JP2022036002A - Ball bearing - Google Patents

Abstract

To provide a ball bearing for hardly causing the deformation of a resin cage due to centrifugal force when used with high speed rotation.SOLUTION: In a radial outside face 23 of a cage claw part 22, an outer diameter side axial groove 24 is formed. In a radial inside face 25 of the cage claw part 22, an inner diameter side axial groove 26 is formed. The cage claw part 22 has a sectional shape perpendicular to the axial direction formed as a H-shape opening radially outward and radially inward by the outer diameter side axial groove 24 and the inner diameter side axial groove 26.SELECTED DRAWING: Figure 5

Description

The present invention relates to ball bearings.

Ball bearings are often used as bearings to support rotating shafts of automobiles and industrial machines. Generally, a ball bearing is a cage that holds an inner ring, an outer ring coaxially provided on the radial outer side of the inner ring, a plurality of balls provided in an annular space between the inner ring and the outer ring, and the plurality of balls. And have.

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

Japanese Patent No. 30357666

In recent years, in the field of electric vehicles such as EV (battery-powered electric vehicle) and HEV (hybrid electric vehicle), high-speed rotation of the electric motor has been promoted in order to reduce the size and weight of the electric motor. Ball bearings that support the axis of rotation to which the rotation of such an electric motor is input are used under conditions where the dmn value (ball pitch circle diameter dm (mm) x rotation speed n (min ^-1 )) exceeds 2 million. It may be done.

The inventors of the present application have considered using a crown cage for ball bearings that support a rotating shaft such as an EV or HEV that rotates at high speed.

However, when a crown-shaped cage is used for a ball bearing that rotates at high speed, the centrifugal force acting on the cantilever-shaped cage claw causes torsional deformation in the direction in which the cage claw is tilted outward in the radial direction. It was found that the cage claws themselves are bent and deformed in the radial direction, and the cage claws may interfere with the balls due to these deformations. If the claws of the cage interfere with the balls, it causes heat generation of the ball bearings.

An object to be solved by the present invention is to provide a ball bearing in which the resin cage is less likely to be deformed by centrifugal force when used at high speed rotation.

In order to solve the above problems, in the present invention, the following configurations are adopted for ball bearings.
Inner ring and
An outer ring coaxially provided on the outer side in the radial direction of the inner ring,
A plurality of balls incorporated in the annular space formed between the inner ring and the outer ring,
A resin cage for holding the plurality of balls is provided.
The resin cage is a cantilever extending axially between a cage ring portion extending in the circumferential direction adjacent to the ball passing region and the ball adjacent in the circumferential direction from the cage annular portion. In a ball bearing with a beam-shaped cage claw
On the radial outer surface of the cage claw portion, an outer diameter side axial 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, an inner diameter side axial groove extending axially from the tip of the cage claw portion toward the cage annular portion is formed.
The cage claw portion has an H shape in which the cross-sectional shape orthogonal to the axial direction is opened outward in the radial direction and inward in the radial direction by the axial groove on the outer diameter side and the axial groove on the inner diameter side. Ball bearings that are characterized by that.

In this way, the cage claw is formed by the outer diameter side axial groove formed on the radial outer surface of the cage claw portion and the inner diameter side axial groove formed on the radial inner side surface of the cage claw portion. Since the cross-sectional shape of the portion is H-shaped, the mass of the cage claw portion can be suppressed while ensuring the moment of inertia of area of the cage claw portion (difficulty in deforming the cage claw portion with respect to the bending moment). .. Therefore, even when used at high speed rotation, the centrifugal force received by the cage claw suppresses torsional deformation of the cage annulus, and the cage claw itself also bends outward in the radial direction. It is possible to suppress the occurrence of deformation.

The axial length of the cage claw portion is set to be larger than the radius of the ball.
The cage claw portion has a circumferential facing surface facing the ball in the circumferential direction.
The portion of the circumferential facing surface that receives the ball in the circumferential direction is a flat surface that extends so that the circumferential facing surface does not interfere with the ball when the cage claw portion moves outward in the radial direction due to centrifugal force. It is preferable to adopt a configuration having a shape.

In this way, since the circumferentially opposed surfaces of the cage claws are planar, when the cage claws move outward in the radial direction due to the centrifugal force acting on the cage claws, the cage claws It is possible to prevent the facing surfaces in the circumferential direction from interfering with the ball. Further, since the shear resistance of the lubricant generated between the circumferential facing surface of the cage claw portion and the ball is suppressed to a low level, it is possible to suppress the heat generation of the ball bearing.

The cage annular portion has an axially opposed surface facing the ball in the axial direction.
It is preferable to adopt a configuration in which the circumferential facing surface and the axial facing surface are connected in a concave arc shape in cross section.

In this way, since the circumferential facing surface and the axial facing surface are connected in a concave arc shape in cross section, the axial direction of the cage claw portion is suppressed while keeping the mass of the axial tip portion of the cage claw portion small. It is possible to secure the cross-sectional area of the root portion of. Therefore, it is possible to effectively suppress the bending of the cage claw portion due to the centrifugal force acting on the cage claw portion.

It is preferable that the axial end portion of the outer diameter side axial groove on the side close to the cage ring portion has a structure in which the outer peripheral portion of the cage annular portion is cut off in a concave arc shape in cross section.

By doing so, the axial end portion of the outer diameter side axial groove near the cage annular portion is cut off in a concave arc shape in cross section, so that the mass of the axial tip portion of the cage claw portion can be increased. It is possible to secure the cross-sectional area of the axial root portion of the cage claw portion while keeping it small. Therefore, it is possible to effectively suppress the bending of the cage claw portion due to the centrifugal force acting on the cage claw portion.

It is preferable to form a cage guided surface that is guided by sliding on the outer circumference of the inner ring on the inner circumference of the cage annular portion.

In this way, the resin cage can be positioned in the radial direction by the sliding contact between the cage guided surface on the inner circumference of the cage annular portion and the outer circumference of the inner ring.

Further comprising an annular sealing member that closes one end opening in the axial direction of the annular space.
The cage annular portion has a cage-side sliding contact surface that is in sliding contact with the seal member so as to face axially in the axial direction.
The seal member has a seal-side sliding contact surface that is in sliding contact with the cage-side sliding contact surface.
On one of the cage side sliding contact surface and the seal side sliding contact surface, a plurality of arcuate axial protrusions having an axially convex cross-sectional shape along the circumferential direction are constant in the circumferential direction. It is preferable to adopt a configuration formed by pitch.

