Rolling bearing, rotating device, and manufacturing method of rolling bearing

Abstract

The present invention relates to a rolling bearing, a rotating device, and a method for manufacturing a rolling bearing, and provides a rolling bearing capable of achieving low torque. The rolling bearing (1) includes an inner ring (10) and an outer ring (20) arranged coaxially with each other, rolling elements (30) arranged between the inner ring (10) and the outer ring (20), a sealing member (50) covering between the inner ring (10) and the outer ring (20) from the outer side in the axial direction, and a grease (60) arranged between the rolling elements (30) and the sealing member (50). The grease (60) has: a first annular portion (61) that extends circumferentially around the common axis (O) of the inner ring (10) and the outer ring (20) and contacts one of the inner ring (10) and 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 outer side in the axial direction, and contacts the sealing member (50).

Description

Technical Field

[0001] The present invention relates to rolling bearings, rotating equipment, and a method for manufacturing rolling bearings. Background Art

[0002] Conventionally, as a rolling bearing, there is a rolling bearing that holds grease between a pair of race rings (inner ring and outer ring). In such a rolling bearing, sometimes the resistance of the grease becomes the main cause of increasing torque. In addition, in a rolling bearing, in order to save power of the rotating equipment mounted thereon, a reduction in torque is desired. Particularly in small rolling bearings used in various motors such as a fan motor, the requirement for torque reduction is strong.

[0003] Then, in order to reduce the torque of the rolling bearing, grease is applied to the axial end portion in the fixed ring (in most cases, the outer ring) of the rolling bearing, or a sealing member disposed on the end side, and the amount of grease in contact with the rolling elements (balls) and the retainer for holding the rolling elements is reduced (for example, refer to Patent Document 1). In the rolling bearing described in Patent Document 1, the grease adheres to the inner peripheral surface of the outer ring that avoids contact with the rolling elements, and is filled in a circular shape on the inner peripheral surface side of the outer ring so as not to contact the outer peripheral surface of the inner ring.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2013-204679. Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] In addition, as a method of applying grease in a circular shape to the race ring, there is a method of relatively rotating the nozzle and the race ring while discharging grease from the nozzle. However, if the grease is applied over a full circle in a circular shape, sometimes the grease slowly collapses due to its own weight immediately after application. In this case, it is possible that the grease contacts the rolling elements and the retainer more than necessary, and the torque of the rolling bearing is larger than the desired torque.

[0009] Accordingly, the present invention provides a rolling bearing, rotating equipment, and a method for manufacturing a rolling bearing that can achieve torque reduction.

[0010] Means for Solving the Problems

[0011] The rolling bearing of the present invention is characterized by including: an inner ring and an outer ring arranged coaxially with each other, rolling elements arranged between the inner ring and the outer ring, a sealing member covering between the inner ring and the outer ring from the outer side in the axial direction, and grease arranged between the rolling elements and the sealing member. The grease includes: a first annular portion that extends circumferentially around the common axis of the inner ring and the outer ring and contacts one of the inner ring and the outer ring; and a second annular portion that extends circumferentially around the common axis, is connected to the first annular portion on the outer side in the axial direction, and contacts the sealing member.

[0012] According to the present invention, when filling the desired amount of grease, compared with the case of applying the grease in a manner of forming a single annular portion, the volume of the first annular portion can be reduced corresponding to the formation of the first annular portion and the second annular portion. Therefore, the first annular portion can be formed before the second annular portion when applying the grease, so that the collapse of the first annular portion due to its own weight is difficult to occur. In addition, by providing the second annular portion, the second annular portion is supported by the sealing member, and the first annular portion is supported not only by one of the inner ring and the outer ring but also by the sealing member via the second annular portion. Therefore, the whole grease is difficult to collapse from the shape just after application due to its own weight. Therefore, it is possible to suppress the grease from contacting the rolling elements and the retainer more than necessary. Therefore, low torque of the rolling bearing can be achieved.

[0013] In the above rolling bearing, the one of the inner ring and the outer ring may also be provided as a fixed ring.

[0014] According to the present invention, since the grease contacts the fixed ring, it is possible to suppress the centrifugal force from acting on the filled grease during the rotation of the rolling bearing, and it is possible to suppress the grease from collapsing from the shape just after application. Therefore, low torque of the rolling bearing can be achieved.

[0015] In the above rolling bearing, the one of the inner ring and the outer ring may be the outer ring.

[0016] According to the present invention, even when the grease rotates and the centrifugal force acts on the filled grease during the rotation of the rolling bearing, the displacement of the grease toward the radial outer side is restricted by the outer ring, so that the grease can be maintained in the shape just after application. Therefore, low torque of the rolling bearing can be achieved.

[0017] In the above rolling bearing, the sealing member may also be assembled to one of the inner ring and the outer ring.

