WO2024018952A1

WO2024018952A1 - Ball bearing

Info

Publication number: WO2024018952A1
Application number: PCT/JP2023/025601
Authority: WO
Inventors: 孝康田窪; 彰悟杉山; 航平西口
Original assignee: Ntn株式会社
Priority date: 2022-07-22
Filing date: 2023-07-11
Publication date: 2024-01-25
Also published as: JP2024014339A

Abstract

Provided is a ball bearing in which even though centrifugal force is applied to the retaining claws, the contact pressure between the retaining claws and the balls can be suppressed, and abnormal noise, abnormal vibration, and increased resistance caused by swinging of the retainer can be suppressed. The ball bearing is characterized by that a retaining claw 32 of a crown-shaped retainer 24 is composed of three portions, from the annular base 30 toward the axially other side, the outer diameter side having a larger centrifugal acceleration than the inner diameter side: a claw base portion 32a that is located on the annular base 30; a claw central portion 32b located on the distal end side of the claw base portion 32a and having an outer diameter smaller than the outer diameter of the claw base portion 32a; and a claw tip portion 32c located on the distal end side of the claw central portion 32b and having an outer diameter smaller than the outer diameter of the claw central portion 32b, the outline of the outer diameter of the claw central portion 32b being configured on the larger diameter side than the center P1 of a ball 23 and a pocket 31.

Description

ball bearing

The present invention relates to a ball bearing that can prevent heat generation and damage caused by interference between a cage and balls that occur during high-speed rotation, and can be applied to all kinds of high-speed rotation applications, including automobile parts and industrial machinery.

Generally, as shown in FIG. 15, a ball bearing includes an inner raceway member 1 having an inner raceway groove 1a formed on its outer periphery, an outer raceway member 2 having an outer raceway groove 2a formed on its inner periphery, and an inner raceway member 2 having an outer raceway groove 2a formed on its inner periphery. It includes a plurality of balls 3 as rolling elements interposed between the groove 1a and the outer raceway groove 2a, and a retainer 4 that holds the balls 3 at equal intervals in the circumferential direction.

As the retainer 4, a crown-shaped retainer 4 as shown in FIG. 16 may be used (Patent Document 1).

The crown-shaped retainer 4 has an annular base 4a located on one axial side of the balls 3 as rolling elements, and a plurality of pairs of holding claws 5a extending from the annular base 4a to the other axial side. A spherical concave pocket 5 is formed on the opposing surfaces of each pair of holding claws 5a and on one axial end surface of the annular portion 4a to hold the balls 3 so as not to slip out in the axial and radial directions. Since the retainer 4 holds the balls 3 in pockets 5 having a spherical concave surface, the retainer 4 is positioned in the axial direction and guided in the circumferential direction by the rotational movement of the balls 3 as rolling elements.

By the way, in electric vehicles, in order to improve electricity consumption and driving performance, it is necessary to increase the rotational speed of the electric motor and make the electric motor smaller and lighter. As the electric motor rotates at higher speeds, the maximum rotational speed of the bearings used also increases, and the centrifugal force acting on the internal parts that make up the bearings increases.

When a crown-shaped cage 4 is used as the cage 4 of such a ball bearing for high-speed rotation applications, the holding claws 5a open in the outer radial direction due to the action of centrifugal force, causing contact between the balls 3 and the holding claws 5a. - Resistance increases and smooth rolling rotation is inhibited, causing problems such as wear and heat generation on the holding claws 5a and balls 3.

Patent Document 2 discloses a ball bearing in which deformation of the holding claws due to centrifugal force in such a crown-shaped cage is suppressed by reducing the weight of the holding claws.

As shown in FIG. 17, the ball bearing disclosed in Patent Document 2 has an outer diameter side reduced diameter part 6 whose diameter is reduced toward the axial tip on the outer diameter part and the inner diameter part of the holding claw 5a, and an axially reduced diameter part 6. By providing the inner diameter enlarged portion 7 whose diameter increases toward the tip, the weight of the holding claw 5a is reduced and deformation of the holding claw 5a due to centrifugal force is suppressed. That is, the holding claw 5a is formed such that the inner diameter (radial dimension d ₂ ) at the tip is larger than the inner diameter (radial dimension d ₁ ) of the annular base 4a, and the outer diameter (radial dimension d 2 ) of the annular base 4a is larger than the inner diameter (radial dimension d 1 ) The outer diameter of the tip (radial dimension D ₁ ) is smaller than the dimension D ₂ ).