In this way, a plurality of arcuate projections having an axially convex cross-sectional shape along the circumferential direction are formed on one of the sliding contact surfaces on the cage side and the sliding contact surface on the seal side. Since it is formed at a constant pitch in the direction, an oil film due to the wedge film effect is formed between the axial protrusion and the sliding contact surface, and the oil film causes a fluid lubrication state between the axial protrusion and the sliding contact surface. The contact resistance between the cage and the sealing member can be kept extremely small. Therefore, it is possible to prevent abnormal heat generation due to the sliding resistance of the contact portion between the cage and the seal member. Further, since the cage annular portion is provided so as to be in sliding contact with the seal member, the axial thickness of the cage annular portion can be set to be large, and the rigidity of the cage annular portion can be increased. Will be. Therefore, even when used at high speed rotation, the torsional deformation of the cage ring portion due to the centrifugal force received by the cage claw portion can be suppressed, and the cage claw portion can be suppressed from tilting outward in the radial direction. be able to.

The axial protrusions are a parallel apex in which the height of an arcuate apex that is convex in the axial direction in a cross section along the circumferential direction is constant along the radial direction, and a circle that is convex in the axial direction in a cross section along the circumferential direction. It is preferable to adopt a configuration having an inclined top portion in which the height of the arc-shaped top portion gradually decreases from the radial outer end of the parallel top portion toward the radial outer direction.

By doing so, when the bearing rotates at a low speed and the centrifugal force applied to the cage claw is relatively small, an oil film due to the wedge film effect is formed between the parallel apex of the axial protrusion and the sliding contact surface. Can be done. In addition, when the bearing rotates at high speed and the centrifugal force received by the cage claw is relatively large, the cage annular portion is in a state where a relatively large torsional deformation occurs, and the parallel top and the inclined top of the axial projection are formed. An oil film due to the wedge film effect can be formed between the sliding contact surface. In this way, it is possible to stably form an oil film due to the wedge film effect between the cage and the sealing member regardless of the rotation speed of the bearing.

It is preferable that the inclined top portion has an R shape having a cross-sectional shape orthogonal to the circumferential direction that smoothly connects to the parallel top portion.

In this way, since the inclined top and the parallel top are smoothly connected, the parallel top and the inclined top and the sliding contact surface are in a state where the cage annular portion is subjected to a relatively large torsional deformation. When forming an oil film due to the wedge film effect, it is possible to stably form the oil film.

It is preferable that the plurality of axial protrusions are arranged at positions overlapping the pitch circles of the balls or radially outside the positions thereof.

In this way, when the centrifugal force acting on the cage claw causes a torsional deformation in the cage annular portion in the direction of tilting the cage claw outward in the radial direction, the torsional deformation causes the cage. It is possible to prevent the cage side sliding contact surface and the seal side sliding contact surface from coming into contact with each other at a position deviated radially outward from the axial protrusion.

It is preferable to adopt a configuration in which the outer diameter side axial groove has a shape in which the position of the groove bottom gradually changes radially outward from the tip end side of the cage claw portion toward the cage annular portion side. ..

By doing so, the position of the groove bottom of the outer diameter side axial groove gradually changes radially outward from the side of the tip of the cage claw portion toward the side of the cage annulus portion, so that the outer diameter side shaft The lubricant supplied into the directional groove moves from the tip end side of the cage claw toward the cage annulus side by the pumping action, and moves into the area between the cage annulus and the seal member. be introduced. Therefore, it is possible to sufficiently lubricate between the sliding contact surface of one of the sliding contact surface on the cage side and the sliding contact surface on the seal side and the axial protrusion, and effectively form an oil film with a wedge film. Become.

Further, the inner diameter side axial groove adopts a shape having a shape in which the position of the groove bottom gradually changes inward in the radial direction from the tip end side of the cage claw portion toward the cage annular portion side. be able to.

The axial end on the side opposite to the axial end on the side closed by the seal member of the annular space is not provided with a seal member so as to receive the lubricant supplied from the outside into the annular space. It is preferable to adopt an open configuration.

By doing so, it is possible to sufficiently lubricate between the sliding contact surface of one of the sliding contact surface on the cage side and the sliding contact surface on the seal side and the axial protrusion, and surely form an oil film with a wedge film. It will be possible.

The above ball bearing 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 reduces the rotation of the electric motor.

The ball bearing of the present invention is held by an outer radial side axial groove formed on the radial outer surface of the cage claw portion and an inner diameter side axial groove formed on the radial inner side surface of the cage claw portion. Since the cross-sectional shape of the vessel claw is H-shaped, the mass of the cage claw can be increased while ensuring the moment of inertia of area of the cage claw (difficulty of deformation of the cage claw with respect to the bending moment). It can be suppressed. Therefore, even when used at high speed rotation, the centrifugal force received by the cage claw suppresses torsional deformation of the cage annulus, and the cage claw itself also bends outward in the radial direction. It is possible to suppress the occurrence of deformation.

Sectional drawing which shows the ball bearing which concerns on 1st Embodiment of this invention Sectional view taken along line II-II of FIG. Sectional drawing along line III-III of FIG. Enlarged sectional view of the vicinity of the resin cage of the ball bearing of FIG. Perspective view of the cage of FIG. 1 as viewed from the side of the cage claw portion. FIG. 1 is an enlarged view showing the vicinity of the seal lip of the seal member of FIG. Sectional drawing along the line VII-VII of FIG. Schematic diagram of a transmission for an electric vehicle incorporating the ball bearings of FIG. Sectional drawing which shows the ball bearing which concerns on 2nd Embodiment of this invention The figure which shows the ball bearing of FIG. 9 corresponding to FIG. The figure which shows the ball bearing of FIG. 9 corresponding to FIG. Enlarged cross-sectional view of the vicinity of the seal member of the ball bearing of FIG. Sectional drawing along line XIII-XIII of FIG. A perspective view of the cage of FIG. 9 as viewed from the side of the cage claw portion. A perspective view of the cage of FIG. 9 as viewed from the side of the annulus of the cage. Side view of the cage of FIG. 9 as viewed from the side of the annulus of the cage. A side view showing a modified example of the cage shown in FIG. The figure which shows the ball bearing which concerns on the 3rd Embodiment of this invention corresponding to FIG. Sectional drawing along the XIX-XIX line of FIG. A view of the axial protrusion shown in FIG. 19 as viewed from the side of the sliding contact surface on the seal side. The figure which shows the ball bearing which concerns on 4th Embodiment of this invention corresponding to FIG. The figure which shows the ball bearing of FIG. 21 corresponding to FIG. The figure which shows the ball bearing of FIG. 21 corresponding to FIG. Enlarged sectional view of the vicinity of the resin cage of the ball bearing of FIG. 21 Partially enlarged view of the cage shown in FIG. A perspective view of the cage of FIG. 21 as viewed from the side of the cage claw portion.