[0018] According to the present invention, since one of the inner ring and the outer ring, and the sealing member are arranged in a non-rotating relative manner, it is possible to suppress the agitation of the grease in contact with both. Therefore, the grease can be maintained in the shape just after coating. Therefore, low torque of the rolling bearing can be achieved.

[0019] In the above-described rolling bearing, the second annular portion may also be arranged on the side opposite to the one of the inner ring and the outer ring in the radial direction centered on the common axis with respect to the first annular portion.

[0020] According to the present invention, compared with the configuration in which the first annular portion and the second annular portion are arranged side by side in the axial direction, a space for arranging the first annular portion can be provided on one side of the inner ring and the outer ring in the radial direction with respect to the second annular portion, and the first annular portion can be arranged on the outer side in the axial direction. Thereby, it is possible to suppress the grease from coming into contact with the rolling elements and the cage more than necessary. Therefore, low torque of the rolling bearing can be achieved.

[0021] In the above-described rolling bearing, the first annular portion may extend 360° or more and less than 720° from one circumferential end portion centered on the common axis to reach the other circumferential end portion, so as to have a first overlapping portion that overlaps each other when viewed from the axial direction, and the second annular portion may extend 360° or more and less than 720° from one circumferential end portion centered on the common axis to reach the other circumferential end portion, so as to have a second overlapping portion that overlaps each other when viewed from the axial direction, and the second overlapping portion is arranged at a position offset in the circumferential direction around the common axis with respect to the first overlapping portion.

[0022] 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. Assuming that the first overlapping portion and the second overlapping portion are arranged at the same position in the circumferential direction, the grease is likely to spread at the position where the first overlapping portion and the second overlapping portion overlap. According to the present invention, since the first overlapping portion and the second overlapping portion are arranged at positions offset from each other in the circumferential direction, it is possible to suppress the grease from spreading in the axial direction and coming into contact with the rolling elements and the cage more than necessary. Therefore, low torque of the rolling bearing can be achieved.

[0023] In the above-described rolling bearing, another grease may also be provided, which is arranged on the side opposite to the grease in the axial direction with respect to the rolling elements.

[0024] According to the present embodiment, it is possible to prevent the other grease from interfering with the first annular portion and the second annular portion and deforming the shape of the grease, and it is possible to increase the total amount of the grease arranged in the bearing by the other grease. Therefore, a bearing with an extended service life can be provided.

[0025] The rotating device of the present invention is characterized by comprising: a rotating body rotatably arranged, a support body rotatably supporting the rotating body, and the rolling bearing interposed between the rotating body and the support body.

[0026] According to the present invention, since a rolling bearing with reduced torque is provided, the rotational resistance of the rotating body relative to the support body can be reduced, and power saving of the rotating device can be achieved.

[0027] The manufacturing method of the rolling bearing of the present invention is the manufacturing method of the above-mentioned rolling bearing, characterized by comprising: a first coating process of discharging grease from a first nozzle at a first coating position to form the first annular portion; and a second coating process of discharging grease from a second nozzle different from the first nozzle at a second coating position different from the first coating position to form the second annular portion.

[0028] According to the present invention, the cycle time at each coating position can be shortened. Therefore, the manufacturing efficiency of the bearing can be improved. In addition, in the manufacturing method of rotating the bearing and coating the grease annularly, a mechanism for driving the nozzle radially with respect to the bearing is unnecessary, so the structure of the grease coating device can be simplified.

[0029] Advantages of the Invention

[0030] According to the present invention, it is possible to provide a rolling bearing, a rotating device, and a manufacturing method of a rolling bearing capable of achieving reduced torque. Description of the Drawings

[0031] Figure 1 is a top view of the rolling bearing according to the first embodiment.

[0032] Figure 2 is Figure 1 a cross-sectional view taken along line II-II of

[0033] Figure 3 is a flowchart showing the grease coating method according to the first embodiment.

[0034] Figure 4 is a top view for explaining the grease coating method.

[0035] Figure 5 is a top view for explaining the grease coating method.

[0036] Figure 6 is Figure 5 a cross-sectional view taken along line VI-VI of

[0037] Figure 7 is a top view for explaining the grease coating method.

