JP7495343B2 - Rolling bearing, rotating device, and method for manufacturing rolling bearing - Google Patents

Description

The present invention relates to rolling bearings, rotating equipment, and methods for manufacturing rolling bearings.

Conventionally, there are rolling bearings that hold grease between a pair of raceways (inner and outer rings). In this type of rolling bearing, the resistance of the grease can be a factor in increasing the torque. However, in order to reduce the power consumption of the rotating equipment in which the rolling bearing is mounted, low torque is desired. There is a strong demand for low torque, especially in small rolling bearings used in various motors such as fan motors.

In order to reduce the torque of the rolling bearing, grease is applied to the axial end of the fixed ring (often the outer ring) of the rolling bearing and to the seal member arranged on this end side, thereby reducing the amount of grease that comes into contact with the rolling elements (balls) and the cage that holds the rolling elements (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.

JP 2013-204679 A

One method for applying grease to a raceway in a circular shape is to rotate the nozzle and the raceway relative to each other while discharging grease from the nozzle. However, when grease is applied in a circular shape around the entire circumference, the grease may gradually break down due to its own weight immediately after application. In this case, the grease may come into contact with the rolling elements and cage more than necessary, causing the torque of the rolling bearing to be greater than desired.

Therefore, the present invention provides a rolling bearing, a rotating device, and a method for manufacturing a rolling bearing that can achieve low torque.

The rolling bearing of the present invention comprises an inner ring and an outer ring arranged coaxially with each other, a rolling element arranged between the inner ring and the outer ring, a seal member covering the space between the inner ring and the outer ring from the outside in the axial direction, and grease arranged between the rolling element and the seal member, the grease having a first annular portion extending circumferentially around a common axis of the inner ring and the outer ring and in contact with one of the inner ring and the outer ring, and a second annular portion extending circumferentially around the common axis, connected to the first annular portion on the outside in the axial direction and in contact with the seal member.

According to the present invention, when filling a desired amount of grease, the volume of the first annular portion can be reduced by the amount of the first annular portion formed, compared to when the grease is applied so that a single annular portion is formed, by forming the first annular portion before the second annular portion when applying the grease. Therefore, by forming the first annular portion before the second annular portion when applying the grease, it is possible to make the first annular portion less likely to collapse due to its own weight. In addition, by providing the second annular portion, the second annular portion is supported by the seal member, and the first annular portion is supported not only by one of the inner ring and the outer ring, but also by the seal member via the second annular portion. Therefore, the grease as a whole is less likely to collapse from the shape immediately after application due to its own weight. Therefore, it is possible to suppress the grease from coming into contact with the rolling elements and the cage more than necessary. Therefore, it is possible to achieve low torque for the rolling bearing.

In the above rolling bearing, one of the inner ring and the outer ring may be provided as a fixed ring.

According to the present invention, since the grease comes into contact with the fixed ring, it is possible to prevent centrifugal force from acting on the grease when the rolling bearing rotates, and it is possible to prevent the grease from losing its shape immediately after application. Therefore, it is possible to achieve low torque for the rolling bearing.

In the above rolling bearing, one of the inner ring and the outer ring may be the outer ring.

According to the present invention, even if the grease rotates and centrifugal force acts on the grease when the rolling bearing rotates, the outer ring restricts the radial outward displacement of the grease, so the grease can be maintained in the shape it had immediately after application. This makes it possible to achieve low torque for the rolling bearing.

In the above rolling bearing, the seal member may be attached to one of the inner ring and the outer ring.

According to the present invention, one of the inner and outer rings and the seal member is arranged so that they do not rotate relative to one another, so that the grease in contact with both can be prevented from being agitated. This allows the grease to maintain the shape it had immediately after application. This makes it possible to achieve low torque for the rolling bearing.

In the above rolling bearing, the second annular portion may be disposed on the opposite side of the first annular portion from one of the inner ring and the outer ring in a radial direction centered on the common axis.

