Rolling bearing, rotating equipment, and method for manufacturing a rolling bearing

Abstract

In rolling bearings equipped with solid lubricants, the increase in rotational torque is suppressed over a long period of time. [Solution] The rolling bearing 1 comprises an inner ring 10 and an outer ring 20 arranged coaxially with respect to each other, rolling elements 30 disposed between the inner ring 10 and the outer ring 20, an annular cage 40 disposed between the inner ring 10 and the outer ring 20 to hold the rolling elements 30 so as to be able to roll, and a solid lubricant 60 disposed between the inner ring 10 and the outer ring 20, in which lubricating oil is held by a solidified resin material. The outer ring 20 has an inner circumferential surface 22b facing the inner ring 10. The inner circumferential surface 22b has an outer ring raceway surface 23 that supports the rolling elements 30 so as to be able to roll, and an adjacent surface 28 that extends axially outward from the axial edge of the outer ring raceway surface 23. The solid lubricant 60 is in contact with a recess 24 formed on the adjacent surface 28.

Description

Technical Field

[0006] , ,

[0005] , , ,

[0001] The present invention relates to a rolling bearing, a rotating device, and a method for manufacturing a rolling bearing.

Background Art

[0002] Conventionally, there is a rolling bearing that holds grease between a pair of raceway rings (inner ring and outer ring). Since an additive for semi-solidifying lubricating oil is used in the grease, the rotational torque of the rolling bearing may increase due to the stirring resistance of the grease. However, in a rolling bearing, low torque is desired for the purpose of power saving of the rotating device to be mounted. In particular, in a small rolling bearing used in various motors such as a fan motor, there is a strong demand for low torque.

[0003] As a means for reducing the rotational torque of a rolling bearing, instead of applying grease, there is a method of disposing a solid lubricant inside the bearing. For example, Patent Document 1 and Patent Document 2 disclose a technique of disposing a solid lubricant formed of a mixture of grease and ultra-high molecular weight polyolefin particles inside a rolling bearing. [[ID=十七]]

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when a solid lubricant is disposed inside a rolling bearing, the solid lubricant may be displaced during use of the rolling bearing and come into contact with rolling elements or the like, causing an increase in the rotational torque of the rolling bearing.

[0006] Therefore, the present invention provides a rolling bearing equipped with a solid lubricant that suppresses the increase in rotational torque over a long period of time. Furthermore, it provides a rotating device equipped with the rolling bearing and a method for manufacturing the rolling bearing. [Means for solving the problem]

[0007] A rolling bearing according to a first aspect of the present invention comprises an inner ring and an outer ring arranged coaxially with respect to each other, rolling elements disposed between the inner ring and the outer ring, an annular cage disposed between the inner ring and the outer ring for rotatably holding the rolling elements, and a solid lubricant disposed between the inner ring and the outer ring, in which lubricating oil is held by a solidified resin material, wherein one of the inner ring and the outer ring has a circumferential surface facing the other raceway, and the circumferential surface has a raceway surface for rotatably supporting the rolling elements and an adjacent surface extending outward in the axial direction from the axial edge of the raceway surface, and the solid lubricant is in contact with the adjacent surface and a recess formed in one of the cage.

[0008] According to the first embodiment, since the solid lubricant is placed on the circumferential surface of one of the raceways or in the cage, the lubricating oil seeping from the solid lubricant is supplied to the sliding part, thereby reducing the rotational torque of the rolling bearing. Furthermore, since the solid lubricant is in contact with the recess, the solid lubricant is less likely to shift position during use of the rolling bearing. This suppresses contact between the solid lubricant and the rolling elements. Therefore, it is possible to provide a rolling bearing that can suppress the increase in rotational torque over a long period of time.

[0009] Furthermore, in conventional technology, it was necessary to demold the solid lubricant, which had been solidified and molded in a mold beforehand, before installing it in the rolling bearing. In contrast, according to the first embodiment, as a method for forming the solid lubricant, a mixture of the solid lubricant before solidification can be applied to the recess and then solidified. This makes it possible to position the solid lubricant in a predetermined location even when it is difficult to place the solidified solid lubricant inside the rolling bearing.

[0010] A rolling bearing according to a second aspect of the present invention is a rolling bearing according to the first aspect described above, wherein the recess may be formed on the adjacent surface.

[0011] If the solid lubricant placed on the adjacent surface is not in contact with the recess, the solid lubricant placed on the adjacent surface is prone to axial displacement. According to the second embodiment, the solid lubricant placed on the adjacent surface engages with the recess, restricting axial displacement. Therefore, the above effects can be effectively achieved.

[0012] A rolling bearing according to a third aspect of the present invention is a rolling bearing according to the second aspect described above, wherein the solid lubricant may be in contact with a portion of the recess that is inclined outward in the axial direction with respect to the radial direction.

[0013] According to the third embodiment, the portion of the recess that is inclined outward in the axial direction with respect to the radial direction restricts the displacement of the solid lubricant inward in the axial direction. This effectively suppresses the displacement of the solid lubricant from its initial position inward in the axial direction and its proximity to the rolling elements during repeated use of the rolling bearing.

[0014] A rolling bearing according to a fourth aspect of the present invention is a rolling bearing according to the second or third aspect described above, wherein the recess may have a portion that is inclined inward in the axial direction with respect to the radial direction.

[0015] According to the fourth embodiment, the portion of the recess that is inclined inward in the axial direction with respect to the radial direction restricts the displacement of the solid lubricant outward in the axial direction. This makes it possible to more reliably suppress the displacement of the solid lubricant outward in the axial direction from its initial position during repeated use of the rolling bearing.

[0016] A rolling bearing according to a fifth aspect of the present invention is a rolling bearing according to any of the second to fourth aspects described above, further comprising a sealing member mounted on the inner ring or the outer ring and covering the space between the inner ring and the outer ring from the outside in the axial direction, wherein the solid lubricant may be in contact with the sealing member from the inside in the axial direction.

[0017] According to the fifth embodiment, the sealing member restricts the displacement of the solid lubricant outward in the axial direction. This makes it possible to more reliably suppress the displacement of the solid lubricant outward in the axial direction from its initial position during repeated use of the rolling bearing.

[0018] A rolling bearing according to a sixth aspect of the present invention is a rolling bearing according to any of the second to fifth aspects described above, wherein the recess may be provided at an axial distance from the raceway surface.

[0019] According to the sixth embodiment, contact between the solid lubricant in the recess and the rolling elements rolling on the raceway surface can be suppressed. This suppresses an increase in the rotational torque of the rolling bearing.

[0020] A rolling bearing according to a seventh aspect of the present invention is a rolling bearing according to any of the second to sixth aspects described above, further comprising a sealing member mounted on the inner ring or the outer ring and covering the space between the inner ring and the outer ring from the outside in the axial direction, wherein one raceway ring has a projection that protrudes toward the other raceway ring and has a circumferential surface formed thereon, the projection has an end face that faces toward the outside in the axial direction and connects to the circumferential surface at the periphery of the other raceway ring, and the recess may be provided at an axial distance from the end face.

[0021] According to the seventh embodiment, it is possible to suppress the lubricating oil contained in the solid lubricant from flowing out from the recess toward the end face and leaking out from the gap between the end face and the sealing member.

[0022] The rolling bearing according to the eighth aspect of the present invention is the rolling bearing according to any one of the second to seventh aspects, wherein the recess may continuously extend over the entire circumferential direction.

[0023] According to the eighth aspect, it is possible to make it difficult for the solid lubricant arranged along the circumferential direction to be displaced axially by the recess over its entire length. Therefore, an increase in the rotational torque of the rolling bearing can be suppressed.

[0024] The rolling bearing according to the ninth aspect of the present invention is the rolling bearing according to any one of the second to eighth aspects, wherein the solid lubricant may be in contact with a ridge portion formed at an edge on the raceway surface side of the recess.

[0025] According to the ninth aspect, since it is not necessary for the lubricating oil that has leaked out from the solid lubricant to overcome the ridge portion in the process of reaching the raceway surface, it is possible to suppress a shortage in the supply of the lubricating oil to the rolling elements.

[0026] The rolling bearing according to the tenth aspect of the present invention is the rolling bearing according to any one of the second to ninth aspects, wherein one of the raceway rings has a protruding portion that protrudes toward the other raceway ring side and on which the circumferential surface is formed, the protruding portion has an end surface that faces the outside in the axial direction and is connected to the circumferential surface at the peripheral edge on the other raceway ring side, the circumferential surface has a connecting surface formed between the recess and the end surface, and the connecting surface may be separated from the other raceway ring farther than the axial edge of the raceway surface in the radial direction.

[0027] According to the tenth embodiment, when inserting the tip of the nozzle from the outside of the rolling bearing into the inside of the outer and inner rings in order to dispense the solid lubricant mixture before it solidifies from the nozzle and apply it to a predetermined location, it is possible to make it difficult for the connection surface to come into contact with the nozzle. As a result, it becomes easier to bring the nozzle closer to the recess when applying the mixture, thereby improving productivity in small-diameter rolling bearings. In addition, because it is easier to bring the nozzle closer to the recess, the mixture can be applied with precision, and contact between the solid lubricant and the rolling elements can be suppressed. Therefore, it is possible to suppress an increase in the rotational torque of the rolling bearing.

[0028] A rolling bearing according to an eleventh aspect of the present invention is a rolling bearing according to any of the second to tenth aspects described above, wherein the circumferential surface may have an inclined portion that extends toward the raceway surface side from the end edge of the recess on the raceway surface side, inclined radially and axially.

[0029] According to the eleventh embodiment, even if the end of the recess on the raceway surface side extends radially, the circumferential surface gradually slopes from the recess toward the raceway surface, which promotes the flow of base oil seeping from the solid lubricant from the recess along the slope toward the raceway surface. Therefore, even without placing the solid lubricant close to the raceway surface, it is possible to suppress insufficient supply of lubricating oil to the rolling elements.

[0030] A rolling bearing according to a twelfth aspect of the present invention is a rolling bearing according to the eleventh aspect described above, wherein the solid lubricant may be arranged so as not to protrude from the inside of the recess toward the inclined portion in the radial direction.

[0031] According to the twelfth embodiment, contact between the solid lubricant and the rolling elements can be suppressed.

[0032] A rolling bearing according to a thirteenth aspect of the present invention is a rolling bearing according to any of the first to twelfth aspects described above, wherein the recess may be formed in the cage.

[0033] According to the 13th embodiment, if the solid lubricant placed in the retainer is not in contact with the recess, the solid lubricant placed in the retainer is prone to displacement. According to the 13th embodiment, the solid lubricant placed in the retainer engages with the recess, thereby restricting displacement. Therefore, the above effects can be effectively achieved.

[0034] A rolling bearing according to a 14th aspect of the present invention is a rolling bearing according to any of the first to 13th aspects described above, wherein the cage may be provided with a projection inserted into the solid lubricant.

[0035] According to the 14th embodiment, since the solid lubricant engages with the protrusion, displacement of the solid lubricant can be suppressed more reliably.

