Rolling bearings and rotating equipment

Abstract

To provide a rolling bearing capable of achieving both of low torque and a long service life.SOLUTION: A rolling bearing 1 includes an inner ring 10 and an outer ring 20 coaxially disposed with each other, a rolling element 30 arranged between the inner ring 10 and the outer ring 20, an annular retainer 40 disposed between the inner ring 10 and the outer ring 20 and holding the rolling element 30 so as to be rotatable, and grease 60 arranged between the inner ring 10 and the outer ring 20. A ball pocket penetrating in a radial direction, opened upward, and holding the rolling element 30 individually so as to be rotatable is formed on the retainer 40. The grease 60 is arranged on a lower end surface 40l of the retainer 40.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Conventionally, rolling bearings have grease held between a pair of raceways (inner and outer rings). In this type of rolling bearing, the resistance of the grease can sometimes increase torque. However, low torque is desirable for rolling bearings in order to reduce the power consumption of the rotating equipment in which they are installed. There is a strong demand for low torque, especially for small rolling bearings used in various motors such as fan motors.

[0003] To reduce the torque of a rolling bearing, it is effective to arrange the grease so that it does not come into contact with both of the components that rotate relative to each other. Therefore, efforts have been made to reduce the amount of grease that comes into contact with the rolling elements (balls) and the cage that holds the rolling elements by applying grease to the axial end of the fixed ring (often the outer ring) of the rolling bearing or to a sealing member arranged on this end side (see, for example, Patent Document 1). In the rolling bearing described in Patent Document 1, the grease adheres to the inner circumferential surface of the outer ring, avoiding the raceway surface that comes into contact with the rolling elements, and is filled in an annular shape biased toward the inner circumferential surface of the outer ring so as not to come into contact with the outer circumferential surface of the inner ring. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-204679 Summary of the Invention [Problem to be solved by the invention]

[0005] However, by limiting the location where the grease can be placed, the amount of grease placed may be reduced compared to the conventional configuration in which grease is sealed between the inner and outer rings, which could result in a reduction in the bearing life due to grease running out.

[0006] Therefore, the present invention provides a rolling bearing and a rotating device that can achieve both low torque and long life. [Means for solving the problem]

[0007] The rolling bearing of the present invention comprises an inner ring and an outer ring arranged coaxially with each other, rolling elements arranged between the inner ring and the outer ring, an annular retainer arranged between the inner ring and the outer ring and holding the rolling elements so that they can roll, and grease arranged between the inner ring and the outer ring, wherein the retainer has ball pockets formed therein that extend radially therethrough and open in a first axial direction and hold the rolling elements individually so that they can roll, and the grease is arranged on the end face of the retainer facing the second axial direction.

[0008] According to the present invention, since grease can be applied to any location around the entire circumference of the end face of the cage in the second direction, the amount of grease placed can be increased while preventing the grease from coming into direct contact with the rolling elements, inner ring, and outer ring, compared to when grease is placed on the end face of the cage in the first direction while avoiding the openings of the ball pockets and the rolling elements, thereby achieving both low torque and a long life for the rolling bearing. Furthermore, by placing grease on the second end face of the cage, the path from the grease along the outer surface of the cage to the rolling elements can be shortened compared to when grease is placed in a grease pocket recessed in the first end face of the cage. This makes it possible to reduce the amount of grease wetting the outer surface of the cage, thereby increasing the ratio of the amount of grease supplied to the rolling elements to the amount of grease placed. This therefore extends the life of the rolling bearing and also makes it possible to reduce the amount of grease applied.

[0009] In the above rolling bearing, a recess recessed in the first direction may be formed in the end surface of the cage, and the grease may be disposed in the recess.

[0010] According to the present invention, the circumferential displacement of the grease is restricted by the side surfaces of the recesses, so that the grease is prevented from shifting in the circumferential direction relative to the cage when the cage rotates, thereby preventing unnecessary outflow of grease and further extending the life of the rolling bearing. Furthermore, the recesses can be used as references for positioning like alignment marks when applying grease, so the grease can be accurately placed in the desired position.

[0011] In the above-mentioned rolling bearing, the retainer may have narrow portions in which the distance between the end face and each of the ball pockets is extremely small, and the recesses may be formed between adjacent narrow portions in the circumferential direction.

[0012] According to the present invention, the recesses are formed at locations that avoid the narrow width portion, so that it is possible to suppress a decrease in rigidity that would otherwise occur due to the thinning of the cage caused by the formation of the recesses.

[0013] The above-mentioned rolling bearing may further include a sealing member that covers the space between the inner ring and the outer ring from the first direction, and the grease may have a raceway application portion that is arranged between the rolling elements and the sealing member and is in contact with one of the inner ring and the outer ring.

[0014] According to the present invention, the amount of grease that can be applied can be increased by the amount of the bearing ring coating portion, thereby further extending the life of the rolling bearing.

[0015] In the above rolling bearing, one of the inner ring and the outer ring may be provided as a fixed ring, and the raceway coating portion may be spaced apart from the other of the inner ring and the outer ring and the rolling element.

[0016] According to the present invention, because the bearing ring coating portion is supported by the fixed ring, centrifugal force acting on the bearing ring coating portion when the rolling bearing rotates can be suppressed, and the bearing ring coating portion can be prevented from losing its shape immediately after coating. As a result, the grease in contact with the fixed ring can be kept separated from the rotating ring and rolling elements, and the grease can be prevented from acting as a resistance to the displacement (rotation) of the rotating ring and rolling elements relative to the fixed ring. Therefore, low torque can be achieved for the rolling bearing.

[0017] A rotating device of the present invention comprises a rotatably arranged rotating body, a support body that rotatably supports the rotating body, and the rolling bearing according to any one of claims 1 to 5 interposed between the rotating body and the support body.