Japanese Patent Application Publication No. 11-125256 Japanese Patent Application Publication No. 2002-147463

However, if the inner diameter enlarged portion 7 is formed on the inner diameter part of the retaining pawl 5a as in the ball bearing of Patent Document 2, the radial guidance of the retainer 4 by the balls 3 is impaired, and the center of rotation of the retainer 4 is becomes unstable. This causes the retainer 4 to oscillate, giving rise to concerns such as abnormal noise, abnormal vibration, and increased resistance.

Therefore, the present invention has developed a system for high-speed rotation that uses a cage that can be easily incorporated into a bearing without impairing the radial and axial guidance of the cage by the balls even if the weight of the holding claws is reduced. The purpose is to provide a ball bearing that can be applied.

In order to solve the above problems, a ball bearing according to the present invention includes an inner raceway member having an inner raceway groove formed on its outer periphery, an outer raceway member having an outer raceway groove formed on its inner periphery, and an inner raceway member having an outer raceway groove formed on its inner periphery. The cage includes a plurality of balls interposed between the groove and the outer raceway groove, and a cage that holds the balls at equal intervals in the circumferential direction, and the cage has a plurality of balls located on one side in the axial direction of the balls. It has an annular base and a plurality of pairs of holding claws extending from the annular base to the other side in the axial direction, and a ball is held in the axial direction and on the opposing surface of each pair of holding claws and one axial end face of the annular base. A ball bearing forming a spherical concave pocket to be accommodated so as not to fall out in the radial direction, wherein the retaining pawl includes a pawl base located on the annular base side and a pawl base located on the tip side of the pawl base. , a nail center portion having an outer diameter smaller than the outside diameter of the nail base portion, and a nail tip portion located on the tip side of the nail center portion and having an outer diameter smaller than the outside diameter of the nail center portion. It is characterized by consisting of parts.

In order to maintain stable guidance of the cage by the balls as rolling elements and to suppress abnormal noises and abnormal vibrations caused by whirling of the cage, the center of the center spherical concave pocket of the ball should be aligned with the claw. The outer diameter of the center part of the claw is set to be larger than the pitch circle diameter of the ball, and the outer diameter of the tip of the claw is set to be larger than the pitch circle diameter of the ball. It is preferable that the diameter is set to be smaller than the pitch circle diameter of the ball, and that the axial tip of the tip of the pawl is within the contour of the ball.

In addition, by providing a groove extending from the inner diameter side to the outer diameter side on the inner peripheral surface of the pocket of the retaining claw, oil as a lubricant can easily flow into the pocket, reducing the frictional resistance between the ball and the retaining claw. It can be reduced.

The rotational movement of the cage is guided by rolling elements guided by balls.

As described above, the retaining claws of the crown-shaped retainer according to the present invention are arranged so that the outer diameter side, which has a larger centrifugal acceleration than the inner diameter side, is located on the annular base side from the annular base toward the other side in the axial direction. The nail base is located on the tip side of the nail base and has an outer diameter smaller than the outside diameter of the nail base, and the nail is located on the tip side of the nail center and has an outer diameter of the nail By being composed of three parts, including the tip of the claw, which has an outer diameter smaller than the diameter of the claw, the centrifugal force applied to the holding claw is alleviated without expanding the inner diameter side of the holding claw. It becomes possible to suppress deformation. Even if the holding claw expands in diameter due to centrifugal force, the radial guidance function and center of rotation are maintained while the contact pressure with the balls is suppressed, so abnormal noises and abnormalities due to whirling of the cage are maintained. Vibration can be suppressed.

Furthermore, the shape of the cage according to the present invention has lighter retaining claws compared to conventional shapes, so the amount of material can be reduced, contributing to lower raw material costs.