According to the present invention, compared to a configuration in which the first annular portion and the second annular portion are aligned in the axial direction, a space is provided for arranging the first annular portion on one side of the inner ring or the outer ring in the radial direction relative to the second annular portion, and the first annular portion can be arranged further outward in the axial direction. This makes it possible to prevent the grease from coming into contact with the rolling elements and the cage more than necessary. Therefore, it is possible to achieve low torque for the rolling bearing.

In the above rolling bearing, the first annular portion has a first overlapping portion that extends from one peripheral end portion around the common axis by 360° or more and less than 720° to the other peripheral end portion, and overlaps with each other when viewed from the axial direction, and the second annular portion has a second overlapping portion that extends from one peripheral end portion around the common axis by 360° or more and less than 720° to the other peripheral end portion, and the second overlapping portion may be disposed at a position shifted in the circumferential direction around the common axis with respect to the first overlapping portion.

Here, the cross-sectional area of the first annular portion is larger in the first overlapping portion than in other portions, and the cross-sectional area of the second annular portion is larger in the second overlapping portion than in other portions. If the first overlapping portion and the second overlapping portion were arranged at the same position in the circumferential direction, the grease would tend to spread where the first overlapping portion and the second overlapping portion overlap. According to the present invention, the first overlapping portion and the second overlapping portion are arranged at positions offset from each other in the circumferential direction, so that the grease can be prevented from spreading in the axial direction and coming into contact with the rolling elements and the cage more than necessary. Therefore, a low torque rolling bearing can be achieved.

The above rolling bearing may further include another grease arranged on the opposite side of the rolling element from the grease in the axial direction.

According to the present invention, it is possible to increase the total amount of grease placed in the bearing by using other grease while preventing the grease from losing its shape due to interference with the first and second annular portions. Therefore, it is possible to provide a bearing with a longer life.

The rotating device of the present invention is characterized by comprising a rotatably arranged rotating body, a support that rotatably supports the rotating body, and the above-mentioned rolling bearing interposed between the rotating body and the support.

The present invention provides a low-torque rolling bearing, which reduces the rotational resistance of the rotating body relative to the support, thereby achieving power savings in rotating equipment.

The manufacturing method of the rolling bearing of the present invention is the manufacturing method of the rolling bearing described above, characterized in that it comprises a first application step in which grease is ejected from a first nozzle at a first application position to form the first annular portion, and a second application step in which grease is ejected from a second nozzle, different from the first nozzle, at a second application position different from the first application position to form the second annular portion.

According to the present invention, the cycle time at each application position can be shortened. This improves the manufacturing efficiency of bearings. Furthermore, in a manufacturing method in which grease is applied in an annular shape while rotating a bearing, a mechanism for driving a nozzle in the radial direction relative to the bearing is not required, so the structure of the grease application device can be simplified.

The present invention provides a rolling bearing, a rotating device, and a method for manufacturing a rolling bearing that can achieve low torque.

FIG. 1 is a plan view of a rolling bearing according to a first embodiment. 2 is a cross-sectional view taken along line II-II in FIG. 4 is a flowchart showing a grease application method according to the first embodiment. FIG. 4 is a plan view illustrating a method of applying grease. FIG. 4 is a plan view illustrating a method of applying grease. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. FIG. 4 is a plan view illustrating a method of applying grease. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7. FIG. 6 is a plan view of a rolling bearing according to a second embodiment. FIG. 11 is a cross-sectional view of a rolling bearing according to a third embodiment. FIG. 13 is a cross-sectional view of a rolling bearing according to a fourth embodiment.

The following describes an embodiment of the present invention with reference to the drawings. In the following description, components having the same or similar functions are given the same reference numerals. Furthermore, duplicate descriptions of those components may be omitted.

[First embodiment]
A first embodiment of the present invention will be described with reference to FIGS. 1 to 8. FIG.
Fig. 1 is a plan view of the rolling bearing according to the first embodiment. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. Note that in Fig. 1, a seal member 50 and a filled grease 60, which will be described later, are partially omitted in order to make it easier to see the internal configuration of the rolling bearing 1. Also, in Fig. 2, the members on which the rolling bearing 1 is mounted are shown by virtual lines.