[0038] Figure 8 isFigure 7 Cross-sectional view on the VIII-VIII line

[0039] Figure 9 is a top view of the rolling bearing according to the second embodiment

[0040] Figure 10 is a cross-sectional view of the rolling bearing according to the third embodiment

[0041] Figure 11 is a cross-sectional view of the rolling bearing according to the fourth embodiment Detailed implementation mode

[0042] Hereinafter, embodiments of the present invention will be described based on the drawings. In addition, in the following description, structures having the same or similar functions are assigned the same reference numerals. Moreover, repeated descriptions of these structures are sometimes omitted

[0043] [First Embodiment]

[0044] Regarding the first embodiment of the present invention, reference is made to Figures 1 to 8 for description Figure 1 is a top view of the rolling bearing according to the first embodiment Figure 2 is Figure 1 Cross-sectional view on the II-II line. In addition, in Figure 1 , in order to facilitate the observation of the internal structure of the rolling bearing 1, a part of each of the sealing member 50 and the filled grease 60 described later is not shown. In addition, in Figure 2 , the members for assembling the rolling bearing 1 are shown by phantom lines

[0045] As shown in Figure 1 and Figure 2 , the rolling bearing 1 is a ball bearing including an inner ring 10 and an outer ring 20 serving as raceways, a plurality of rolling elements 30, a retainer 40, a pair of sealing members 50, and 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 body) fixedly provided and rotatably supporting the shaft 3. The rolling bearing 1 is interposed between the shaft 3 and the housing 4. In addition, hereinafter, the rolling bearing may sometimes be simply referred to as a bearing. In addition, in the present embodiment, the grease in the state before being filled into the bearing 1 is simply referred to as grease, and the grease in the state filled into the bearing 1 by applying the grease is referred to as filled grease 60

[0046] The outer ring 10 and the inner ring 20 are coaxially arranged with each other so that their respective central axes are arranged on the common axis O. In the present embodiment, the extending direction of the common axis O is referred to as the axial direction, the direction radially extending from the common axis O orthogonally to the common axis O is referred to as the radial direction, and the direction surrounding the common axis O is referred to as the circumferential direction.

[0047] The inner ring 10 is provided as a rotating ring. The inner ring 10 is externally inserted into 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 the concave portion (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 outer ring 20 and the inner ring 10. A plurality of rolling elements 30 are arranged between the inner ring 10 and the outer ring 20 and are rotatably held by a retainer 40. The retainer 40 rotatably holds each of the rolling elements 30 in a state where the plurality of rolling elements 30 are equally arranged in the circumferential direction. A sealing member 50 covers the annular space between the inner ring 10 and the outer ring 20 from the outside in the axial direction.

[0048] The outer ring 20 is formed into 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 of other materials. The outer ring 20 has an outer ring body 21 having a width along the axial direction equal to the width of the inner ring 10 along the axial direction, and a protruding portion 22 protruding inward in the radial direction from the outer ring body 21. The protruding portion 22 is formed at a portion of the outer ring body 21 located at the axial center. The width of the protruding portion 22 along the axial direction is shorter than the width of the outer ring body 21 along the axial direction and larger than the outer diameter of the rolling element 30.

[0049] On the inner peripheral surface of the protruding portion 22, an outer ring raceway surface 23 recessed outward in the radial direction is formed. The outer ring raceway surface 23 is formed in a hemispherical shape in a cross-sectional view so as to follow the outer surface of the rolling element 30 and is formed as an annular shape extending in the circumferential direction over the entire circumference of the inner peripheral surface of the protruding portion 22. The outer ring raceway surface 23 is formed at a portion of the inner peripheral surface of the protruding portion 22 located at the axial center. The portion of the inner peripheral surface of the protruding portion 22 other than the outer ring raceway surface 23 extends along the axial direction with a certain inner diameter. The protruding portion 22 has a pair of end faces 22a facing the axial direction. Each end face 22a extends parallel in both the radial and axial directions.

[0050] The outer ring body 21 has a pair of inner peripheral surfaces 21a extending from the outer peripheral edge of each end face 22a of the protruding portion 22 to the opening edge of the outer ring 20. The portion of each inner peripheral surface 21a located on the inner side in the axial direction is located more on the outer side in the radial direction than the portion located on the outer side in the axial direction.

[0051] The inner ring 10 is formed into an annular shape from metallic materials such as stainless steel and bearing steel. However, the inner ring 10 is not limited to being made of metal and may also be formed from other materials. On the outer peripheral surface of the inner ring 10, an inner ring raceway surface 11 that is recessed inward in the radial direction is formed. The inner ring raceway surface 11 is formed in a hemispherical shape in cross-section so as to follow the outer surface of the rolling elements 30, and is formed as an annular shape extending in the circumferential direction over the entire circumference of the outer peripheral surface. The inner ring raceway surface 11 is formed in a portion that is axially centered among the outer peripheral surface of the inner ring 10, and is arranged to face the outer ring raceway surface 23 in the radial direction. The portion of the inner peripheral surface of the inner ring 10 other than the inner ring raceway surface 11 extends axially with a constant outer diameter.

[0052] The plurality of rolling elements 30 are formed into spherical shapes from metallic materials such as stainless steel and bearing steel. The plurality of rolling elements 30 are arranged between the outer ring raceway surface 23 and the inner ring raceway surface 11, and are rotatably supported by the outer ring raceway surface 23 and the inner ring raceway surface 11.