FIG. 1 shows a ball bearing 1 according to a first embodiment of the present invention. The ball bearing 1 is incorporated in the inner ring 2, the outer ring 3 coaxially provided on the radial outer side of the inner ring 2, and the annular space 4 formed between the inner ring 2 and the outer ring 3 at intervals in the circumferential direction. Made of resin that maintains the circumferential distance between the plurality of balls 5 and the annular sealing member 6 that closes one of the end openings on both sides of the annular space 4 in the axial direction. It has a cage 7 (hereinafter simply referred to as "retractor 7").

On the outer circumference of the inner ring 2, the inner ring raceway groove 8 in which the ball 5 rolls and contacts, the pair of inner ring groove shoulder portions 9 located on the axially outer side of the inner ring raceway groove 8, and the inner ring groove shoulder portion 9 located on the axially outer side of the inner ring groove shoulder portion 9. A sliding recess 10 is formed. The inner ring raceway groove 8 is an arc groove having a concave arcuate cross section along the surface of the ball 5, and is formed by extending the center of the outer circumference of the inner ring 2 in the axial direction in the circumferential direction. The pair of inner ring groove shoulder portions 9 are bank-shaped portions extending in the circumferential direction on both sides of the inner ring raceway groove 8 in the axial direction. The sliding recess 10 is a recess extending in the circumferential direction formed adjacent to the lateral side of the inner ring groove shoulder portion 9 in the axial direction. A seal lip 11 provided at the inner diameter side end of the seal member 6 is in sliding contact with the inner surface of the sliding recess 10. In the figure, the surface of the inner surface of the sliding recess 10 with which the seal lip 11 slides is a cylindrical surface having a constant outer diameter along the axial direction.

On the inner circumference of the outer ring 3, the outer ring raceway groove 12 with which the balls 5 roll and contact, the pair of outer ring groove shoulder portions 13 located on the axially outer side of the outer ring raceway groove 12, and the outer ring groove shoulder portion 13 on the axially outer side. A positioned seal fixing groove 14 is formed. The outer ring raceway groove 12 is an arc groove having a concave arcuate cross section along the surface of the ball 5, and is formed so as to extend in the circumferential direction at the center of the inner circumference of the outer ring 3 in the axial direction. The pair of outer ring groove shoulder portions 13 are bank-shaped portions extending in the circumferential direction on both sides of the outer ring track groove 12 in the axial direction. The seal fixing groove 14 is a groove formed in the outer ring groove shoulder portion 13 adjacent to the outer side in the axial direction and extending in the circumferential direction. A fitting portion 15 provided at the outer diameter side end portion of the seal member 6 is fitted and fixed in the seal fixing groove 14.

The ball 5 is radially sandwiched between the outer ring raceway groove 12 and the inner ring raceway groove 8. The axial width dimension of the outer ring raceway groove 12 is larger than half the diameter of the ball 5. Further, the axial width dimension of the inner ring raceway groove 8 is larger than half the diameter of the ball 5. The ball 5 is a steel ball. A ceramic ball may be adopted as the ball 5.

As shown in FIG. 4, the sealing member 6 is an annular member formed by vulcanizing and adhering a rubber material 17 (for example, nitrile rubber, acrylic rubber, etc.) to the surface of the annular core metal 16. The seal member 6 includes a fitting portion 15 that fits into the seal fixing groove 14, an annular plate portion 18 that extends radially inward from the fitting portion 15, and a seal lip 11 that is in sliding contact with the inner surface of the sliding recess 10. Has. The core metal 16 has an annular plate-shaped flange portion 19 and a cylindrical portion 20 bent inward in the axial direction along the radial outer end of the flange portion 19. The flange portion 19 is embedded in the annular plate portion 18 of the seal member 6, and the cylindrical portion 20 is embedded in the fitting portion 15 of the seal member 6.

As shown in FIG. 1, the seal member 6 is provided only in one end opening of the both end openings in the axial direction of the annular space 4. That is, the axial end on the side (left side in the figure) opposite to the axial end on the side (right side in the figure) closed by the seal member 6 of the annular space 4 is annularly supplied with lubricating oil supplied from the outside. The seal member 6 is not provided and is open so as to be received in the space 4.

The cage 7 has a cage claw extending axially between a cage ring portion 21 extending in the circumferential direction adjacent to the passing region of the ball 5 and balls 5 adjacent to each other in the circumferential direction from the cage annular portion 21. It has a part 22 and. The cage ring portion 21 and the cage claw portion 22 are seamlessly and integrally formed by the resin composition. The resin composition forming the cage ring portion 21 and the cage claw portion 22 may be made of only a resin material, but here, a fiber reinforcing material is added to the resin material. Is used. The cage 7 is preferably manufactured by injection molding.

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

The cage claw portion 22 is formed in a cantilever shape having one end in the axial direction as a fixed end fixed to the annular portion 21 of the cage and the other end in the axial direction as a free end. The axial length of the cage claw portion 22 is set to be larger than the radius of the ball 5. The cage claw portion 22 has a constant shape without changing its radial thickness in the axial direction.

As shown in FIGS. 2 and 4, the radial outer surface 23 of the cage claw portion 22 has an outer diameter side axial direction extending axially from the tip of the cage claw portion 22 toward the cage annular portion 21. The groove 24 is formed. Further, an inner diameter side axial groove 26 extending axially from the tip of the cage claw portion 22 toward the cage annular portion 21 is formed on the radial inner side surface 25 of the cage claw portion 22. As shown in FIG. 2, the outer diameter side axial groove 24 has a groove width having a size of half or more of the circumferential width of the tip of the cage claw portion 22. Further, the inner diameter side axial groove 26 also has a groove width having a size of more than half the width in the circumferential direction of the tip of the cage claw portion 22. Then, by the outer diameter side axial groove 24 and the inner diameter side axial groove 26, the cage claw portion 22 has an H shape in which the cross-sectional shape orthogonal to the axial direction is opened outward in the radial direction and inward in the radial direction. It is said that. Further, the outer diameter side axial groove 24 and the inner diameter side axial groove 26 have an H shape so that the shape of the cage claw portion 22 when the cage claw portion 22 is viewed axially from the tip side thereof is H-shaped. It is formed open to the tip of the cage claw portion 22.