As shown in Figs. 1 and 2, the rolling bearing 1 is a ball bearing including an inner ring 10 and an outer ring 20, which are raceways, a plurality of rolling elements 30, a retainer 40, a pair of seal members 50, and a filled grease 60. The rolling bearing 1 is provided in a rotating device 2 such as a fan motor. The rotating device 2 includes a shaft 3 (rotating body) formed to be rotatable about a common axis O, and a housing 4 (support) that is fixedly set and rotatably supports the shaft 3. The rolling bearing 1 is interposed between the shaft 3 and the housing 4. In the following, the rolling bearing may be simply referred to as a bearing. In this embodiment, the grease before being filled in the bearing 1 is simply referred to as grease, and the grease filled in the bearing 1 by applying the grease is referred to as filled grease 60.

The inner ring 10 and the outer ring 20 are arranged coaxially with each other so that their respective central axes are located on a 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.

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) of 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 provided between the inner ring 10 and the outer ring 20. The multiple rolling elements 30 are disposed between the inner ring 10 and the outer ring 20, and are held by the retainer 40 so that they can roll. The retainer 40 holds each rolling element 30 rotatably, with the multiple rolling elements 30 evenly arranged in the circumferential direction. The seal member 50 covers the annular space between the inner ring 10 and the outer ring 20 from the outside in the axial direction.

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 at the center of 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 element 30.

The inner peripheral surface of the protrusion 22 is formed with an outer ring rolling surface 23 that is recessed radially outward. The outer ring rolling surface 23 is formed in a hemispherical shape in cross section so as to conform to the outer surface of the rolling body 30, and is formed in an annular shape extending in the circumferential direction around the entire circumference of the inner peripheral surface of the protrusion 22. The outer ring rolling surface 23 is formed on a portion of the inner peripheral surface of the protrusion 22 that is located at the center in the axial direction. The portion of the inner peripheral surface of the protrusion 22 excluding the outer ring rolling surface 23 extends in the axial direction with a constant inner diameter. The protrusion 22 has a pair of end faces 22a facing in the axial direction. Each end face 22a extends parallel in both the radial and circumferential directions.

The outer ring body 21 has a pair of inner peripheral 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 axially inner portion of each inner peripheral surface 21a is located radially outward from the axially outer portion.

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. The inner ring 10 has an inner ring rolling surface 11 formed on its outer peripheral surface, which is recessed radially inward. The inner ring rolling surface 11 is formed in a hemispherical shape in cross section so as to follow the outer surface of the rolling element 30, and is formed in an annular shape extending in the circumferential direction around the entire circumference of the 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 at the center in the axial direction, and is arranged 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 other than the inner ring rolling surface 11 extends in the axial direction with a constant outer diameter.

The multiple rolling elements 30 are formed into a spherical shape from a metal material such as stainless steel or bearing steel. The multiple rolling elements 30 are disposed between the outer ring rolling surface 23 and the inner ring rolling surface 11, and are supported by the outer ring rolling surface 23 and the inner ring rolling surface 11 so as to be capable of rolling.

The retainer 40 is made of synthetic resin or metal material and is generally annular. The retainer 40 is arranged around the common axis O. The retainer 40 includes a main body 41 formed in an annular shape and arranged on the other side of the axial direction with respect to the plurality of rolling elements 30, and a pair of claws 42 rising from the main body 41 on one side of the axial direction. The pair of claws 42 rotatably hold one rolling element 30. The pair of claws 42 rise in an arc shape from the main body 41 toward the tip so that the distance between them approaches each other. The retainer 40 is arranged with a gap between the inner ring 10 and the outer ring 20 so as not to interfere with the inner ring 10 and the outer ring 20. In this embodiment, the entire retainer 40 is located axially inward of the pair of end faces 22a of the protruding portion 22 of the outer ring 20.