[0018] According to the present invention, since a rolling bearing with low torque and long life is provided, the rotational resistance of the rotating body relative to the support can be reduced, and power saving and long life of the rotating equipment can be achieved. [Effects of the Invention]

[0019] According to the present invention, it is possible to provide a rolling bearing and a rotating device that can achieve both low torque and long life. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a plan view of a rolling bearing according to a first embodiment. [Figure 2] FIG. 1 is a plan view of a rolling bearing according to a first embodiment. [Figure 3] FIG. 2 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 2 is a cross-sectional view showing the cage and grease according to the first embodiment. [Figure 5] FIG. 10 is a cross-sectional view showing a cage and grease according to a second embodiment. [Figure 6] FIG. 10 is a cross-sectional view showing a cage and grease according to a third embodiment. [Figure 7] FIG. 10 is a plan view of a rolling bearing according to a fourth embodiment. [Figure 8] 8 is a cross-sectional view taken along the line VIII-VIII in FIG. 7. [Figure 9] FIG. 10 is a plan view of a rolling bearing according to a fifth embodiment. [Figure 10] 10 is a cross-sectional view taken along the line XX in FIG. 9. [Figure 11] FIG. 10 is a plan view of a rolling bearing according to a sixth embodiment. [Figure 12] 12 is a cross-sectional view taken along the line XII-XII in FIG. 11. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, components having the same or similar functions will be denoted by the same reference numerals. Duplicate descriptions of those components may be omitted.

[0022] [First embodiment] A first embodiment of the present invention will be described with reference to FIGS. Figures 1 and 2 are plan views of the rolling bearing according to the first embodiment. Figure 3 is a cross-sectional view taken along line III-III in Figure 1. Note that a sealing member 50, which will be described later, is omitted from Figure 2. Also, in Figure 3, a rotating device 2 on which the rolling bearing 1 is mounted is shown by an imaginary line.

[0023] As shown in Figures 1 to 3, the rolling bearing 1 is a ball bearing comprising an inner ring 10 and an outer ring 20 that serve as raceways, a plurality of rolling elements 30, a cage 40, a pair of seal members 50, and grease 60. The rolling bearing 1 is provided in a rotating device 2 such as a fan motor. The rotating device 2 comprises a shaft 3 (rotating body) that is formed so as to be rotatable about a common axis O, and a housing 4 (support) that is fixedly installed and rotatably supports the shaft 3. The rolling bearing 1 is interposed between the shaft 3 and the housing 4. Note that hereinafter, the rolling bearing may also be simply referred to as a bearing.

[0024] The inner ring 10 and the outer ring 20 are arranged coaxially with each other so that their respective central axes coincide with the common axis O. In this embodiment, the direction in which the common axis O extends is referred to as the axial direction, the direction extending radially from the common axis O perpendicular to the common axis O is referred to as the radial direction, and the direction going around the common axis O is referred to as the circumferential direction. Furthermore, of the directions parallel to the axial direction and pointing in opposite directions, one is defined as an upward direction (first direction), and the other is defined as a downward direction (second direction).

[0025] 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 fixed 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 outside in the radial direction, with an annular space formed between the inner ring 10 and the outer ring 20. A plurality of rolling elements 30 are disposed between the inner ring 10 and the outer ring 20 and are rotatably held by a cage 40. The cage 40 rotatably holds each of the rolling elements 30 with the plurality of rolling elements 30 evenly arranged in the circumferential direction. A seal member 50 covers the annular space between the inner ring 10 and the outer ring 20 from the outside in the axial direction.

[0026] The outer ring 20 is formed in an annular shape from a metal material such as stainless steel or bearing steel. However, the outer ring 20 is not limited to being made of metal and may be formed from other materials. The outer ring 20 has an outer ring body 21 whose axial width is equal to the axial width of the inner ring 10, and a protrusion 22 that protrudes radially inward from the outer ring body 21. The protrusion 22 is formed in a portion of the outer ring body 21 that is located centrally in the axial direction. The axial width of the protrusion 22 is shorter than the axial width of the outer ring body 21 and is larger than the outer diameter of the rolling elements 30.

[0027] An outer ring rolling surface 23 is formed on the inner circumferential surface of the protruding portion 22, recessed radially outward. The outer ring rolling surface 23 is formed hemispherically in cross section so as to fit along the outer surface of the rolling element 30, and is formed in an annular shape extending circumferentially around the entire circumference of the inner circumferential surface of the protruding portion 22. The outer ring rolling surface 23 is formed on a portion of the inner circumferential surface of the protruding portion 22 that is located at the center in the axial direction. The portion of the inner circumferential surface of the protruding portion 22 excluding the outer ring rolling surface 23 extends axially at a constant inner diameter. The protruding portion 22 has a pair of end faces 22a facing in the axial direction. Each end face 22a extends parallel to both the radial and circumferential directions.

[0028] The outer ring body 21 has a pair of inner circumferential surfaces 21a extending from the outer peripheral edges of the end faces 22a of the protrusions 22 to the opening edges of the outer ring 20. The axially inner portion of each inner circumferential surface 21a is located radially outward of the axially outer portion.

[0029] The inner ring 10 is formed in an annular shape from a metal material such as stainless steel or bearing steel. However, the inner ring 10 is not limited to being made of metal and may be formed from other materials. An inner ring rolling surface 11 is formed on the outer peripheral surface of the inner ring 10, recessed radially inward. The inner ring rolling surface 11 is formed hemispherically in cross section so as to fit along the outer surfaces of the rolling elements 30, and is formed in an annular shape extending circumferentially around the entire outer peripheral surface. The inner ring rolling surface 11 is formed on a portion of the outer peripheral surface of the inner ring 10 that is located centrally in the axial direction, and is disposed so as to face the outer ring rolling surface 23 in the radial direction. The portion of the inner peripheral surface of the inner ring 10 excluding the inner ring rolling surface 11 extends axially at a constant outer diameter.