[0053] The cage 40 is integrally formed into an annular shape from synthetic resin or a metallic material. The cage 40 is arranged centered on the common axis O. The cage 40 includes a body portion 41 that is formed in an annular shape and is arranged on the other side in the axial direction with respect to the plurality of rolling elements 30, and a plurality of pairs of claw portions 42 that stand up from the body portion 41 toward the one side in the axial direction. A pair of claw portions 42 rotatably holds one rolling element 30. The pair of claw portions 42 stand up in an arcuate shape such that the distance between them approaches the front end from the body portion 41. The cage 40 is arranged with a clearance from 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 the present embodiment, the entire cage 40 is located more on the inner side in the axial direction than the pair of end faces 22a of the protruding portion 22 of the outer ring 20.

[0054] The sealing member 50 is formed in a circular plate shape. The sealing member 50 is arranged centered on the common axis O. The sealing member 50 is assembled to the outer ring 20. One sealing member 50 is arranged on each of the two axial sides with respect to the plurality of rolling elements 30. The sealing member 50 includes: a base portion 51 that overlaps the end face 22a of the protruding portion 22 of the outer ring 20 from the outer side in the axial direction; a stepped portion 52 that extends outward in the axial direction from the inner peripheral edge of the base portion 51; a cover portion 53 that projects inward in the radial direction from the end edge on the outer side in the axial direction of the stepped portion 52; and a locking portion 54 that extends outward in the radial direction and outward in the axial direction from the outer peripheral edge of the base portion 51. The sealing member 50 extends in the radial direction so as to at least straddle the center of the rolling element 30 in a plan view. In the present embodiment, the cover portion 53 overlaps the center of the rolling element 30 in a plan view. However, it is also possible that the stepped portion 52 extends outward in the axial direction and inward in the radial direction from the inner peripheral edge of the base portion 51 and overlaps the center of the rolling element 30 in a plan view. The inner peripheral edge of the cover portion 53 is arranged 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 inner side in the axial direction. Thus, the sealing member 50 is fixed to the outer ring 20.

[0055] The packed grease 60 is arranged between the rolling element 30 and the sealing member 50. The packed grease 60 is arranged only on one axial side with respect to the rolling element 30 in the annular space between the inner ring 10 and the outer ring 20. In the present embodiment, the packed grease 60 is arranged on one axial side with respect to the rolling element 30. That is to say, the packed grease 60 is arranged on the side opposite to the body portion 41 of the retainer 40 with the rolling element 30 interposed therebetween in the axial direction. The packed grease 60 is arranged in a circular ring shape in a plan view and is arranged coaxially with the common axis O. The packed grease 60 contacts the outer ring 20 provided as a fixed ring and is separated from the inner ring 10 provided as a rotating ring. In addition, the packed grease 60 is separated from the rolling element 30 and the retainer 40. However, the packed grease 60 may also contact at least any one of the rolling element 30 and the retainer 40.

[0056] The grease filling 60 has a first annular portion 61 that contacts the outer ring 20 and a second annular portion 62 that is connected to the first annular portion 61 and contacts the sealing member 50. The first annular portion 61 and the second annular portion 62 are formed by applying the grease in two coats. The first annular portion 61 extends circumferentially about the common axis O. The first annular portion 61 contacts a portion of the inner circumferential surface of the protrusion 22 of the outer ring 20 that is axially outside of the outer ring rolling surface 23. The second annular portion 62 extends circumferentially about the common axis O. The second annular portion 62 is separated from the outer ring 20 that the first annular portion 61 contacts among the raceway rings. The second annular portion 62 is disposed on the opposite side (i.e., the inner side in the radial direction) of the outer ring 20 relative to the first annular portion 61 in the radial direction. Specifically, in a plan view, the outer peripheral edge of the second annular portion 62 is more radially inward than the outer peripheral edge of the first annular portion 61, and the inner peripheral edge of the second annular portion 62 is more radially inward than the inner peripheral edge of the first annular portion 61. The second annular portion 62 is connected and integrated with the first annular portion 61 on the outer side in the axial direction. The second annular portion 62 is connected over the entire circumference of the first annular portion 61. The second annular portion 62 contacts the surface of the sealing member 50 that faces axially inward, and is thus supported by the sealing member 50. In the present embodiment, the second annular portion 62 contacts the inner surface of the lid portion 53 of the sealing member 50.