FIG. 1 is a longitudinal cross-sectional view showing a first embodiment of a ball bearing according to the present invention. FIG. 2 is a partially enlarged view of a cage used in the ball bearing of FIG. 1. FIG. FIG. 2 is a partially enlarged view of the cage used in the ball bearing of FIG. 1 viewed from the radially outer surface. FIG. 2 is a perspective view of a cage used in the ball bearing of FIG. 1; 2 is a graph showing the results of an experiment on the amount of deformation of the retaining pawl toward the outer diameter side when the retainer used in the ball bearing of FIG. 1 and the conventional retainer are rotated individually. It is a longitudinal cross-sectional view showing a second embodiment of a ball bearing according to the present invention. FIG. 3 is a partially enlarged view showing another embodiment of a cage used in a ball bearing according to the present invention. FIG. 8 is a perspective view of the retainer of FIG. 7; FIG. 3 is a partially enlarged view showing another embodiment of a cage used in a ball bearing according to the present invention. 10 is a perspective view of the retainer of FIG. 9. FIG. FIG. 3 is a partially enlarged view showing another embodiment of a cage used in a ball bearing according to the present invention. FIG. 12 is a perspective view of the retainer of FIG. 11; FIG. 3 is a partially enlarged view showing another embodiment of a cage used in a ball bearing according to the present invention. FIG. 14 is a perspective view of the retainer of FIG. 13; FIG. 3 is a vertical cross-sectional view showing a conventional ball bearing. FIG. 16 is a perspective view of a cage used in the ball bearing of FIG. 15; It is a longitudinal cross-sectional view showing another conventional ball bearing.

Hereinafter, embodiments of the present invention will be described based on the accompanying drawings.

FIG. 1 shows an oil-lubricated ball bearing 20 according to a first embodiment of the present invention. This ball bearing 20 is incorporated into a drive motor for an electric vehicle, a drive motor for a hybrid electric vehicle, a drive device of a vehicle, an electrical component, an auxiliary component, etc., and is used at high speed rotation. 1 is a longitudinal sectional view of the ball bearing 20, FIG. 2 is a partially enlarged view of the cage 24 used in the ball bearing 20 of FIG. 1, and FIG. 3 is a diagram of the cage 24 of FIG. 2 viewed from the outside in the radial direction. , FIG. 4 is a perspective view of the retainer 24 of FIG.

The ball bearing 20 includes an inner raceway member 21 having an inner raceway groove 21a formed on its outer circumference, and an outer raceway member 22 disposed outside the inner raceway member 21 and having an outer raceway groove 22a formed on its inner circumference. , includes a plurality of balls 23 as rolling elements that are rotatably interposed between the inner raceway groove 21a and the outer raceway groove 22a, and a retainer 24 that holds the balls 23 at equal intervals in the circumferential direction. .

In the ball bearing 20 shown in FIG. 1, the outer raceway member 22 is attached to a stationary member such as a housing, and the inner raceway member 21 is attached to a rotating shaft that is rotationally driven by mechanical force such as an electric motor. The present invention is also applicable to a type in which the inner raceway member 21 is attached to a stationary member such as a shaft, and the outer raceway member 22 is attached to a rotating shaft and rotates.

The retainer 24 used in this ball bearing 20 can be used in a rolling element guide where rotational movement is guided by the balls 23. Further, the bearing to which the present invention is applied can be used in a rotation range where the dmN value exceeds 1 million.

The retainer 24 has a ring base 30 (axial width L1) located on one side of the ball 23 in the axial direction, and a plurality of pairs of holding claws 32 extending from the ring base 30 to the other side in the axial direction, A spherical concave pocket 31 is formed on the opposing surface of each pair of holding claws 32 and on one end surface in the axial direction of the annular base 4a to hold the ball 23 so that it does not slip out in the axial and radial directions.

The holding claws 32 include a claw base portion 32a (axial width L3) located on the annular base portion 30 side from the annular base portion 30 toward the other side in the axial direction, and a claw base portion 32a (axial width L3) located on the tip side of the claw base portion 32a. A claw center portion 32b (axial width L4) having an outer diameter smaller than the outer diameter of the base portion 32a, and a claw center portion 32b (axial width L4) located on the tip side of the claw center portion 32b and having an outer diameter smaller than the outer diameter of the claw center portion 32b. The claw tip portion 32c (axial width L5) has three parts.

The annular base 30 has holding claws 32 disposed in the circumferential direction, and has a clearance CLi between it and the inner raceway member 21 and a clearance CLo between it and the outer raceway member 22. CLo supplies oil as a lubricant to the inside of the bearing and discharges oil to the outside of the bearing.

The annular base 30 is continuous with the claw base 32a, and the axial tip of the annular base 30 (the left end of L1 in FIG. 1) is located between the center of the ball 23 and the center P1 of the pocket 31, and the bottom P2 of the pocket 31. It is located in between.

