member having an annular second raceway surface on its inner circumferential surface that faces the first raceway surface; a plurality of cylindrical rollers arranged side by side in a circumferential direction in an annular rolling path along the first raceway surface and the second raceway surface so as to contact the first raceway surface and the second raceway surface; a separator disposed adjacent to the cylindrical roller in the circumferential direction, The separator has a cylindrical shape, The separator has an annular groove formed on its outer peripheral surface, the groove wall surface having an arc-shaped cross section including the central axis, the separator is disposed so that the groove wall surface comes into contact with the outer circumferential surface of the cylindrical roller adjacent in the circumferential direction, a radius of curvature of the groove wall surface is larger than a radius of curvature of the outer peripheral surface of the cylindrical roller, The first orbital surface is a first contact surface with which an outer peripheral surface of the cylindrical roller comes into contact; a second contact surface with which an end face of the cylindrical roller comes into contact, which is continuous with the first contact surface at an inner diameter side end of the first contact surface and is perpendicular to the first contact surface, The second orbital surface is a third contact surface with which the outer peripheral surface of the cylindrical roller comes into contact; a fourth contact surface with which an end face of the cylindrical roller comes into contact, which is continuous with the third contact surface at an inner diameter side end of the third contact surface, and which is perpendicular to the third contact surface, the cylindrical rollers are disposed on both sides of the separator in the circumferential direction, the separator is sandwiched between the cylindrical rollers arranged on both sides in the circumferential direction so as to come into contact with the groove wall surfaces, so that the outer circumferential surface faces the fourth contact surface and is spaced apart from the second contact surface, so that a first end surface in the direction in which the central axis extends faces the first contact surface and a second end surface opposite to the first end surface faces the third contact surface; Bearings.

2. The separator has a cross section including the central axis, A first corner portion; a second corner portion located on a diagonal line of the separator relative to the first corner portion, 2. The bearing according to claim 1, wherein in a cross section of the separator that includes the central axis, the length of the diagonal is equal to or greater than the outer diameter of the separator.

3. 3. The bearing according to claim 1, wherein the plurality of cylindrical rollers are arranged to form a plurality of rows spaced apart in the width direction.

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