JP2023077683A - Ball bearing with seal - Google Patents

Abstract

To provide a ball bearing with a seal suitable for use at high speed rotation.SOLUTION: In a ball bearing with a seal, a seal side sliding surface 34 is formed with a plurality of axial projections 36 at intervals in a circumferential direction, each axial projection 36 has a sliding contact tip surface 37 extending linearly in a radial direction in a cross-sectional view perpendicular to the circumferential direction, a holder side sliding surface 35 is formed with a sliding contact flat surface 38 that slides in sliding contact with the sliding contact tip surface 37 when the bearing rotates, and the sliding contact tip surface 37 and the sliding contact flat surface 38 are arranged so as to face each other in a non-parallel manner at an angle α in a direction in which a gap widens from a radially inner side to a radially outer side when the bearing is stationary.SELECTED DRAWING: Figure 7

Description

TECHNICAL FIELD The present invention relates to a sealed ball bearing having a seal member provided between an inner ring and an outer ring.

Ball bearings are often used as bearings that support rotating shafts in automobiles, industrial machinery, and the like. Generally, a ball bearing consists of an inner ring, an outer ring provided coaxially on the radially outer side of the inner ring, a plurality of balls provided in an annular space between the inner ring and the outer ring, and a cage that holds the plurality of balls. and

As for the retainer, for example, as in Patent Document 1, a retainer annular portion extending in the circumferential direction adjacent to the ball passage area and axially extending between the balls adjacent in the circumferential direction from the retainer annular portion A retainer having a cantilever-like retainer claw portion extending to the rim (a so-called crown-shaped retainer) is known. The cage claw portion has a ball guide surface facing the surface of the ball, and the ball guide surface is formed as a concave spherical surface along the surface of the ball so as to hold the ball.

In addition, for example, as in Patent Document 2, it is possible to prevent foreign matter from entering the ball bearing from the outside, or to prevent lubricant (lubricating oil, grease, etc.) from leaking from the inside of the ball bearing to the outside. In order to prevent this, a sealed ball bearing is sometimes used in which the axial end opening of the annular space formed between the inner ring and the outer ring is closed with an annular sealing member.

Japanese Patent No. 3035766 International Publication No. 2016/143786

2. Description of the Related Art In recent years, in the field of electric vehicles such as EVs (battery electric vehicles) and HEVs (hybrid electric vehicles), high-speed rotation of electric motors has been promoted in order to reduce the size and weight of electric motors. The ball bearing that supports the rotating shaft to which the rotation of such an electric motor is input is used under the condition that the dmn value (ball pitch circle diameter dm (mm) x number of revolutions n (min ^-1 )) exceeds 2,000,000. Sometimes it is done.

The inventors of the present application have studied using a crown retainer for a ball bearing that supports a rotating shaft that rotates at high speed in EVs, HEVs, and the like.

However, when a crown-shaped cage is used in a ball bearing that rotates at high speed, torsional deformation in the direction of tilting the claws of the cage radially outward is caused by the centrifugal force acting on the cantilever-like claws of the cage. It was found that there is a risk that the cage claws will interfere with the balls due to the deformation of the ring portion of the cage. Interference of the retainer claws with the balls causes heat generation in the ball bearings.

In particular, when a bearing using a crown cage is also a sealed ball bearing, if the cage ring portion of the crown cage contacts the seal member, there is a risk of abnormal heat generation due to the sliding resistance of the contact portion. Therefore, it is necessary to suppress the axial width dimension of the retainer annular portion so that the retainer annular portion does not come into contact with the seal member. Therefore, it is difficult to increase the rigidity of the retainer annular portion, the centrifugal force acting on the retainer claw portion tends to cause torsional deformation in the retainer annular portion, and the cage claw portion easily interferes with the balls.

Thus, when a crown cage is used in a sealed ball bearing, it is difficult to use the sealed ball bearing for high-speed rotation applications. In addition, since it is difficult to prevent the crown cage from contacting the seal member when the space where the bearing is installed is narrow and the width of the bearing must be kept small, sealed ball bearings are used. In some cases, it was necessary to give up on this and adopt an open-type ball bearing in which both ends in the axial direction are open without providing a seal member.

The problem to be solved by the present invention is to provide a sealed ball bearing suitable for use at high speed rotation.

In order to solve the above problems, the present invention employs the following configuration for a sealed ball bearing.
inner ring;
an outer ring coaxially provided radially outside the inner ring;
a plurality of balls incorporated in an annular space formed between the inner ring and the outer ring;
an annular seal member provided at one end opening in the axial direction of the annular space;
a retainer that retains the plurality of balls,
The retainer includes a retainer annular portion extending in a circumferential direction in an area axially sandwiched between the ball passage area and the seal member, and between the balls circumferentially adjacent to the retainer annular portion. In a sealed ball bearing having a cantilever-like retainer pawl portion extending in the axial direction,
the seal member has a seal-side sliding surface facing the retainer in the axial direction,
The retainer has a retainer-side sliding surface axially facing the seal-side sliding surface,
one of the seal-side sliding surface and the retainer-side sliding surface is formed with a plurality of axial projections spaced apart in the circumferential direction,
each of the axial projections has a sliding contact tip surface extending linearly in a radial direction in a cross-sectional view perpendicular to the circumferential direction;
The other sliding surface is in sliding contact with the sliding contact end surface when the bearing rotates, and a smooth sliding contact plane is formed over the entire circumference,
With a seal, the sliding contact tip surface and the sliding contact plane face each other non-parallel at an angle in a direction in which the distance widens from the radially inner side to the radially outer side when the bearing is stationary. ball bearings.

With this configuration, when the bearing rotates, the sliding contact tip surface of the axial projection formed on one of the seal-side sliding surface and the retainer-side sliding surface is formed on the other sliding surface. When sliding on the smooth sliding contact plane over the entire circumference, the sliding contact tip surface of the axial projection has a shape extending linearly in the radial direction. is likely to be drawn into the sliding contact portion of the axial projection. As a result, an oil film is formed between the sliding contact tip surface of the axial projection and the sliding contact plane due to the wedge film effect. The contact resistance between the sealing members can be kept extremely low.

In addition, when the bearing is stationary, the sliding contact tip surface and the sliding contact plane face each other non-parallel at an angle in the direction in which the distance widens from the radially inner side to the radially outer side. In addition, it is possible to form a stable oil film by the wedge film effect between the sliding contact end face and the sliding contact plane. In other words, assuming a configuration in which the sliding contact end face and the sliding contact plane face each other in parallel when the bearing is stationary, when the bearing rotates at high speed, the centrifugal force acting on the claws of the cage will cause the cage ring to move. As a result of the deformation, the sliding surface on the cage side is tilted, and the sliding contact tip surface and the sliding contact plane become non-parallel. There is a problem that it becomes difficult to form. To solve this problem, when the bearing is stationary, the sliding contact tip surface and the sliding contact plane face each other non-parallel at an angle in the direction in which the gap widens from the radially inner side to the radially outer side. Occasionally, the cage annular portion is deformed by the centrifugal force acting on the claw portions of the cage. It is possible to form a stable oil film due to the wedge film effect.