The seal member 50 is formed in a circular plate shape. The seal member 50 is arranged around the common axis O. The seal member 50 is attached to the outer ring 20. The seal member 50 is arranged on both sides of the rolling elements 30 in the axial direction. The seal member 50 includes a base 51 that overlaps the end face 22a of the protruding portion 22 of the outer ring 20 from the outside in the axial direction, a step portion 52 that extends from the inner peripheral edge of the base 51 to the outside in the axial direction, a cover portion 53 that protrudes radially inward from the axially outer edge of the step portion 52, and a locking portion 54 that extends radially outward and axially outward from the outer peripheral edge of the base 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 step portion 52 may extend from the inner peripheral edge of the base portion 51 axially outward and radially inward, overlapping the center of the rolling element 30 in plan view. The inner peripheral edge of the cover portion 53 is disposed with a gap on 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 fixes the seal member 50 to the outer ring 20.

The filled grease 60 is disposed between the rolling element 30 and the seal member 50. The filled grease 60 is disposed only on one side of the axial direction of the rolling element 30 in the annular space between the inner ring 10 and the outer ring 20. In this embodiment, the filled grease 60 is disposed on one side of the axial direction of the rolling element 30. That is, the filled grease 60 is disposed on the opposite side of the main body 41 of the retainer 40 across the rolling element 30 in the axial direction. The filled grease 60 is disposed in a circular ring shape in a plan view and is disposed coaxially with the common axis O. The filled grease 60 is in contact with the outer ring 20 provided as a fixed ring and is spaced apart from the inner ring 10 provided as a rotating ring. The filled grease 60 is also spaced apart from the rolling element 30 and the retainer 40. However, the filled grease 60 may be in contact with at least one of the rolling element 30 and the retainer 40.

The filled grease 60 includes a first annular portion 61 in contact with the outer ring 20, and a second annular portion 62 that is connected to the first annular portion 61 and is in contact with the seal member 50. The first annular portion 61 and the second annular portion 62 are formed by applying the grease twice. The first annular portion 61 extends circumferentially around the common axis O. The first annular portion 61 contacts a portion of the inner circumferential surface of the protruding portion 22 of the outer ring 20 that is axially outward from the outer ring rolling surface 23. The second annular portion 62 extends circumferentially around the common axis O. The second annular portion 62 is spaced apart from the outer ring 20 with which the first annular portion 61 contacts the raceway. The second annular portion 62 is disposed radially opposite the outer ring 20 (i.e., radially inward) with respect to the first annular portion 61. Specifically, in a plan view, the outer peripheral edge of the second annular portion 62 is located radially inward from the outer peripheral edge of the first annular portion 61, and the inner peripheral edge of the second annular portion 62 is located radially inward from the inner peripheral edge of the first annular portion 61. The second annular portion 62 is connected to the first annular portion 61 on the outside in the axial direction and is integrated with it. The second annular portion 62 is connected to the entire circumference of the first annular portion 61. The second annular portion 62 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 62 is in contact with the inner surface of the cover portion 53 of the seal member 50.

Each of the first annular portion 61 and the second annular portion 62 is formed by applying grease discharged from a nozzle in a circumferential manner over 360°. Each of the first annular portion 61 and the second annular portion 62 extends continuously around the entire circumference so that no intermittent portions are formed in a plan view. The first annular portion 61 extends from one peripheral end portion 61a to the other peripheral end portion 61b over 360° and less than 720° around the common axis O. As a result, the first annular portion 61 has a first overlapping portion 63 including one peripheral end portion 61a and the other peripheral end portion 61b, which overlap each other in a plan view. It is desirable that the length of the first overlapping portion 63 in the circumferential direction is sufficiently small. For example, the length of the first overlapping portion 63 in the circumferential direction is set to be approximately the same as the width of the first annular portion 61 in a plan view. The second annular portion 62 extends from one peripheral end 62a to the other peripheral end 62b by 360° or more and less than 720° about the common axis O. As a result, the second annular portion 62 has a second overlapping portion 64 including one peripheral end 62a and the other peripheral end 62b, which overlap each other in a planar view. It is desirable that the length of the second overlapping portion 64 in the circumferential direction is sufficiently small. For example, the length of the second overlapping portion 64 in the circumferential direction is set to be approximately the same as the width of the second annular portion 62 in a planar view. At least a portion of the second overlapping portion 64 is disposed at the same position in the circumferential direction as the first overlapping portion 63, and is continuous with the first overlapping portion 63.