The outer diameter D1 of the annular base 30 is smaller than the inner diameter of the outer raceway member 22, and as described above, a clearance CLo is secured between it and the outer raceway member 22. If the outer diameter D1 of the annular base 30 is made too large, the clearance CLo becomes small, and there is a concern that the annular base 30 and the outer raceway member 22 will interfere and the retainer 24 will be damaged, and oil permeability will deteriorate. There are concerns. On the other hand, if the outer diameter D1 of the annular base 30 is made too small, the rigidity of the entire retainer 24 including the retaining claws 32 will decrease, making it impossible to maintain the shape of the retainer 24. In addition, if there is a concern that the annular base 30 will centrifugally expand due to centrifugal force due to high-speed operation and the outer diameter D1 of the annular base 30 will come into contact with the inner diameter of the outer raceway member 22, grind the inner diameter of the outer raceway member 22 in advance. It may be designed to be processed to suppress friction between the inner diameter of the outer raceway member 22 and the retainer.

The inner diameter D2 of the annular base 30 is larger than the inner diameter of the inner raceway member 21, and as described above, a clearance CLi is ensured between it and the inner raceway member 21. If the inner diameter D2 of the annular base 30 is made too small, the clearance CLi will become small, and there is a concern that the annular base 30 and the inner raceway member 21 will interfere and damage the retainer 24, as well as that oil permeability will deteriorate. There is. On the other hand, if the inner diameter D2 of the annular base 30 is made too large, the rigidity of the entire retainer 24 including the retaining claws 32 decreases, and the shape of the retainer 24 cannot be maintained.

The axial width L1 of the annular base 30 is larger than the axial width L2 from one end of the annular base 30 (the end opposite to the direction in which the holding claw 32 extends, the right end in FIG. 1) to the bottom P2 of the pocket 31. That is, the left end of L1 in FIG. 1 is located on the left side of the bottom P2 of the pocket 31 in FIG. If the axial width L1 of the annular base portion 30 is too small, the rigidity of the entire cage 24 including the retaining claws 32 will decrease, making it impossible to maintain the shape of the cage 24.

The claw base portion 32a of the holding claw 32 is a portion that is continuous with the annular base portion 30, maintains the overall shape of the retainer 24 including the retaining claw 32, and positions the retainer 24 in the axial direction and the radial direction.

The axial tip position of the claw base 32a is between the center of the ball 23 and the center P1 of the pocket 31, and the bottom P2 of the pocket 31.

The upper limit of the outer diameter of the claw base portion 32a is equal to the outer diameter D1 of the annular base portion 30 and smaller than the inner diameter of the outer raceway member 22, and a clearance CLo is secured between the claw base portion 32a and the outer raceway member 22. If the outer diameter of the claw base 32a is made too large, the clearance CLo will become small, and there is a concern that the cage 24 will be damaged due to interference between the claw base 32a and the outer raceway member 22, and there is also a concern that oil permeability will deteriorate. There is. The lower limit of the outer diameter of the claw base portion 32a is larger than the outer diameter of the claw center portion 32b. Note that if there is a concern that the outer diameter of the claw base 32a will centrifugally expand due to centrifugal force due to high-speed operation and the outer diameter of the claw base 32a and the inner diameter of the outer raceway member 22 will come into contact, the inner diameter of the outer raceway member 22 should be adjusted in advance. It is also possible to apply a grinding process to the inner diameter of the outer raceway member 22 to suppress friction between the inner diameter of the outer raceway member 22 and the retainer.

The upper limit of the inner diameter of the claw base 32a is set to be equal to the inner diameter D2 of the annular base 30. The lower limit of the inner diameter of the claw base portion 32a is set within a range that falls within the contour of the ball 23.

If the inner diameter of the claw base portion 32a is made too large, the rigidity of the entire retainer 24 including the retaining claws 32 will decrease, making it impossible to maintain the shape of the retainer 24. Furthermore, if the inner diameter of the pawl base portion 32a is made too small, there is a risk that the pawl base portion 32a and the inner raceway member 21 will interfere and the retainer 24 will be damaged, and there is also a concern that oil permeability will deteriorate.

The axial tip of the claw base 32a is located on the axial tip side (left side in FIG. 1) than the axial tip of the annular base 30. The smaller the axial width L3 of the claw base portion 32a, the lighter the mass of the retainer 24, and the lower the moment of inertia during rotation. However, if it is set too small, the width of the claw base portion 32a There is a concern that the rigidity will decrease and the deformation of the tip of the holding claw 32 will increase.

As shown in FIG. 3, if the circumferential width T1 of the claw base 32a on the annular base 30 side is made too large, the centrifugal force applied to the holding claw 32 will increase, and the amount of deformation of the holding claw 32 in the radial direction will increase. increases. On the other hand, if the circumferential width T1 of the claw base portion 32a on the annular base portion 30 side is made too small, the strength of the claw base portion 32a decreases, and there is a fear that the holding claw 32 may be damaged. The circumferential width T1 of the claw base portion 32a can be formed to gradually become narrower toward the claw center portion 32b.