[0030] The plurality of rolling elements 30 are formed into a spherical shape from a metal material such as stainless steel or bearing steel. The plurality of rolling elements 30 are arranged between the outer ring rolling surface 23 and the inner ring rolling surface 11 and are supported for rollability by the outer ring rolling surface 23 and the inner ring rolling surface 11. The plurality of rolling elements 30 are spaced apart in the circumferential direction by a cage 40.

[0031] FIG. 4 is a cross-sectional view showing the cage and grease according to the first embodiment. As shown in FIGS. 2 to 4 , the cage 40 is made of synthetic resin or metal and has an overall annular shape. The cage 40 is arranged around a common axis O. The cage 40 includes a base 41 formed in an annular shape and positioned below the rolling elements 30, and a plurality of pillars 42 projecting upward from the base 41 and spaced apart in the circumferential direction. The pillars 42 are evenly spaced apart in the circumferential direction. A pair of adjacent pillars 42 in the circumferential direction forms a ball pocket B therebetween. The ball pocket B extends radially through the cage 40 and opens upward at an upper end surface 40u of the cage 40. The ball pockets B are provided in a number corresponding to the number of rolling elements 30 and hold each rolling element 30 for individual rollability. As a result, the cage 40 evenly spaces the rolling elements 30 in the circumferential direction. The inner surface of the ball pocket B extends in an arc shape when viewed radially. As a result, the portion of base 41 located below the center of each ball pocket B becomes narrow portion 43 where the distance between lower end surface 40l of cage 40 and each ball pocket B is minimal.

[0032] As shown in FIG. 4, an upper recess 47 recessed downward is formed in the upper end surface 40u of the cage 40. The upper recess 47 is formed between a pair of ball pockets B adjacent in the circumferential direction. That is, the upper recess 47 is formed in each pillar portion 42. The portion of the pillar portion 42 located between the upper recess 47 and the ball pocket B is made into a claw portion 44. The pair of claw portions 44, arranged to sandwich each ball pocket B, rise in an arc shape so as to approach each other as they extend upward. As a result, the claw portions 44 hold the rolling elements 30 placed in the ball pocket B from above.

[0033] The lower end surface 40l of the cage 40 is formed with lower recesses 48 (recesses) that are recessed upward. The lower recesses 48 are formed between adjacent narrow width portions 43 in the circumferential direction. That is, the lower recesses 48 are formed in portions of the base 41 that are located below the upper recesses 47. The lower recesses 48 are arranged at equal intervals in the circumferential direction. The lower recesses 48 open downward and also open radially outward and inward. The lower recesses 48 have 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 in a direction inclined with respect to the axial direction so as to move away from each other from the circumferential ends of the bottom surface 48a. The portion of the lower end surface 40l of the cage 40 other than the lower recesses 48 is a flat surface perpendicular to the axial direction.

[0034] As shown in FIGS. 1 and 3 , the seal member 50 is formed in the shape of an annular plate. The seal member 50 is disposed about the common axis O. The seal member 50 is attached to the outer ring 20. One seal member 50 is disposed on each axial side of the rolling elements 30. The seal member 50 includes a base portion 51 that overlaps the end face 22 a of the protruding portion 22 of the outer ring 20 from the axial outside, a stepped portion 52 that extends axially outward from the inner peripheral edge of the base portion 51, a cover portion 53 that protrudes radially inward from the axially outer edge of the stepped portion 52, and a locking portion 54 that extends radially outward and axially outward from the outer peripheral edge of the base portion 51. The seal member 50 extends radially so as to straddle at least the center of the rolling elements 30 in a plan view. In this embodiment, the cover portion 53 overlaps the center of the rolling elements 30 in a plan view. However, the stepped portion 52 may extend axially outward and radially inward from the inner peripheral edge of the base portion 51 and overlap the center of the rolling element 30 in a plan view. The inner peripheral edge of the cover portion 53 is disposed with a gap from the outer peripheral surface of the inner ring 10. The outer peripheral edge of the locking portion 54 is locked to the inner peripheral surface 21a of the outer ring body 21 from the inside in the axial direction. This secures the seal member 50 to the outer ring 20.

[0035] As shown in FIGS. 3 and 4 , grease 60 is disposed in the annular space between the inner ring 10 and the outer ring 20. Grease 60 is disposed between a pair of seal members 50. Grease 60 is disposed only on the base portion 41 side of the cage 40 relative to the rolling elements 30. In other words, grease 60 is disposed only below the rolling elements 30. Grease 60 is disposed on the lower end surface 40l of the cage 40. Grease 60 is applied to portions of the lower end surface 40l of the cage 40 other than the lower recessed portions 48. In other words, grease 60 is applied to each portion of the lower end surface 40l of the cage 40 located between adjacent lower recessed portions 48 in the circumferential direction, and is disposed at intervals in the circumferential direction. One drop (one grain) of grease 60 is applied to each portion between adjacent lower recessed portions 48. Grease 60 is evenly distributed in the circumferential direction. In this embodiment, the grease 60 is applied to the narrow portion 43 of the base portion 41 of the cage 40. However, the grease may be applied in multiple drops to each of the locations between the lower recessed portions 48, or may be applied so as to extend in an arc. The grease 60 is spaced apart from the inner ring 10, the outer ring 20, and the seal member 50. Furthermore, the grease 60 is spaced apart from the rolling elements 30.

[0036] As described above, the bearing 1 of this embodiment includes a cage 40 having a ball pocket B that opens to the upper end surface 40u, and grease 60 that is disposed on the lower end surface 40l of the cage. With this configuration, the grease 60 can be applied to any location around the entire circumference of the lower end surface 40l of the cage 40. This makes it possible to increase the amount of grease 60 while minimizing direct contact of the grease 60 with the rolling elements 30, inner ring 10, and outer ring 20, compared to when grease is applied to the upper end surface 40u of the cage 40 while avoiding the opening of the ball pocket B and the rolling elements 30. This makes it possible to achieve both low torque and a long life for the bearing 1, and also to reduce the amount of grease 60 that is applied.