The cage claw portion 22 has a circumferential facing surface 27 facing the ball 5 in the circumferential direction. The portion of the circumferential facing surface 27 that receives the ball 5 in the circumferential direction has a planar shape that extends so that the circumferential facing surface 27 does not interfere with the ball 5 when the cage claw portion 22 moves outward in the radial direction due to centrifugal force. It is said that. In the figure, the circumferential facing surface 27 is a plane (of the cage claw portion 22) extending in parallel with a virtual straight line connecting the center of the cage ring portion 21 and the center of the cage claw portion 22 when viewed in the axial direction. A plane extending so that the circumferential width does not change along the radial direction and is constant). The center of the cage ring portion 21 is at the same position as the center of the inner ring 2 or the center of the outer ring 3. Further, the center of the cage claw portion 22 is an intermediate position of a pair of circumferential facing surfaces 27 located on both sides of the cage claw portion 22 in the circumferential direction when viewed in the axial direction.

The distance between the cage claws 22 adjacent to each other in the circumferential direction (that is, the distance between the circumferential facing surfaces 27 facing in the circumferential direction) is 1.02 to 1.11 times the diameter of the ball 5 on the pitch circle of the ball 5. It is preferable to set so as to be. By doing so, the vibration of the cage 7 can be reduced.

As shown in FIGS. 3 and 5, the portion of the circumferential facing surface 27 that receives the ball 5 in the circumferential direction is viewed in the radial direction so as not to generate an axial component force when the ball 5 is received. It extends straight in the axial direction without tilting in the circumferential direction. The cage ring portion 21 has an axially facing surface 28 that faces the ball 5 in the axial direction. The circumferential facing surface 27 and the axial facing surface 28 are connected in a concave arc shape in cross section. In the figure, the curved surface connecting the circumferential facing surface 27 and the axial facing surface 28 is a single R curved surface (a partially cylindrical surface having a constant radius of curvature).

As shown in FIG. 4, the axial end portion of the outer diameter side axial groove 24 on the side close to the cage annular portion 21 is cut off in a concave arc shape in cross section on the outer periphery of the cage annular portion 21. The axial end of the inner diameter side axial groove 26 on the side closer to the cage ring portion 21 is also cut off to the inner circumference of the cage annular portion 21. A cage guided surface 29 is formed on the inner circumference of the cage annular portion 21 so as to be guided by sliding contact with the inner ring groove shoulder portion 9 on the outer periphery of the inner ring 2. The cage guided surface 29 is an annular surface that is in direct sliding contact with the inner ring groove shoulder portion 9. If the sliding gap between the guided surface 29 of the cage and the shoulder portion 9 of the inner ring groove is set to a size of 0.22 mm or less, the vibration of the cage 7 can be reduced. The portion of the inner diameter side axial groove 26 that is cut off to the inner circumference of the cage annular portion 21 is open to the cage guided surface 29.

As shown in FIGS. 6 and 7, a plurality of protrusions 30 that are in sliding contact with the sliding recess 10 on the outer periphery of the inner ring 2 are provided at the inner diameter side end of the seal lip 11 at intervals in the circumferential direction. The protrusion 30 is formed so as to extend in a direction orthogonal to the circumferential direction. As shown in FIG. 7, each protrusion 30 has a convex arcuate cross-sectional shape.

As shown in FIG. 8, the ball bearing 1 is used as a bearing for a transmission 32 for an electric vehicle that reduces the rotation of an electric motor 31 of an electric vehicle such as an EV (battery-powered electric vehicle) or HEV (hybrid electric vehicle). It is possible to do. The bearing of the transmission 32 for an electric vehicle rotates at a wide range of rotation speeds from a low speed range to a high speed range while the vehicle is running, and when the bearing rotates at the highest speed, the dmn value (pitch circle diameter (mm) of the ball 5 × It is used under the condition that the number of revolutions (min ^-1 )) exceeds 2 million.

The transmission shown in FIG. 8 includes a stator 33 of an electric motor 31, a rotor 34 of the electric motor 31, a rotary shaft 35 connected to the rotor 34, a ball bearing 1 that rotatably supports the rotary shaft 35, and a rotary shaft. The second rotary shaft 36 and the third rotary shaft 37 arranged in parallel with the 35, the first gear train 38 that transmits the rotation of the rotary shaft 35 to the second rotary shaft 36, and the rotation of the second rotary shaft 36 are the first. It has a second gear row 39 that transmits to the three rotation shafts 37. The stator 33 is an annular stationary member, and a rotor 34 as a rotating member is arranged inside the stator 33. When the stator 33 is energized, the rotor 34 is rotated by the electromagnetic force acting between the stator 33 and the rotor 34, and the rotation of the rotor 34 is input to the rotating shaft 35.

As shown in FIG. 5, the ball bearing 1 is formed on the outer radial side axial groove 24 formed on the radial outer surface 23 of the cage claw portion 22 and the radial inner side surface 25 of the cage claw portion 22. Since the cross-sectional shape of the cage claw portion 22 is H-shaped due to the inner diameter side axial groove 26 formed, the cross-sectional secondary moment of the cage claw portion 22 (deformation of the cage claw portion 22 with respect to the bending moment). The mass of the cage claw portion 22 can be suppressed while ensuring the difficulty). Therefore, even when used at high speed rotation, the centrifugal force received by the cage claw portion 22 suppresses torsional deformation of the cage annular portion 21, and the cage claw portion 22 itself is also radially outward. It is possible to suppress bending deformation toward the direction. The cage claw portion 22 having the outer diameter side axial groove 24 and the inner diameter side axial groove 26 did not form the outer diameter side axial groove 24 and the inner diameter side axial groove 26. It has been found by data analysis by the inventors that the amount of deformation of the cage claw portion 22 due to centrifugal force can be reduced to at least 77% or less.

Further, as shown in FIG. 2, in this ball bearing 1, a portion that receives the ball 5 of the circumferential facing surface 27 in the circumferential direction connects the center of the cage annular portion 21 and the center of the cage claw portion 22. Since the planar shape extends parallel to the straight line, when the cage claw portion 22 moves outward in the radial direction due to the centrifugal force acting on the cage claw portion 22, the circumferential facing surface 27 of the cage claw portion 22 becomes a ball. It is possible to prevent it from interfering with 5. Further, since the shear resistance of the lubricating oil generated between the circumferential facing surface 27 of the cage claw portion 22 and the ball 5 is suppressed to a low level, it is possible to suppress the heat generation of the ball bearing 1.

Further, as shown in FIG. 5, in this ball bearing 1, since the circumferential facing surface 27 and the axial facing surface 28 are connected in a concave arc shape in cross section, the tip portion of the cage claw portion 22 in the axial direction is connected. It is possible to secure the cross-sectional area of the axial root portion of the cage claw portion 22 while keeping the mass small. Therefore, it is possible to effectively suppress the bending of the cage claw portion 22 due to the centrifugal force acting on the cage claw portion 22.