Next, the claw center part 32b is located on the tip side of the claw base part 32a, has an outer diameter smaller than the outer diameter of the claw base part 32a, is connected to the claw base part 32a and the claw tip part 32c, and has a ball. This is the part that determines the circumferential position of 23.

The upper limit of the outer diameter of the claw center portion 32b is equal to or smaller than the outer diameter D1 of the claw base portion 32a, and the lower limit is the ball 23 that passes through the center of the ball 23, the center P1 of the pocket 31, and the bottom P2 of the pocket 31. The pitch circle diameter dA is set larger than the pitch circle diameter dA. Thereby, the guide of the retainer 24 by the balls 23 as rolling elements can be maintained in a stable state, and abnormal noises and abnormal vibrations caused by whirling of the retainer 24 can be suppressed.

When the outer diameter of the claw center portion 32b becomes larger than the outer diameter D1 of the claw base portion 32a, the centrifugal force applied to the holding claw 32 increases, and the amount of radial deformation of the holding claw 32 increases. On the other hand, when the outer diameter of the pawl central portion 32b becomes smaller than the pitch circle diameter dA of the balls 23, the radial component force increases with respect to the circumferential contact pressure between the retainer 32 and the balls 23. It may become impossible to hold the balls 23, and it may become impossible to position the retainer 24 in the circumferential direction and to smoothly roll the balls 23.

The upper limit of the inner diameter of the claw center portion 32b is set to be equal to the inner diameter D2 of the claw base portion 32a. The lower limit of the inner diameter of the pawl central portion 32b is set within a range that falls within the contour of the ball 23.

If the inner diameter of the claw center portion 32b is made too large, the strength of the claw center portion 32b will decrease, and there is a risk that the retainer 24 will be damaged. Furthermore, if the inner diameter of the pawl central portion 32b is made too small, there is a concern that oil permeability may deteriorate.

The axial tip of the claw central portion 32b is located on the axial tip side (left side in FIG. 1) of the center of the ball 23 and the center P1 of the pocket 31. If the axial tip of the pawl central portion 32b is located closer to the pawl base portion 32a than the center of the balls 23 and the center P1 of the pocket 31, the balls 23 cannot be held stably, and the circumferential direction between the retainer 24 and the balls 23 With respect to the contact pressure, the component force in the radial direction increases, and there is a possibility that positioning in the circumferential direction and smooth rolling of the balls 23 cannot be performed.

As shown in FIG. 3, the circumferential width T2 of the claw center portion 32b on the claw base portion 32a side is equal to or less than the circumferential width T1 of the claw base portion 32a. The force increases, and the amount of radial deformation of the holding claws 32 increases. On the other hand, if the circumferential width T2 of the claw center portion 32b on the claw base portion 32a side is made too small, the strength of the claw center portion 32b will decrease, and there is a risk that the holding claw 32 will be damaged. The circumferential width T2 of the claw center portion 32b can be formed to gradually become narrower toward the claw tip portion 32c.

Next, the claw tip portion 32c is located on the tip side of the claw center portion 32b, has an outer diameter smaller than the outer diameter of the claw center portion 32b, is continuous with the claw center portion 32b, and is attached to the inner peripheral surface of the pocket 31. and the tip end, which are the parts that determine the axial and radial positions of the retainer 24.

The outer diameter of the claw tip 32c is set smaller than the pitch circle diameter dA of the ball 23 from the viewpoint of suppressing the diameter expansion of the claw due to centrifugal force.

When the outer diameter of the claw tip 32c becomes larger than the pitch circle diameter dA of the ball 23, the centrifugal force applied to the holding claw 32 increases, and the amount of radial deformation of the holding claw 32 increases.

The upper limit of the inner diameter of the claw tip portion 32c is set to be equal to the inner diameter D2 of the claw center portion 32b. The lower limit of the inner diameter of the claw tip 32c is within the contour of the ball 23.

The axial tip of the claw tip 32c is within the contour of the ball 23. If the axial tip of the claw tip 32c is located outside the contour of the ball 23, there will be interference with the inner raceway member 21, an increase in deformation due to an increase in centrifugal force, and a decrease in ease of installation.