[0057] The first annular portion 61 and the second annular portion 62 are each formed by circumferentially applying the grease discharged from the nozzle by 360° or more. The first annular portion 61 and the second annular portion 62 each extend continuously over the entire circumference without forming a discontinuity in a plan view. The first annular portion 61 extends from one circumferential end portion 61a by 360° or more and less than 720° about the common axis O and reaches the other circumferential end portion 61b. Thus, the first annular portion 61 has a first overlapping portion 63 that includes one circumferential end portion 61a and the other circumferential end portion 61b and overlaps each other in a plan view. Preferably, 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 about the same as the width of the first annular portion 61 in a plan view. The second annular portion 62 extends from one circumferential end portion 62a by 360° or more and less than 720° about the common axis O and reaches the other circumferential end portion 62b. Thus, the second annular portion 62 has a first overlapping portion 64 that includes one circumferential end portion 62a and the other circumferential end portion 62b and overlaps each other in a plan view. Preferably, 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 about the same as the width of the second annular portion 62 in a plan view. At least a part of the second overlapping portion 64 is disposed at the same position as the first overlapping portion 63 in the circumferential direction and is connected to the first overlapping portion 63.

[0058] Next, as a method for manufacturing the bearing 1 of the present embodiment, a method for applying the grease will be described.Figure 3 is a flowchart showing a method of applying grease according to the first embodiment. As Figure 3 shown, the method of applying grease in this embodiment includes a first coating step S10 and a second coating step S20.

[0059] Figure 4 , Figure 5 and Figure 7 is a top view for explaining the method of applying grease. Figure 6 is Figure 5 a cross-sectional view taken along line VI-VI of Figure 8 is Figure 7 a cross-sectional view taken along line VIII-VIII of Figure 4 shown, the first coating step S10 is performed in a state where the sealing member 50 is not assembled to the outer ring 20. That is, the annular space between the inner ring 10 and the outer ring 20 is open in the axial direction, and grease is applied in a state where the rolling elements 30 and the cage 40 are exposed.

[0060] As Figure 5 and Figure 6 shown, in the first coating step S10, a nozzle (not shown) is rotated about the common axis O with respect to the outer ring 20, and grease G1 is discharged from the nozzle. At this time, the position of the nozzle is adjusted so that the discharged grease G1 contacts the axial end portion of the inner peripheral surface of the protruding portion 22 of the outer ring 20. Since the grease G1 is discharged while the nozzle rotates relative to the outer ring 20, the grease G1 extends in an arc shape. The grease G1 attached to the outer ring 20 extends more than 360° from the start end 71 corresponding to the discharge start point to the end end 72 corresponding to the discharge end point. Thereby, a first annular portion 61 having a first overlapping portion 63 is formed.

[0061] As Figure 7 and Figure 8As shown, in the second coating process S20, the nozzle is offset from the position in the first coating process S10, and then while rotating the nozzle around the common axis O relative to the outer ring 20 again, the grease G is discharged 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 outer side in the axial direction and the inner side in the radial direction, and the coated grease G2 protrudes more toward the outer side in the axial direction than the first annular portion 61. The grease G2 in contact with the first annular portion 61 extends more than 360° from the start end 73 corresponding to the discharge start point to the end end 74 corresponding to the discharge end point. At this time, the start end 73 of the grease G2 in the second coating process S20 and the start end 71 of the grease G1 in the first coating process S10 are located at the same position in the circumferential direction. In addition, the end end 74 of the grease G2 in the second coating process S20 and the end end 72 of the grease G1 in the first coating process S10 are located at the same position in the circumferential direction. Thereby, the second annular portion 62 having the second overlapping portion 64 is formed.

[0062] Through the above, the coating of the grease is completed. After that, the sealing member 50 is inserted into the annular space between the inner ring 10 and the outer ring 20 from the outer side in the axial direction, and the sealing member 50 is assembled to the outer ring 20. At this time, the grease coated in the second coating process S20 contacts the lid portion 53 of the sealing member 50 and becomes Figure 2 the state shown.

[0063] As described above, the first annular portion 61 and the second annular portion 62 are formed of greases discharged in different processes. Therefore, the portion of the cross-sectional profile of the first annular portion 61 that does not contact the outer ring 20 or the second annular portion 62 extends in an arc shape or an elliptical arc shape centered on the position overlapping the first annular portion 61. In addition, the portion of the cross-sectional profile of the second annular portion 62 that does not contact the sealing member 50 or the first annular portion 61 extends in an arc shape or an elliptical arc shape centered on the position overlapping the second annular portion 62.