Further, as shown in FIG. 4, the ball bearing 1 is held because the axial end portion of the outer diameter side axial groove 24 near the cage annular portion 21 is cut off in a concave arc shape in cross section. It is possible to secure the cross-sectional area of the axial root portion of the cage claw portion 22 while keeping the mass of the axial tip portion of the vessel claw portion 22 small. Further, since the axial end portion of the inner diameter side axial groove 26 near the cage annular portion 21 is also cut off to the inner circumference of the cage annular portion 21, the axial end portion of the cage claw portion 22 is formed. It is possible to more effectively secure the cross-sectional area of the root portion. Therefore, it is possible to effectively suppress the bending of the cage claw portion 22 due to the centrifugal force acting on the cage claw portion 22.

Further, as shown in FIG. 4, the ball bearing 1 has a cage guided surface 29 formed on the inner circumference of the cage annular portion 21 so as to be guided by sliding on the outer periphery of the inner ring 2. The cage 7 can be positioned in the radial direction by the sliding contact between the cage guided surface 29 on the inner circumference of the cage ring portion 21 and the outer periphery of the inner ring 2.

In the above embodiment, the oil-lubricated ball bearing 1 using lubricating oil as a lubricant for lubricating the inside of the bearing has been described as an example, but the present invention uses grease as a lubricant for lubricating the inside of the bearing. It can also be applied to the grease-lubricated ball bearing 1. Grease is a semi-solid lubricant containing a lubricating oil and a thickener dispersed in the lubricating oil.

9 to 16 show the ball bearing 1 according to the second embodiment. The same reference numerals are given to the parts corresponding to the first embodiment, and the description thereof will be omitted.

As shown in FIG. 10, the portion of the circumferential facing surface 27 of the cage claw portion 22 that receives the ball 5 in the circumferential direction is the circumferential direction when the cage claw portion 22 moves radially outward due to centrifugal force. The facing surface 27 has a planar shape extending in parallel with a virtual straight line connecting the center of the cage ring portion 21 and the center of the cage claw portion 22 when viewed in the axial direction so as not to interfere with the ball 5. ..

As shown in FIG. 11, the portion of the circumferential facing surface 27 that receives the ball 5 in the circumferential direction is in the circumferential direction when viewed in the radial direction so as not to generate an axial component force when the ball 5 is received. It has no inclination and extends straight in the axial direction.

As shown in FIG. 12, the cage claw portion 22 has a tapered shape in which the radial thickness gradually decreases from the side near the cage ring portion 21 (root side) to the side far from the cage ring portion 21 (tip side). There is. The axial thickness of the cage ring portion 21 is approximately the same as the axial distance between the ball 5 and the seal member 6 (specifically, the axial distance between the ball 5 and the seal member 6). 95% or more and less than 100% of the size). The cage annular portion 21 has a cage-side sliding contact surface 40 that is in sliding contact with the seal member 6 in the axial direction, and the seal member 6 is in sliding contact with the cage-side sliding contact surface 40. It has a surface 41.

As shown in FIG. 13, a plurality of axial protrusions 42 are formed on the cage side sliding contact surface 40 at a constant pitch in the circumferential direction. Each axial projection 42 is formed so that the cross-sectional shape along the circumferential direction is an arc shape convex in the axial direction. Further, the axial height of the axial protrusion 42 is set to 5% or less of the width dimension in the circumferential direction of the axial protrusion 42. In the figure, the axial height of the axial protrusion 42 is exaggerated in order to make it easier to understand the existence of the axial protrusion 42. On the other hand, the seal-side sliding contact surface 41 is an annular plane perpendicular to the axial direction, and the axial protrusion 42 is not formed.

As shown in FIG. 12, the axial protrusion 42 is arranged at a position overlapping the pitch circle of the balls 5 (a virtual circle connecting the centers of the plurality of balls 5) or radially outside the position thereof. Here, the fact that the axial protrusion 42 is arranged at a position overlapping the pitch circle of the ball 5 means that the virtual cylindrical surface passing through the pitch circle of the ball 5 has a positional relationship of passing through the position of the axial protrusion 42. When the axial protrusion 42 is arranged radially outside the pitch circle of the ball 5, the entire axial protrusion 42 is radially outside the virtual cylindrical surface passing through the pitch circle of the ball 5. Refers to the positional relationship in. In the figure, the axial protrusion 42 is arranged radially outside the pitch circle of the ball 5.

As shown in FIGS. 12 and 15, the axial projection 42 has a parallel apex 43, a first inclined apex 44, and a second inclined apex 45. The parallel apex 43 is a portion in which the height of the arcuate apex that is convex in the axial direction in the cross section along the circumferential direction is constant along the radial direction. The first inclined top portion 44 is a portion in which the height of the arcuate top portion convex in the axial direction in the cross section along the circumferential direction gradually decreases from the radial outer end of the parallel top portion 43 toward the radial outward direction. .. The second inclined top portion 45 is a portion in which the height of the arcuate top portion convex in the axial direction of the cross section along the circumferential direction gradually decreases from the radial inner end of the parallel top portion 43 toward the radial inward direction. .. As shown in FIG. 12, the first inclined top portion 44 has an R shape in which the cross-sectional shape orthogonal to the circumferential direction is smoothly connected to the parallel top portion 43. The second inclined top portion 45 also has a cross-sectional shape orthogonal to the circumferential direction, which is an R shape that smoothly connects to the parallel top portion 43.

As shown in FIG. 16, the cage guided surface 29 is an annular surface that is in direct sliding contact with the inner ring groove shoulder portion 9. As shown in FIG. 17, the cage guided surface 29 can be an annular surface formed by a plurality of convex arc-shaped protrusions 46 protruding inward in the radial direction at intervals in the circumferential direction. be. If the sliding gap between the protrusion 46 and the inner ring 2 is set to a size of 0.22 mm or less, the vibration of the cage 7 can be reduced.

As shown in FIG. 12, the inner diameter side axial groove 26 of the radial inner side surface 25 of the cage claw portion 22 axially aligns the radial inner side surface 25 of the cage claw portion 22 with the cage guided surface 29. It is formed through. As shown in FIG. 10, the inner diameter side axial groove 26 has a groove width having a size of half or more of the circumferential width of the tip of the cage claw portion 22.

As shown in FIG. 12, the cage ring portion 21 has a chamfered portion 47 that diagonally connects between the cage side sliding contact surface 40 and the cage guided surface 29 in a cross section orthogonal to the circumferential direction. .. With the provision of the chamfered portion 47, the axial width of the radial inner end of the cage annular portion 21 is less than half of the axial width of the portion where the axial width of the cage annular portion 21 is the largest. It is the axial width of the size of. Further, the cage annular portion 21 has a chamfered portion 48 that diagonally connects between the cage side sliding contact surface 40 and the outer peripheral surface of the cage annular portion 21 in a cross section orthogonal to the circumferential direction.