The angle formed by the sliding contact tip surface and the sliding contact plane when the bearing is stationary can be set within a range of 0.5° or more and 6° or less.

the axial length of the retainer claw portion is set larger than the radius of the ball,
When the retainer claw portion has a pocket side surface facing the ball in the circumferential direction,
A portion of the pocket side surface that receives the ball in the circumferential direction is formed in a planar shape so that the pocket side surface does not interfere with the ball when the retainer claw portion moves radially outward due to centrifugal force. configuration is preferred.

With this configuration, when the bearing rotates at high speed, the cage annular portion is deformed by the centrifugal force acting on the cage claw portion, and when the deformation causes the cage claw portion to move radially outward, It is possible to prevent the pocket side surfaces of the retainer claws from interfering with the balls and generating abnormal heat.

The pocket side surface may adopt a plane along a straight line extending radially through the bearing center.

Further, as the pocket side surfaces, planes along straight lines parallel to each other in the circumferential direction with a straight line connecting the center of the bearing and the center of the retainer claw portion in the circumferential direction interposed therebetween can be adopted.

With this arrangement, even if the cage claws move radially along the straight line connecting the center of the bearing and the center of the cage claws in the circumferential direction, the distance between the balls and the side surfaces of the pockets does not change. When the retainer ring portion is deformed by the centrifugal force acting on the retainer claw portion during rotation, and the deformation causes the retainer claw portion to move radially outward, the retainer cannot retain the balls. becomes stable.

The retainer annular portion has a pocket bottom surface axially facing the balls,
The bottom surface of the pocket has a shape extending linearly in a radial direction in a cross-sectional view perpendicular to the circumferential direction,
A configuration in which the pocket side surface and the pocket bottom surface are connected in a concave arc shape when viewed from the radial direction can be adopted.

In this way, since the pocket side surface and the pocket bottom surface are connected in a concave arc shape, the mass of the axial tip portion of the retainer claw portion can be kept small, and the axial root portion of the retainer claw portion can be reduced. A cross-sectional area can be secured. Therefore, it is possible to effectively suppress bending of the retainer claws due to the centrifugal force acting on the retainer claws.

It is preferable to form a built-up portion protruding axially inward without contacting the ball at the radially inner end portion of the bottom surface of the pocket.

By doing so, it is possible to effectively prevent the retainer annular portion from being damaged by the influence of the centrifugal force. That is, when the cage annular portion is torsionally deformed by the centrifugal force acting on the cage claw portion, the radially inner side of the cage annular portion at a position corresponding to the middle of the circumferentially adjacent cage claw portions (the radially inner end of the bottom surface of the pocket) is prone to stress concentration. Therefore, by forming a built-up portion that protrudes axially inward at the radially inner end of the bottom surface of the pocket, it is possible to effectively prevent damage to the cage annular portion due to stress concentration caused by centrifugal force. It becomes possible.

A radially outer oil groove extending axially from the distal end of the retainer claw toward the retainer annular portion is formed on the radially outer surface of the retainer claw,
An inner diameter side oil groove extending axially from the tip of the cage claw portion toward the cage annular portion is formed on the radial inner surface of the cage claw portion,
The retainer claw portion has an H-shaped cross-section perpendicular to the axial direction formed by the outer diameter side oil groove and the inner diameter side oil groove and is open radially outwardly and radially inwardly. It is preferable to adopt

With this configuration, the outer diameter oil groove formed on the radially outer surface of the cage claw portion and the inner diameter oil groove formed on the radially inner surface of the cage claw portion allow the maintenance of the cage claw portion. Since the cross-sectional shape is H-shaped, the mass of the cage claws can be suppressed while ensuring the secondary moment of area of the cage claws (difficulty in deformation of the cage claws against bending moment). Therefore, it is possible to suppress the torsional deformation of the retainer annular portion and the bending deformation of the retainer claw portion itself caused by the centrifugal force that the retainer claw portions receive when the bearing rotates at high speed.

The outer diameter side oil groove is formed such that the position of the groove bottom surface of the outer diameter side oil groove gradually changes radially outward from the distal end side of the retainer claw portion toward the root side thereof,
It is preferable to employ a configuration in which a flat rising surface rising radially outward from the base of the cage claw portion is formed on the cage annular portion.

With this configuration, the outer diameter oil groove is formed such that the position of the groove bottom surface of the outer diameter oil groove gradually changes radially outward from the distal end side of the retainer claw portion toward the root side thereof. When the bearing rotates, the lubricating oil in the oil groove on the outer diameter side moves from the tip side toward the root side of the retainer claw portion due to the pumping effect. Then, the lubricating oil that has moved from the distal end side to the root side of the cage claw portion in the outer diameter side oil groove is returned axially inward by the rising surface that rises radially outward from the root side of the cage claw portion. . By repeating this action, it becomes possible to efficiently circulate the lubricating oil in the bearing.

A configuration may be employed in which outer diameter side through grooves axially penetrating the outer periphery of the retainer annular portion are formed at circumferential positions corresponding to the retainer claw portions.

With this configuration, lubricating oil passes through the outer diameter side through-grooves and can easily move back and forth between the region axially inner than the retainer annular portion and the region axially outer than the retainer annular portion. , can promote the circulation of lubricating oil inside the bearing. Further, the outer diameter-side through grooves are formed at circumferential positions corresponding to the cage claw portions in the cage annular portion (that is, positions in the cage annular portion where the rigidity is ensured by the cage claw portions). Therefore, it is possible to effectively prevent a decrease in rigidity of the retainer annular portion due to the formation of the outer diameter side through groove.

Further, between the outer diameter side through grooves adjacent in the circumferential direction, the outer circumference of the retainer annular portion extends in the axial direction and is open to the axial outer side of the retainer annular portion. It is preferable to employ a configuration in which a non-penetrating axial groove is formed axially inside the annular portion.

In this way, the lubricating oil can easily flow through the axial grooves between the region axially inner than the retainer annular portion and the region axially outer than the retainer annular portion. Circulation of lubricating oil inside can be promoted. In addition, since the axial groove is formed so as not to penetrate the retainer annular portion in the axial direction, it is possible to effectively prevent damage to the retainer annular portion due to stress concentration. That is, when the cage annular portion is torsionally deformed by the centrifugal force acting on the claw portions of the cage, stress concentration tends to occur on the inner side of the outer periphery of the cage annular portion in the axial direction. Therefore, by forming the axial grooves on the outer periphery of the retainer annular portion so that they do not penetrate axially inward, it is possible to effectively prevent damage to the retainer annular portion due to stress concentration. becomes.