[0064] As described above, the bearing 1 of the present embodiment includes a grease 60 filled therein, which has: a first annular portion 61 that extends circumferentially about a common axis O and contacts the outer ring 20; and a second annular portion 62 that extends circumferentially about the common axis O, is connected to the first annular portion 61 on the outer side in the axial direction, and contacts the seal member 50. According to this configuration, when filling the desired amount of grease, compared with the case where the grease is applied in a manner of forming a single annular portion, the volume of the first annular portion 61 can be reduced corresponding to the formation of the first annular portion 61 and the second annular portion 62. Therefore, the first annular portion 61 can be formed before the second annular portion 62 when applying the grease, so that the collapse of the first annular portion 61 due to its own weight is difficult to occur. 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 not only supported by the outer ring 20 but also supported by the seal member 50 via the second annular portion 62. Therefore, the entire filled grease 60 is difficult to collapse from the shape just after application due to its own weight. Therefore, it is possible to suppress the filled grease 60 from contacting the rolling elements 30 and the cage 40 more than necessary. Therefore, the low torque of the bearing 1 can be achieved.

[0065] In addition, the outer ring 20 of the raceway ring contacted by the filled grease 60 is provided as a fixed ring. According to this configuration, since the filled grease 60 contacts the fixed ring, it is possible to suppress the centrifugal force from acting on the filled grease 60 during the rotation of the bearing 1, and it is possible to suppress the filled grease 60 from collapsing from the shape just after application. Therefore, the low torque of the bearing 1 can be achieved.

[0066] The seal member 50 is assembled to the outer ring 20 of the raceway ring contacted by the filled grease 60. According to this configuration, since the outer ring 20 and the seal member 50 are provided so as not to rotate relative to each other, it is possible to suppress the filled grease 60 contacting both from being agitated. Therefore, the filled grease 60 can be maintained in the shape just after application. Therefore, the low torque of the bearing 1 can be achieved.

[0067] The second annular portion 62 is arranged on the opposite side of the first annular portion 61 in the radial direction with respect to the outer ring 20. According to this configuration, compared with the configuration in which the first annular portion and the second annular portion are arranged side by side in the axial direction, a space for arranging the first annular portion 61 can be provided on the outer side in the radial direction of the second annular portion 62, and the first annular portion 61 can be arranged on the outer side in the axial direction. Thereby, it is possible to suppress the filled grease 60 from contacting the rolling elements 30 and the cage 40 more than necessary. Therefore, the low torque of the bearing 1 can be achieved.

[0068] Here, in the present embodiment, the outer peripheral edge of the sealing member 50 is engaged with the inner peripheral surface of the outer ring 20. In a configuration where grease is arranged in a single annular portion as in the past, in order to prevent the grease from collapsing due to its own weight and coming into contact with the rolling elements and the cage more than necessary, assuming that the grease is arranged at a position further away from the rolling elements toward the outer side in the axial direction, there is a possibility that the grease is crushed by the sealing member and leaks from the gap between the outer peripheral edge of the sealing member and the outer ring. According to the present embodiment, the second annular portion 62 located further axially outside than the first annular portion 61 is arranged on the side opposite to the outer peripheral edge of the sealing member 50 with the first annular portion 61 interposed therebetween, so that leakage of the second annular portion 62 from the gap between the outer peripheral edge of the sealing member 50 and the outer ring 20 can be suppressed. Therefore, leakage of the grease of the bearing 1 can be suppressed.

[0069] Moreover, since the rotating device 2 of the present embodiment includes the above-described bearing 1, the rotational resistance of the shaft 3 to the housing 4 can be reduced, and power saving of the rotating device 2 can be achieved.

[0070] In addition, in the manufacturing method of the bearing 1 of the present embodiment, the nozzle for discharging grease is shared in the first coating step S10 and the second coating step S20, but it is not limited to this method. The first nozzle used in the first coating step S10 and the second nozzle used in the second coating step S20 may be prepared separately. In this case, it is preferable that the first coating step S10 and the second coating step S20 are performed at different coating positions. That is, the first coating step S10 is performed at the first coating position, and the bearing that has completed the first coating step S10 is transported to the second coating position, and the second coating step S20 is performed at the second coating position. Alternatively, the first coating step S10 may be performed on the next bearing at the first coating position while the second coating step S20 is being performed. According to this method, the cycle time at each coating position can be shortened. Therefore, the manufacturing efficiency of the bearing 1 can be improved. In addition, in the manufacturing method of rotating the bearing and coating the grease annularly, a mechanism for driving the nozzle in the radial direction with respect to the bearing is unnecessary, so the structure of the grease coating device can be simplified.

[0071] [Second Embodiment]

[0072] For the second embodiment of the present invention, reference is made to Figure 9 for description. In addition, the structure other than that described below is the same as that of the first embodiment.

[0073] Figure 9 is a plan view of the rolling bearing according to the second embodiment. In addition, in Figure 9 in order to easily observe the internal structure of the bearing 1A, the illustration of the sealing member 50 is omitted. In Figure 1In the first embodiment shown, the second overlapping portion 64 filled with the grease 60 is arranged at the same position in the circumferential direction with respect to the first overlapping portion 63. In contrast, in Figure 9 In the second embodiment shown, the second overlapping portion 64 filled with the grease 60 is arranged at a position offset in the circumferential direction with respect to the first overlapping portion 63. The second overlapping portion 64 is formed by offsetting the start and end points of the grease in the circumferential direction with respect to the first overlapping portion 63 in the same second coating process as in the first embodiment.

