JP2022082025A - Bearing device for wheel - Google Patents

Abstract

To suppress damage to a ball occurring when a slinger is moved from a predetermined position of a hub shaft to a vehicle inner side and contacts the ball, in a bearing device for a wheel.SOLUTION: A bearing device 10 for a wheel comprises: a hub shaft 11 having, on a vehicle outer side, a flange 56 to which a wheel is mounted; an outer ring 12 provided in a radial outside portion of the hub shaft 11; a plurality of balls 13 provided between the hub shaft 11 and the outer ring 12; a cage 14 holding the plurality of balls 13; an annular sealing member 20 mounted to the outer ring 12; and an annular slinger 30 which is externally fitted and mounted to the hub shaft 11 and with which the sealing member 20 comes in sliding contact, wherein the slinger 30 has a radially extending circular ring portion 32, and a cylindrical portion 31 extending from the circular ring portion 32 to the vehicle inner side, and wherein on the whole periphery of the end face on the vehicle inner side of the cylindrical portion 31, there is formed a concave surface 33 which is recessed to the vehicle outer side and curved and can come into surface contact with the balls 13.SELECTED DRAWING: Figure 2

Description

The present invention relates to a wheel bearing device.

In vehicles such as automobiles, a wheel bearing device (hub unit) is used to rotatably support the wheels. A wheel bearing device includes a hub axle having a flange on the vehicle outer side to which wheels are mounted, an outer ring provided on the radial outer side of the hub axle, and a plurality of wheels provided between the hub axle and the outer ring. It is equipped with a ball (rolling body), a cage for holding a plurality of balls, and a sealing device provided between the hub shaft and the outer ring. The sealing device is provided to prevent foreign matter such as muddy water from entering from the outside of the bearing inside the bearing where multiple balls are provided, and the hub axle is equipped with an annular slinger (stainless steel). (See, for example, Patent Document 1).

Since the slinger is externally fitted to a part of the hub axle and held by the hub axle only by a tense force, the slinger may eventually move to the vehicle inner side when the vehicle travels (hereinafter, this). The phenomenon is also called a walkout). When the slinger walks out, the end of the slinger on the vehicle inner side may come into contact with the ball and the ball may be scratched. The scratches on the balls cause an increase in the rotational resistance of the wheel bearing device and the generation of abnormal noise, and also cause a decrease in the life of the wheel bearing device.

JP-A-2017-207124

Therefore, as shown in FIG. 9, a claw portion 93 is provided on the slinger 92, and the claw portion 93 is engaged with a part 91 of the outer periphery of the hub shaft 90 to suppress the movement of the slinger 92 toward the vehicle inner side. There is a wheel bearing device 80 for which countermeasures have been taken. In the wheel bearing device 80, it is possible to prevent the ball 94 from being scratched by suppressing the movement of the slinger 92 toward the vehicle inner side.

INDUSTRIAL APPLICABILITY The present invention provides a new technical means capable of suppressing damage to a ball even if the slinger moves from a predetermined position of the hub axle to the vehicle inner side and comes into contact with the ball in the wheel bearing device. The purpose is to do.

The wheel bearing device of the present invention has a hub shaft having a flange on which a wheel is mounted on one side in the axial direction, an outer ring provided on the radial outer side of the hub shaft, and between the hub shaft and the outer ring. A plurality of balls provided, a cage for holding the plurality of balls, an annular sealing member attached to one side of the outer ring in the axial direction, and a shaft of the flange fitted outside the hub shaft. The slinger comprises an annular slinger attached to the other side in the direction and with which the sealing member slides into contact, wherein the slinger has an annular portion extending radially and a tubular portion extending axially from the annular portion to the other side. A concave curved surface that is recessed and curved on one side in the axial direction and is capable of surface contact with the ball is formed on the entire circumference of the end surface on the other side in the axial direction of the tubular portion.

According to this wheel bearing device, when the slinger moves from a predetermined position of the hub axle to the vehicle inner side, the ball can be brought into surface contact with the concave curved surface of the slinger. As a result, the contact surface pressure between the slinger and the ball can be suppressed, and even if the slinger walks out, the ball can be prevented from being scratched.

Further, it is preferable that the concave curved surface is formed with a radius of curvature equal to or larger than the radius of the ball.
According to this configuration, the concave curved surface and the ball can be brought into surface contact with each other, and the contact surface pressure between the slinger and the ball can be suppressed.

Further, it is preferable that the concave curved surface comes into contact with the ball outside the radial inner end of the concave curved surface and inside the radial outer end.
According to this configuration, since the edge-shaped portions existing at both ends of the concave curved surface in the radial direction do not come into contact with the ball, the concave curved surface and the ball can be reliably surface-contacted, and the slinger and the ball can be brought into contact with each other. It is possible to reliably suppress the contact surface pressure.