It is preferable that the axial length of the axial groove is set to 2/3 or less of the axial width of the retainer annular portion.

By doing so, it is possible to effectively prevent deterioration of the rigidity of the retainer annular portion due to the formation of the axial grooves on the outer periphery of the retainer annular portion, thereby effectively preventing breakage of the retainer annular portion due to stress concentration. can be prevented.

A configuration may be employed in which an inner diameter side through-groove axially penetrating the inner periphery of the retainer annular portion is formed at a circumferential position corresponding to the retainer claw portion.

In this way, the lubricating oil passes through the inner diameter side through-groove and can easily move back and forth between the region axially inner than the retainer annular portion and the region axially outer than the retainer annular portion. Circulation of lubricating oil inside the bearing can be promoted. In addition, the inner diameter side through groove is formed at a circumferential position corresponding to the cage claw portion in the retainer annular portion (that is, at a position in the retainer annular portion where the rigidity is ensured by the retainer claw portion). Therefore, it is possible to effectively prevent a decrease in rigidity of the retainer annular portion due to the formation of the inner diameter side through groove.

The seal member has a seal-side inclined surface extending linearly and inclined axially inward from the seal-side sliding surface in a cross-sectional view perpendicular to the circumferential direction,
The retainer annular portion includes, in a cross-sectional view orthogonal to the circumferential direction, a retainer-side inclined surface that extends linearly and is inclined axially inward from the retainer-side sliding surface toward the radial direction inward from the retainer-side sliding surface; a chamfer extending linearly from the side sliding surface toward the outside in the radial direction and inclined inward in the axial direction;
an angle formed by the retainer-side inclined surface and the seal-side inclined surface is set to 10° or less,
It is preferable to employ a configuration in which the angle formed by the chamfered portion and the seal-side sliding surface is set to be greater than 10° and 48° or less.

With this configuration, the angle formed between the cage-side inclined surface and the seal-side inclined surface formed radially inward from the sliding contact portion between the cage-side sliding surface and the seal-side sliding surface is equal to the cage-side sliding surface. It is smaller than the angle formed between the seal-side sliding surface and the chamfered portion formed radially outside the sliding contact portion between the moving surface and the seal-side sliding surface. That is, the angle formed between the cage and the seal member radially inward with respect to the sliding contact portion between the cage-side sliding surface and the seal-side sliding surface is the angle between the cage-side sliding surface and the seal-side sliding surface. It is smaller than the angle formed between the retainer and the seal member on the radially outer side with respect to the sliding contact portion of the face. Therefore, in the region sandwiched in the axial direction between the cage and the seal member, the cage-side inclined surface and the seal-side inclined surface are arranged from the inner side in the radial direction of the sliding contact portion between the cage-side inclined surface and the seal-side inclined surface. A flow of lubricating oil is generated radially outward of the sliding contact portion, and it is possible to efficiently lubricate the inside of the bearing.

It is preferable to employ a configuration in which notches are formed at the tips of the retainer claws so as to penetrate circumferentially both groove shoulders of the outer diameter side oil groove and the inner diameter side oil groove.

By doing so, it is possible to increase the amount of lubricating oil supplied to the balls from the circumferential direction and improve the lubricating performance of the balls.

A resin retainer can be adopted as the retainer.

The sealed ball bearing configured as described above is particularly suitable for use as a bearing for an electric motor of an electric vehicle or a bearing for a transmission for an electric vehicle that decelerates the rotation of the electric motor.

In the sealed ball bearing of the present invention, when the bearing rotates, the sliding contact tip surface of the axial projection formed on one of the seal-side sliding surface and the retainer-side sliding surface slides against the sliding surface of the other sliding surface. Since the sliding contact tip surface of the axial projection has a shape extending linearly in the radial direction when sliding on the smooth sliding contact plane formed on the entire circumference of the moving surface, the axial projection pushes the lubricating oil aside. lubricating oil is likely to be drawn into the sliding contact portion of the axial projection. As a result, an oil film is formed between the sliding contact tip surface of the axial projection and the sliding contact plane due to the wedge film effect. The contact resistance between the sealing members can be kept extremely low.

In addition, when the bearing is stationary, the sliding contact tip surface and the sliding contact plane face each other non-parallel at an angle in the direction in which the distance widens from the radially inner side to the radially outer side. In addition, it is possible to form a stable oil film by the wedge film effect between the sliding contact end face and the sliding contact plane. That is, when the bearing rotates at high speed, the cage annular portion is deformed by the centrifugal force acting on the claw portion of the cage. It is possible to form a stable oil film between the tip surface and the sliding contact plane by the wedge film effect.

BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing which shows the sealed ball bearing concerning embodiment of this invention Cross-sectional view along the cross-section orthogonal to the axial direction of the sealed ball bearing of FIG. Cross-sectional view of the sealed ball bearing shown in FIG. 1 cut along the circumferential direction and viewed from the outer diameter side Cross-sectional view along the IV-IV line in Fig. 3 Cross-sectional view along the V-V line in Fig. 3 FIG. 2 is a perspective view of the retainer of FIG. 1 as seen from the retainer claw portion side; (a) is an enlarged view of the vicinity of the cage-side sliding surface and the seal-side sliding surface in FIG. 4, and (b) is the cage-side sliding when the sealed ball bearing in FIG. Enlarged view of the vicinity of the moving surface and the sliding surface on the seal side Cross-sectional view along line VIII-VIII in FIG. 7(b) A diagram showing the relationship between the pocket side and the bearing center (the center of the retainer annular portion) shown in FIG. A diagram showing a modified example of the side surface of the pocket shown in FIG. 2 corresponding to FIG. Schematic diagram of an electric vehicle transmission incorporating the sealed ball bearing of Fig. 1

FIG. 1 shows a sealed ball bearing 1 according to an embodiment of the invention. This sealed ball bearing 1 comprises an inner ring 2, an outer ring 3 provided coaxially on the radially outer side of the inner ring 2, and an annular space 4 formed between the inner ring 2 and the outer ring 3 with a space therebetween in the circumferential direction. a plurality of balls 5 that are incorporated in a space, a resin retainer 6 (hereinafter simply referred to as "retainer 6") that retains the circumferential spacing of the plurality of balls 5, and both ends in the axial direction of the annular space 4. It has an annular seal member 7 that closes one end opening (the right end opening in the figure) of the openings, and an annular seal member 8 that closes the other end opening (the left end opening in the figure). . The annular space 4 is filled with a lubricant (not shown) such as grease.