Next, a method of applying grease will be described as a method of manufacturing the bearing 1 of this embodiment.
FIG. 3 is a flowchart showing the grease application method according to the first embodiment.
As shown in FIG. 3, the grease application method of the present embodiment includes a first application step S10 and a second application step S20.

Figures 4, 5 and 7 are plan views for explaining a method of applying grease. Figure 6 is a cross-sectional view taken along line VI-VI in Figure 5. Figure 8 is a cross-sectional view taken along line VIII-VIII in Figure 7.
4, the first application step S10 is performed in a state where the seal member 50 is not attached to the outer ring 20. That is, the annular space between the inner ring 10 and the outer ring 20 is opened in the axial direction, and the grease is applied in a state where the rolling elements 30 and the cage 40 are exposed.

As shown in Figures 5 and 6, in the first application step S10, grease G1 is discharged from a nozzle (not shown) while rotating the nozzle about a common axis O relative to the outer ring 20. At this time, the position of the nozzle is adjusted so that the discharged grease G1 contacts the axial end of the inner peripheral surface of the protruding portion 22 of the outer ring 20. Since the grease G1 is discharged while rotating the nozzle relative to the outer ring 20, the grease G1 extends in an arc. The grease G1 attached to the outer ring 20 extends 360° or more from the starting point 71 corresponding to the discharge start point, and reaches the end point 72 corresponding to the discharge end point. This forms a first annular portion 61 having a first overlapping portion 63.

7 and 8, in the second application process S20, the nozzle is shifted from the position in the first application process S10, and the nozzle is rotated again around the common axis O relative to the outer ring 20 to discharge the grease G2 from the nozzle. At this time, the position of the nozzle is adjusted so that the discharged grease G2 contacts the first annular portion 61 from the outside in the axial direction and the inside in the radial direction, and the applied grease G2 protrudes axially outward from the first annular portion 61. The grease G2 that contacts the first annular portion 61 extends 360° or more from the starting end 73 corresponding to the discharge start point, and reaches the end 74 corresponding to the discharge end point. At this time, the starting end 73 of the grease G2 in the second application process S20 is located at the same position in the circumferential direction as the starting end 71 of the grease G1 in the first application process S10. In addition, the end 74 of the grease G2 in the second application process S20 is located at the same position in the circumferential direction as the end 72 of the grease G1 in the first application process S10. This forms the second annular portion 62 having the second overlapping portion 64.

This completes the application of grease. After that, the seal member 50 is inserted from the outside in the axial direction into the annular space between the inner ring 10 and the outer ring 20, and the seal member 50 is attached to the outer ring 20. At this time, the grease applied in the second application process S20 comes into contact with the cover portion 53 of the seal member 50, resulting in the state shown in FIG. 2.

As described above, the first annular portion 61 and the second annular portion 62 are formed from greases discharged in different processes. Therefore, the portion of the cross-sectional contour of the first annular portion 61 that is not in contact with the outer ring 20 or the second annular portion 62 extends in an arc or elliptical shape with the position where it overlaps with the first annular portion 61 as the center. In addition, the portion of the cross-sectional contour of the second annular portion 62 that is not in contact with the seal member 50 or the first annular portion 61 extends in an arc or elliptical shape with the position where it overlaps with the second annular portion 62 as the center.

As described above, the bearing 1 of this embodiment includes a filled grease 60 having a first annular portion 61 that extends circumferentially around the common axis O and contacts the outer ring 20, and a second annular portion 62 that extends circumferentially around the common axis O, is connected to the first annular portion 61 on the axial outside, and contacts the seal member 50. According to this configuration, when filling a desired amount of grease, the volume of the first annular portion 61 can be reduced by the amount of the first annular portion 61 and the second annular portion 62 formed, compared to when grease is applied to form a single annular portion. Therefore, by forming the first annular portion 61 before the second annular portion 62 when applying grease, it is possible to make it difficult for the first annular portion 61 to collapse due to its own weight. In addition, by providing the second annular portion 62, the second annular portion 62 is supported by the seal member 50, and the first annular portion 61 is supported not only by the outer ring 20 but also by the seal member 50 via the second annular portion 62. As a result, the filled grease 60 as a whole is less likely to collapse from the shape it had immediately after application due to its own weight. This makes it possible to prevent the filled grease 60 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 1.