[0036] A rotating device according to a 15th aspect of the present invention comprises a rotatably arranged rotating body, a support that rotatably supports the rotating body, and a rolling bearing interposed between the rotating body and the support, according to any of the first to 14th aspects described above.

[0037] According to the 15th embodiment, since a rolling bearing is provided that can suppress the increase in rotational torque over a long period of time, it is possible to achieve a longer lifespan and lower power consumption for the rotating equipment.

[0038] A method for manufacturing a rolling bearing according to a sixteenth aspect of the present invention comprises an inner ring and an outer ring arranged coaxially with respect to each other, rolling elements disposed between the inner ring and the outer ring, an annular cage disposed between the inner ring and the outer ring for holding the rolling elements rotatably, and a solid lubricant disposed between the inner ring and the outer ring, wherein one of the inner ring and the outer ring has a circumferential surface facing the other raceway, and the circumferential surface has a raceway surface for supporting the rolling elements rotatably and an adjacent surface extending outward in the axial direction from the axial edge of the raceway surface, wherein the method for manufacturing a rolling bearing comprises heating a mixture of a resin material and a lubricating oil to a temperature above the gelling temperature of the resin material, then cooling and solidifying it to form the solid lubricant, and bringing the solid lubricant into contact with the adjacent surface or a recess formed in the cage.

[0039] According to the 16th embodiment, since the solid lubricant is placed on the circumferential surface of one of the raceway rings or in the cage, a rolling bearing can be manufactured in which rotational torque is reduced by supplying lubricating oil seeping from the solid lubricant to the sliding part. Furthermore, since the solid lubricant is in contact with the recess, the solid lubricant is less likely to shift position during use of the rolling bearing. As a result, a rolling bearing can be manufactured in which the increase in rotational torque caused by the solid lubricant contacting the rolling elements is suppressed over a long period of time.

[0040] A method for manufacturing a rolling bearing according to the 17th aspect of the present invention may be the method for manufacturing a rolling bearing according to the 16th aspect described above, wherein the mixture may be heated to a temperature above the gelation temperature while in contact with the recess, and then cooled to solidify.

[0041] According to the 17th embodiment, the mixture can be placed inside the rolling bearing in an unsolidified state. This makes it possible to place the solid lubricant in a predetermined position even when it is difficult to place a solidified solid lubricant inside the rolling bearing.

[0042] A method for manufacturing a rolling bearing according to the 18th aspect of the present invention is the method for manufacturing a rolling bearing according to the 16th aspect described above, wherein the recess is formed on the adjacent surface and the solid lubricant, which has been solidified in advance into a predetermined shape, is fitted into one of the raceways.

[0043] According to the 18th embodiment, since there is no need to perform the step of applying a semi-solid mixture to the inside of the rolling bearing, the manufacturing process of the rolling bearing can be simplified. In addition, the solid lubricant can be formed with precision using a mold, and contact between the solid lubricant and the rolling elements can be more reliably suppressed. [Effects of the Invention]

[0044] According to the present invention, in a rolling bearing equipped with a solid lubricant, it is possible to suppress the increase in rotational torque over a long period of time. [Brief explanation of the drawing]

[0045] [Figure 1] This is a plan view of a rolling bearing according to the first embodiment. [Figure 2] This is a longitudinal cross-sectional view along line II-II in Figure 1. [Figure 3] This is a cross-sectional view showing a retainer according to the first embodiment. [Figure 4] This is a longitudinal cross-sectional view of a rolling bearing illustrating a method for forming a solid lubricant according to the first embodiment. [Figure 5] This is a longitudinal cross-sectional view of a rolling bearing illustrating a method for forming a solid lubricant according to the first embodiment. [Figure 6] This is a longitudinal cross-sectional view of a rolling bearing according to a first modified example of the first embodiment. [Figure 7] This is a longitudinal cross-sectional view of a rolling bearing according to a second modified example of the first embodiment. [Figure 8] This is a longitudinal cross-sectional view of a rolling bearing according to the second embodiment. [Figure 9] This is a longitudinal cross-sectional view of a rolling bearing according to the third embodiment. [Figure 10] This is a longitudinal cross-sectional view of a rolling bearing according to a modified example of the third embodiment. [Figure 11] This is a longitudinal cross-sectional view of a rolling bearing according to the fourth embodiment. [Figure 12] This is a longitudinal cross-sectional view of a rolling bearing according to the first modified example of the fourth embodiment. [Figure 13] This is a longitudinal cross-sectional view of a rolling bearing according to a second modified example of the fourth embodiment. [Figure 14] This is a longitudinal cross-sectional view of a rolling bearing according to the fifth embodiment. [Figure 15] This is a longitudinal cross-sectional view of a rolling bearing according to the first modified example of the fifth embodiment. [Figure 16] This is a longitudinal cross-sectional view of a rolling bearing according to a second modified example of the fifth embodiment. [Figure 17] This is a longitudinal cross-sectional view of a rolling bearing according to the sixth embodiment. [Figure 18] This is a longitudinal cross-sectional view of a rolling bearing according to the seventh embodiment. [Figure 19] This is a longitudinal cross-sectional view of a rolling bearing according to the first modified example of the seventh embodiment. [Figure 20] This is a longitudinal cross-sectional view of a rolling bearing according to a second modified example of the seventh embodiment. [Figure 21] This is a cross-sectional view showing a retainer according to the eighth embodiment. [Figure 22] This is a cross-sectional view showing a retainer according to the ninth embodiment. [Modes for carrying out the invention]

[0046] Embodiments of the present invention will be described below with reference to the drawings. In the following description, components having the same or similar functions will be denoted by the same reference numerals. Duplication of these components may be omitted.

[0047] [First Embodiment] A first embodiment of the present invention will be described with reference to Figures 1 and 2. Figure 1 is a plan view of a rolling bearing according to the first embodiment. Figure 2 is a longitudinal cross-sectional view taken along line II-II in Figure 1. In Figure 2, the rotating equipment 2 on which the rolling bearing 1 is mounted is shown by dashed lines.

[0048] As shown in Figures 1 and 2, the rolling bearing 1 is a radial ball bearing comprising an inner ring 10 and an outer ring 20 which are raceway rings, a plurality of rolling elements 30, a cage 40, and a pair of sealing members 50. The rolling bearing 1 is installed in a rotating device 2 such as a fan motor. The rotating device 2 comprises a shaft 3 (rotating body) formed to be rotatable about a common axis O, and a housing 4 (support) which is fixedly installed and rotatably supports the shaft 3. The rolling bearing 1 is interposed between the shaft 3 and the housing 4.

[0049] The inner ring 10 and the outer ring 20 are arranged coaxially with each other such that their respective central axes coincide with the common axis O. In this embodiment, the direction in which the common axis O extends is called the axial direction, the direction perpendicular to the common axis O and extending radially from the common axis O is called the radial direction, and the direction that circles around the common axis O is called the circumferential direction. Furthermore, one of the directions parallel to the axial direction and pointing in opposite directions is defined as upward, and the other is defined as downward.

[0050] The inner ring 10 is provided as a rotating ring. The inner ring 10 is fitted onto the shaft 3 and fixed to the shaft 3. The outer ring 20 is provided as a stationary ring. The outer ring 20 is fitted into a recess (or through hole) in the housing 4 and fixed to the housing 4. The outer ring 20 surrounds the inner ring 10 from the radial outside, with an annular space between them. Multiple rolling elements 30 are arranged between the inner ring 10 and the outer ring 20 and are held in a rotatable position by a cage 40. The cage 40 rotatably holds each rolling element 30 with the multiple rolling elements 30 evenly arranged in the circumferential direction. The sealing member 50 is mounted on the outer ring 20 and covers the annular space between the inner ring 10 and the outer ring 20 from the axial outside.

[0051] The outer ring 20 is formed in an annular shape from a metallic material such as stainless steel or bearing steel. However, the outer ring 20 is not limited to metal and may be formed from other materials. The outer ring 20 has an outer ring body 21 whose width along the axial direction is equal to the width along the axial direction of the inner ring 10, and a projection 22 that protrudes radially inward from the outer ring body 21 and extends along the entire circumference. The projection 22 is formed in the part of the outer ring body 21 that is located in the axial center. The width of the projection 22 along the axial direction is shorter than the width of the outer ring body 21 along the axial direction and is larger than the outer diameter of the rolling element 30.

[0052] The projection 22 comprises a pair of end faces 22a facing outward in the axial direction, and an inner circumferential surface 22b (circumferential surface) connecting the inner edges of the pair of end faces 22a. Each end face 22a extends parallel to each other in both the radial and circumferential directions. The inner circumferential surface 22b has an outer ring raceway surface 23 that is recessed outward in the radial direction, and a pair of upper and lower adjacent surfaces 28 that extend outward in the axial direction from the axial edge of the outer ring raceway surface 23. The outer ring raceway surface 23 is formed in a hemispherical shape in cross-section so as to follow the outer surface of the rolling element 30, and is also formed in an annular shape that extends circumferentially over the entire circumference of the inner circumferential surface 22b. The outer ring raceway surface 23 is formed in the portion of the inner circumferential surface 22b located in the axial center.

[0053] The adjacent surface 28 is located between the end surface 22a and the outer ring raceway surface 23. The adjacent surface 28 is a cylindrical surface extending in the axial direction. A recess 24 is formed in the upper adjacent surface 28, recessed radially outward. The recess 24 is provided at an axial distance from the outer ring raceway surface 23. The recess 24 is provided at an axial distance from the upward-facing end surface 22a. The recess 24 extends continuously over the entire circumferential direction. The recess 24 extends in an arc shape on the longitudinal cross-section of the rolling bearing 1. For example, on the longitudinal cross-section of the rolling bearing 1, the radius of curvature of the recess 24 may be the same as the radius of curvature of the outer ring raceway surface 23, or it may be different from the radius of curvature of the outer ring raceway surface 23. Note that the recess 24 does not have to extend with a constant curvature on the longitudinal cross-section of the rolling bearing 1. The recess 24 comprises an outward-facing surface 24a that faces in a direction inclined axially outward with respect to the radial direction (radially inward and upward, or upward), and an inward-facing surface 24b that faces in a direction inclined axially inward with respect to the radial direction (radially inward and downward, or downward). The portion of the adjacent surface 28 excluding the recess 24 extends axially with a constant inner diameter.

[0054] The adjacent surface 28 includes a ridge 25 formed on the outer ring raceway surface 23 side (axially inward) edge of the recess 24. The ridge 25 may be rounded or pointed on the longitudinal cross-section of the rolling bearing 1.

[0055] The outer ring body 21 has a pair of inner circumferential surfaces 21a that extend from the outer peripheral edge of each end face 22a of the protrusion 22 to the opening edge of the outer ring 20. The portion of each inner circumferential surface 21a located axially inward is located radially outward than the portion located axially outward.