[0074] Here, the cross-sectional area of the first annular portion 61 is larger in the first overlapping portion 63 than in other portions. In addition, the cross-sectional area of the second annular portion 62 is larger in the second overlapping portion 64 than in other portions. Assuming that the first overlapping portion 63 and the second overlapping portion 64 are arranged at the same position in the circumferential direction, the filled grease 60 is likely to spread at the position where the first overlapping portion 63 and the second overlapping portion 64 overlap. According to the present embodiment, since the first overlapping portion 63 and the second overlapping portion 64 are arranged at positions offset from each other in the circumferential direction, it is possible to suppress 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, low torque of the bearing 1A can be achieved.

[0075] [Third Embodiment]

[0076] Regarding the third embodiment of the present invention, reference is made to Figure 10 for description. In addition, the structure other than that described below is the same as that of the first embodiment.

[0077] Figure 10 is a cross-sectional view of the rolling bearing of the third embodiment. In Figure 10 In the third embodiment shown, the bearing 1B includes another grease 65 in addition to the filled grease 60. The other grease 65 is arranged on the opposite side of the rolling elements 30 in the axial direction from the filled grease 60. That is, the other grease 65 is arranged on the same side as the main body portion 41 of the cage 40 with respect to the rolling elements 30 in the axial direction. The other grease 65 is arranged between the rolling elements 30 and the seal member 50. The other grease 65 is arranged in the annular space between the inner ring 10 and the outer ring 20. The other grease 65 contacts the contact object (the outer ring 20 in this embodiment) of the filled grease 60 among the inner ring 10 and the outer ring 20. The other grease 65, like the filled grease 60, contacts one of the inner ring 10 and the outer ring 20 and is separated from the other. The other grease 65 is separated from the rolling elements 30 and the cage 40. The other grease 65 extends circumferentially around the common axis O. The other grease 65 contacts a portion of the inner circumferential surface of the protruding portion 22 of the outer ring 20 that is more axially outward than the outer ring rolling surface 23.

[0078] However, the structure of the other grease is not limited to the above structure. The other grease may also be in contact with the inner ring 10 and separated from the outer ring 20. Additionally, the other grease may also be in contact with at least one of the rolling elements 30 and the cage 40. Moreover, the other grease may not extend in a circumferential shape. For example, the other grease may extend in an arc shape or may be arranged pointwise in the circumferential direction.

[0079] According to the present embodiment, it is possible to prevent the other grease 65 from interfering with the filled grease 60 and deforming the shape of the filled grease 60, and it is possible to increase the total amount of grease disposed in the bearing 1B by the other grease 65. Therefore, it is possible to provide a bearing 1B that aims for a longer service life.

[0080] [Fourth Embodiment]

[0081] For the fourth embodiment of the present invention, reference is made to Figure 11 for description. In addition, the structure other than that described below is the same as that of the first embodiment.

[0082] Figure 11 is a cross-sectional view of the rolling bearing of the fourth embodiment. In Figure 11 the fourth embodiment shown, the bearing 1C includes, in addition to the filled grease 60, another grease 66. The other grease 66 is supported by the cage 40. The other grease 66 is disposed in the notch between a pair of claw portions 42 on the side opposite to the rolling elements 30 with respect to the claw portions 42 in the cage 40. In the illustrated example, the other grease 66 is in contact with the main body portion 41 of the cage 40, but may also be in contact with the claw portions 42. The other grease 66 is separated from the rolling elements 30 and the filled grease 60. In addition, the other grease 66 may be disposed in all the notches of the cage 40 or may be disposed only in a part of the notches.

[0083] According to the present embodiment, it is possible to increase the total amount of grease disposed in the bearing 1C by the other grease 66. Therefore, it is possible to provide a bearing 1C that aims for a longer service life.

[0084] In addition, the present invention is not limited to the above-described embodiments illustrated with reference to the accompanying drawings, and various modifications can be considered within its technical scope. For example, in the above-described embodiments, the inner ring 10 is provided as a rotating ring, and the outer ring 20 is provided as a fixed ring. Moreover, the packed grease 60 contacts the outer ring 20 which is the fixed ring. However, the raceway ring with which the packed grease contacts may not be the fixed ring. That is, it may also be that the inner ring is provided as the fixed ring, the outer ring is provided as the rotating ring, and the packed grease contacts the inner ring which is the fixed ring. Additionally, it may also be that the inner ring is provided as the fixed ring, the outer ring is provided as the rotating ring, and the packed grease contacts the outer ring which is the rotating ring. In this case, the packed grease rotates together with the outer ring, but even if centrifugal force acts on the packed grease, the displacement of the grease toward the radially outer side is restricted by the outer ring, and thus the packed grease can be maintained in the shape just after coating. However, preferably, the packed grease contacts the raceway ring on which the sealing member is assembled among the inner ring and the outer ring.