The outer circumference of the inner ring 2 includes an inner ring raceway groove 9 with which the balls 5 roll and contact, a pair of inner ring groove shoulder portions 10 positioned axially outside the inner ring raceway groove 9, and axially outside the inner ring groove shoulder portions 10. A pair of sliding recesses 11 are formed. The inner ring raceway groove 9 is an arcuate groove having a concave arcuate cross section along the surface of the ball 5 and is formed to extend in the axial center of the outer circumference of the inner ring 2 in the circumferential direction. The pair of inner ring groove shoulder portions 10 are embankment-like portions extending in the circumferential direction on both sides sandwiching the inner ring raceway groove 9 in the axial direction. The sliding recessed portion 11 is a recessed portion formed adjacent to the axially outer side of the inner ring groove shoulder portion 10 and extending in the circumferential direction. Seal members 7 and 8 are in sliding contact with the inner surfaces of the pair of sliding recesses 11, respectively.

The inner circumference of the outer ring 3 includes an outer ring raceway groove 12 with which the balls 5 roll and contact, a pair of outer ring groove shoulders 13 positioned axially outside the outer ring raceway groove 12, and a pair of outer ring groove shoulders 13 axially outside the outer ring groove shoulders 13. A pair of positioned seal fixing grooves 14 are formed. The outer ring raceway groove 12 is an arcuate groove having a concave arcuate cross section along the surface of the ball 5 and is formed to extend in the axial center of the inner circumference of the outer ring 3 in the circumferential direction. The pair of outer ring groove shoulder portions 13 are bank-like portions extending in the circumferential direction on both sides sandwiching the outer ring raceway groove 12 in the axial direction. The seal fixing groove 14 is a circumferentially extending groove formed adjacent to the axially outer side of the outer ring groove shoulder portion 13 . The seal members 7 and 8 are fitted and fixed in the seal fixing grooves 14, respectively.

The ball 5 is radially sandwiched between the outer ring raceway groove 12 and the inner ring raceway groove 9 . This sealed ball bearing 1 is a deep groove ball bearing. That is, the axial width dimension of the outer ring raceway groove 12 is larger than half the diameter of the balls 5 , and the axial width dimension of the inner ring raceway groove 9 is larger than half the diameter of the balls 5 .

As shown in FIG. 4, the seal member 7 is an annular member comprising an annular core 15 and a rubber material 16 (for example, nitrile rubber, acrylic rubber, etc.) fixed to the core 15 . The rubber material 16 is fixed to the core metal 15 by vulcanization insert molding. That is, by vulcanizing the rubber material 16 with the core metal 15 placed in a vulcanization mold for the rubber material 16, the rubber material 16 is adhered and fixed to the surface of the core metal 15. .

The seal member 7 includes a fitting portion 17 fitted into the seal fixing groove 14 , an annular plate portion 18 extending radially inward from the fitting portion 17 , and a seal lip 19 slidingly contacting the inner surface of the sliding recess 11 . have The fitting portion 17 is provided at the outer diameter side end portion of the seal member 7 . The seal lip 19 is provided at the inner diameter side end of the seal member 7 . The surface of the inner surface of the sliding recess 11 with which the seal lip 19 slides is a cylindrical surface having a constant outer diameter along the axial direction.

The retainer 6 includes a retainer ring portion 20 (see FIG. 5) extending in the circumferential direction in a region sandwiched between the passage region of the balls 5 and the seal member 7 in the axial direction. and retainer claws 21 extending axially between adjacent balls 5 . The retainer annular portion 20 and the retainer claw portion 21 are seamlessly integrally formed of a resin composition. The resin composition forming the retainer annular portion 20 and the retainer claw portions 21 may be composed only of a resin material. is used.

Polyamide (PA) or super engineering plastics can be used as the resin material that serves as the base of the resin composition. Polyamide 46 (PA46), polyamide 66 (PA66), polynonamethylene terephthalamide (PA9T), and the like can be used as the polyamide. As super engineering plastics, polyetheretherketone (PEEK) and polyphenylene sulfide (PPS) can be employed. Glass fiber, carbon fiber, aramid fiber or the like can be used as the fiber reinforcing material added to the resin material.

One axial end of the retainer claw portion 21 is a fixed end fixed to the retainer annular portion 20 (the base of the retainer claw portion 21), and the other axial end is a free end (the base of the retainer claw portion 21). tip) is formed in a cantilever shape. The axial length of the retainer claw portion 21 is set larger than the radius of the ball 5 . The retainer claw portion 21 has a tapered shape in which the radial thickness gradually decreases from the side (root side) closer to the retainer annular portion 20 toward the far side (tip side).

As shown in FIG. 2, the retainer claw portion 21 has a pocket side surface 22 facing the ball 5 in the circumferential direction. A portion of the pocket side surface 22 for receiving the balls 5 in the circumferential direction is formed in a planar shape so that the pocket side surface 22 does not interfere with the balls 5 when the retainer claw portion 21 moves radially outward due to centrifugal force. As shown in FIG. 9, the pocket side surface 22 is a plane along a straight line _L1 extending in the radial direction through the bearing center O when viewed from the axial direction. is a plane extending radially such that

As shown in FIG. 3, the portion of the pocket side surface 22 that receives the ball 5 in the circumferential direction is inclined in the circumferential direction when viewed from the radial direction so as not to generate an axial force component when receiving the ball 5. It has a straight shape that extends straight in the axial direction. The retainer annular portion 20 has a pocket bottom surface 23 axially facing the balls 5 . The pocket side surface 22 and the pocket bottom surface 23 are connected in a concave arc shape when viewed from the radial direction.

As shown in FIG. 5, the pocket bottom surface 23 has a shape extending linearly in the radial direction in a cross-sectional view perpendicular to the circumferential direction. A built-up portion 24 protruding axially inward is integrally formed at the radially inner end portion of the pocket bottom surface 23 . The padding portion 24 has a shape protruding radially inward within a range in which contact with the ball 5 does not occur.

The retainer 6 is an inner ring guide type retainer that is radially positioned by contact with the inner ring 2 . A retainer guided surface 42 that is guided by the inner ring groove shoulder portion 10 on the outer periphery of the inner ring 2 is formed on the inner periphery of the retainer annular portion 20 . The cage guided surface 42 is an annular surface that is supported in sliding contact with the inner ring groove shoulder portion 10 .