In the axial groove 24 on the outer diameter side of the radial outer surface 23 of the cage claw portion 22, the position of the groove bottom gradually decreases in the radial direction from the tip side of the cage claw portion 22 toward the cage annular portion 21 side. It has a shape that changes outward. As shown in FIGS. 11 and 14, the outer diameter side axial groove 24 has a groove width having a size of half or more of the circumferential width of the tip of the cage claw portion 22. Further, an axial notch 49 is formed on the outer periphery of the cage annular portion 21 at a position corresponding to the outer diameter side axial groove 24.

As shown in FIGS. 11 and 14, the outer diameter side axial direction is provided on both sides of the circumferential direction (groove shoulders on both sides of the outer diameter side axial groove 24) of the tip portion of the radial outer surface 23 of the cage claw portion 22. A toe oil passage 50 is formed that penetrates the groove shoulder of the groove 24 in the circumferential direction. The toe oil passage 50 is a stepped notch that rises from the far side to the near side of the cage ring portion 21. By providing the toe oil passage 50, the lubrication performance of the ball 5 can be improved.

As shown in FIG. 13, the ball bearing 1 has a plurality of axial protrusions 42 having an arcuate shape whose cross-sectional shape is convex in the circumferential direction and having a constant pitch in the circumferential direction on the cage side sliding contact surface 40. An oil film due to the wedge film effect is formed between the axial projection 42 and the seal-side sliding contact surface 41, and the oil film causes a fluid between the axial projection 42 and the seal-side sliding contact surface 41. It becomes a lubricated state, and the contact resistance between the cage 7 and the seal member 6 can be suppressed to an extremely small level. Therefore, it is possible to prevent abnormal heat generation due to the sliding resistance of the contact portion between the cage 7 and the seal member 6.

Here, the lubrication state between the sliding contact surfaces is divided into a boundary lubrication state and a fluid lubrication state. In the boundary lubrication state, the sliding contact surface is lubricated with an oil film consisting of several molecular layers (about ^10-5 to ^10-6 mm) of lubricating oil adsorbed on each sliding contact surface, and the fine irregularities of the sliding contact surface are directly applied. In the fluid lubrication state, an oil film (for example, about 10 ^-3 to 10 ^-1 mm) is formed between the sliding contact surfaces due to the wedge film effect, and the oil film forms an oil film between the sliding contact surfaces. A state in which direct contact does not occur (a state in which only indirect contact via an oil film occurs). When the wedge film effect is generated and the fluid is lubricated, the sliding resistance becomes almost zero, so that it can be used at a high peripheral speed, which was not possible in the past.

Further, as shown in FIG. 12, the ball bearing 1 is provided with the cage annular portion 21 in sliding contact with the seal member 6, so that the axial thickness of the cage annular portion 21 is set large. , It is possible to increase the rigidity of the cage ring portion 21. Therefore, even when used at high speed rotation, the torsional deformation of the cage annular portion 21 due to the centrifugal force received by the cage claw portion 22 can be suppressed, and the cage claw portion 22 tilts outward in the radial direction. Can be suppressed.

Further, in this ball bearing 1, the space of the bearing installation portion is narrow, and the width dimension of the bearing needs to be kept small (that is, conventionally, it is unavoidable to give up adopting a ball bearing with a seal. It can also be installed in a place where an open type ball bearing with both ends open in the axial direction had to be adopted without providing the seal member 6).

Further, as shown in FIG. 11, the ball bearing 1 has a straight shape in which the portion of the circumferential facing surface 27 that receives the ball 5 in the circumferential direction does not have an inclination in the circumferential direction and extends straight in the axial direction. Therefore, when the ball 5 is received by the cage claw portion 22, no axial component force is generated in the cage claw portion 22. Therefore, it is possible to prevent the cage 7 from being strongly pressed against the seal member 6 in the axial direction, and it is possible to effectively suppress the sliding resistance of the contact portion between the cage 7 and the seal member 6.

Further, as shown in FIG. 12, the ball bearing 1 employs an axial protrusion 42 having a parallel top portion 43 and a first inclined top portion 44, so that the bearing rotates at a low speed and the cage claw portion. When the centrifugal force received by 22 is relatively small, an oil film due to the wedge film effect can be formed between the parallel top portion 43 of the axial projection 42 and the sliding contact surface 41 on the seal side. Further, when the bearing rotates at high speed and the centrifugal force received by the cage claw portion 22 is relatively large, the parallel top portion 43 of the axial projection 42 is in a state where the cage annular portion 21 is subjected to a relatively large torsional deformation. An oil film due to the wedge film effect can be formed between the first inclined top portion 44 and the sliding contact surface 41 on the seal side. In this way, it is possible to stably form an oil film due to the wedge film effect between the cage 7 and the seal member 6 regardless of the rotation speed of the bearing.

Further, as shown in FIG. 12, the ball bearing 1 has an R-shaped cross-sectional shape orthogonal to the circumferential direction of the first inclined top portion 44, and the first inclined top portion 44 and the parallel top portion 43 are smoothly connected to each other. Therefore, in a state where the cage ring portion 21 is subjected to a relatively large torsional deformation, an oil film due to the wedge film effect is formed between the parallel top portion 43 and the first inclined top portion 44 and the sealing side sliding contact surface 41. When forming, it is possible to stably form the oil film.

Further, as shown in FIG. 12, the ball bearing 1 acts on the cage claw portion 22 because the axial projection 42 is arranged at a position where the axial protrusion 42 overlaps the pitch circle of the ball 5 or radially outside the position thereof. When a torsional deformation in the direction of tilting the cage claw portion 22 radially outward occurs due to the centrifugal force, the torsional deformation causes a seal with the cage side sliding contact surface 40. It is possible to prevent a situation in which the side sliding contact surface 41 comes into contact with the lateral sliding contact surface 41 at a position deviated from the axial projection 42 in the radial direction.

Further, as shown in FIG. 12, in this ball bearing 1, the position of the groove bottom of the outer diameter side axial groove 24 is from the tip end side of the cage claw portion 22 toward the cage annular portion 21 side. Since the lubricating oil gradually changes outward in the radial direction, the lubricating oil supplied into the outer diameter side axial groove 24 is pumped from the tip side of the cage claw portion 22 toward the cage annular portion 21 side. It moves and is introduced into the area between the cage ring portion 21 and the seal member 6. Therefore, it is possible to sufficiently lubricate between the sliding contact surface 41 on the seal side and the axial protrusion 42 to effectively form an oil film formed by a wedge film.