[0037] Furthermore, by disposing grease 60 on the lower end surface 40l of the retainer 40, the path from the grease 60 along the outer surface of the retainer 40 to the rolling elements 30 can be shortened compared to when grease is disposed in upper recesses 47 (grease pockets) recessed in the upper end surface 40u of the retainer 40. This makes it possible to reduce the amount of grease wetting the outer surface of the retainer 40, and increase the ratio of the amount of grease supplied to the rolling elements 30 to the amount of grease 60 disposed thereon. This therefore enables the life of the bearing 1 to be extended.

[0038] Furthermore, because the grease 60 is arranged at intervals in the circumferential direction, even if one grease 60 is displaced by centrifugal force due to rotation of the cage 40, it is possible to prevent other grease 60 from being pulled and displaced. Therefore, unnecessary outflow of grease 60 is prevented, and the life of the bearing 1 can be further extended.

[0039] Furthermore, since the rotating device 2 of this embodiment includes the above-described bearing 1, the rotational resistance of the shaft 3 relative to the housing 4 can be reduced, and the rotating device 2 can achieve reduced power consumption and a longer lifespan.

[0040] [Second embodiment] A second embodiment of the present invention will be described with reference to Fig. 5. Note that the configuration other than that described below is the same as that of the first embodiment. FIG. 5 is a cross-sectional view showing a cage and grease according to the second embodiment. In the first embodiment shown in FIG. 1, grease 60 is applied to the lower end surface 40l of the cage 40, except for the lower recessed portions 48. In contrast, in the second embodiment shown in FIG. 5, grease 60A is applied to the lower recessed portions 48 of the lower end surface 40l of the cage 40. The grease 60A is disposed on the bottom surfaces 48a of the lower recessed portions 48. One drop of grease 60A is applied to each of the bottom surfaces 48a of the lower recessed portions 48. The grease 60A is evenly distributed in the circumferential direction. However, multiple drops of grease may be applied to each of the bottom surfaces 48a of the lower recessed portions 48, or the grease may be applied so as to extend in an arc. Furthermore, the grease may be in contact with the side surfaces 48b of the lower recessed portions 48.

[0041] As described above, the grease 60A of this embodiment is disposed on the lower end surface 401 of the cage 40. Therefore, the bearing 1A of this embodiment has the same effects as the first embodiment.

[0042] Furthermore, the grease 60A is disposed in a lower recess 48 formed in the lower end surface 40l of the retainer 40. With this configuration, the circumferential displacement of the grease 60A is restricted by the side surface 48b of the lower recess 48, and therefore, the grease 60A can be prevented from shifting in the circumferential direction relative to the retainer 40 when the retainer 40 rotates. Therefore, unnecessary outflow of the grease 60A can be prevented, and the life of the bearing 1A can be further extended. Furthermore, the lower recess 48 can be used as a reference for positioning like an alignment mark when applying the grease 60A, so the grease 60A can be accurately placed in a desired position.

[0043] Furthermore, the lower recessed portion 48 is formed between adjacent narrow width portions 43 of the retainer 40 in the circumferential direction. According to this configuration, the lower recessed portion 48 is formed at a location that avoids the narrow width portions 43, and therefore, a decrease in rigidity that would otherwise be caused by a reduction in the thickness of the retainer 40 due to the formation of the lower recessed portion 48 can be suppressed.

[0044] [Third embodiment] A third embodiment of the present invention will be described with reference to Fig. 6. Note that the configuration other than that described below is the same as that of the first embodiment. FIG. 6 is a cross-sectional view showing a cage and grease according to the third embodiment. In the first embodiment shown in Fig. 1, lower recesses 48 are formed in the lower end surface 40l of the cage 40, and grease 60 is disposed at intervals in the circumferential direction. In contrast, in the third embodiment shown in Fig. 6, the lower end surface 40l of the cage 40 is formed flat over the entire circumference, and grease 60B extends continuously in the circumferential direction on the lower end surface 40l of the cage 40. For example, the grease 60B extends circumferentially over the entire circumference on the lower end surface 40l of the cage 40. However, the grease 60B may extend in an arc shape.

[0045] As described above, the grease 60B of this embodiment is disposed on the lower end surface 401 of the cage 40. Therefore, the bearing 1B of this embodiment has the same effects as the first embodiment.

[0046] Furthermore, because the grease 60B extends continuously in the circumferential direction, the amount of grease 60B can be increased compared to a configuration in which the grease is spaced apart in the circumferential direction, thereby further extending the life of the bearing 1B.

[0047] [Fourth embodiment] A fourth embodiment of the present invention will be described with reference to Figures 7 and 8. Note that the configuration other than that described below is the same as that of the first embodiment. Fig. 7 is a plan view of a rolling bearing according to a fourth embodiment. Fig. 8 is a cross-sectional view of a portion corresponding to line VIII-VIII in Fig. 7. Note that in Fig. 7, the seal member 50 is omitted to make it easier to see the internal configuration of the bearing 1C. In the first embodiment shown in Fig. 1, the grease 60 is applied only to the cage 40. In contrast to this, in the fourth embodiment shown in Figs. 7 and 8, the grease 160 is also applied to the bearing rings.

[0048] 7 and 8, the grease 160 includes a cage application portion 161 applied to the cage 40 and a raceway application portion 162 applied to the raceway. The cage application portion 161 is applied in the same manner as the grease 60 of the first embodiment. Note that the cage application portion 161 may also be applied in the same manner as the grease 60A of the second embodiment or the grease 60B of the third embodiment.