[0056] The inner ring 10 is formed in an annular shape from a metallic material such as stainless steel or bearing steel. However, the inner ring 10 is not limited to metal and may be formed from other materials. An inner ring raceway surface 11 is formed on the outer circumferential surface of the inner ring 10, which is recessed radially inward. The inner ring raceway surface 11 is formed in a hemispherical shape in cross-section, following the outer surface of the rolling element 30, and is formed in an annular shape that extends circumferentially around the entire circumference of the outer circumferential surface. The inner ring raceway surface 11 is formed in the portion of the outer circumferential surface of the inner ring 10 that is located in the axial center, and is arranged to face the outer ring raceway surface 23 radially. The portion of the outer circumferential surface of the inner ring 10 excluding the inner ring raceway surface 11 extends axially with a constant outer diameter.

[0057] As shown in Figure 2, the multiple rolling elements 30 are formed spherically from a metallic material such as stainless steel or bearing steel. The multiple rolling elements 30 are arranged between the outer ring raceway surface 23 and the inner ring raceway surface 11 and are supported so as to be able to roll by the outer ring raceway surface 23 and the inner ring raceway surface 11. The multiple rolling elements 30 are spaced apart in the circumferential direction by a cage 40.

[0058] Figure 3 is a cross-sectional view showing a retainer according to the first embodiment. As shown in Figures 2 and 3, the retainer 40 is formed in an annular shape as a whole. The retainer 40 is made of synthetic resin or metal material. The retainer 40 is arranged around a common axis O. The retainer 40 comprises a base 41 that is annular in shape and positioned below the plurality of rolling elements 30, and a plurality of columnar portions 42 that protrude upward from the base 41 and are spaced apart in the circumferential direction. The columnar portions 42 are evenly arranged in the circumferential direction. A pair of adjacent columnar portions 42 in the circumferential direction form a ball pocket B between them. The ball pocket B penetrates the retainer 40 radially and opens upward at the upper end surface 40u of the retainer 40. The ball pocket B is provided in a number corresponding to the number of rolling elements 30 and holds each rolling element 30 so that it can roll individually. As a result, the retainer 40 arranges the rolling elements 30 evenly spaced apart in the circumferential direction. The retainer 40 is positioned with a gap between it and the inner ring 10 and the outer ring 20 so as not to interfere with the inner ring 10 and the outer ring 20.

[0059] As shown in Figure 3, an upper recess 47 is formed on the upper end surface 40u of the retainer 40, which is recessed downwards. The upper recess 47 is formed between a pair of adjacent ball pockets B in the circumferential direction. That is, the upper recess 47 is formed on each column portion 42. The portion of the column portion 42 located between the upper recess 47 and the ball pocket B is designated as a claw portion 44. The pair of claw portions 44, which are arranged to sandwich each ball pocket B, rise in an arc shape so that they approach each other as they extend upwards. As a result, the claw portions 44 hold the rolling elements 30 placed in the ball pockets B from above.

[0060] A lower recess 48 is formed in the lower end surface 40l of the retainer 40, which is recessed upward. The lower recess 48 is formed in the portion of the base 41 located below the upper recess 47. However, the position of the lower recess 48 is not limited to this. The lower recesses 48 are evenly spaced apart in the circumferential direction. The lower recesses 48 open downward, as well as radially outward and inward. The lower recess 48 comprises a bottom surface 48a and a pair of side surfaces 48b. The bottom surface 48a is a flat surface perpendicular to the axial direction. The pair of side surfaces 48b extend downward along a direction inclined with respect to the axial direction, away from each other from the circumferential ends of the bottom surface 48a. The portion of the lower end surface 40l of the retainer 40 other than the lower recess 48 is a flat surface perpendicular to the axial direction.

[0061] As shown in Figures 1 and 2, the sealing member 50 is formed in the shape of an annular plate. The sealing member 50 is positioned around a common axis O. The sealing member 50 is uniformly formed around its entire circumference. The sealing member 50 is fitted onto the outer ring 20 from the outside in the axial direction. One sealing member 50 is positioned on each side in the axial direction relative to the plurality of rolling elements 30. The sealing member 50 has an annular base portion 51 that contacts the outer ring 20 from the outside in the axial direction, an extension portion 52 that extends outward in the axial direction from the inner peripheral edge of the base portion 51, a flat portion 53 that extends radially toward the inner ring 10 from the outer axial edge of the extension portion 52, and a locking portion 54 that extends outward in both the radial and axial directions from the outer peripheral edge of the base portion 51.

[0062] As shown in Figure 2, the base portion 51 overlaps the end face 22a of the projection 22 of the outer ring 20 from the axially outward direction. The base portion 51 extends substantially parallel to the end face 22a of the projection 22 of the outer ring 20. In a plan view from the axial direction, the base portion 51 protrudes radially inward from the end face 22a of the projection 22. The distance that the base portion 51 protrudes radially inward from the end face 22a of the projection 22 is 10% or less of the radial distance between the inner ring 10 and the outer ring 20, and preferably 5% or less. The extension portion 52 extends axially outward and radially inward from the inner circumferential edge of the base portion 51. The planar portion 53 overlaps the center of the rolling element 30 in a plan view. The inner circumferential edge of the planar portion 53 is positioned with a gap between it and the outer circumferential surface of the inner ring 10. The surface of the planar portion 53 that faces inward in the axial direction is a flat surface that extends in the circumferential and radial directions. The outer edge of the locking portion 54 is locked to the inner circumferential surface 21a of the outer ring body 21 from the inside in the axial direction. As a result, the sealing member 50 is fixed to the outer ring 20 and rotates integrally with the outer ring 20 relative to the inner ring 10.

[0063] A solid lubricant 60 is placed inside the rolling bearing 1. The solid lubricant 60 is placed between the rolling elements 30 and the sealing member 50. The solid lubricant 60 is placed in the annular space between the inner ring 10 and the outer ring 20, on the same side in the axial direction as the recess 24 for the rolling elements 30. In this embodiment, the solid lubricant 60 is placed on the side opposite the base 41 of the cage 40, with the rolling elements 30 in the axial direction. The solid lubricant 60 is placed above the rolling elements 30. The solid lubricant 60 is placed along the circumferential direction. The solid lubricant 60 extends in an annular or arc shape and is placed coaxially with the common axis O.

[0064] The solid lubricant 60 comprises an outer ring contact portion 61 that contacts the inner circumferential surface 22b of the projection 22 of the outer ring 20, and a seal member contact portion 62 that contacts the flat portion 53 of the seal member 50 axially outward and radially inward from the outer ring contact portion 61. These outer ring contact portion 61 and seal member contact portion 62 extend circumferentially along the entire length of the solid lubricant 60. The outer ring contact portion 61 has an axial width throughout its entire circumferential direction. The outer ring contact portion 61 contacts the recess 24 of the inner circumferential surface 22b of the projection 22. The outer ring contact portion 61 contacts the recess 24 around its entire circumference. The outer ring contact portion 61 contacts the outward-facing surface 24a of the recess 24. In this case, it is desirable that the outer ring contact portion 61 also contacts at least a portion of the ridge portion 25 of the adjacent surface 28. Furthermore, the outer ring contact portion 61 is in contact with the inward-facing surface 24b of the recess 24 and with the radially inward-facing portion of the recess 24. In this embodiment, the outer ring contact portion 61 is in contact with the entire recess 24. It is desirable that the solid lubricant 60 is not in contact with the outer ring 20 at any location other than the recess 24. That is, the outer ring contact portion 61 is provided at an axial distance from the contact portion between the outer ring 20 and the base portion 51 of the seal member 50. The seal member contact portion 62 has a radial width over its entire circumferential direction. The seal member contact portion 62 is in contact with the flat portion 53 at a location radially spaced from the connection portion between the extension portion 52 and the flat portion 53 of the seal member 50.

[0065] The solid lubricant 60 extends axially outward and radially inward from the outer ring contact portion 61 toward the seal member contact portion 62. The solid lubricant 60 has an inner surface 63 and an outer surface 64.

[0066] The inner surface 63 connects the axially inner edge of the outer ring contact portion 61 and the radially inner edge of the seal member contact portion 62. The inner surface 63 faces the outer circumferential surface of the inner ring 10 and the rolling elements 30. The upper half of the inner surface 63 extends axially and radially inward from the radially inner edge of the seal member contact portion 62. The lower half of the inner surface 63 extends axially outward and radially inward from the axially inner edge of the outer ring contact portion 61 and connects to the lower edge of the upper half. The boundary between the upper and lower halves of the inner surface 63 forms the innermost radially inward edge of the solid lubricant 60. The inner surface 63 is spaced apart from the inner ring 10, the rolling elements 30 and the cage 40. As a result, the solid lubricant 60 is not in contact with the inner ring 10, the rolling elements 30 and the cage 40.

[0067] The outer surface 64 connects the axially outer edge of the outer ring contact portion 61 and the radially outer edge of the seal member contact portion 62. The outer surface 64 faces the inner circumferential surface 22b of the projection 22 of the outer ring 20 and the seal member 50. The outer surface 64 extends axially inward and radially outward from the radially outer edge of the seal member contact portion 62 and connects to the axially outer edge of the outer ring contact portion 61. The outer surface 64 is spaced apart from the base portion 51 and extension portion 52 of the seal member 50. As a result, the solid lubricant 60 does not come into contact with the base portion 51 and extension portion 52 of the seal member 50 that are located on the outer ring 20 side of the flat portion 53.

[0068] The solid lubricant 60 is formed such that the cross-sectional area of ​​the section along the vertical plane of the common axis O gradually increases from the axially outer end toward the axially inner end. In this embodiment, the solid lubricant 60 is formed in the portion corresponding to the upper half of the inner surface 63 such that the cross-sectional area of ​​the section along the vertical plane of the common axis O gradually increases from the axially outer end toward the axially inner end.

[0069] The composition of the solid lubricant 60 will be described below. The solid lubricant 60 is a solidified mixture of grease and resin material, and is sometimes referred to as plastic grease. The grease is included in the solid lubricant 60 as a lubricating component. The grease comprises a base oil as a lubricant and a thickener. The grease may also contain components other than the base oil and thickener as needed. For example, the grease may contain a gelling agent. If the grease contains a gelling agent, it does not need to contain a thickener.

[0070] The base oil is not particularly limited, but examples include mineral oil and synthetic oil. As for the mineral oil, known mineral oils used as base oils can be used, such as naphthenic mineral oil, paraffinic mineral oil, hydrogenated mineral oil, solvent-refined mineral oil, and highly refined mineral oil. One type of mineral oil may be used alone, or two or more types may be used in combination. For example, multiple types of mineral oil may be mixed and adjusted to achieve the desired properties.

[0071] As the synthetic oil, known synthetic oils used as base oils can be used, such as aliphatic hydrocarbon oils such as poly-alpha-olefin (PAO) and polybutene, aromatic hydrocarbon oils such as alkylbenzene and alkylnaphthalene, ester oils such as polyol esters and phosphate esters, ether oils such as polyphenyl ethers, polyalkylene glycol oil, silicone oil, and fluorine oil. These synthetic oils may be used individually or in combination of two or more. For example, multiple types of synthetic oils may be mixed and adjusted to achieve the desired properties.