As shown in FIG. 4 , an outer diameter oil groove 26 extending axially from the distal end of the cage claw portion 21 toward the cage annular portion 20 is formed in the radial outer surface 25 of the cage claw portion 21 . It is An inner diameter side oil groove 28 extending axially from the tip of the cage claw portion 21 toward the cage ring portion 20 is formed in the radial inner side surface 27 of the cage claw portion 21 . The outer diameter side oil groove 26 and the inner diameter side oil groove 28 allow the retainer claw portion 21 to have an H-shaped cross section perpendicular to the axial direction that is open radially outward and radially inward. It is

The outer diameter oil groove 26 is formed such that the position of the groove bottom surface of the outer diameter oil groove 26 gradually changes radially outward from the distal end side of the retainer claw portion 21 toward the root side. Further, the inner diameter oil groove 28 is formed such that the position of the groove bottom surface of the inner diameter oil groove 28 gradually changes radially inward from the distal end side of the retainer claw portion 21 toward the root side. The retainer annular portion 20 is formed with a flat rising surface 29 that rises radially outward from the base of the retainer claw portion 21 . The rising surface 29 is a plane orthogonal to the axial direction, and intersects the root side end of the retainer claw portion 21 on the inner surface of the outer diameter side oil groove 26 with a step. Further, as shown in FIG. 6, the rising surface 29 is formed at the root side end of the retainer claw portion 21 of the radial outer surface 25 of the retainer claw portion 21 (the surface on which the outer diameter side oil groove 26 is not formed). It also intersects with steps.

As shown in FIGS. 2 and 4 , on the outer circumference of the retainer annular portion 20 , an outer diameter extending through the outer periphery of the retainer annular portion 20 in the axial direction is provided at a circumferential position corresponding to the retainer claw portion 21 . A side through groove 30 is formed. Similarly, on the inner circumference of the retainer annular portion 20, at circumferential positions corresponding to the retainer claw portions 21, inner diameter side through grooves 31 axially penetrating the inner periphery of the retainer annular portion 20 are formed. It is The inner diameter side through groove 31 communicates with the inner diameter side oil groove 28 of the retainer claw portion 21 .

As shown in FIGS. 5 and 6 , on the outer circumference of the retainer annular portion 20 , there is provided an axially extending outer periphery of the retainer annular portion 20 between the outer diameter side through grooves 30 adjacent in the circumferential direction. An axial groove 32 is formed. Axial groove 32 is formed so as to be open to the outside in the axial direction of retainer annular portion 20 and not to penetrate to the inner side in the axial direction of retainer annular portion 20 . That is, the axial groove 32 is formed only in a portion of the outer periphery of the retainer annular portion 20 from the axial intermediate portion to the axial outer end, and is located at the axially inner end of the outer periphery of the retainer annular portion 20 . not formed in the The axial length of the axial groove 32 is set to 2/3 or less of the axial width of the retainer annular portion 20 .

As shown in FIGS. 3 and 4, at the tip of the retainer claw portion 21, a notch 33 circumferentially penetrates the groove shoulders on both circumferential sides of the outer diameter side oil groove 26 and the inner diameter side oil groove 28, respectively. formed. By providing this notch 33 , it is possible to increase the amount of lubricating oil supplied to the balls 5 from the circumferential direction and improve the lubricating performance of the balls 5 .

As shown in FIG. 4 , the seal member 7 has a seal-side sliding surface 34 axially facing the retainer 6 . The seal-side sliding surface 34 is an annular surface formed on the inner side in the axial direction of the annular plate portion 18 of the seal member 7 over the entire circumference. The seal-side sliding surface 34 is formed on the surface of the rubber material 16 rather than on the surface of the metal core 15 . The retainer 6 also has a retainer-side sliding surface 35 axially facing the seal-side sliding surface 34 . The retainer-side sliding surface 35 is an annular surface formed along the entire periphery of the retainer annular portion 20 on the outer side in the axial direction.

As shown in FIG. 3, a plurality of axial protrusions 36 are formed on the seal-side sliding surface 34 at regular intervals in the circumferential direction. In the drawing, the axial height of the axial projection 36 is exaggerated in order to make the presence of the axial projection 36 easier to understand, but the axial height of the axial projection 36 is 0.5 mm or less. extremely small.

As shown in FIG. 7(a), each axial projection 36 has a sliding contact tip surface 37 extending linearly in the radial direction in a cross-sectional view perpendicular to the circumferential direction. In other words, the axial protrusion 36 has a shape in which the apexes of the same height extend continuously in the radial direction, and the apex forms a sliding contact end surface 37 . As shown in FIG. 8, the axial protrusion 36 is formed so that the cross-sectional shape perpendicular to the radial direction is an arcuate shape that protrudes in the axial direction. The axial protrusion 36 may be formed so that the cross-sectional shape perpendicular to the radial direction is a trapezoidal shape protruding in the axial direction.

On the other hand, as shown in FIGS. 7A and 8, the retainer-side sliding surface 35 is formed with a smooth sliding contact plane 38 over the entire circumference. As shown in FIG. 7(a), when the bearing is stationary, the sliding contact end face 37 and the sliding contact flat surface 38 face each other non-parallel at an angle α in the direction in which the distance increases from the radially inner side to the radially outer side. It is said that Here, the angle α formed by the sliding contact end face 37 and the sliding contact flat surface 38 when the bearing is stationary is set within the range of 0.5° or more and 6° or less (preferably 1° or more and 5° or less).

As shown in FIG. 4, the axial projection 36 is arranged at a position overlapping the pitch circle of the balls 5 (an imaginary circle connecting the centers of the plurality of balls 5) or radially outside thereof. Here, the fact that the axial projection 36 is arranged at a position overlapping the pitch circle of the ball 5 means that the imaginary cylindrical surface passing through the pitch circle of the ball 5 has a positional relationship that passes through the position of the axial projection 36. , and that the axial projections 36 are arranged radially outward of the pitch circle of the ball 5 means that the axial projections 36 as a whole are radially outward of an imaginary cylindrical surface passing through the pitch circle of the ball 5. refers to the positional relationship in In the figure, the axial protrusions 36 are arranged radially outside the pitch circle of the ball 5 .

As shown in FIG. 7( a ), the seal member 7 has a seal-side slant extending straight from the seal-side sliding surface 34 radially inward and axially inwardly slanted in a cross-sectional view perpendicular to the circumferential direction. It has a face 39 . In a cross-sectional view orthogonal to the circumferential direction, the retainer annular portion 20 includes a retainer-side inclined surface 40 extending linearly from the retainer-side sliding surface 35 toward the radially inward direction and inclined axially inward, A chamfered portion 41 linearly extending from the device-side sliding surface 35 radially outward and axially inwardly inclined.

The cage-side inclined surface 40 and the seal-side inclined surface 39 are axially opposed to each other at an angle β in the direction in which the distance increases from the radially outer side to the radially inner side. The angle β formed by the retainer-side inclined surface 40 and the seal-side inclined surface 39 is set to 10° or less. The chamfered portion 41 and the seal-side sliding surface 34 are axially opposed to each other at an angle γ such that the axial distance gradually widens from the radially inner side to the radially outer side. The angle γ between the chamfered portion 41 and the seal-side sliding surface 34 is set to be greater than 10° and 48° or less.