[0085] In addition, in the above-described embodiments, the discharge of the grease in the first coating step S10 and the discharge of the grease in the second coating step S20 are performed separately. However, the discharge of the grease in the first coating step S10 and the discharge of the grease in the second coating step S20 may also be performed continuously. As a result, one circumferential end portion in the first annular portion of the packed grease and the other circumferential end portion in the second annular portion may also be connected to each other.

[0086] In addition, in the above-described embodiments, the volume ratio of the first annular portion 61 and the second annular portion 62 of the packed grease 60 is not particularly limited. For example, the cross-sectional areas of the first annular portion 61 and the second annular portion 62 may be equal to each other, or may be different from each other.

[0087] In addition, in the above-described embodiments, the packed grease 60 has two annular portions 61 and 62, but may also have three or more annular portions.

[0088] In addition, in the above-described embodiments, a fan motor is illustrated as a rotating device, but the rotating device is not limited thereto. For example, as the rotating device, the present invention can also be applied to at least any one of the spindle motor and the swing arm of a hard disk drive.

[0089] In addition, within the scope not departing from the gist of the present invention, the structural elements in the above-described embodiments can be appropriately replaced with known structural elements, and also, the above-described respective embodiments can be appropriately combined. For example, another grease 65 of the third embodiment or another grease 66 of the fourth embodiment can also be arranged in the bearing 1A of the second embodiment.

[0090] Reference Signs

[0091] 1, 1A, 1B, 1C Rolling Bearings

[0092] 2 Rotating device

[0093] 3 Axes (rotating body)

[0094] 4 Housing (support body)

[0095] 10 Inner ring

[0096] 20 Outer ring

[0097] 30 Rolling elements

[0098] 50 Sealing member

[0099] 60 Filled grease (grease)

[0100] 61 First annular portion

[0101] 62 Second annular portion

[0102] 63 First overlapping portion

[0103] 64 Second overlapping portion

[0104] 65 Another grease

[0105] O Common axis.

Claims

1. A rolling bearing, comprising: An inner ring and an outer ring arranged coaxially with each other; Rolling elements arranged between the inner ring and the outer ring; A sealing member covering between the inner ring and the outer ring from the outer side in the axial direction; and Grease arranged between the rolling elements and the sealing member, The grease having: A first annular portion that extends circumferentially around the common axis of the inner ring and the outer ring and contacts one of the inner ring and the outer ring; and A second annular portion that extends circumferentially around the common axis, is connected to the first annular portion on the outer side in the axial direction, and contacts the sealing member.

2. The rolling bearing according to claim 1, wherein, One of the inner ring and the outer ring is provided as a fixed ring.

3. The rolling bearing according to claim 1 or claim 2, wherein, One of the inner ring and the outer ring is the outer ring.

4. The rolling bearing according to any one of claims 1 to 3, wherein, The sealing member is assembled to one of the inner ring and the outer ring.

5. The rolling bearing according to any one of claims 1 to 4, wherein, The second annular portion is arranged on the side opposite to one of the inner ring and the outer ring in the radial direction centered on the common axis with respect to the first annular portion.

6. The rolling bearing according to any one of claims 1 to 5, wherein The first annular portion extends 360° or more and less than 720° from one circumferential end around the common axis to reach the other circumferential end, so as to have a first overlapping portion that overlaps each other when viewed from the axial direction, The second annular portion extends 360° or more and less than 720° from one circumferential end around the common axis to reach the other circumferential end, so as to have a second overlapping portion that overlaps each other when viewed from the axial direction, The second overlapping portion is arranged at a position offset in the circumferential direction around the common axis with respect to the first overlapping portion.

7. The rolling bearing according to any one of claims 1 to 6, wherein, It further comprises another grease, which is arranged on the side opposite to the grease in the axial direction with respect to the rolling elements.

8. A rotating device, comprising: A rotating body rotatably arranged; A support body that rotatably supports the rotating body; and The rolling bearing according to any one of claims 1 to 7 interposed between the rotating body and the support body.

9. A manufacturing method of a rolling bearing, which is a manufacturing method of the rolling bearing according to any one of claims 1 to 7, comprising: A first coating step of discharging grease from a first nozzle at a first coating position to form the first annular portion; and A second coating step of discharging grease from a second nozzle different from the first nozzle at a second coating position different from the first coating position to form the second annular portion.

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