[0072] The thickener plays a role in keeping the grease in a semi-solid state. As the thickener, known thickeners commonly used in rolling bearing greases can be used. From among the known thickeners, those that satisfy the dropping point conditions for the grease, as described later, should be selected. For example, examples of thickeners include lithium soap, complex lithium soap, urea compounds, polytetrafluoroethylene, clay, and calcium sulfonate complex soap. The thickener may be used alone or in combination of two or more types. For example, multiple types of thickeners may be mixed to adjust the desired properties.

[0073] The resin material is included in the solid lubricant 60 as a component that holds the grease. The resin material has a form in which resin particles dispersed in the solid lubricant 60 are bonded to each other. The resin material holds the grease in the voids formed by the dispersed resin particles. The resin material is, for example, a super-high molecular weight polyolefin. Other resin materials that can be used include polyacetal and nylon 6.

[0074] Next, regarding the manufacturing method of the rolling bearing 1 of this embodiment, a method for forming the solid lubricant 60 will be described. The method for forming the solid lubricant 60 of this embodiment comprises a coating step and a heating and cooling step.

[0075] Figures 4 and 5 are longitudinal cross-sectional views of a rolling bearing illustrating a method for forming a solid lubricant according to the first embodiment. As shown in Figure 4, in the coating process, a semi-solid mixture 70 of grease and resin material particles is placed inside the rolling bearing 1 and molded into the shape of a solid lubricant 60. First, the mixture 70 is placed inside the rolling bearing 1 with the seal member 50 not attached to the outer ring 20. That is, the annular space between the inner ring 10 and the outer ring 20 is open in the axial direction, and the mixture 70 is applied with the rolling elements 30 and the cage 40 exposed. In this embodiment, the mixture is discharged from the nozzle A while rotating the nozzle A around a common axis O with respect to the outer ring 20. At this time, the orientation of the nozzle A is adjusted so that the mixture 70 is discharged radially outward and axially inward. Furthermore, the position of the nozzle A is adjusted so that the discharged mixture 70 comes into contact with the recess 24 on the adjacent surface 28 of the outer ring 20, and the mixture 70 does not come into contact with the rolling elements 30 and the cage 40. As the mixture 70 is discharged while nozzle A rotates relative to the outer ring 20, the mixture 70 applied to the outer ring 20 extends in a circumferential or arc-shaped manner. Furthermore, the mixture 70 is applied in a manner that follows the discharge direction from nozzle A, protruding axially outward and radially inward from the contact point with the outer ring 20. The axially outward end face of the applied mixture 70 is formed in a convex shape that bulges outward in the axial direction.

[0076] Next, as shown in Figure 5, the sealing member 50 is brought closer to the outer ring 20 from the axial outside and attached to the outer ring 20. In the process of displacing the sealing member 50 in the axial direction, the flat portion 53 of the sealing member 50 is first brought into contact with the axially outer edge of the entire mixture 70 before the base portion 51 contacts the end face 22a of the protrusion 22 of the outer ring 20. At this time, the mixture 70 is brought into contact with the radially intermediate portion of the flat portion 53. Note that the radially intermediate portion only needs to be located radially inward from the outer peripheral edge of the flat portion 53 and radially outward from the inner peripheral edge. After that, the sealing member 50 is brought further closer to the outer ring 20 and the base portion 51 contacts the end face 22a of the protrusion 22 of the outer ring 20 from the axial outside. At this time, the flat portion 53 of the sealing member 50 pushes the mixture 70 inward in the axial direction. As a result, the mixture 70 spreads radially as it is pushed by the flat portion 53, forming the area that becomes the sealing member contact portion 62.

[0077] As a result, the mixture 70 is substantially formed into the final shape of the solid lubricant 60. In this embodiment, the mixture 70 is applied while the nozzle A is rotated relative to the outer ring 20 during the application process. However, the mixture 70 may also be discharged from a nozzle having a discharge hole that extends in the circumferential direction, and the mixture 70 may be applied circumferentially or in an arc shape all at once.

[0078] Following the coating process, a heating and cooling process is performed. In the heating and cooling process, the molded mixture 70 is heated and cooled. In the heating and cooling process of this embodiment, the mixture 70 is heated and cooled together with the rolling bearing 1. First, the mixture 70 is heated to a temperature above the gelation temperature of the resin material. At this time, it is desirable to heat the mixture 70 to a temperature lower than the dropping point of the grease. Next, the mixture 70 is cooled to a temperature lower than the gelation temperature of the resin material to solidify the mixture 70. As a result, the resin material particles dispersed in the mixture 70 bond together, and a solid lubricant 60 is formed in which grease is held in the voids of the resin material.

[0079] As described above, in this embodiment, the rolling bearing 1 has the following configuration. The rolling bearing 1 is equipped with a solid lubricant 60 in which grease is held by a solidified resin material. On the inner circumferential surface 22b of the projection 22 of the outer ring 20, an outer ring raceway surface 23 is formed that supports the rolling element 30 so as to be able to roll, and an adjacent surface 28 is formed that extends axially from the axial edge of the outer ring raceway surface 23. The solid lubricant 60 is in contact with a recess 24 formed on the adjacent surface 28. With this configuration, since the solid lubricant 60 is placed on the inner circumferential surface 22b of the outer ring 20, the base oil of the grease that seeps out from the solid lubricant 60 is supplied to the sliding parts such as the rolling element 30, thereby reducing the rotational torque of the rolling bearing 1. Furthermore, since the solid lubricant 60 is in contact with the recess 24, the solid lubricant 60 engages with the recess 24, making it less likely for the rolling bearing 1 to shift position during use. In particular, in this embodiment, since the recess 24 is formed on the inner circumferential surface 22b, the axial displacement of the solid lubricant 60 is restricted. This prevents the solid lubricant 60 from coming into contact with the rolling elements 30, etc. Therefore, a rolling bearing 1 can be provided that can suppress the increase in rotational torque over a long period of time.

[0080] Furthermore, in conventional technology, it was necessary to demold the solid lubricant, which had been solidified and molded in a mold beforehand, before installing it in the rolling bearing. In contrast, in this embodiment, as a method for forming the solid lubricant 60, a method can be adopted in which the mixture of the solid lubricant 60 before solidification is applied to the recess 24 and then solidified. In the method for forming the solid lubricant 60 in this embodiment, the mixture of the resin material and grease is heated to a temperature above the gelation temperature of the resin material while in contact with the recess 24, and then cooled to solidify. With this method, the mixture can be placed inside the rolling bearing 1 in an unsolidified state. This makes it possible to place the solid lubricant 60 in a predetermined position even when it is difficult to place a solidified solid lubricant inside the rolling bearing.

[0081] The solid lubricant 60 is in contact with the outward-facing surface 24a of the recess 24, which is inclined outward in the axial direction relative to the radial direction. With this configuration, the outward-facing surface 24a of the recess 24 restricts the displacement of the solid lubricant 60 inward in the axial direction. This effectively prevents the solid lubricant 60 from shifting inward from its initial position and approaching the rolling elements 30 during repeated use of the rolling bearing 1.

[0082] The recess 24 has an inward-facing surface 24b that is inclined inward in the axial direction with respect to the radial direction. With this configuration, the inward-facing surface 24b of the recess 24 restricts the displacement of the solid lubricant 60 outward in the axial direction. This makes it possible to more reliably suppress the displacement of the solid lubricant 60 outward from its initial position during repeated use of the rolling bearing 1.

[0083] The solid lubricant 60 is in contact with the sealing member 50 from the inside in the axial direction. With this configuration, the sealing member 50 restricts the displacement of the solid lubricant 60 outward in the axial direction. This makes it possible to more reliably suppress the displacement of the solid lubricant 60 outward in the axial direction from its initial position during repeated use of the rolling bearing 1.

[0084] The recess 24 is provided at an axial distance from the outer ring raceway surface 23. This configuration prevents the solid lubricant 60 in the recess 24 from coming into contact with the rolling elements 30 that roll on the outer ring raceway surface 23. This prevents an increase in the rotational torque of the rolling bearing 1.

[0085] The recess 24 is provided at an axial distance from the end face 22a of the protrusion 22. This configuration prevents the base oil of the grease contained in the solid lubricant 60 from flowing out from the recess 24 towards the end face 22a and leaking out through the gap between the end face 22a and the base portion 51 of the sealing member 50.

[0086] The recess 24 extends continuously along its entire circumferential direction. This configuration makes it difficult for the solid lubricant 60, which is arranged along the circumferential direction, to be displaced axially along its entire length by the recess 24. Therefore, an increase in the rotational torque of the rolling bearing 1 can be suppressed.

[0087] The solid lubricant 60 is in contact with the ridge 25 formed on the edge of the recess 24 on the outer ring raceway surface 23 side. With this configuration, the grease base oil seeping out from the solid lubricant 60 does not need to cross the ridge 25 in the process of reaching the outer ring raceway surface 23, thus preventing insufficient supply of grease base oil to the rolling elements 30.

[0088] The solid lubricant 60 has an outer ring contact portion 61 that contacts the inner circumferential surface 22b of the protrusion 22 of the outer ring 20, and a seal member contact portion 62 that contacts the flat portion 53 of the seal member 50, located axially outward and radially inward from the outer ring contact portion 61. The area of ​​the seal member contact portion 62 is larger than the contact area between the solid lubricant 60 and the extension portion 52 and base portion 51 of the seal member 50. With this configuration, when the seal member 50 is installed after applying the mixture of the solid lubricant 60 before it solidifies to a predetermined location, there is room for the mixture, which is pushed axially inward by the flat portion 53 of the seal member 50, to spread radially toward the extension portion 52 and base portion 51. Therefore, it is possible to suppress the semi-solid mixture from spreading too much toward the inner ring 10 and rolling element 30. Thus, it is possible to suppress the solid lubricant 60 from contacting the rolling element 30 and the cage 40 and increasing the rotational torque.

[0089] Furthermore, since the sealing member 50 is provided with an extension 52 between the flat portion 53 and the base portion 51, the solid lubricant 60 can be positioned further away from the rolling element 30 compared to a configuration in which the flat portion extends radially inward from the base portion. Therefore, the amount of solid lubricant 60 can be increased.

[0090] Furthermore, the seal member contact portion 62 includes the radial center position of the solid lubricant 60 in a plan view. With this configuration, when the seal member 50 is installed, the semi-solid mixture is pressed against the flat portion 53 and spreads radially. As a result, the seal member contact portion 62 includes the radial center position of the solid lubricant 60 in a plan view, thus suppressing the mixture from spreading significantly inward in the axial direction toward the rolling element 30. Therefore, direct contact between the solid lubricant 60 and the rolling element 30 can be easily suppressed.

[0091] The solid lubricant 60 is not in contact with the extension portion 52. With this configuration, when the sealing member 50 is installed, the semi-solid mixture, which is pushed inward in the axial direction by the flat portion 53 of the sealing member 50, has more room to spread radially toward the extension portion 52. As a result, the mixture can be prevented from spreading too much toward the inner ring 10 and the rolling element 30. Therefore, contact between the solid lubricant 60 and the rolling element 30, the cage 40, and the inner ring 10 can be easily prevented.