As shown in FIG. 11, the sealed ball bearing 1 is used as a bearing for an electric vehicle transmission 50 that slows down the rotation of an electric motor of an electric vehicle such as an EV (battery electric vehicle) or HEV (hybrid electric vehicle). It is possible to use The bearing of this electric vehicle transmission 50 rotates at a wide range of rotation speeds from a low speed range to a high speed range while the vehicle is running. It is used under the condition that the number of rotations (min ⁻¹ )) exceeds 2,000,000.

A transmission 50 shown in FIG. 11 includes a stator 52 of an electric motor 51, a rotor 53 of the electric motor 51, a rotating shaft 54 connected to the rotor 53, and a sealed ball bearing 1 that rotatably supports the rotating shaft 54. , a second rotating shaft 55 and a third rotating shaft 56 arranged parallel to the rotating shaft 54, a first gear train 57 for transmitting the rotation of the rotating shaft 54 to the second rotating shaft 55, and the second rotating shaft 55. and a second gear train 58 that transmits rotation to the third rotating shaft 56 . The stator 52 is an annular stationary member, and a rotor 53 as a rotating member is arranged inside the stator 52 . When the stator 52 is energized, the electromagnetic force acting between the stator 52 and the rotor 53 rotates the rotor 53 , and the rotation of the rotor 53 is input to the rotating shaft 54 .

In the sealed ball bearing 1 of this embodiment, as shown in FIGS. When sliding contact is made on the smooth sliding contact flat surface 38 formed on the cage-side sliding surface 35 over the entire circumference, the sliding contact tip surface 37 of the axial projection 36 moves radially as shown in FIG. 7(b). Since it has a shape extending linearly (a shape in which the same height continues in the radial direction), the lubricating oil is less likely to be pushed aside by the axial projections 36 when the bearing rotates, and the lubricating oil is drawn into the sliding contact portions of the axial projections 36. easy to fall off. Therefore, as shown in FIG. 8, an oil film is formed by the wedge film effect between the sliding contact end face 37 of the axial projection 36 and the sliding contact plane 38, and the oil film causes the sliding contact end face 37 and the sliding contact plane 38 to move. The space between 38 is fluidly lubricated, and the contact resistance between the retainer 6 and the seal member 7 can be kept extremely low. Therefore, it is possible to prevent abnormal heat generation due to the sliding resistance of the contact portion between the retainer 6 and the seal member 7 .

Here, the state of lubrication between sliding surfaces is classified into a state of boundary lubrication and a state of fluid lubrication. In the boundary lubrication state, the sliding surface is lubricated with an oil film consisting of several molecular layers (approximately 10 ^-5 to 10 ^-6 mm) of lubricating oil adsorbed on each sliding surface. On the other hand, in the fluid lubrication state, an oil film (for example, about 10 ^-3 to 10 ^-1 mm) is formed between the sliding surfaces by the wedge film effect, and the oil film keeps the sliding surfaces together. This refers to the state in which there is no direct contact (only indirect contact through the oil film). When the wedge film effect occurs and fluid lubrication occurs, the sliding resistance becomes almost zero.

In addition, as shown in FIG. 7(a), when the bearing is stationary, the sealed ball bearing 1 is arranged so that the distance between the sliding contact end face 37 and the sliding contact flat surface 38 widens from the radially inner side toward the radially outer side. Since they are arranged to face each other non-parallel at an angle α, an oil film can be stably formed between the sliding contact end surface 37 and the sliding contact flat surface 38 by the wedge film effect when the bearing rotates at high speed. is possible.

That is, assuming that the sliding contact end surface 37 and the sliding contact flat surface 38 shown in FIG. The cage annular portion 20 is deformed by the centrifugal force acting on the cage claw portion 21 shown in , and the deformation causes the cage-side sliding surface 35 to incline, and the sliding contact tip surface 37 and the sliding contact plane 38 are not parallel. As a result, there is a problem that the edge of the sliding contact end surface 37 abuts against the sliding contact flat surface 38, making it difficult to form an oil film between the sliding contact end surface 37 and the sliding contact flat surface 38 due to the wedge film effect. In order to solve this problem, the sealed ball bearing 1 of the above-described embodiment, as shown in FIG. Since the bearings are arranged to face each other non-parallel at an angle α in the direction in which the gap widens toward them, when the bearing rotates at high speed, centrifugal force acting on the cage claws 21 shown in FIG. The portion 20 is deformed, and as a result of the deformation, as shown in FIG. In addition, it is possible to form a stable oil film by the wedge film effect.

In addition, as shown in FIGS. 2 and 9, the sealed ball bearing 1 has a pocket side surface 22 which is a flat surface along a straight line _L1 passing through the bearing center O and extending in the radial direction. When the retainer annular portion 20 is deformed by the centrifugal force acting on the retainer claw portion 21 during high-speed rotation, and the deformation causes the retainer claw portion 21 to move radially outward, the retainer claw portion is deformed. It is possible to prevent the pocket side surface 22 of 21 from interfering with the ball 5 and generating abnormal heat.

As shown in FIG. 10, the pocket side surfaces 22 are planes along parallel straight lines _L3 that face each other in the circumferential direction with a straight line _L2 connecting the bearing center O and the circumferential center of the retainer claw portion 21 interposed therebetween. may be adopted. Even in this way, when the cage annular portion 20 is deformed by the centrifugal force acting on the cage claw portion 21 and the cage claw portion 21 is moved radially outward due to the deformation, the cage claw portion It is possible to prevent the pocket side surface 22 of 21 from interfering with the ball 5 (see FIG. 2) and generating abnormal heat.

Further, when the pocket side surface ₂₂ shown in FIG. 5 (see FIG. 2) and the pocket side 22 remain unchanged. Therefore, when the bearing rotates at high speed, the cage annular portion 20 is deformed by the centrifugal force acting on the cage claw portion 21, and the deformation causes the cage claw portion 21 to move radially outward. , the holding of the ball 5 by the retainer 6 becomes stable.

Further, in the sealed ball bearing 1 of the above-described embodiment, as shown in FIG. The cross-sectional area of the root portion of the retainer claw portion 21 in the axial direction can be ensured while keeping the mass small. Therefore, it is possible to effectively suppress bending of the retainer claw portions 21 due to the centrifugal force acting on the retainer claw portions 21 .