In addition, the outer ring 20, which is the raceway that the filled grease 60 contacts, is provided as a fixed ring. With this configuration, the filled grease 60 contacts the fixed ring, so centrifugal force is prevented from acting on the filled grease 60 when the bearing 1 rotates, and the filled grease 60 is prevented from losing its shape immediately after application. Therefore, low torque can be achieved for the bearing 1.

The seal member 50 is attached to the outer ring 20, which is the raceway that the filled grease 60 comes into contact with. With this configuration, the outer ring 20 and the seal member 50 are arranged so that they do not rotate relative to each other, so that the filled grease 60 that comes into contact with both can be prevented from being agitated. This allows the filled grease 60 to maintain the shape it had immediately after application. This allows the bearing 1 to have a low torque.

The second annular portion 62 is disposed radially opposite the outer ring 20 with respect to the first annular portion 61. 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 is provided for disposing the first annular portion 61 radially outward of the second annular portion 62, and the first annular portion 61 can be disposed further outward in the axial direction. This makes it possible to prevent the filled grease 60 from coming into contact with the rolling elements 30 and the cage 40 more than necessary. Therefore, it is possible to achieve low torque for the bearing 1.

Here, in this embodiment, the outer peripheral edge of the seal member 50 is engaged with the inner peripheral surface of the outer ring 20. In a conventional configuration in which grease is arranged to form a single annular portion, if the grease is arranged at a position farther outward in the axial direction from the rolling elements to prevent the grease from collapsing under its own weight and coming into contact with the rolling elements and the cage more than necessary, the grease may be crushed by the seal member and leak from the gap between the outer peripheral edge of the seal member and the outer ring. According to this embodiment, the second annular portion 62, which is located axially outward from the first annular portion 61, is arranged on the opposite side of the outer peripheral edge of the seal member 50 across the first annular portion 61, so that the second annular portion 62 can be prevented from leaking from the gap between the outer peripheral edge of the seal member 50 and the outer ring 20. Therefore, leakage of grease from the bearing 1 can be suppressed.

The rotating device 2 of this embodiment is equipped with the above-mentioned bearing 1, so that the rotational resistance of the shaft 3 relative to the housing 4 can be reduced, and power saving of the rotating device 2 can be achieved.

In the manufacturing method of the bearing 1 of this embodiment, the nozzle for discharging the grease is shared in the first application step S10 and the second application step S20, but this is not limited to this method. A first nozzle for use in the first application step S10 and a second nozzle for use in the second application step S20 may be prepared. In this case, it is desirable to perform the first application step S10 and the second application step S20 at different application positions. That is, the first application step S10 is performed at the first application position, the bearing that has completed the first application step S10 is transported to the second application position, and the second application step S20 is performed at the second application position. Also, while the second application step S20 is being performed, the first application step S10 may be performed on the next bearing at the first application position. According to this method, the cycle time at each application position can be shortened. Therefore, the manufacturing efficiency of the bearing 1 can be improved. In addition, in the manufacturing method in which grease is applied in a ring shape while rotating the bearing, a mechanism for driving the nozzle in the radial direction relative to the bearing is not required, so the structure of the grease application device can be simplified.

[Second embodiment]
A second embodiment of the present invention will be described with reference to Fig. 9. Note that the configuration other than that described below is similar to that of the first embodiment.

9 is a plan view of a rolling bearing according to the second embodiment. Note that in FIG. 9, the seal member 50 is omitted in order to make it easier to see the internal configuration of the bearing 1A.
In the first embodiment shown in Fig. 1, the second overlapping portion 64 of the filled grease 60 is disposed at the same position in the circumferential direction relative to the first overlapping portion 63. In contrast, in the second embodiment shown in Fig. 9, the second overlapping portion 64 of the filled grease 60 is disposed at a position shifted in the circumferential direction relative to the first overlapping portion 63. The second overlapping portion 64 is formed by shifting the start point and end point of the grease in the circumferential direction relative to the first overlapping portion 63 in the second application step similar to the first embodiment.