[0049] The raceway coating portion 162 is disposed between the rolling elements 30 and the seal member 50. The raceway coating portion 162 is disposed on only one axial side of the rolling elements 30 in the annular space between the inner ring 10 and the outer ring 20. In this embodiment, the raceway coating portion 162 is disposed on the opposite side of the cage coating portion 161 across the rolling elements 30 in the axial direction, and is provided as a separate body from the cage coating portion 161. The raceway coating portion 162 extends in the circumferential direction about the common axis O. The raceway coating portion 162 contacts the outer ring 20, which serves as a fixed ring, and is spaced apart from the inner ring 10, which serves as a rotating ring. Furthermore, the raceway coating portion 162 contacts the inner surface of the cover portion 53 of the seal member 50 and is supported by the seal member 50. The raceway coating portion 162 is spaced apart from the rolling elements 30 and the cage 40. However, the raceway coating portion 162 may be in contact with at least one of the rolling elements 30 and the cage 40 .

[0050] The bearing ring coating portion 162 includes a single arc-shaped portion 163 that extends continuously in an arc shape centered on the common axis O at a predetermined axial and radial position. That is, the arc-shaped portion 163 extends uninterrupted without changing its axial or radial position. The arc-shaped portion 163 extends from a first end 163a, which is one circumferential end, to a second end 163b, which is the other circumferential end, over an angle of 180° or more and less than 360°. As a result, the first end 163a of the arc-shaped portion 163 is spaced apart from the second end 163b in the circumferential direction. The circumferential distance between the first end 163a and the second end 163b of the arc-shaped portion 163 is preferably narrow enough to prevent contact between the first end 163a and the second end 163b. For example, the circumferential distance between the first end 163a and the second end 163b of the arc-shaped portion 163 is set to be smaller than the width of the arc-shaped portion 163 in a plan view. Furthermore, for example, the circumferential distance between the first end 163a and the second end 163b of the arc-shaped portion 163 is set to be smaller than the axial thickness of the arc-shaped portion 163. The arc-shaped portion 163 is in contact with the outer ring 20 and the seal member 50. Specifically, the arc-shaped portion 163 is in contact with a location on the inner circumferential surface of the protruding portion 22 of the outer ring 20 that is axially outward of the outer ring rolling surface 23. Note that the arc-shaped portion 163 may be separated from the seal member 50, and the race coating portion 162 may not be supported by the seal member 50.

[0051] As described above, the grease 160 of this embodiment has a cage application portion 161 arranged on the lower end surface 40l of the cage 40. Therefore, the bearing 1C of this embodiment has the same effects as the first embodiment.

[0052] Furthermore, the grease 160 is disposed between the rolling element 30 and the seal member 50 and has a raceway application portion 162 that contacts the outer ring 20. With this configuration, the amount of grease 160 disposed can be increased by the amount of raceway application portion 162 disposed, thereby further extending the life of the bearing 1C.

[0053] Furthermore, the first end 163a of the arc-shaped portion 163 is disposed at a distance in the circumferential direction from the second end 163b of the arc-shaped portion 163. With this configuration, a distance is provided between the first end 163a and the second end 163b of the arc-shaped portion 163, which prevents overlapping portions from being formed in the arc-shaped portion 163. This makes it difficult for the grease 160 to collapse under its own weight. This prevents the grease 160 from coming into contact with the rolling elements 30 and the cage 40 more than necessary. This allows for low torque for the bearing 1C.

[0054] Moreover, because only a single arc-shaped portion 163 is provided at a predetermined position in the axial and radial directions, the only location in the circumferential direction where no arc-shaped portion 163 is provided is the space between the first end 163a and the second end 163b. Therefore, compared to a configuration in which the raceway coating portions 162 are arranged intermittently along the circumferential direction, there are fewer locations in the circumferential direction where the raceway coating portions 162 are not arranged, allowing the raceway coating portions 162 to be arranged narrowly when filling the desired amount of raceway coating portions 162. This prevents the raceway coating portions 162 from coming into contact with the rolling elements 30 and the cage 40 more than necessary. This allows for low torque for the bearing 1C.

[0055] Furthermore, the raceway coating portion 162 is spaced apart from the inner ring 10, which is the rotating ring of the raceway, and the rolling elements 30. With this configuration, the raceway coating portion 162 is supported by the outer ring 20, which is the fixed ring, so that centrifugal force acting on the raceway coating portion 162 when the bearing 1C rotates can be suppressed, and the raceway coating portion 162 can be prevented from losing its shape immediately after application. As a result, the grease 160 in contact with the outer ring 20 can be maintained spaced apart from the inner ring 10 and the rolling elements 30, and the grease 160 can be prevented from acting as a resistance to the displacement (rotation) of the inner ring 10 and the rolling elements 30 relative to the outer ring 20. This makes it possible to achieve low torque for the bearing 1C.

[0056] The bearing ring coating portion may have a plurality of arc-shaped portions that are arranged at different positions in the axial and radial directions and are connected together to form an integrated unit.

[0057] [Fifth embodiment] A fifth embodiment of the present invention will be described with reference to Figures 9 and 10. Note that the configuration other than that described below is the same as that of the fourth embodiment. Fig. 9 is a plan view of a rolling bearing according to a fifth embodiment. Fig. 10 is a cross-sectional view of a portion corresponding to line XX in Fig. 9. Note that in Fig. 9, the seal member 50 is omitted to make it easier to see the internal configuration of the bearing 1D. In a fourth embodiment shown in Figures 7 and 8, a raceway coating portion 162 includes an arc-shaped portion 163 that extends in an arc shape. In contrast, in a fifth embodiment shown in Figures 9 and 10, a raceway coating portion 162 includes a first annular portion 164 and a second annular portion 165 that extend circumferentially.