In addition, as shown in FIGS. 5 and 6, this sealed ball bearing 1 has a built-up portion 24 formed at the radially inner end portion of the bottom surface 23 of the pocket. It is possible to effectively prevent the ring portion 20 from being damaged. That is, when the retainer annular portion 20 is torsionally deformed by the centrifugal force acting on the retainer claw portions 21 , the retainer annular portion 20 is positioned at the middle of the retainer claw portions 21 adjacent in the circumferential direction. stress concentration tends to occur at the radially inner portion of the pocket bottom surface 23 (the radially inner end portion of the pocket bottom surface 23). Therefore, if the built-up portion 24 that protrudes axially inward is formed at the radially inner end portion of the pocket bottom surface 23 as in the above-described embodiment, the cage ring portion 20 is damaged due to the concentration of stress generated by the centrifugal force. It is possible to effectively prevent

In addition, as shown in FIG. Since the cross-sectional shape of the retainer claw portion 21 is H-shaped due to the inner diameter side oil groove 28 formed in 27, the secondary moment of area of the retainer claw portion 21 (the deformation of the retainer claw portion 21 against the bending moment) is reduced. It is possible to reduce the mass of the retainer claw portion 21 while ensuring the resistance to corrosion. Therefore, the torsional deformation of the retainer ring portion 20 and the bending deformation of the retainer claw portions 21 themselves caused by the centrifugal force applied to the retainer claw portions 21 when the bearing rotates at high speed can be suppressed.

Further, in this sealed ball bearing 1, as shown in FIG. 4, the position of the groove bottom surface of the outer diameter side oil groove 26 gradually changes radially outward from the tip side of the retainer claw portion 21 toward the root side. Since the outer diameter oil groove 26 is formed as described above, the lubricating oil in the outer diameter oil groove 26 moves from the tip side toward the root side of the retainer claw portion 21 due to the pumping effect when the bearing rotates. . Then, the lubricating oil that has moved in the outer diameter oil groove 26 from the distal end side of the retainer claw portion 21 toward the root side is moved in the axial direction by the rising surface 29 that rises radially outward from the root of the retainer claw portion 21 . returned inside. By repeating this action, it is possible to efficiently circulate the lubricating oil in the bearing.

Further, as shown in FIG. 4, this sealed ball bearing 1 has an outer diameter side through groove 30 that axially penetrates the outer periphery of the retainer annular portion 20, and Since the inner diameter side through groove 31 penetrates in the direction, the lubricating oil passes through the outer diameter side through groove 30 and the inner diameter side through groove 31 and flows between the region axially inner than the retainer annular portion 20 and the retainer circle. It is easy to come and go between the regions on the outer side in the axial direction of the annular portion 20, and it is possible to promote the circulation of lubricating oil inside the bearing.

As shown in FIGS. 2 and 6, the outer diameter side through groove 30 and the inner diameter side through groove 31 are located at circumferential positions corresponding to the cage claw portions 21 in the cage annular portion 20 (that is, at the cage 20 of the ring portion 20 where the rigidity is ensured by the retainer claw portions 21 . It is possible to effectively prevent a decrease in rigidity.

In addition, as shown in FIG. 5, the sealed ball bearing 1 has an axial groove 32 formed in the outer periphery of the retainer annular portion 20, so that lubricating oil passes through the axial groove 32 and flows into the retainer. It becomes easier to move between the region axially inner than the ring portion 20 and the region axially outer than the retainer ring portion 20, thereby promoting the circulation of lubricating oil inside the bearing.

In addition, as shown in FIG. 6, the axial groove 32 is formed so as not to penetrate the retainer annular portion 20 axially inwardly. It is possible to prevent That is, when the retainer annular portion 20 is torsionally deformed by the centrifugal force acting on the retainer claw portion 21 , stress concentration tends to occur on the inner side of the outer periphery of the retainer annular portion 20 in the axial direction. Therefore, by forming the axial groove 32 on the outer periphery of the retainer annular portion 20 so as not to penetrate axially inwardly, damage to the retainer annular portion 20 due to stress concentration can be effectively prevented. becomes possible.

Further, in this sealed ball bearing 1, the axial length of the axial groove 32 shown in FIG. By forming the axial grooves 32 on the outer periphery of the ring portion 20, it is possible to effectively prevent a decrease in the rigidity of the retainer annular portion 20, and effectively prevent damage to the retainer annular portion 20 due to stress concentration. It is possible to

In addition, as shown in FIG. 7(a), the seal-equipped ball bearing 1 has a retainer-side sliding surface formed radially inwardly of the sliding contact portion between the retainer-side sliding surface 35 and the seal-side sliding surface 34. The angle β formed by the inclined surface 40 and the seal-side inclined surface 39 is a chamfered portion 41 formed radially outside the sliding contact portion between the retainer-side sliding surface 35 and the seal-side sliding surface 34, and the seal-side sliding surface. It is smaller than the angle γ with the moving surface 34 . That is, the angle β formed between the cage 6 and the seal member 7 radially inward with respect to the sliding contact portion between the cage-side sliding surface 35 and the seal-side sliding surface 34 is the same as the cage-side sliding surface. formed between the retainer 6 and the seal member 7 on the radially outer side with respect to the sliding contact portion between 35 and the seal-side sliding surface 34 . Therefore, in the region sandwiched in the axial direction between the retainer 6 and the seal member 7 , the retainer-side inclined surface 40 and the seal-side inclined surface 40 and the seal-side inclined surface 39 are arranged from the inner side in the radial direction of the sliding contact portion between the cage-side inclined surface 40 and the seal-side inclined surface 39 . A flow of lubricating oil is generated radially outward from the sliding contact portion of the seal-side inclined surface 39, and it is possible to efficiently lubricate the inside of the bearing.

In the above-described embodiment, the seal-side sliding surface 34 is formed with the axial protrusion 36 having the sliding contact tip surface 37, and the retainer-side sliding surface 35 is provided with the sliding contact flat surface 38 with which the sliding contact tip surface 37 slides. Although the formed structure has been described as an example, the configurations of the seal-side sliding surface 34 and the retainer-side sliding surface 35 may be reversed. That is, the cage-side sliding surface 35 is formed with an axial protrusion 36 having a sliding contact tip surface 37, and the seal-side sliding surface 34 is formed with a sliding contact flat surface 38 with which the sliding contact tip surface 37 slides. can be

In the above-described embodiment, the cage 6 is made of a resin composition only. In addition, it is also possible to employ a resin retainer in which a metal annular core is insert-molded into the retainer annular portion 20 . It is also possible to adopt a soft steel retainer in which the retainer annular portion 20 and the retainer claw portions 21 are integrally formed of soft steel.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the scope and meaning of equivalents of the scope of the claims.