Here, the cross-sectional area of the first annular portion 61 is larger in the first overlapping portion 63 than in other portions. Also, the cross-sectional area of the second annular portion 62 is larger in the second overlapping portion 64 than in other portions. If the first overlapping portion 63 and the second overlapping portion 64 were arranged at the same position in the circumferential direction, the filled grease 60 would easily spread at the position where the first overlapping portion 63 and the second overlapping portion 64 overlap. According to this embodiment, since the first overlapping portion 63 and the second overlapping portion 64 are arranged at positions shifted from each other in the circumferential direction, it is possible to prevent the filled grease 60 from spreading in the axial direction and coming into contact with the rolling elements 30 and the cage 40 more than necessary. Therefore, it is possible to achieve low torque for the bearing 1A.

[Third embodiment]
A third embodiment of the present invention will be described with reference to Fig. 10. Note that the configuration other than that described below is similar to that of the first embodiment.

FIG. 10 is a cross-sectional view of a rolling bearing according to the third embodiment.
In the third embodiment shown in FIG. 10, the bearing 1B includes another grease 65 in addition to the filled grease 60. The other grease 65 is disposed on the opposite side of the filled grease 60 with respect to the rolling element 30 in the axial direction. That is, the other grease 65 is disposed on the same side as the main body 41 of the cage 40 with respect to the rolling element 30 in the axial direction. The other grease 65 is disposed between the rolling element 30 and the seal member 50. The other grease 65 is disposed in an annular space between the inner ring 10 and the outer ring 20. The other grease 65 is in contact with the contact object of the filled grease 60 among the inner ring 10 and the outer ring 20 (the outer ring 20 in this embodiment). The other grease 65 is in contact with one of the inner ring 10 and the outer ring 20 and is spaced from the other, like the filled grease 60. The other grease 65 is spaced from the rolling element 30 and the cage 40. The other grease 65 extends circumferentially around the common axis O. The other grease 65 is in contact with a portion of the inner circumferential surface of the protruding portion 22 of the outer ring 20 that is axially outer than the outer ring rolling surface 23 .

However, the configuration of the other grease is not limited to the above configuration. The other grease may be in contact with the inner ring 10 and spaced apart from the outer ring 20. The other grease may be in contact with at least one of the rolling elements 30 and the cage 40. Furthermore, the other grease does not have to extend circumferentially. For example, the other grease may extend in an arc or may be arranged in dots along the circumferential direction.

According to this embodiment, the other grease 65 can increase the total amount of grease placed in the bearing 1B while preventing the other grease 65 from interfering with the filled grease 60 and causing the filled grease 60 to lose its shape. Therefore, it is possible to provide a bearing 1B with a long life.

[Fourth embodiment]
A fourth embodiment of the present invention will be described with reference to Fig. 11. Note that the configuration other than that described below is similar to that of the first embodiment.

FIG. 11 is a cross-sectional view of a rolling bearing according to the fourth embodiment.
In the fourth embodiment shown in Fig. 11, the bearing 1C includes another grease 66 in addition to the filled grease 60. The other grease 66 is supported by the cage 40. The other grease 66 is disposed in a pocket between a pair of claw portions 42 on the opposite side of the cage 40 from the rolling elements 30 with the claw portions 42 in between. In the illustrated example, the other grease 66 is in contact with the body portion 41 of the cage 40, but may be in contact with the claw portions 42. The other grease 66 is separated from the rolling elements 30 and the filled grease 60. The other grease 66 may be disposed in all pockets of the cage 40, or may be disposed in only some of the pockets.

According to this embodiment, the total amount of grease placed in the bearing 1C can be increased by using the other grease 66. Therefore, it is possible to provide a bearing 1C with a longer life.