Further, since the ball bearing 1 has an open axial end on the side opposite to the axial end on the side closed by the seal member 6 of the annular space 4, the seal side sliding contact surface 41 and the shaft are open. It is possible to sufficiently lubricate the space between the directional protrusion 42 and surely form an oil film formed by a wedge film.

FIG. 18 shows a ball bearing 1 according to a third embodiment. In the second embodiment, the axial projection 42 is provided on the cage side sliding contact surface 40 of the cage side sliding contact surface 40 and the seal side sliding contact surface 41, whereas in the third embodiment, the seal side is provided. The difference is that the axial projection 42 is provided on the sliding contact surface 41, and the other configurations are the same. Therefore, the same reference numerals are given to the parts corresponding to the second embodiment, and the description thereof will be omitted.

As shown in FIG. 19, a plurality of axial protrusions 42 are formed on the seal-side sliding contact surface 41 at a constant pitch in the circumferential direction. The axial protrusion 42 is formed by a mold on the rubber material 17 constituting the seal member 6. Each axial projection 42 is formed so that the cross-sectional shape along the circumferential direction is an arc shape convex in the axial direction. Further, the axial height of the axial protrusion 42 is set to 5% or less of the width dimension in the circumferential direction of the axial protrusion 42. In the figure, the axial height of the axial protrusion 42 is exaggerated in order to make it easier to understand the existence of the axial protrusion 42. On the other hand, the cage side sliding contact surface 40 is an annular plane perpendicular to the axial direction, and the axial protrusion 42 is not formed.

As shown in FIG. 18, the axial protrusion 42 is arranged at a position overlapping the pitch circle of the balls 5 (a virtual circle connecting the centers of the plurality of balls 5) or radially outside the position thereof.

As shown in FIGS. 18 and 20, the axial projection 42 has a parallel apex 43, a first inclined apex 44, and a second inclined apex 45. The parallel apex 43 is a portion in which the height of the arcuate apex that is convex in the axial direction in the cross section along the circumferential direction is constant along the radial direction. The first inclined top portion 44 is a portion in which the height of the arcuate top portion convex in the axial direction in the cross section along the circumferential direction gradually decreases from the radial outer end of the parallel top portion 43 toward the radial outward direction. .. The second inclined top portion 45 is a portion in which the height of the arcuate top portion convex in the axial direction of the cross section along the circumferential direction gradually decreases from the radial inner end of the parallel top portion 43 toward the radial inward direction. .. As shown in FIG. 18, the first inclined top portion 44 has an R shape in which the cross-sectional shape orthogonal to the circumferential direction is smoothly connected to the parallel top portion 43. The second inclined top portion 45 also has an R shape whose cross-sectional shape orthogonal to the circumferential direction smoothly connects to the parallel top portion 43.

As shown in FIG. 19, the ball bearing 1 has a plurality of axial protrusions 42 having an arcuate shape whose cross-sectional shape is convex in the axial direction along the circumferential direction on the sliding contact surface 41 on the seal side at a constant pitch in the circumferential direction. Since it is formed, an oil film due to the wedge film effect is formed between the axial projection 42 and the cage side sliding contact surface 40, and the oil film forms a space between the axial projection 42 and the cage side sliding contact surface 40. The fluid lubrication state is established, and the contact resistance between the cage 7 and the seal member 6 can be suppressed to an extremely small level. Therefore, it is possible to prevent abnormal heat generation due to the sliding resistance of the contact portion between the cage 7 and the seal member 6.

Further, as shown in FIG. 18, this ball bearing 1 employs an axial protrusion 42 having a parallel top portion 43 and a first inclined top portion 44, so that the bearing rotates at a low speed and the cage claw portion. When the centrifugal force received by 22 is relatively small, an oil film due to the wedge film effect can be formed between the parallel top portion 43 of the axial projection 42 and the cage side sliding contact surface 40. Further, when the bearing rotates at high speed and the centrifugal force received by the cage claw portion 22 is relatively large, the parallel top portion 43 of the axial projection 42 is in a state where the cage annular portion 21 is subjected to a relatively large torsional deformation. An oil film due to the wedge film effect can be formed between the first inclined top portion 44 and the cage side sliding contact surface 40. In this way, it is possible to stably form an oil film due to the wedge film effect between the cage 7 and the seal member 6 regardless of the rotation speed of the bearing.

Further, as shown in FIG. 18, the ball bearing 1 has an R-shaped cross-sectional shape orthogonal to the circumferential direction of the first inclined top portion 44, and the first inclined top portion 44 and the parallel top portion 43 are smoothly connected to each other. Therefore, in a state where the cage annular portion 21 is subjected to a relatively large torsional deformation, an oil film due to a wedge film effect is formed between the parallel top portion 43 and the first inclined top portion 44 and the cage side sliding contact surface 40. It is possible to stably form the oil film when forming the oil film.

Further, as shown in FIG. 18, since the ball bearing 1 is provided with the inner peripheral side axial groove 26 on the inner circumference of the cage 7, the lubrication supplied to the radial inner region of the cage claw portion 22 is provided. Oil is introduced into the region between the cage ring portion 21 and the seal member 6 through the inner diameter side axial groove 26. Therefore, it is possible to sufficiently lubricate between the cage side sliding contact surface 40 and the axial protrusion 42 to effectively form an oil film formed by a wedge film.

Other effects are the same as those in the first embodiment and the second embodiment.

21 to 26 show the ball bearing 1 according to the fourth embodiment. In the fourth embodiment, the seal member 51 is added and the shape of the cage 7 is partially different from that in the third embodiment, but the other configurations are the same. Therefore, the same reference numerals are given to the parts corresponding to the third embodiment, and the description thereof will be omitted.

As shown in FIG. 21, a seal member 6 is provided at one end opening of the end openings on both sides of the annular space 4 in the axial direction, and a seal member 51 is also provided at the other end opening. .. A lubricant is sealed in the annular space 4 between the seal member 6 and the seal member 51.

As shown in FIGS. 22 and 23, the cage claw portion 22 has a circumferential facing surface 27 facing the ball 5 in the circumferential direction. The portion of the circumferential facing surface 27 that receives the ball 5 in the circumferential direction has a planar shape that extends so that the circumferential facing surface 27 does not interfere with the ball 5 when the cage claw portion 22 moves outward in the radial direction due to centrifugal force. It is said that. As shown in FIG. 22, the circumferential facing surface 27 has the center of the cage ring portion 21 and the center of the cage claw portion 22 from the radial outer side to the radial inner side when viewed in the axial direction. It is a plane inclined in a direction gradually approaching a virtual straight line connecting the cages (a plane extending so that the circumferential width of the cage claw portion 22 gradually decreases from the outside in the radial direction to the inside in the radial direction).