Further, it is preferable that the slinger has a heterogeneous portion made of a material having a hardness lower than that of the jade at the end portion on the other side in the axial direction of the tubular portion, and the concave curved surface is formed on the heterogeneous portion. ..
According to this configuration, when the slinger comes into contact with the ball, the slinger side can be worn. As a result, it is possible to more reliably prevent the ball from being scratched by contact with the slinger.

According to the present invention, even if the slinger moves from a predetermined position of the hub axle to the vehicle inner side and comes into contact with the ball in the wheel bearing device, it is possible to prevent the ball from being scratched.

It is sectional drawing of the bearing device for a wheel. It is an enlarged sectional view which shows the sealing device and its surroundings. It is sectional drawing of slinga. It is explanatory drawing which shows the relationship between the radius of curvature of a concave curved surface and the radius of a ball. It is explanatory drawing which shows the setting method of the curved surface shape of a concave curved surface. It is explanatory drawing which shows the setting method of the curved surface shape of a concave curved surface. It is explanatory drawing which shows the formation mode of the concave curved surface. It is explanatory drawing which shows the formation mode of the concave curved surface. It is explanatory drawing which shows the formation mode of the concave curved surface. It is sectional drawing of the slinger which has a heterogeneous part. It is explanatory drawing which shows the fixing mode of a foreign part. It is explanatory drawing which shows the fixing mode of a foreign part. It is sectional drawing which shows the conventional sealing apparatus and its surroundings.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Overall configuration of wheel bearing device]
FIG. 1 is a cross-sectional view of a wheel bearing device. The wheel bearing device (hub unit) 10 is attached to, for example, a suspension device (knuckle) on the vehicle body side of an automobile to rotatably support the wheels. The wheel bearing device 10 includes a hub shaft 11, an outer ring 12, a ball 13, a cage 14, and sealing devices 15 and 17. The sealing device 15 shown in FIG. 1 includes a slinger 30 according to a first embodiment described later.

The outer ring 12 is a cylindrical member, and is manufactured of, for example, carbon steel for machine structure. The outer ring 12 has a cylindrical outer ring main body 51 and a fixing flange portion 52 extending radially outward from the outer ring main body 51. By fixing the flange portion 52 to a knuckle (not shown) which is a member on the vehicle body side, the wheel bearing device 10 including the outer ring 12 is fixed to the knuckle.

With the wheel bearing device 10 fixed to the vehicle body side, the wheel mounting flange 56 side of the hub axle 11, which will be described later, is the outside of the vehicle. That is, the left side (flange 56 side) of FIG. 1 is the vehicle outer side, and the right side of FIG. 1 is the vehicle inner side. Further, the direction of the center line C of the outer ring 12 (hereinafter referred to as the bearing center line C) (the left-right direction in FIG. 1) is the axial direction of the wheel bearing device 10. Further, the direction orthogonal to this axial direction is the radial direction of the wheel bearing device 10. In this description, one side in the axial direction on the side where the flange 56 is formed in the wheel bearing device 10 is defined as the vehicle outer side, and the other side in the axial direction on the opposite side is defined as the vehicle inner side.

An outer ring raceway surface 12a on the vehicle outer side and an outer ring raceway surface 12b on the vehicle inner side are formed on the inner peripheral surface of the outer ring 12.

The hub axle 11 has a shaft body portion 55, a flange 56 for mounting wheels, and an inner ring 57. These are manufactured, for example, from carbon steel for machine structural use. The shaft body 55 is a shaft member that is long in the axial direction. The flange 56 is provided so as to extend radially outward from the vehicle outer side of the shaft main body portion 55, and has an annular shape. A plurality of holes are formed in the flange 56 along the circumferential direction, and a wheel mounting bolt 69 is attached to the holes. A brake rotor is attached to the flange 56 in addition to the wheels (not shown). The inner ring 57 is an annular member, and is fitted and attached to the vehicle inner side of the shaft main body portion 55. The shaft raceway surface 11a is formed on the outer peripheral surface of the shaft main body 55 on the vehicle outer side, and the inner ring raceway surface 11b is formed on the outer peripheral surface of the inner ring 57.

The outer ring raceway surface 12a on the vehicle outer side and the shaft raceway surface 11a face each other in the radial direction, and the outer ring raceway surface 12b and the inner ring raceway surface 11b on the vehicle inner side face each other in the radial direction. A ball 13 which is a rolling element is arranged between the raceway planes. The balls 13 are provided in two rows, and the balls 13 in each row are held by an annular cage 14. By providing a plurality of balls 13 between the hub shaft 11 and the outer ring 12, the outer ring 12 is provided concentrically with the hub shaft 11 on the radial outer side of the hub shaft 11 (shaft body portion 55). It becomes a composition. The ball 13 is a spherical member made of metal, and has a diameter D in the present embodiment. The ball 13 is manufactured of, for example, high carbon chromium bearing steel.