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 filled grease 60 is in contact with the outer ring 20, which is a fixed ring. However, the raceway with which the filled grease comes in contact 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 filled grease may come in contact with the inner ring, which is a fixed ring. Also, the inner ring may be provided as a fixed ring, the outer ring may be provided as a rotating ring, and the filled grease may come in contact with the outer ring, which is a rotating ring. In this case, the filled grease rotates together with the outer ring, but even if centrifugal force acts on the filled grease, the outer ring restricts the radial outward displacement of the grease, so that the filled grease can be maintained in the shape it had immediately after application. However, it is preferable that the filled grease comes in contact with the raceway to which the seal member is attached, among the inner ring and the outer ring.

In the above embodiment, the grease is discharged separately in the first application step S10 and the second application step S20. However, the grease may be discharged continuously in the first application step S10 and the second application step S20. This allows one peripheral end of the first annular portion of the filled grease to be connected to the other peripheral end of the second annular portion.

In addition, in the above embodiment, the volume ratio of the first annular portion 61 and the second annular portion 62 of the filled grease 60 is not particularly limited. For example, the cross-sectional areas of the transverse sections of the first annular portion 61 and the second annular portion 62 may be equal to each other or different from each other.

In addition, in the above embodiment, the filled grease 60 has two annular portions 61, 62, but it may have three or more annular portions.

In addition, in the above embodiment, a fan motor is used as an example of a rotating device, but the rotating device 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.

In addition, the components in the above-described embodiments may be replaced with known components as appropriate without departing from the spirit of the present invention, and the above-described embodiments may be combined as appropriate. For example, the bearing 1A of the second embodiment may be provided with the other grease 65 of the third embodiment or the other grease 66 of the fourth embodiment.

1, 1A, 1B, 1C... rolling bearing 2... rotating device 3... shaft (rotating body) 4... housing (support) 10... inner ring 20... outer ring 30... rolling body 50... seal member 60... filled grease (grease) 61... first annular portion 62... second annular portion 63... first overlapping portion 64... second overlapping portion 65... other grease O... common axis

Claims (9)

An inner ring and an outer ring arranged coaxially with each other;
A rolling element 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 an outside in the axial direction;
grease disposed between the rolling element and the seal member;
Equipped with
The grease is
a first annular portion extending circumferentially about a common axis of the inner ring and the outer ring and in contact with one of the inner ring and the outer ring;
a second annular portion extending circumferentially about the common axis, connected to the first annular portion on the outside in the axial direction, and in contact with the seal member;
having
Rolling bearing. The one of the inner ring and the outer ring is provided as a fixed ring.
2. The rolling bearing according to claim 1. The one of the inner ring and the outer ring is the outer ring.
3. The rolling bearing according to claim 1 or 2. The seal member is attached to one of the inner ring and the outer ring.
The rolling bearing according to any one of claims 1 to 3. the second annular portion is disposed on an opposite side to the one of the inner ring and the outer ring in a radial direction about the common axis line with respect to the first annular portion,
A rolling bearing according to any one of claims 1 to 4. the first annular portion has a first overlapping portion that extends from one peripheral end portion to the other peripheral end portion by 360° or more and less than 720° about the common axis line, and thereby overlaps with each other when viewed in the axial direction;
the second annular portion has a second overlap portion that extends from one peripheral end portion around the common axis line by 360° or more and less than 720° to the other peripheral end portion, so that the second annular portion overlaps with the first peripheral end portion when viewed in the axial direction,
The second overlapping portion is disposed at a position shifted in a circumferential direction around the common axis with respect to the first overlapping portion.
A rolling bearing according to any one of claims 1 to 5. Further, another grease is disposed on the opposite side of the grease in the axial direction with respect to the rolling element.
A rolling bearing according to any one of claims 1 to 6. A rotating body that is rotatably arranged;
A support that rotatably supports the rotating body;
The rolling bearing according to any one of claims 1 to 7, which is interposed between the rotating body and the support body;
A rotating device comprising: A method for manufacturing a rolling bearing according to any one of claims 1 to 7, comprising the steps of:
a first application step of discharging grease from a first nozzle at a first application position to form the first annular portion;
a second application step of discharging grease from a second nozzle different from the first nozzle at a second application position different from the first application position to form the second annular portion;
A method for manufacturing a rolling bearing comprising the steps of:

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