[0058] As shown in FIGS. 7 and 8 , the bearing ring coating portion 162 includes a first annular portion 164 that contacts the outer ring 20, and a second annular portion 165 that is continuous with the first annular portion 164 and that contacts the seal member 50. The first annular portion 164 extends continuously circumferentially about the common axis O. The first annular portion 164 contacts a location on the inner circumferential surface of the protruding portion 22 of the outer ring 20 that is axially outward of the outer ring rolling surface 23. The second annular portion 165 extends continuously circumferentially about the common axis O. The second annular portion 165 is spaced apart from the outer ring 20 that the first annular portion 164 contacts. The second annular portion 165 is disposed on the radially opposite side of the outer ring 20 (i.e., radially inward) with respect to the first annular portion 164. Specifically, in a plan view, the outer peripheral edge of the second annular portion 165 is located radially inward of the outer peripheral edge of the first annular portion 164, and the inner peripheral edge of the second annular portion 165 is located radially inward of the inner peripheral edge of the first annular portion 164. The second annular portion 165 is connected to and integrated with the first annular portion 164 on the outside in the axial direction. The second annular portion 165 is connected to the first annular portion 164 around the entire circumference. The second annular portion 165 is supported by the seal member 50 by contacting a surface of the seal member 50 facing inward in the axial direction. In this embodiment, the second annular portion 165 is in contact with the inner surface of the cover portion 53 of the seal member 50.

[0059] Each of the first annular portion 164 and the second annular portion 165 is formed by applying grease from a nozzle in a circumferential direction over 360°. Each of the first annular portion 164 and the second annular portion 165 extends continuously around the entire circumference without forming any intermittent portions in a plan view. The first annular portion 164 extends from one peripheral end 164a over an angle of 360° or more but less than 720° about the common axis O to the other peripheral end 164b. This allows the first annular portion 164 to have a first overlapping portion 164c that includes the one peripheral end 164a and the other peripheral end 164b and overlaps each other in a plan view. It is desirable for the circumferential length of the first overlapping portion 164c to be sufficiently short. For example, the circumferential length of the first overlapping portion 164c is set to be approximately the same as the width of the first annular portion 164 in a plan view. The second annular portion 165 extends from one circumferential end 165a over an angle of 360° or more but less than 720° about the common axis O to the other circumferential end 165b. This allows the second annular portion 165 to have a second overlapping portion 165c that includes the one circumferential end 165a and the other circumferential end 165b and overlaps them in a planar view. It is desirable that the circumferential length of the second overlapping portion 165c be sufficiently small. For example, the circumferential length of the second overlapping portion 165c is set to be approximately the same as the width of the second annular portion 165 in a planar view. At least a portion of the second overlapping portion 165c is positioned at the same circumferential position as the first overlapping portion 164c and is continuous with the first overlapping portion 164c.

[0060] The bearing 1D of this embodiment described above provides the following advantageous effects in addition to the advantageous effects of the bearing 1C of the fourth embodiment. The grease 160 of the bearing 1D of this embodiment includes a raceway application portion 162 having a first annular portion 164 that extends circumferentially about the common axis O and contacts the outer race 20, and a second annular portion 165 that also extends circumferentially about the common axis O, connects to the first annular portion 164 on the axially outer side, and contacts the seal member 50. With this configuration, when filling a desired amount of raceway application portion 162, the volume of the first annular portion 164 can be reduced by the amount that the first annular portion 164 and the second annular portion 165 are formed, compared to when the raceway application portion 162 is applied so as to form a single annular portion. Therefore, by positioning the first annular portion 164 before the second annular portion 165 when applying the raceway application portion 162, it is possible to reduce the collapse of the first annular portion 164 due to its own weight. Furthermore, by providing the second annular portion 165, the second annular portion 165 is supported by the seal member 50, and the first annular portion 164 is supported not only by the outer ring 20 but also by the seal member 50 via the second annular portion 165. This makes it less likely that the bearing ring coating portion 162 as a whole will lose its shape immediately after coating due to its own weight. This makes it possible to prevent the bearing ring coating portion 162 from coming into contact with the rolling elements 30 and the cage 40 more than necessary. This therefore makes it possible to achieve low torque for the bearing 1D.

[0061] Furthermore, the seal member 50 is attached to the outer ring 20, which is the raceway with which the raceway coating portion 162 comes into contact. With this configuration, the outer ring 20 and the seal member 50 are arranged so that they do not rotate relative to each other, which prevents the raceway coating portion 162, which comes into contact with both the outer ring 20 and the seal member 50, from being agitated. This allows the raceway coating portion 162 to maintain the shape it had immediately after coating. This, in turn, allows for low torque for the bearing 1D.

[0062] The second annular portion 165 is disposed radially opposite the outer ring 20 relative to the first annular portion 164. With this configuration, compared to a configuration in which the first annular portion and the second annular portion are aligned in the axial direction, a space for disposing the first annular portion 164 is provided radially outward of the second annular portion 165, allowing the first annular portion 164 to be disposed further outward in the axial direction. This prevents the raceway coating portion 162 from coming into contact with the rolling elements 30 and the cage 40 more than necessary. This therefore enables the bearing 1D to achieve low torque.

[0063] Here, the cross-sectional area of ​​the first annular portion 164 is larger at the first overlapping portion 164c than at other portions, and the cross-sectional area of ​​the second annular portion 165 is larger at the second overlapping portion 165c than at other portions. If the first overlapping portion 164c and the second overlapping portion 165c are arranged at the same position in the circumferential direction, grease will easily spread where the first overlapping portion 164c and the second overlapping portion 165c overlap. For this reason, the first overlapping portion 164c and the second overlapping portion 165c may be arranged at positions offset from each other in the circumferential direction to prevent the raceway coating portion 162 from expanding in the axial direction and contacting the rolling elements 30 and the cage 40 more than necessary.