As shown in FIG. 24, the cage ring portion 21 is provided with a step portion 52 that rises radially outward from the radial outer surface of the root portion of the cage claw portion 22. By providing the stepped portion 52, when the lubricant enclosed in the annular space 4 moves toward the cage annular portion 21 along the outer diameter side axial groove 24, a part of the lubricant is provided. Can be received by the step portion 52 and returned to the side of the ball 5.

As shown in FIG. 25, the circumferential facing surface 27 and the axial facing surface 28 are connected by a curved surface of the composite R. In the figure, the curved surface connecting the circumferential facing surface 27 and the axial facing surface 28 is a partially cylindrical tip side R surface 53 having a radius of curvature R2 smaller than the radius R1 of the ball 5 connected to the circumferential facing surface 27. And the partially cylindrical root side R surface 54 which is connected to the axially opposed surface 28 and has a radius of curvature R3 larger than the radius R1 of the ball 5, and the tip side R surface 53 and the root side R surface 54 are smoothly connected. It is composed of an intermediate R surface 55.

The ball bearing 1 has the same effect as that of the third embodiment.

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

1 Ball bearing 2 Inner ring 3 Outer ring 4 Ring space 5 Ball 6 Sealing member 7 Resin cage 21 Cage ring 22 Claw 23 Radial outer surface 24 Outer diameter side Axial groove 25 Radial inner side surface 26 Inner diameter Side axial groove 27 Circumferential facing surface 28 Axial facing surface 29 Cage guided surface 31 Electric motor 32 Transmission for electric vehicle 40 Cage side sliding contact surface 41 Seal side sliding contact surface 42 Axial projection 43 Parallel top 44 No. Inclined top of 1

Claims (13)

Inner ring (2) and
An outer ring (3) coaxially provided on the outer side in the radial direction of the inner ring (2), and the outer ring (3).
A plurality of balls (5) incorporated in the annular space (4) formed between the inner ring (2) and the outer ring (3), and
A resin cage (7) for holding the plurality of balls (5) is provided.
The resin cage (7) has a cage annular portion (21) extending in the circumferential direction adjacent to the passing region of the ball (5) and a cage annular portion (21) adjacent to the cage annular portion (21) in the circumferential direction. In a ball bearing having a cantilever-shaped cage claw portion (22) extending axially between the matching balls (5).
On the radial outer surface (23) of the cage claw portion (22), an outer diameter side shaft extending axially from the tip of the cage claw portion (22) toward the cage annular portion (21). A directional groove (24) is formed and
On the radial inner side surface (25) of the cage claw portion (22), the inner diameter side axial direction extending axially from the tip of the cage claw portion (22) toward the cage annular portion (21). A groove (26) is formed and
The cage claw portion (22) has a cross-sectional shape orthogonal to the axial direction by the outer diameter side axial groove (24) and the inner diameter side axial groove (26). A ball bearing characterized by having an H shape that opens to the outside. The axial length of the cage claw portion (22) is set to be larger than the radius of the ball (5).
The cage claw portion (22) has a circumferential facing surface (27) facing the ball (5) in the circumferential direction.
The portion of the circumferential facing surface (27) that receives the ball (5) in the circumferential direction is the circumferential facing surface (22) when the cage claw portion (22) is moved outward in the radial direction by centrifugal force. The ball bearing according to claim 1, wherein the ball bearing has a planar shape in which 27) extends so as not to interfere with the ball (5). The cage annular portion (21) has an axially facing surface (28) that faces the ball (5) in the axial direction.
The ball bearing according to claim 2, wherein the circumferential facing surface (27) and the axial facing surface (28) are connected in a concave arc shape in cross section. The axial end portion of the outer diameter side axial groove (24) on the side close to the cage ring portion (21) is cut off in a concave arc shape in a cross section on the outer circumference of the cage annular portion (21). The ball bearing according to any one of claims 1 to 3. According to any one of claims 1 to 4, a cage guided surface (29) is formed on the inner circumference of the cage annular portion (21) so as to be guided by sliding on the outer periphery of the inner ring (2). Described ball bearings. Further having an annular sealing member (6) that closes one end opening in the axial direction of the annular space (4).
The cage annular portion (21) has a cage-side sliding contact surface (40) that is in sliding contact with the seal member (6) so as to face axially.
The seal member (6) has a seal-side sliding contact surface (41) that is in sliding contact with the cage-side sliding contact surface (40).
A plurality of axial directions having an arc shape whose cross-sectional shape along the circumferential direction is convex in the axial direction on one of the sliding contact surfaces of the cage side sliding contact surface (40) and the seal side sliding contact surface (41). The ball bearing according to any one of claims 1 to 5, wherein the protrusions (42) are formed at a constant pitch in the circumferential direction. The axial projection (42) has a parallel apex (43) in which the height of an arcuate apex convex in the axial direction is constant along the radial direction in a cross section along the circumferential direction, and a cross section along the circumferential direction. The ball according to claim 6, wherein the ball has an inclined top portion (44) in which the height of an arcuate top portion convex in the axial direction gradually decreases from the radial outer end of the parallel top portion (43) toward the radial outward direction. bearing. The ball bearing according to claim 7, wherein the inclined top portion (44) has an R shape having a cross-sectional shape orthogonal to the circumferential direction smoothly connected to the parallel top portion (43). The ball bearing according to any one of claims 6 to 8, wherein the plurality of axial protrusions (42) are arranged at positions overlapping the pitch circle of the ball (5) or radially outside the position. In the outer diameter side axial groove (24), the position of the groove bottom gradually changes radially outward from the side of the tip of the cage claw portion (22) toward the side of the cage annular portion (21). The ball bearing according to any one of claims 1 to 9, which has a shape to be formed. In the inner diameter side axial groove (26), the position of the groove bottom gradually changes inward in the radial direction from the tip end side of the cage claw portion (22) toward the cage annular portion (21) side. The ball bearing according to any one of claims 1 to 10 having a shape. At the axial end on the side opposite to the axial end on the side closed by the seal member (6) of the annular space (4), a lubricant supplied from the outside is applied to the annular space (4). The ball bearing according to any one of claims 6 to 11, which is open without providing the sealing member (6) so as to be accepted. The ball bearing according to any one of claims 1 to 12, which is used as a bearing of an electric motor (31) of an electric vehicle or a bearing of a transmission (32) for an electric vehicle for decelerating the rotation of the electric motor (31).

Images