As shown in FIG. 3, the circumferential width T3 of the claw tip portion 32c is equal to or less than the circumferential width T2 of the claw center portion 32b, and the width can be narrowed toward the tip.

Next, the outer diameter shape of the claw center portion 32b in the embodiment of FIGS. It curves into an arc shape so that it gradually becomes smaller, extends linearly with the same outer diameter from near the center P1 toward the tip, and becomes an arc shape so that the outer diameter gradually decreases from the tip toward the claw tip 32c. It's curved.

The outer diameter shape of the claw tip 32c is such that the portion connected to the claw central portion 32b is curved, and the tip extends linearly with the same diameter.

Next, on the inner peripheral surface of the pocket 31 near the tip of the holding claw 32, a groove 35 is provided extending from the inner diameter side to the outer diameter side. By providing this groove 35, oil as a lubricant can easily flow into the pocket 31, and the frictional resistance between the ball 23 and the holding claw 32 can be reduced.

As described above, the holding claws 32 of the crown-shaped retainer 24 according to the present invention extend from the annular base 30 toward the other side in the axial direction, with the outer diameter side having a larger centrifugal acceleration than the inner diameter side. a nail base portion 32a located on the 30 side; a nail center portion 32b located on the tip side of the nail base portion 32a and having an outer diameter smaller than the outer diameter of the nail base portion 32a; and a nail center portion 32b located on the tip side of the nail center portion 32b. Since the retaining claw 32 is located at The centrifugal force applied to the holding claws 32 is alleviated, and deformation of the holding claws 32 can be suppressed.

As a result, even if centrifugal force is applied to the holding claws 32, the radial guiding function is maintained while the contact pressure between the holding claws 32 and the balls 23 is suppressed, and the revolution of the balls 23 as rolling elements is maintained. Since the center of rotation of the retainer 24 is maintained concentrically with the center, it is possible to suppress abnormal noise, abnormal vibration, and increase in resistance caused by whirling of the retainer 24.

Next, as the material for the cage 24, resin with excellent wear resistance and seizure resistance can be used, and in particular, resin with excellent tensile elongation, tensile strength, impact resistance, abrasion resistance, lubricity, etc. can be used. Good polyamide resins such as PA66 (polyamide 66), PA46 (polyamide 46), PA6T (polyamide 6T), PA9T (polyamide 9T), or PA6 (polyamide 6) are desirable. In addition, by combining these resins with fibrous reinforcing materials such as carbon fiber, glass fiber, or aramid, it is possible to increase the elastic modulus, strength, and impact resistance, and to suppress dimensional changes and creep deformation. .

In this invention, the outer diameter side of the retaining claw 32 of the retainer 24 is arranged from the annular base 30 toward the other side in the axial direction, to the claw base 32a located on the annular base 30 side, and the tip of the claw base 32a. A claw center portion 32b located on the side and having an outer diameter smaller than the outer diameter of the claw base portion 32a; and a claw center portion 32b located on the tip side of the claw center portion 32b and having an outer diameter smaller than the outer diameter of the claw center portion 32b. Since the retaining claw 32 is composed of three parts including the claw tip 32c having a diameter, the holding claw 32 tends to fall toward the inner diameter side during assembly. Therefore, the cage 24 can be easily assembled using a hard resin having high strength such as PA9T (polyamide 9T).

Furthermore, since the retainer 24 according to the present invention has the claw base portion 32a, the claw center portion 32b, and the claw tip portion 32c formed on the outer diameter side of the retaining claw 32, the retainer 24 is manufactured by injection molding of synthetic resin. When molding, it is easy to pull out from the mold and injection molding is easy.

The inner raceway member 21, the outer raceway member 22, and the balls 23 are made of metal such as bearing steel or carburized steel.

Next, the retainer 24 of the first embodiment shown in FIGS. 1 to 4, that is, the outer diameter side of the retaining claw 32, which has a larger centrifugal acceleration than the inner diameter side, is moved from the annular base 30 toward the other side in the axial direction. A nail base part 32a located on the annular base 30 side, a nail central part 32b located on the tip side of the nail base part 32a and having an outer diameter smaller than the outer diameter of the nail base part 32a, The retainer 24 is composed of three parts: a claw tip part 32c located on the tip side of the part 32b and having an outer diameter smaller than the outer diameter of the claw center part 32b; and the retainer claw has a linear outer diameter. The results of an experiment in which the conventional retainer 4 shown in FIGS. 15 and 16 was rotated alone and the amount of deformation of the retaining claws toward the outer diameter at that time was actually measured are shown in FIG. 5 as a graph. The measurements were carried out by adjusting the cage surface temperature to 25°C and 100°C. At any temperature, the cage 24 of the first embodiment shown in FIGS. 1 to 4 can greatly suppress the amount of deformation, as shown in the graph of FIG. 5, compared to the conventional cage 4. I was able to confirm that.