[0092] The outer ring contact portion 61 is provided at an axial distance from the contact portion between the outer ring 20 and the base portion 51. This configuration prevents the solid lubricant 60 from coming into contact with the contact portion between the outer ring 20 and the base portion 51. This prevents the base oil of the grease contained in the solid lubricant 60 from leaking out to the outside of the sealing member 50 through the contact portion between the outer ring 20 and the base portion 51 due to capillary action.

[0093] The solid lubricant 60 is not in contact with the base portion 51. This configuration prevents the solid lubricant 60 from coming into contact with the contact area between the outer ring 20 and the base portion 51. This prevents the base oil of the grease contained in the solid lubricant 60 from leaking out to the outside of the sealing member 50 through the contact area between the outer ring 20 and the base portion 51 due to capillary action.

[0094] Furthermore, according to the rotating equipment 2 of this embodiment, since it is equipped with a rolling bearing 1 that can suppress the increase in rotational torque over a long period of time, it is possible to achieve a longer lifespan and lower power consumption for the rotating equipment 2.

[0095] In the first embodiment, the recess 24 extends in a curved shape on the longitudinal cross-section of the rolling bearing 1, but the configuration is not limited to this. As shown in Figure 6, the recess 24A may be formed to define a rectangular space on the longitudinal cross-section of the rolling bearing 1. In this case, the recess 24A is provided with an outward-facing surface 24Aa that faces in a direction inclined outward in the axial direction with respect to the radial direction (radially inward and upward, or upward), and an inward-facing surface 24Ab that faces in a direction inclined inward in the axial direction with respect to the radial direction (radially inward and downward, or downward). It is desirable that the solid lubricant 60 is in contact with the outward-facing surface 24Aa of the recess 24A and the ridge portion 25 of the adjacent surface 28.

[0096] Furthermore, in the first embodiment, the recess 24 opens only to the adjacent surface 28, but the configuration is not limited to this. As shown in Figure 7, the recess 24B may be provided without axial spacing from the upward-facing end surface 22a and may open to the adjacent surface 28 and the upward-facing end surface 22a. In this case, the recess 24B is provided with an outward-facing surface 24Ba that is inclined outward in the axial direction with respect to the radial direction (radially inward and upward, or upward). It is desirable that the solid lubricant 60 is in contact with the outward-facing surface 24Ba of the recess 24B and the ridge portion 25 of the adjacent surface 28.

[0097] Furthermore, in the first embodiment, the recess 24 extends continuously over the entire circumferential direction, but the configuration is not limited to this. The recess may be formed discontinuously in the circumferential direction such that an intermittent portion is formed in at least a part of the circumferential direction.

[0098] Furthermore, in the first embodiment, the base portion 51 of the sealing member 50 protrudes radially inward from the end face 22a of the projection 22 of the outer ring 20 in a plan view, but it is desirable that the base portion be arranged so as not to protrude radially inward from the end face 22a of the projection 22 in a plan view. With this configuration, even if the outer ring contact portion 61 of the solid lubricant 60 spreads outward in the axial direction and exceeds the inner peripheral edge of the end face 22a, it is possible to suppress the solid lubricant 60 from adhering to the base portion. Therefore, it is possible to avoid the solid lubricant 60 coming into contact with the contact portion between the outer ring 20 and the base portion. This prevents the solid lubricant 60 from leaking to the outside of the sealing member through the contact portion between the outer ring 20 and the base portion due to capillary action.

[0099] Furthermore, in the first embodiment, the solid lubricant 60 is not in contact with the base portion 51 and the extension portion 52 of the sealing member 50, but the configuration is not limited to this. The solid lubricant may be in contact with at least one of the base portion 51 and the extension portion 52 of the sealing member 50, as long as the area of ​​the contact portion with the sealing member is larger than the contact area between the solid lubricant and the extension portion 52 and the base portion 51.

[0100] Furthermore, in the first embodiment, the solid lubricant 60 is formed by heating a mixture of resin material and grease to a temperature above the gelation temperature of the resin material while in contact with the recess 24, and then cooling and solidifying it. However, the method of forming the solid lubricant 60 is not limited to this. The solid lubricant 60, which has been solidified in a predetermined shape in advance, may be fitted onto the outer ring 20. In this case, the solid lubricant 60 is formed by heating and cooling the semi-solid mixture in a mold. This method eliminates the need to apply a semi-solid mixture to the inside of the rolling bearing 1, thus simplifying the manufacturing process of the rolling bearing 1. In addition, the solid lubricant 60 can be formed with high precision using a mold, and contact between the solid lubricant 60 and the rolling elements 30 can be more reliably suppressed.

[0101] [Second Embodiment] Next, a second embodiment will be described with reference to Figure 8. The second embodiment differs from the first embodiment in that the rolling bearing 1A is equipped with a solid lubricant 160 instead of the solid lubricant 60 of the first embodiment. Other than what is described below, the configuration is the same as that of the first embodiment.

[0102] Figure 8 is a longitudinal cross-sectional view of a rolling bearing according to the second embodiment. As shown in Figure 8, the solid lubricant 160 is arranged along the circumferential direction. The solid lubricant 160 extends in an annular shape and is arranged coaxially with the common axis O. The solid lubricant 160 has an outer ring contact portion 161 that contacts the inner circumferential surface 22b of the projection 22 of the outer ring 20, and is not in contact with the inner ring 10, the sealing member 50, the rolling elements 30, and the cage 40. The outer ring contact portion 161 extends circumferentially along the entire length of the solid lubricant 160. The outer ring contact portion 161 has an axial width along its entire circumferential direction. The outer ring contact portion 161 is in contact with the recess 24 of the adjacent surface 28. It is desirable that the solid lubricant 160 does not contact the outer ring 20 at any location other than the recess 24. That is, the outer ring contact portion 161 is provided with an axial gap from the contact portion between the outer ring 20 and the base portion 51 of the sealing member 50.

[0103] This embodiment provides the same effects as the first embodiment. In addition, in this embodiment, since the solid lubricant 160 is not in contact with the sealing member 50, the mixture of the solid lubricant 160 before solidification is not pressed against the sealing member 50 when the sealing member 50 is mounted on the outer ring 20. This suppresses the axial inward movement of the semi-solid mixture and prevents the solid lubricant 160 from contacting the rolling elements 30 or the cage 40 more than necessary. Therefore, an increase in the rotational torque of the rolling bearing 1A can be suppressed.

[0104] In the second embodiment, the solid lubricant 160 extends in an annular shape, but the configuration is not limited to this. The solid lubricant may extend in an arc shape so as to form intermittent portions, or it may consist of a plurality of granules arranged as points around its entire circumference. If the solid lubricant has a plurality of granules, the circumferentially aligned granules may be integrated or spaced apart from each other.

[0105] [Third Embodiment] Next, a third embodiment will be described with reference to Figure 9. The rolling bearing 1C of the third embodiment differs from the rolling bearing 1 of the first embodiment in that the solid lubricant 260 is in contact only with the outward-facing surface 24Ca of the recess 24C. Other than what is described below, the configuration is the same as that of the first embodiment.

[0106] Figure 9 is a longitudinal cross-sectional view of a rolling bearing according to the third embodiment. As shown in Figure 9, recesses 24C are formed on adjacent surfaces 28 of the outer ring 20, recessed radially outward. The recesses 24C are provided without axial spacing from the end face 22a of the upward-facing projection 22, and open to the adjacent surfaces 28 and the upward-facing end face 22a. The recesses 24C consist of an outward-facing surface 24Ca that faces inclined axially outward with respect to the radial direction (radially inward and upward, or upward), and a cylindrical surface 24Cc that faces radially inward. The outward-facing surface 24Ca is a concave curved surface. The cylindrical surface 24Cc extends axially and is smoothly connected to the outward-facing surface 24Ca at its axially inward edge, such that a tangent line is continuous.

[0107] The solid lubricant 260 comprises an outer ring contact portion 261 that contacts the inner circumferential surface 22b of the projection 22 of the outer ring 20, and a seal member contact portion 262 that contacts the seal member 50 axially outward and radially inward from the outer ring contact portion 261. The outer ring contact portion 261 is in contact with the recess 24C of the adjacent surface 28. The outer ring contact portion 261 is in contact with the recess 24C over its entire circumference. The outer ring contact portion 261 is in contact only with the outward-facing surface 24Ca of the recess 24C. In this case, it is desirable that the outer ring contact portion 261 also contacts at least a part of the ridge portion 25 of the adjacent surface 28. However, the outer ring contact portion 261 does not have to contact the ridge portion 25 of the adjacent surface 28. In this embodiment, the seal member contact portion 262 is the portion of the solid lubricant 260 that is in contact with the flat portion 53 of the seal member 50. In this embodiment, the solid lubricant 260 is in contact with both the base portion 51 and the extension portion 52 of the sealing member 50. However, if the solid lubricant 260 is in contact with at least one of the base portion 51 and the extension portion 52 of the sealing member 50, it is desirable that the area of ​​the sealing member contact portion 262 be larger than the contact area between the solid lubricant 260 and the extension portion 52 and the base portion 51. The solid lubricant 260 may not be in contact with at least one of the base portion 51 and the extension portion 52. The solid lubricant 260 is formed such that the cross-sectional area of ​​the cross section along the vertical plane of the common axis O gradually increases from the axially outer end toward the axially inner end.

[0108] The solid lubricant 260 comprises a first annular portion 260a that contacts the outer ring 20, and a second annular portion 260b that is connected to the first annular portion 260a and contacts the sealing member 50. The first annular portion 260a and the second annular portion 260b are formed by applying the mixture of the solid lubricant 260 before solidification in two separate applications. The first annular portion 260a and the second annular portion 260b each extend circumferentially around a common axis O. However, at least one of the first annular portion 260a and the second annular portion 260b may extend less than 360° around the common axis O. The first annular portion 260a includes an outer ring contact portion 261. The second annular portion 260b is positioned radially opposite to the outer ring 20 (i.e., radially inward) relative to the first annular portion 260a. The second annular portion 260b is connected to and integrated with the first annular portion 260a on its axially outer side. The second annular portion 260b includes a seal member contact portion 262.

[0109] This embodiment provides the same effects as the first embodiment. In addition, in this embodiment, the recess 24C opens to the end face 22a of the upward-facing projection 22, and the solid lubricant 260 is in contact only with the outward-facing surface 24Ca of the recess 24C. This configuration prevents the base oil of the grease contained in the solid lubricant 260 from flowing out from the recess 24C towards the end face 22a and leaking out through the gap between the end face 22a and the base portion 51 of the sealing member 50.

[0110] In the third embodiment, the first annular portion 260a and the second annular portion 260b extend in a circular shape, but the configuration is not limited to this. At least one of the first annular portion and the second annular portion may be provided with granular bodies arranged in a point-like manner around its entire circumference. In this case, the multiple granular bodies aligned in the circumferential direction may be integrated or spaced apart from one another.