[0064] [Sixth embodiment] A sixth embodiment of the present invention will be described with reference to Figures 11 and 12. Note that the configuration other than that described below is the same as that of the fifth embodiment. Fig. 11 is a plan view of a rolling bearing according to a sixth embodiment. Fig. 12 is a cross-sectional view of a portion corresponding to line XII-XII in Fig. 11. Note that in Fig. 11, the seal member 50 is omitted to make it easier to see the internal configuration of the bearing 1E. 9 and 10, the bearing ring coating portions 162 extend continuously in the circumferential direction with a substantially constant width. In contrast, in the sixth embodiment shown in Figures 11 and 12, the bearing ring coating portions 162 are arranged in a dotted pattern in the circumferential direction.

[0065] As shown in FIGS. 11 and 12 , the raceway application portion 162 is integrally formed with a raceway contact portion 166 that contacts the outer ring 20 and a seal member contact portion 167 that is continuous with the raceway contact portion 166 and that contacts the seal member 50. The raceway contact portion 166 is disposed along the circumferential direction at a predetermined radial and axial position. The raceway contact portion 166 contacts a portion of the inner circumferential surface of the protruding portion 22 of the outer ring 20 that is axially outward of the outer ring rolling surface 23. The seal member contact portion 167 is disposed along the circumferential direction at a predetermined radial and axial position different from the raceway contact portion 166. The seal member contact portion 167 is spaced apart from the outer ring 20 that the raceway contact portion 166 contacts. The seal member contact portion 167 is disposed on the radially opposite side of the outer ring 20 (i.e., on the radially inner side) of the raceway contact portion 166. The seal member contact portion 167 is directly connected to and integrated with the raceway contact portion 166 on the outside in the axial direction. The seal member contact portion 167 is connected around the entire circumference of the raceway contact portion 166. The seal member contact portion 167 is supported by the seal member 50 by contacting the surface of the seal member 50 facing inward in the axial direction. The seal member contact portion 167 is in contact with the inner surface of the cover portion 53 of the seal member 50.

[0066] The raceway contact portion 166 has first granules 168 arranged in a dot pattern around the entire circumference. The first granules 168 are formed in the same shape. The first granules 168 have a spherical, ellipsoidal, or teardrop-shaped shape, with portions of the grease contacting the surrounding components and being crushed. As a result, the exposed portions of the outer surfaces of the first granules 168 are formed in a convex curved shape. The first granules 168 are aligned in the circumferential direction. Pairs of first granules 168 adjacent to each other in the circumferential direction are in contact with each other and integrated. Note that in the illustrated example, adjacent pairs of first granules 168 are in point contact with each other, but they may also be in contact with each other and crushed. However, adjacent pairs of first granules 168 may also be spaced apart from each other. Each first granule 168 is in contact with the outer ring 20. The contact portions between the first granules 168 and the outer ring 20 are spaced apart in the circumferential direction.

[0067] The seal member contact portion 167 has second granules 169 arranged in a dotted pattern around the entire circumference. The number of second granules 169 is the same as the number of first granules 168. The second granules 169 are formed in the same shape as each other. The second granules 169 have a spherical, ellipsoidal, or teardrop-shaped shape, resulting from a portion of the grease coming into contact with a surrounding member and being crushed. As a result, the exposed portion of the outer surface of the second granules 169 is formed into a convex curved shape. The second granules 169 are aligned in the circumferential direction. The second granules 169 are arranged circumferentially offset relative to the first granules 168. Specifically, the second granules 169 are arranged such that, when viewed axially, a straight line passing through the center of the second granule 169 and the common axis O passes through the midpoint between the centers of a pair of adjacent first granules 168. The second granules 169 contact and are integrated with the raceway contact portion 166. Each second particle 169 is in contact with a pair of first particles 168. Each second particle 169 is in contact with the sealing member 50. A pair of second particles 169 adjacent to each other in the circumferential direction are in contact with each other and integrated. However, a pair of second particles 169 adjacent to each other in the circumferential direction may be spaced apart from each other. The second particles 169 are formed larger in the radial direction than the first particles 168. As a result, the volume of the second particles 169 is larger than the volume of the first particles 168.

[0068] The bearing 1E of this embodiment described above provides the following advantages in addition to the same advantages as the bearing 1D of the fifth embodiment.

[0069] The raceway application portion 162 has a raceway contact portion 166 arranged circumferentially and in contact with the outer ring 20, and a seal member contact portion 167 arranged circumferentially, connected to the raceway contact portion 166 on the axially outer side, and in contact with the seal member 50. The raceway contact portion 166 has first granules 168 arranged in a dotted pattern around the entire circumference. With this configuration, the first granules 168 are supported by the outer ring 20 and the seal member contact portion 167. This makes the raceway application portion 162 less likely to collapse from its shape immediately after application due to its own weight, compared to a configuration in which grease arranged in dotted patterns around only one circumference along the circumferential direction is supported by one of the inner ring 10, the outer ring 20, and the seal member 50. The same is true for the seal member contact portion 167. Furthermore, compared to the configuration in which the same amount of grease as the raceway coating portion 162 of this embodiment is circumferentially arranged, the raceway coating portion 162 has scattered portions close to the rolling elements 30 and the cage 40, which reduces the amount of grease that can come into contact with the rolling elements 30 and the cage 40. This prevents the raceway coating portion 162 from coming into contact with the rolling elements 30 and the cage 40 more than necessary. This makes it possible to achieve low torque for the bearing 1E.