Next, in FIG. 6, a retainer 24 similar to that of the first embodiment shown in FIGS. In the ball according to the second embodiment, a sealing member 26 is provided to seal an annular space 25 formed between outer raceway members 22, and a lubricant such as grease is sealed in the annular space 25 sealed by the sealing member 26. A bearing 20 is shown.

In the case of the ball bearing 20 shown in FIG. 6 assuming grease lubrication, most of the grease inside the bearing moves toward the outer raceway member 22 as the balls 23 as rolling elements revolve. According to the cage 24 according to the present invention, contact between the outer diameter portion of the cage 24 and the grease is suppressed, stirring resistance is reduced, and operation at low torque is possible. Furthermore, since the volume of the retainer 24 relative to the space volume inside the bearing is reduced, the volume of grease per space volume is reduced. This can also be expected to have the effect of making it difficult for grease to leak.

The seal member 26 is composed of an annular core metal 26a and a rubber-like member 26b that is integrally fixed to the core metal 26a. Fixed in mated state. The inner raceway member 21 is provided with a seal groove 28 made of a circumferential groove at a position corresponding to the inner circumference of the seal member 26, and a seal lip 26c formed at the inner circumference side end of the seal member 26 is formed on the inner circumference of the seal member 26. It is close to the seal groove 28 in sliding contact or non-contact.

During operation, the ball bearing 20 according to the second embodiment maintains a state in which the seal lip 26c at the tip of the seal member 26 is in sliding contact with the outer peripheral end of the inner raceway member 21 or in a non-contact state. , the inner raceway member 21 rotates. This prevents foreign matter such as water and dust from entering the bearing, or from lubricant leaking from the inside of the bearing to the outside.

Further, as the lubricant filled in the ball bearing 20 according to the second embodiment, semi-solid grease consisting of base oil, thickener, and additives can be used. Examples of base oils constituting this grease include mineral oils such as paraffinic mineral oils and naphthenic mineral oils, hydrocarbon synthetic oils such as polybutene, poly-α-olefins, alkylbenzenes, alkylnaphthalenes, and alicyclic compounds; Natural oils and fats, polyol ester oils, phosphate esters, diester oils, polyglycol oils, silicone oils, polyphenyl ether oils, alkyldiphenyl ether oils, non-hydrocarbon synthetic oils such as fluorinated oils, etc. are generally used as base oils for lubricating greases. Any conventional oil can be used without particular limitation.

Examples of thickeners include metal soap thickeners such as aluminum soap, lithium soap, sodium soap, composite lithium soap, composite calcium soap, and composite aluminum soap, and urea compounds such as diurea compounds and polyurea compounds. These thickeners may be used alone or in combination of two or more.

Known additives for grease include, for example, extreme pressure agents, amine-based and phenolic antioxidants, metal deactivators such as benzotriazole, viscosity index improvers such as polymethacrylate and polystyrene, molybdenum disulfide, Examples include solid lubricants such as graphite. These can be added alone or in combination of two or more.

Next, in the retainer 24 shown in FIGS. 7 and 8, the outer diameter shapes of the claw center portion 32b and the claw tip portion 32c of the holding claws 32 are different from those in the first embodiment and the second embodiment. ing.

The retaining claws 32 of the retainer 24 used in the ball bearings 20 of the first embodiment and the second embodiment have an outer diameter shape of the claw center portion 32b that extends from the claw base portion 32a side in the axial direction. 23 and around the center P1 of the pocket 31 are curved in an arc shape so that the outer diameter gradually decreases. On the other hand, in the retainer 24 shown in FIGS. 7 and 8, the outer diameter shape of the claw center portion 32b is linearly inclined from the claw base portion 32a side without being curved in the axial direction.

Furthermore, in the retainer 24 used in the ball bearings 20 of the first embodiment and the second embodiment, the outer diameter shape of the claw tip portion 32c is curved at the portion continuous to the claw center portion 32b. On the other hand, in the retainer 24 shown in FIGS. 7 and 8, the outer diameter shape of the claw tip portion 32c is linearly inclined from the claw center portion 32b side without being curved in the axial direction.