[0111] Furthermore, in the third embodiment, the solid lubricant 260 has a first annular portion 260a and a second annular portion 260b, but the configuration is not limited to this. As shown in Figure 10, the solid lubricant 260A may be formed by a single annular portion having an outer ring contact portion 261 and a seal member contact portion 262.

[0112] [Fourth Embodiment] Next, a fourth embodiment will be described with reference to Figure 11. The rolling bearing 1D of the fourth embodiment differs from the rolling bearing 1 of the first embodiment in that the solid lubricant 360 is arranged axially along the recess 24D. Other than what is described below, the configuration is the same as that of the first embodiment.

[0113] Figure 11 is a longitudinal cross-sectional view of a rolling bearing according to the fourth embodiment. As shown in Figure 11, a recess 24D is formed on the adjacent surface 28 of the outer ring 20, recessed radially outward. The recess 24D is provided without axial spacing from the end face 22a of the upward-facing projection 22, and opens to the adjacent surface 28 and the upward-facing end face 22a. The recess 24D comprises an outward-facing surface 24Da that faces inclined axially outward with respect to the radial direction (radially inward and upward, or upward), and a cylindrical surface 24Dc that faces radially inward. The outward-facing surface 24Da is a concave curved surface. The cylindrical surface 24Dc extends axially and is smoothly connected to the outward-facing surface 24Da at its axially inward edge such that the tangent is continuous. The recess 24D extends axially on the longitudinal cross-section of the rolling bearing 1D such that its axial width is greater than its radial depth. The outward-facing surface may be a flat surface facing outward in the axial direction, or a conical surface facing outward in the axial direction and inward in the radial direction.

[0114] The solid lubricant 360 includes an outer ring contact portion 361 that contacts the inner circumferential surface 22b of the projection 22 of the outer ring 20. The outer ring contact portion 361 is in contact with the recess 24D of the adjacent surface 28. The outer ring contact portion 361 is in contact with the recess 24D around its entire circumference. The outer ring contact portion 361 is in contact with the outward-facing surface 24Da and the cylindrical surface 24Dc of the recess 24D. The outer ring contact portion 361 is also in contact with at least a portion of the ridge 25 of the adjacent surface 28. The solid lubricant 360 is in contact with the sealing member 50. In this embodiment, the solid lubricant 360 is in contact with the base portion 51 and the extension portion 52 of the sealing member 50.

[0115] The solid lubricant 360 is axially positioned along the recess 24D on the longitudinal cross-section of the rolling bearing 1D. The solid lubricant 360 comprises a first annular portion 360a, a second annular portion 360b, and a third annular portion 360c, which are aligned axially. The first annular portion 360a, the second annular portion 360b, and the third annular portion 360c are formed by applying a mixture of the solid lubricant 360 before solidification in three separate applications. The first annular portion 360a, the second annular portion 360b, and the third annular portion 360c each extend circumferentially around a common axis O. However, at least one of the first annular portion 360a, the second annular portion 360b, and the third annular portion 360c may extend less than 360° around the common axis O. The first annular portion 360a is in contact with the outward-facing surface 24Da and the cylindrical surface 24Dc of the recess 24D. The second annular portion 360b is connected to the first annular portion 360a on its axially outward side. The second annular portion 360b is in contact with the cylindrical surface 24Dc of the recess 24D. The third annular portion 360c is connected to the second annular portion 360b on its axially outward side. The third annular portion 360c is in contact with the cylindrical surface 24Dc of the recess 24D and the sealing member 50.

[0116] This embodiment provides the same effects as the first embodiment. In addition, in this embodiment, since the solid lubricant 360 is arranged axially along the recess 24D, the recess 24D can effectively restrict the axial displacement of the solid lubricant 360, thereby suppressing the displacement of the solid lubricant 360 and preventing it from contacting the rolling element 30 or the cage 40. Therefore, a rolling bearing 1D with suppressed rotational torque increase can be provided.

[0117] In the fourth embodiment, the first annular portion 360a, the second annular portion 360b, and the third annular portion 360c extend in a circular shape, but the configuration is not limited to this. At least one of the first annular portion, the second annular portion, and the third annular portion may be equipped with granular bodies arranged in a point-like manner around its entire circumference. In this case, the multiple granular bodies aligned in the circumferential direction may be integrated or spaced apart from one another.

[0118] Furthermore, in the fourth embodiment, the solid lubricant 360 has a first annular portion 360a, a second annular portion 360b, and a third annular portion 360c, but the configuration is not limited to this. As shown in Figure 12, the solid lubricant 360A may extend axially along the recess 24D on the longitudinal cross-section of the rolling bearing 1D.

[0119] Furthermore, in the fourth embodiment, the solid lubricant 360 is in contact with the ridge portion 25 of the adjacent surface 28 of the outer ring 20, but the configuration is not limited to this. As shown in Figure 13, the solid lubricant 360B may not be in contact with the ridge portion 25. In this case, the first annular portion 360a may be formed smaller on the longitudinal cross-section of the rolling bearing 1D than the second annular portion 360b and the third annular portion 360c so as not to contact the ridge portion 25. With this configuration, although the supply of grease base oil to the rolling elements 30 may be insufficient, the total amount of solid lubricant 360B can be increased, thereby providing the rolling bearing 1D with higher durability.

[0120] [Fifth Embodiment] Next, a fifth embodiment will be described with reference to Figure 14. The rolling bearing 1E of the fifth embodiment differs from the rolling bearing 1 of the first embodiment in that the deepest part of the recess 24E in the radial direction is formed axially inward from the axial midpoint of the recess 24E. Other than what is described below, the configuration is the same as that of the first embodiment.

[0121] Figure 14 is a longitudinal cross-sectional view of a rolling bearing according to the fifth embodiment. As shown in Figure 14, recesses 24E are formed on adjacent surfaces 28 of the outer ring 20, recessed radially outward. The recesses 24E are spaced axially from the outer ring raceway surface 23. The recesses 24E are spaced axially from the upward-facing end face 22a. The recesses 24E are formed such that their axial width is greater than their radial depth on the longitudinal cross-section of the rolling bearing 1E. The recesses 24E include an outward-facing surface 24Ea that faces inclined radially outward (radially inward and upward, or upward), an inward-facing surface 24Eb that faces radially inward (radially inward and downward, or downward), and a cylindrical surface 24Ec that faces radially inward. In this embodiment, the outward-facing surface 24Ea and the inward-facing surface 24Eb are oriented axially. As a result, the recesses 24E are formed in a rectangular shape on the longitudinal cross-section of the rolling bearing 1E. The cylindrical surface 24Ec is located at the deepest point in the radial direction of the recess 24E and axially straddles the axial midpoint of the recess 24E. As a result, the deepest point in the radial direction of the recess 24E is formed axially inward from the axial midpoint of the recess 24E.

[0122] The solid lubricant 460 comprises an outer ring contact portion 461 that contacts the inner circumferential surface 22b of the projection 22 of the outer ring 20, and a seal member contact portion 462 that contacts the flat portion 53 of the seal member 50 axially outward and radially inward from the outer ring contact portion 461. The outer ring contact portion 461 is in contact with the recess 24E of the adjacent surface 28. The outer ring contact portion 461 is in contact with the recess 24E around its entire circumference. The outer ring contact portion 461 is in contact with the outward surface 24Ea and the cylindrical surface 24Ec of the recess 24E. The outer ring contact portion 461 is also in contact with at least a portion of the ridge portion 25 of the adjacent surface 28. The solid lubricant 460 is not in contact with the inward surface 24Eb of the recess 24E. However, the solid lubricant 460 may be in contact with the inward surface 24Eb of the recess 24E. In this embodiment, the seal member contact portion 462 is the portion of the solid lubricant 460 that contacts the flat portion 53 of the seal member 50. In this embodiment, the solid lubricant 460 does not contact the base portion 51 and the extension portion 52 of the seal member 50. However, the solid lubricant 460 may contact at least one of the base portion 51 and the extension portion 52 of the seal member 50, in which case it is desirable that the area of ​​the seal member contact portion 462 is larger than the contact area between the solid lubricant 260 and the extension portion 52 and the base portion 51. The solid lubricant 460 extends axially outward and radially inward from the outer ring contact portion 461 toward the seal member contact portion 462.

[0123] This embodiment provides the same effects as the first embodiment. In addition, in this embodiment, the deepest part of the recess 24E in the radial direction is formed axially inward from the axial midpoint of the recess 24E. With this configuration, when discharging the mixture of solid lubricant 460 before solidification from the nozzle and applying it to a predetermined location, the tip of the nozzle can be inserted from the outside of the rolling bearing 1E into the inside of the outer ring 20 and inner ring 10, bringing it closer to the recess 24E. Therefore, productivity can be improved for small-diameter rolling bearings 1E. Also, since the nozzle can be brought closer to the recess 24E, the mixture can be applied with precision, and contact between the solid lubricant 460 and the rolling elements 30 can be suppressed. Therefore, an increase in the rotational torque of the rolling bearing 1E can be suppressed.

[0124] In the fifth embodiment, the recesses 24E are formed symmetrically on the vertical cross-section of the rolling bearing 1E, but the configuration is not limited to this. As shown in Figures 15 and 16, the recesses 124E and 224E may be formed asymmetrically on the vertical cross-section of the rolling bearing 1E. The following describes the modified examples shown in Figures 15 and 16.

[0125] In the first modified example shown in Figure 15, the recess 124E is formed on the longitudinal cross-section of the rolling bearing 1E such that its axial width is greater than its radial depth. The recess 124E comprises an outward-facing surface 124Ea that faces in a direction inclined axially outward with respect to the radial direction (radially inward and upward, or upward) and an inward-facing surface 124Eb that faces in a direction inclined axially inward with respect to the radial direction (radially inward and downward, or downward). The outward-facing surface 124Ea is a curved surface that is recessed axially inward and radially outward. The inward-facing surface 124Eb is a conical surface that extends axially outward and radially inward from the axially outward edge of the outward-facing surface 124Ea. The connection between the outward-facing surface 124Ea and the inward-facing surface 124Eb is located axially inward from the axial midpoint of the recess 124E. As a result, the deepest point of the recess 124E in the radial direction is formed axially inward from the axial midpoint of the recess 124E.

[0126] The solid lubricant 460A comprises an outer ring contact portion 461A that contacts the inner circumferential surface 22b of the projection 22 of the outer ring 20, and a seal member contact portion 462A that contacts the flat portion 53 of the seal member 50 axially outward and radially inward from the outer ring contact portion 461A. The outer ring contact portion 461A is in contact with the recess 124E of the adjacent surface 28. The outer ring contact portion 461A is in contact with the recess 124E over its entire circumference. The outer ring contact portion 461A is in contact with the outward surface 124Ea of the recess 124E. The outer ring contact portion 461A is in contact with the inward surface 124Eb of the recess 124E. The outer ring contact portion 461A is in contact with the connection between the outward surface 124Ea and the inward surface 124Eb of the recess 124E. The solid lubricant 460A is not in contact with the edges 25 of the adjacent surface 28. However, the solid lubricant 460A may be in contact with the edges 25 of the adjacent surface 28.