[0070] Furthermore, the second granules 169 of the seal member contact portion 167 are arranged circumferentially offset relative to the first granules 168. With this configuration, the seal member contact portion 167 can be arranged so that the second granules 169 fit between a pair of first granules 168. This makes it less likely that the raceway contact portion 166 will be pushed axially inward by the seal member contact portion 167 pressed from the axially outer side by the seal member 50, compared to a configuration in which the first granules and the second granules are arranged so as not to be offset relative to each other in the circumferential direction. Therefore, it is possible to make the raceway contact portion 166 less likely to lose its shape immediately after application. Furthermore, compared to a configuration in which the first granules and the second granules are arranged so as not to be shifted from each other in the circumferential direction, the total amount of the entire raceway ring coating portion 162 can be increased while preventing the entire raceway ring coating portion 162 from becoming larger in the axial direction.

[0071] Additionally, the number of second granules 169 provided is the same as the number of first granules 168. With this configuration, a pair of second granules 169 contacts each first granule 168. This increases the contact area between the raceway contact portion 166 and the seal member contact portion 167 compared to a configuration in which the first granules and second granules are arranged so as not to shift circumferentially relative to each other, and allows the raceway contact portion 166 to be stably held by the seal member contact portion 167 in contact with the seal member 50. This makes it possible to make the raceway contact portion 166 less likely to lose its shape immediately after application.

[0072] Furthermore, the second granules 169 are formed to be smaller in the radial direction than the first granules 168 that contact the second granules 169. With this configuration, the volume of each first granule 168 can be made smaller than the volume of each second granule 169. This reduces the amount of grease that can come into contact with the rolling elements 30 and the cage 40 at the raceway contact portion 166. This prevents the raceway application portion 162 from coming into contact with the rolling elements 30 and the cage 40 more than necessary. Furthermore, the increased volume of each second granule 169 increases the support force of the seal member 50 on the seal member contact portion 167, thereby increasing the overall holding force of the raceway coating portion 162, including the raceway contact portion 166. This makes it possible to make the raceway coating portion 162 less likely to collapse from its shape immediately after coating due to its own weight.

[0073] In the above embodiment, the raceway contact portion 166 and the seal member contact portion 167 of the raceway application portion 162 are arranged in a dotted pattern in the circumferential direction, but one of the raceway contact portion and the seal member contact portion may extend continuously in a circumferential or arc-like pattern, and the other may have particles arranged in a dotted pattern.

[0074] In the above embodiment, the first particles 168 and the second particles 169 are provided in equal numbers, but the numbers of the first particles and the second particles are not particularly limited. For example, the number of the second particles may be half the number of the first particles.

[0075] In the above embodiment, the second particles 169 are arranged circumferentially offset from the first particles 168, but the positional relationship between the first particles and the second particles is not limited to this. For example, the second particles may be arranged relative to the first particles so that the first particles and the second particles are aligned in the radial direction.

[0076] The present invention is not limited to the above-described embodiment explained with reference to the drawings, and various modifications are possible within the technical scope of the present invention. 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 fixed ring. The raceway coating portion 162 contacts the outer ring 20, which is a fixed ring. However, the raceway that the raceway coating portion contacts does not have to be a fixed ring. That is, the inner ring may be provided as a fixed ring, the outer ring may be provided as a rotating ring, and the raceway coating portion may contact the inner ring, which is a fixed ring. Alternatively, the inner ring may be provided as a fixed ring, the outer ring may be provided as a rotating ring, and the raceway coating portion may contact the outer ring, which is a rotating ring.

[0077] Furthermore, in the above embodiment, the grease placed on the retainer 40 is applied only to the lower end surface 40l of the retainer 40, but it may also be applied to the upper end surface 40u (for example, the upper recess 47).

[0078] In addition, in the above embodiment, the upper recess 47 is formed in the upper end surface 40u of the cage 40, but this configuration is not limited to this. In other words, the upper end surface of the cage may be formed flat over the entire periphery.

[0079] In the above embodiment, a fan motor is used as an example of a rotating device, but the present invention is not limited to this. For example, the present invention may be applied to at least one of a spindle motor and a swing arm of a hard disk drive as a rotating device.

[0080] In addition, within the scope of the spirit of the present invention, it is possible to replace the components in the above-described embodiments with well-known components as appropriate, and the above-described embodiments may be combined as appropriate. [Explanation of symbols]

[0081] 1, 1A, 1B, 1C, 1D, 1E... bearing 2... rotating device 10... inner ring 20... outer ring 30... rolling element 40... cage 40l... lower end face (end face) 48... lower recess (recess) 43... narrow width portion 50... sealing member 60... grease 60A... grease 60B... grease 160... grease 162... bearing ring application portion B... ball pocket

Claims

1. an inner ring and an outer ring arranged coaxially with each other; a rolling element disposed between the inner ring and the outer ring; an annular cage disposed between the inner ring and the outer ring and configured to rotatably hold the rolling elements; grease disposed between the inner ring and the outer ring; a seal member that covers a gap between the inner ring and the outer ring from a first axial direction; A rolling bearing comprising: The cage is formed with ball pockets that penetrate in the radial direction and open in the first direction, and that individually hold the rolling elements so that they can roll, a recessed portion recessed in the first direction and opening to the outside and inside in the radial direction is formed on an end surface of the cage facing the second axial direction, The grease is a retainer application portion disposed in the recess and spaced apart from the rolling elements in a state before use of the rolling bearing; a raceway coating portion disposed between the rolling element and the seal member and in contact with one of the inner ring and the outer ring; having Rolling bearing.

2. the cage has narrow portions where the distance between the end faces and each of the ball pockets is minimal, The recessed portion is formed between adjacent narrow width portions in the circumferential direction.

2. The rolling bearing according to claim 1.

3. one of the inner ring and the outer ring is provided as a fixed ring, the raceway coating portion is spaced apart from the other of the inner ring and the outer ring and the rolling element; 3. The rolling bearing according to claim 1 or 2.

4. a rotatably arranged rotating body; a support that rotatably supports the rotating body; The rolling bearing according to any one of claims 1 to 3, which is interposed between the rotating body and the support body; A rotating device comprising:

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