1 Sealed ball bearing 2 Inner ring 3 Outer ring 4 Annular space 5 Ball 6 Cage 7 Seal member 20 Cage annular portion 21 Cage claw portion 22 Pocket side surface 23 Pocket bottom surface 24 Build-up portion 25 Radial direction outer surface 26 Outer diameter side Oil groove 27 Radial direction inner surface 28 Inner diameter side oil groove 29 Rise surface 30 Outer diameter side through groove 31 Inner diameter side through groove 32 Axial groove 33 Notch 34 Seal side sliding surface 35 Cage side sliding surface 36 Axial projection 37 Sliding tip surface 38 Sliding flat surface 39 Seal-side inclined surface 40 Cage-side inclined surface 41 Chamfered portion 50 Electric vehicle transmission 51 Electric motor α, β, γ Angles L ₁ , L ₂ , L ₃ Straight line O Bearing center

Claims (17)

an inner ring (2);
an outer ring (3) provided coaxially on the radially outer side of the inner ring (2);
a plurality of balls (5) incorporated in an annular space (4) formed between the inner ring (2) and the outer ring (3);
an annular seal member (7) provided at one end opening in the axial direction of the annular space (4);
a cage (6) for holding the plurality of balls (5),
The retainer (6) includes a retainer annular portion (20) extending circumferentially in a region axially sandwiched between the ball (5) passing region and the seal member (7), and the retainer circular portion (20). A sealed ball bearing having a cantilever-like retainer pawl portion (21) axially extending from a ring portion (20) between the balls (5) adjacent in the circumferential direction,
The seal member (7) has a seal-side sliding surface (34) axially facing the retainer (6),
The retainer (6) has a retainer-side sliding surface (35) axially facing the seal-side sliding surface (34),
One of the seal-side sliding surface (34) and the retainer-side sliding surface (35) is formed with a plurality of axial projections (36) spaced apart in the circumferential direction,
Each of the axial projections (36) has a sliding contact tip surface (37) linearly extending in the radial direction in a cross-sectional view perpendicular to the circumferential direction,
On the other sliding surface, a smooth sliding contact plane (38) is formed over the entire circumference, which is in sliding contact with the sliding contact tip surface (37) when the bearing rotates,
The sliding contact tip surface (37) and the sliding contact flat surface (38) are arranged to face each other non-parallel at an angle (α) in the direction in which the distance widens from the radially inner side to the radially outer side when the bearing is stationary. A sealed ball bearing characterized by: 2. The seal according to claim 1, wherein an angle (α) formed by said sliding contact end face (37) and said sliding contact plane (38) when the bearing is stationary is set within a range of 0.5° or more and 6° or less. ball bearing. The axial length of the cage claw (21) is set larger than the radius of the ball (5),
The retainer claw portion (21) has a pocket side surface (22) facing the ball (5) in the circumferential direction,
The portion of the pocket side surface (22) that receives the ball (5) in the circumferential direction is such that when the retainer claw portion (21) moves radially outward due to centrifugal force, the pocket side surface (22) 3. The sealed ball bearing according to claim 1 or 2, wherein the ball bearing has a planar shape so as not to interfere with the ball (5). 4. A sealed ball bearing according to claim 3, wherein said pocket side surface (22) is a plane along a straight line ( _L1 ) extending radially through the bearing center (O). The pocket side surfaces (22) are parallel straight lines _{( L3} 4. The sealed ball bearing according to claim 3, which is a plane along ). The retainer annular portion (20) has a pocket bottom surface (23) axially facing the balls (5),
The pocket bottom surface (23) has a shape extending linearly in the radial direction in a cross-sectional view orthogonal to the circumferential direction,
The sealed ball bearing according to any one of claims 3 to 5, wherein said pocket side surface (22) and said pocket bottom surface (23) are connected in a concave arc shape when viewed from the radial direction. 7. The ball with seal according to claim 6, wherein a build-up portion (24) protruding axially inward without contacting the ball (5) is formed at the radially inner end of the pocket bottom surface (23). bearing. A radially outer surface (25) of the retainer claw (21) is provided with an outer diameter side oil extending axially from the tip of the retainer claw (21) toward the retainer annular portion (20). a groove (26) is formed;
An inner diameter side oil groove extending axially from the tip end of the cage claw portion (21) toward the cage annular portion (20) is formed in the radial inner surface (27) of the cage claw portion (21). (28) is formed,
The retainer claw portion (21) has a cross-sectional shape perpendicular to the axial direction that is open radially outward and radially inward due to the outer diameter side oil groove (26) and the inner diameter side oil groove (28). 8. The sealed ball bearing according to any one of claims 1 to 7, which has an H shape that The outer diameter oil groove (26) is arranged such that the position of the groove bottom surface of the outer diameter oil groove (26) gradually changes radially outward from the tip side of the retainer claw portion (21) toward the root side thereof. is formed in
9. The seal according to claim 8, wherein the retainer annular portion (20) is formed with a flat rising surface (29) rising radially outward from the base of the retainer claw portion (21). ball bearings. 2. From Claim 1, wherein an outer diameter side through-groove (30) axially penetrating the outer periphery of the retainer annular portion (20) is formed at a circumferential position corresponding to the retainer claw portion (21). 10. The sealed ball bearing according to any one of 9. Between the outer diameter side through grooves (30) adjacent in the circumferential direction, a 11. The sealed ball bearing according to claim 10, wherein the retainer ring portion (20) is formed axially inwardly with a non-penetrating axial groove (32). 12. The sealed ball bearing according to claim 11, wherein the axial length of the axial groove (32) is set to 2/3 or less of the axial width of the retainer annular portion (20). 2. From Claim 1, wherein an inner diameter side through groove (31) axially penetrating the inner periphery of the retainer annular portion (20) is formed at a circumferential position corresponding to the retainer claw portion (21). 13. The sealed ball bearing according to any one of 12. The seal member (7) has a seal-side inclined surface (39) extending linearly from the seal-side sliding surface (34) radially inwardly and axially inwardly inclined in a cross-sectional view perpendicular to the circumferential direction. have
The retainer annular portion (20) extends in a straight line inclined axially inward from the retainer-side sliding surface (35) in a cross-sectional view orthogonal to the circumferential direction. a surface (40), and a chamfered portion (41) linearly extending radially outward from the cage-side sliding surface (35) and inclined axially inward,
an angle (β) formed by the cage-side inclined surface (40) and the seal-side inclined surface (39) is set to 10° or less,
14. The seal according to any one of claims 1 to 13, wherein an angle (γ) formed by the chamfered portion (41) and the seal-side sliding surface (34) is set to be greater than 10° and 48° or less. ball bearings. A notch (33) is formed at the tip of the retainer claw (21) so as to circumferentially pass through the groove shoulders on both circumferential sides of the outer diameter side oil groove (26) and the inner diameter side oil groove (28). 15. The sealed ball bearing according to any one of claims 8 to 14. The sealed ball bearing according to any one of claims 1 to 15, wherein the retainer (6) is a resin retainer. 17. The sealed ball bearing according to any one of claims 1 to 16, which is used as a bearing for an electric motor (51) of an electric vehicle or a bearing for an electric vehicle transmission (50) that reduces rotation of the electric motor (51). .

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