[0127] In this modified example, the seal member contact portion 462A is the portion of the solid lubricant 460A that contacts the flat portion 53 of the seal member 50. In this modified example, the solid lubricant 460A does not contact the base portion 51 and the extension portion 52 of the seal member 50. However, the solid lubricant 460A may contact at least one of the base portion 51 and the extension portion 52 of the seal member 50, in which case it is desirable that the area of ​​the seal member contact portion 462A is larger than the contact area between the solid lubricant 460A and the extension portion 52 and the base portion 51. The solid lubricant 460A may be formed such that the cross-sectional area of ​​the cross section along the vertical plane of the common axis O gradually increases from the axially outer end toward the axially inner side. The solid lubricant 460A extends axially outward and radially inward from the outer ring contact portion 461A toward the seal member contact portion 462A. The solid lubricant 460A extends from the outer ring contact portion 461A along the inward surface 124Eb of the recess 124E.

[0128] In the second modified example shown in Figure 16, the recess 224E is formed such that its axial width is greater than its radial depth on the longitudinal cross-section of the rolling bearing 1E. The recess 224E comprises an outward-facing surface 224Ea that faces inclined axially outward with respect to the radial direction (radially inward and upward, or upward) and an inward-facing surface 224Eb that faces inclined axially inward with respect to the radial direction (radially inward and downward, or downward). The outward-facing surface 224Ea is a plane facing axially outward. The inward-facing surface 224Eb is a conical surface extending axially outward and radially inward from the radially outward edge of the outward-facing surface 224Ea. The connection between the outward-facing surface 224Ea and the inward-facing surface 224Eb is located axially inward from the axial midpoint of the recess 224E. As a result, the deepest point of the recess 224E in the radial direction is formed axially inward from the axial midpoint of the recess 224E.

[0129] The solid lubricant 460B comprises an outer ring contact portion 461B that contacts the inner circumferential surface 22b of the projection 22 of the outer ring 20, and a seal member contact portion 462B that contacts the flat portion 53 of the seal member 50 axially outward and radially inward from the outer ring contact portion 461B. The outer ring contact portion 461B is in contact with the recess 224E of the adjacent surface 28. The outer ring contact portion 461B is in contact with the recess 224E over its entire circumference. The outer ring contact portion 461B is in contact with the outward surface 224Ea of the recess 224E. The outer ring contact portion 461B is in contact with the inward surface 224Eb of the recess 224E. The outer ring contact portion 461B is not in contact with the connection between the outward surface 224Ea and the inward surface 224Eb of the recess 224E. The solid lubricant 460B is not in contact with the edges 25 of the adjacent surface 28. However, the solid lubricant 460B may be in contact with the edges 25 of the adjacent surface 28.

[0130] In this modified example, the seal member contact portion 462B is the portion of the solid lubricant 460B that contacts the flat portion 53 of the seal member 50. In this modified example, the solid lubricant 460B does not contact the base portion 51 and the extension portion 52 of the seal member 50. However, the solid lubricant 460B may contact at least one of the base portion 51 and the extension portion 52 of the seal member 50, in which case it is desirable that the area of ​​the seal member contact portion 462B is larger than the contact area between the solid lubricant 460B and the extension portion 52 and the base portion 51. The solid lubricant 460B may be formed such that the cross-sectional area of ​​the cross section along the vertical plane of the common axis O gradually increases from the axially outer end toward the axially inner side. The solid lubricant 460B extends axially outward and radially inward from the outer ring contact portion 461B toward the seal member contact portion 462B. The solid lubricant 460B extends from the outer ring contact portion 461B along the inward surface 224Eb of the recess 224E.

[0131] Even these modified rolling bearings 1E produce the same effects as the fifth embodiment.

[0132] [Sixth Embodiment] Next, the sixth embodiment will be described with reference to Figure 17. The rolling bearing 1F of the sixth embodiment differs from the rolling bearing 1 of the first embodiment in the shape of the inner circumferential surface 22b of the protrusion 22 of the outer ring 20. Other than what is described below, the configuration is the same as that of the first embodiment.

[0133] Figure 17 is a longitudinal cross-sectional view of a rolling bearing according to the sixth embodiment. As shown in Figure 17, the adjacent surface 28 has a recess 24 and a connecting surface 26. The recess 24 is provided at an axial distance from the end face 22a facing upward of the projection 22. The connecting surface 26 is formed between the recess 24 and the end face 22a facing upward of the projection 22. The connecting surface 26 extends in the axial direction and faces radially inward. The connecting surface 26 is located radially outward from the axial edge of the outer ring raceway surface 23, away from the inner ring 10.

[0134] This embodiment provides the same effects as the first embodiment. In addition, in this embodiment, a connecting surface 26 is formed on the adjacent surface 28 of the outer ring 20, between the recess 24 and the end surface 22a. The connecting surface 26 is located radially outward from the axial edge of the outer ring raceway surface 23 in the radial direction. With this configuration, when inserting the tip of the nozzle from the outside of the rolling bearing 1F into the inside of the outer ring 20 and inner ring 10 in order to discharge the solid lubricant mixture 60 before it solidifies and apply it to a predetermined location, the connecting surface 26 is less likely to come into contact with the nozzle. As a result, it becomes easier to bring the nozzle closer to the recess 24 when applying the mixture, thereby improving productivity in small-diameter rolling bearings 1F. Furthermore, because it becomes easier to bring the nozzle closer to the recess 24, the mixture can be applied with precision, and contact between the solid lubricant 60 and the rolling elements 30 can be suppressed. Therefore, an increase in the rotational torque of the rolling bearing 1F can be suppressed.

[0135] [Seventh Embodiment] Next, the seventh embodiment will be described with reference to Figure 18. The rolling bearing 1G of the seventh embodiment differs from the rolling bearing 1 of the first embodiment in the shape of the inner circumferential surface 22b of the protrusion 22 of the outer ring 20. Other than what is described below, the configuration is the same as that of the first embodiment.

[0136] Figure 18 is a longitudinal cross-sectional view of a rolling bearing according to the seventh embodiment. As shown in Figure 18, the adjacent surface 28 has a recess 224 and an inclined portion 227. The recess 224 is provided without axial spacing from the upward-facing end face 22a of the projection 22 and opens to the adjacent surface 28 and the upward-facing end face 22a. The recess 224 comprises an outward-facing surface 224a that is inclined axially outward with respect to the radial direction (radially inward and upward, or upward) and a cylindrical surface 224c that faces radially inward. The outward-facing surface 224a is a concave curved surface. The radially inward edge of the outward-facing surface 224a is located radially outward from the axial edge of the outer ring raceway surface 23 in the radial direction. The cylindrical surface 224c extends axially and connects to the axially outward edge of the outward-facing surface 224a. The inclined portion 227 extends toward the outer ring raceway surface 23 from the edge of the recess 224 on the outer ring raceway surface 23 side (the radially inner edge of the outward-facing surface 224a), inclined radially and axially. That is, the inclined portion 227 extends radially inward and axially inward from the ridge portion 25 of the adjacent surface 28. In this embodiment, the inclined portion 227 extends linearly from the edge of the recess 224 on the longitudinal cross-section of the rolling bearing 1G. However, the inclined portion only needs to extend with a steeper radial inclination than the recess 224, with respect to the connection between the inclined portion and the recess 224 on the longitudinal cross-section of the rolling bearing 1G. The inclined portion 227 is provided with an axial gap from the outer ring raceway surface 23.

[0137] The solid lubricant 560 includes an outer ring contact portion 561 that contacts the inner circumferential surface 22b of the projection 22 of the outer ring 20. The outer ring contact portion 561 is in contact with the recess 224 of the adjacent surface 28. The outer ring contact portion 561 is in contact with the recess 224 around its entire circumference. The outer ring contact portion 561 is in contact with the outward-facing surface 224a and the cylindrical surface 224c of the recess 224. The outer ring contact portion 561 is also in contact with at least a portion of the ridge portion 25 of the adjacent surface 28. It is desirable that the outer ring contact portion 561 is not in contact with the inclined portion 227. The solid lubricant 560 may also be in contact with the sealing member 50.

[0138] This embodiment provides the same effects as the first embodiment. In addition, in this embodiment, the adjacent surface 28 of the outer ring 20 has an inclined portion 227 that extends toward the outer ring raceway surface 23 from the edge of the recess 224 on the outer ring raceway surface 23 side, inclined radially and axially. With this configuration, even if the end of the recess 224 on the outer ring raceway surface 23 side extends radially, the adjacent surface 28 gradually inclins toward the outer ring raceway surface 23 from the recess 224, thereby promoting the flow of the grease base oil seeping from the solid lubricant 560 from the recess 224 along the inclined portion 227 toward the outer ring raceway surface 23. Therefore, even if the solid lubricant 560 is not placed close to the outer ring raceway surface 23, it is possible to suppress insufficient supply of grease base oil to the rolling elements 30.

[0139] As shown in Figure 19, the solid lubricant 560A may be arranged so as not to protrude radially from the inside of the recess 224 toward the inclined portion 227 (inward). In other words, the solid lubricant 560A may be arranged so as not to be located within the formation range of the inclined portion 227 in the radial direction. This configuration makes it possible to suppress contact between the solid lubricant 560A and the rolling element 30. On the other hand, since the amount of solid lubricant 560A is reduced, it is possible to suitably obtain the effect of suppressing the insufficient supply of grease base oil to the rolling element 30 as described above.

[0140] In the seventh embodiment, the recess 224 is provided without axial spacing from the upward-facing end face 22a of the protruding portion 22, but the configuration is not limited to this. That is, as shown in Figure 20, the recess 224A may be provided with axial spacing from the upward-facing end face 22a. In the illustrated example, the recess 224A includes an outward-facing surface 224Aa that is inclined outward in the axial direction with respect to the radial direction, and an inward-facing surface 224Ab that is inclined inward in the axial direction with respect to the radial direction, but the shape of the recess is not particularly limited.

[0141] [Eighth Embodiment] Next, the eighth embodiment will be described with reference to Figure 21. The rolling bearing 1H of the eighth embodiment differs from the rolling bearing 1 of the first embodiment in that it has a solid lubricant 660 arranged in the cage 40. Other than what is described below, the configuration is the same as that of the first embodiment.