Note that the other configurations of the retainer 24 shown in FIGS. 7 and 8 are the same as those in the first embodiment shown in FIGS. 1 to 4, so detailed explanations will be omitted.

Next, in the retainer 24 shown in FIGS. 9 and 10, the outer diameter shape of the retaining claw 32 forming the claw center portion 32b and the claw tip portion 32c is a different shape from the first embodiment and the second embodiment. doing.

The outer diameter shape of the retaining pawl 32 of the retainer 24 shown in FIGS. 9 and 10 is such that the axial tip side of the pawl base 32a is formed into an inclined surface that is inclined in two steps, and the inclined surface on the tip side is formed at the pawl base. The slope is larger than that of the slope on the side 32a.

Note that the other configurations of the retainer 24 shown in FIGS. 9 and 10 are the same as those in the first embodiment shown in FIGS. 1 to 4, so detailed explanations will be omitted.

Next, in the retainer 24 shown in FIGS. 11 and 12, the outer diameter shape of the retaining claw 32 forming the claw center portion 32b and the claw tip portion 32c is a different shape from the first embodiment and the second embodiment. doing.

The outer diameter shape of the holding pawl 32 of the retainer 24 shown in FIGS. 11 and 12 is such that the tip end side in the axial direction of the pawl base portion 32a is formed into a two-stage inclined surface, and the sloped surface on the tip side is The slope is smaller than that of the slope on the side 32a.

Note that the other configurations of the retainer 24 shown in FIGS. 11 and 12 are the same as those in the first embodiment shown in FIGS. 1 to 4, so detailed explanations will be omitted.

Next, in the retainer 24 shown in FIGS. 13 and 14, the outer diameter shape of the retaining claw 32 forming the claw center portion 32b and the claw tip portion 32c is different from that in the first, second, and third embodiments. doing.

The outer diameter shape of the holding pawl 32 of the retainer 24 shown in FIGS. 13 and 14 is such that the axial tip side of the pawl base 32a is formed into a two-stage curved surface.

Note that the other configurations of the retainer 24 shown in FIGS. 13 and 14 are the same as those in the first embodiment shown in FIGS. 1 to 4, so detailed explanations will be omitted.

This invention is not limited to the embodiments described above in any way, and may be implemented in various forms, such as combining the claw parts and shapes of the first to fourth embodiments, without departing from the gist of the invention. Needless to say, the scope of the present invention is indicated by the claims, and further includes the meaning of equivalents described in the claims and all changes within the scope.

20 Ball bearing 21 Inner raceway member 21a Inner raceway groove 22 Outer raceway member 22a Outer raceway groove 23 Balls 24 Cage 30 Annular base 31 Pocket 32 Holding claw

32a Claw base

32b Claw center

32c Claw tip 35 Concave groove

Claims

An inner raceway member having an inner raceway groove formed on its outer periphery, an outer raceway member having an outer raceway groove formed on its inner periphery, and a plurality of balls interposed between the inner raceway groove and the outer raceway groove. , a cage that holds the balls at equal intervals in the circumferential direction, and the cage has a ring base located on one side in the axial direction of the balls, and a plurality of pairs extending from the ring base to the other side in the axial direction. holding claws, and a spherical concave pocket is formed on the opposing surface of each pair of holding claws and on one end surface in the axial direction of the annular base to accommodate the ball so as not to slip out in the axial and radial directions. The holding pawl includes a pawl base located on the annular base side, and a pawl center located on the tip side of the pawl base and having an outer diameter smaller than the outside diameter of the pawl base. A ball bearing is characterized in that it consists of three parts: a pawl tip portion located on the tip side of the pawl central portion and having an outer diameter smaller than the outer diameter of the pawl central portion.
The ball bearing according to claim 1, wherein the center of the central spherical concave pocket of the ball is located within the axial width of the central portion of the pawl.
The ball bearing according to claim 2, wherein the outer diameter of the center portion of the pawl is set to be larger than the pitch circle diameter of the ball.
The ball bearing according to claim 3, wherein the outer diameter of the tip of the pawl is set to be smaller than the pitch circle diameter of the ball.
The ball bearing according to any one of claims 1 to 4, wherein the axial tip of the claw tip fits within the contour of the ball.
The ball bearing according to any one of claims 1 to 5, wherein the inner peripheral surface of the pocket of the holding claw is provided with a groove extending from the inner diameter side to the outer diameter side.
The ball bearing according to any one of claims 1 to 6, wherein the rotational movement of the retainer is guided by rolling elements guided by balls.