[0142] Figure 21 is a cross-sectional view showing a retainer according to the eighth embodiment. As shown in Figure 21, the solid lubricant 660 is located in the annular space between the inner ring 10 and the outer ring 20. The solid lubricant 660 is located between the pair of sealing members 50. The solid lubricant 660 is located only on the base 41 side of the retainer 40 relative to the rolling elements 30. That is, the solid lubricant 660 is located only below the rolling elements 30. The solid lubricant 660 is located in the lower recess 48 on the lower end surface 40l of the retainer 40. The solid lubricant 660 is in contact with the bottom surface 48a of the lower recess 48. One drop of solid lubricant 660 is applied to each of the bottom surfaces 48a of the lower recess 48. The solid lubricant 660 is evenly distributed in the circumferential direction. However, multiple drops of solid lubricant may be applied to each of the bottom surfaces 48a of the lower recess 48, or it may be applied in an arc-shaped manner. The solid lubricant may also be in contact with the side surface 48b of the lower recess 48. Furthermore, the solid lubricant may be in contact with the opening edge of the lower recess 48. In this embodiment, the rolling bearing 1H does not need to have a solid lubricant in contact with the recess 24 formed in the outer ring 20. In this case, the outer ring 20 does not need to have a recess 24.

[0143] In this embodiment, the solid lubricant 660 is in contact with a lower recess 48 formed in the cage 40. With this configuration, since the solid lubricant 660 is placed in the cage 40, the base oil of the grease that seeps out from the solid lubricant 660 is supplied to the sliding parts such as the rolling elements 30, thereby reducing the rotational torque of the rolling bearing 1H. Furthermore, since the solid lubricant 660 is in contact with the lower recess 48, the solid lubricant 660 engages with the lower recess 48, making it less likely for the rolling bearing 1H to shift position during use. This prevents the solid lubricant 660 from coming into contact with the rolling elements 30, the outer ring 20, the inner ring 10, the sealing member 50, etc. Therefore, it is possible to provide a rolling bearing 1H that can suppress the increase in rotational torque over a long period of time.

[0144] Furthermore, since the solid lubricant 660 is positioned in the lower recess 48, the circumferential displacement of the solid lubricant 660 is restricted by the side surface 48b of the lower recess 48. This prevents the solid lubricant 660 from shifting circumferentially relative to the cage 40 and coming into contact with the rolling elements 30 or the like when the cage 40 rotates. Therefore, a rolling bearing 1H can be provided that can suppress the increase in rotational torque over a long period of time.

[0145] Furthermore, by bringing the solid lubricant 660 into contact with the opening edge of the lower recess 48, the solid lubricant 660 can be locked into the holder 40. This makes it even more difficult for the solid lubricant 660 to shift position.

[0146] In this embodiment, the method for forming the solid lubricant 660 is not particularly limited. A semi-solid mixture of grease and resin material particles may be placed in the cage 40 and then heated and cooled together with the rolling bearing to form the solid lubricant 660, or a solid lubricant 660 that has been solidified in a predetermined shape in advance may be placed in the cage 40.

[0147] [Ninth Embodiment] Next, the ninth embodiment will be described with reference to Figure 22. In the ninth embodiment, the rolling bearing 1I differs from the rolling bearing 1H of the eighth embodiment in the position of the solid lubricant 760 arranged in the cage 40. Other than what is described below, the configuration is the same as in the eighth embodiment.

[0148] Figure 22 is a cross-sectional view showing a retainer according to the ninth embodiment. As shown in Figure 22, the solid lubricant 760 is placed in the upper recess 47 of the upper end surface 40u of the retainer 40. The solid lubricant 660 is in contact with the bottom surface of the upper recess 47. One drop of the solid lubricant 760 is applied to each bottom surface of the upper recess 47. The solid lubricant 760 is evenly distributed in the circumferential direction. However, multiple drops of the solid lubricant may be applied to each bottom surface of the upper recess 47, or it may be applied in an arc shape. The solid lubricant may also be in contact with the side surface of the upper recess 47. Furthermore, the solid lubricant may be in contact with the opening edge of the upper recess 47.

[0149] The retainer 40 includes a projection 49 that protrudes from the bottom surface of the upper recess 47. The projection 49 is inserted into the solid lubricant 760. In this embodiment, the entire projection 49 is covered by the solid lubricant 760. The projection 49 is engaged with the solid lubricant 760 in the radial and circumferential directions.

[0150] This embodiment provides the same effects as the eighth embodiment. In addition, in this embodiment, the projection 49 of the retainer 40 is inserted into the solid lubricant 760. As a result, the solid lubricant 760 engages with the projection 49, restricting radial and circumferential displacement. Therefore, the solid lubricant 760 can be made even less prone to displacement.

[0151] It should be noted that the present invention is not limited to the embodiments described above with reference to the drawings, and various modifications are conceivable within its technical scope. For example, in the above embodiment, the inner ring 10 is provided as a rotating ring, and the outer ring 20 is provided as a stationary ring. The solid lubricant is in contact with the stationary outer ring 20. However, the raceway ring in contact with the solid lubricant does not have to be a stationary ring. That is, the inner ring may be provided as a stationary ring, the outer ring as a rotating ring, and the solid lubricant may be in contact with the stationary inner ring. Alternatively, the inner ring may be provided as a stationary ring, the outer ring as a rotating ring, and the solid lubricant may be in contact with the rotating outer ring.

[0152] Furthermore, in each of the above embodiments, the solid lubricant that contacts the recess of the outer ring is arranged only on one side (above) in the axial direction relative to the rolling element, but the configuration is not limited to this. That is, the recess may be formed on both sides in the axial direction relative to the outer ring raceway surface, and the solid lubricant may be arranged on both sides in the axial direction relative to the rolling element.

[0153] Furthermore, in each of the above embodiments, the solid lubricant in contact with the outer ring is in contact with the recess over its entire circumference, but the configuration is not limited to this. The solid lubricant may be in contact with only a portion of the recess in the circumferential direction.

[0154] Furthermore, although a fan motor was used as an example of a rotating device in the above embodiment, the rotating device is not limited to this. For example, the present invention may be applied to dental handpieces, spindle motors of hard disk drives, and the like as rotating devices.

[0155] Furthermore, although the solid lubricant in the above embodiment contains grease, the solid lubricant only needs to have the lubricating oil held in place by a solidified resin material.

[0156] Furthermore, without departing from the spirit of the present invention, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described embodiments and modifications may be combined as appropriate. For example, in the second to seventh embodiments, a solid lubricant that has been solidified in advance into a predetermined shape may be fitted into the outer ring 20, following the modification of the first embodiment. [Explanation of Symbols]

[0157] 1,1A,1C,1D,1E,1F,1G,1H,1I…Bearing 2…Rotating equipment 10…Inner ring 20…Outer ring 22…Protrusion 22a…End face 22b…Inner circumferential surface (circumferential surface) 23…Outer ring raceway surface (raceway surface) 24,24A,24B,24C,24D,24E,124E,224A,224E…Recess 25…Ridge 26…Connecting surface 28…Adjacent surface 30…Rolling element 40…Cage 49…Projection 50…Sealing member 60,160,260,260A,360,360A,360B,460,460A,460B,560,560A,660,760…Solid lubricant 70…Mixture 227…Inclined portion

Claims

1. The inner and outer rings are arranged coaxially with each other, A rolling element disposed between the inner ring and the outer ring, An annular retainer positioned between the inner ring and the outer ring, which holds the rolling element so that it can roll; A solid lubricant is placed between the inner ring and the outer ring, and the lubricating oil is held by a solidified resin material. Equipped with, One of the inner and outer raceways has a circumferential surface facing the other raceway. The aforementioned circumferential surface has, A raceway surface that supports the rolling element so that it can roll, Adjacent surfaces extending outward in the axial direction from the axial edge of the raceway surface, Formed, The solid lubricant is in contact with the recess formed on either the adjacent surface or the retainer. Rolling bearings.

2. The recess is formed on the adjacent surface, The rolling bearing according to claim 1.

3. The solid lubricant is in contact with a portion of the recess that is inclined outward in the axial direction with respect to the radial direction. The rolling bearing according to claim 2.

4. The recess has a portion that faces in a direction inclined inward in the axial direction with respect to the radial direction. A rolling bearing according to claim 2 or claim 3.

5. The system further comprises a sealing member mounted on the inner ring or the outer ring, covering the space between the inner ring and the outer ring from the outside in the axial direction, The solid lubricant is in contact with the sealing member from the axial inner side. A rolling bearing according to claim 2 or claim 3.

6. The recess is provided at an interval in the axial direction relative to the raceway surface. A rolling bearing according to claim 2 or claim 3.

7. The system further comprises a sealing member mounted on the inner ring or the outer ring, covering the space between the inner ring and the outer ring from the outside in the axial direction, One of the raceways has a projection that protrudes toward the other raceway and has the circumferential surface formed thereon. The aforementioned projection has an end face that faces outward in the axial direction and connects to the circumferential surface at the periphery on the other raceway side, The recess is provided at an interval in the axial direction from the end face. A rolling bearing according to claim 2 or claim 3.

8. The recess extends continuously over the entire circumferential direction. A rolling bearing according to claim 2 or claim 3.

9. The solid lubricant is in contact with the ridge formed on the edge of the recess on the raceway surface side. A rolling bearing according to claim 2 or claim 3.

10. One of the raceways has a projection that protrudes toward the other raceway and has the circumferential surface formed thereon. The aforementioned projection has an end face that faces outward in the axial direction and connects to the circumferential surface at the periphery on the other raceway side, The circumferential surface has a connecting surface formed between the recess and the end face, The connecting surface is located radially further away from the other raceway ring than the axial edge of the raceway surface. A rolling bearing according to claim 2 or claim 3.

11. The circumferential surface has an inclined portion that extends toward the raceway surface from the edge of the recess on the raceway surface side, inclined radially and axially. A rolling bearing according to claim 2 or claim 3.

12. The solid lubricant is arranged so as not to protrude from the inside of the recess toward the inclined portion in the radial direction. The rolling bearing according to claim 11.

13. The recess is formed in the retainer. The rolling bearing according to claim 1.

14. The retainer comprises a projection inserted into the solid lubricant. The rolling bearing according to claim 13.

15. A rotating body arranged to be rotatable, A support that rotatably supports the aforementioned rotating body, A rolling bearing according to claim 1, interposed between the rotating body and the support, A rotating device equipped with the following features.

16. The inner and outer rings are arranged coaxially with each other, A rolling element disposed between the inner ring and the outer ring, An annular retainer positioned between the inner ring and the outer ring, which holds the rolling element so that it can roll; A solid lubricant is placed between the inner ring and the outer ring, Equipped with, One of the inner and outer raceways has a circumferential surface facing the other raceway. The aforementioned circumferential surface has, A raceway surface that supports the rolling element so that it can roll, Adjacent surfaces extending outward in the axial direction from the axial edge of the raceway surface, A method for manufacturing a rolling bearing in which the following is formed: A mixture of resin material and lubricating oil is heated to a temperature above the gelation temperature of the resin material, and then cooled to solidify it, thereby forming the solid lubricant. The solid lubricant is brought into contact with the adjacent surface or the recess formed in the retainer. A method for manufacturing rolling bearings.

17. The mixture is heated to a temperature above the gelation temperature while in contact with the recess, and then cooled to solidify. A method for manufacturing a rolling bearing according to claim 16.

18. The recess is formed on the adjacent surface, The solid lubricant, which has been solidified in advance into a predetermined shape, is fitted into one of the raceway rings. A method for manufacturing a rolling bearing according to claim 16.

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