The cage 14 on the vehicle outer side holds a plurality of balls 13 included in the rolling element row located on the vehicle outer side at intervals in the circumferential direction. The cage 14 on the vehicle inner side holds a plurality of balls 13 included in the rolling element row located on the vehicle inner side at intervals in the circumferential direction. The cage 14 can be made of resin, for example.

The sealing device 17 on the vehicle inner side is composed of an annular sealing member 40 and an annular slinger 50. The seal member 40 is fitted and attached to the inner peripheral side of the outer ring 12 (outer ring main body 51) and to the inner side of the vehicle. The slinger 50 is fitted and attached to the outer peripheral surface of the inner ring 57 in a tightly fitted state. When the seal member 40 (the lip of the seal member 40) slides into contact with the slinger 50 (sliding contact), it is possible to prevent foreign matter from entering the bearing from the outside on the inner side of the vehicle. The inside of the bearing is a region between the hub shaft 11 and the outer ring 12 where two rows of balls 13 are provided.

The sealing device 15 on the vehicle outer side is composed of an annular sealing member 20 and an annular slinger 30. The seal member 20 is attached to the inner peripheral side of the outer ring 12 (outer ring main body 51) so as to be fitted to the outer side of the vehicle. FIG. 2 is an enlarged cross-sectional view showing the sealing device 15 and its surroundings. The slinger 30 is attached to the vehicle outer side of the shaft main body 55. The lip 21a of the seal member 20 slides into contact with the slinger 30 to prevent foreign matter from entering the bearing from the outside on the outer side of the vehicle.

The seal member 20 has a metal member 25 made of metal and a rubber seal body 26. The metal member 25 is attached to the inner peripheral surface of the end portion 12c on the vehicle outer side of the outer ring 12 (outer ring main body 51) in a tightly fitted state. The seal body 26 is fixed (vulcanized and bonded) to the metal member 25, and has a first lip 21a, a second lip 21b, and a third lip 21c that slide into contact with the slinger 30. The first lip 21a and the second lip 21b have a function of preventing foreign matter such as muddy water from entering the inside of the bearing from between the slinger 30. The third lip 21c mainly has a function of preventing the grease inside the bearing from flowing out. The first lip 21a and the second lip 21b come into axial contact with the slinger 30. The third lip 21c comes into contact with the shaft body 55 in the radial direction.

The seal body 26 shown in FIG. 2 further has a fourth lip 22 that is in contact with the outer peripheral surface of the end portion 12c of the outer ring 12 (outer ring body 51) on the vehicle outer side with a tightening allowance. The lip 22 has a function of preventing foreign matter such as muddy water from entering the inside of the bearing by passing between the outer ring 12 and the metal member 25.

[Slinger according to the first embodiment]
2 and 3 show the slinger 30 according to the first embodiment. The slinger 30 is an annular member made of metal, and is made of stainless steel (SUS430) in this embodiment. The slinger 30 has an annular portion 32 on the vehicle outer side and a tubular portion 31 extending from the annular portion 32 to the vehicle inner side. The annular portion 32 is a portion in the shape of an annular plate extending in the radial direction, and is in axial contact with the side surface 56a (of the hem portion 56b) of the flange 56 of the hub shaft 11. The tubular portion 31 is a portion having a tubular shape.

In the cross section of the wheel bearing device 10 (see FIG. 1) including the bearing center line C (see FIG. 2), the portion between the flange 56 and the shaft body portion 55 has a surface 58 having a concave radius shape. Therefore, the tubular portion 31 of the slinger 30 has a rounded tubular portion 31b according to this shape. That is, in FIGS. 2 and 3, the cylindrical portion 31 has a cylindrical portion 31a on the vehicle inner side and a rounded tubular portion 31b on the vehicle outer side continuous with the cylindrical portion 31a. The cylindrical portion 31a has a shape along a virtual cylindrical surface centered on the bearing center line C. The radius of the rounded tubular portion 31b increases toward the outer side of the vehicle, and has a rounded shape (arc shape as a whole) in the cross section. In addition to this, the rounded tubular portion 31b may have a shape bent along an arc.

The cylindrical portion 31a of the cylindrical portion 31 of the slinger 30 is fitted onto a part (29) of the shaft main body portion 55 on the vehicle outer side in a tightly fitted state. Of the hub shaft 11, a portion (part of the above) to which the tubular portion 31 of the slinger 30 is fitted and attached is also referred to as a “mounting portion 29”. The outer peripheral surface of the mounting portion 29 is formed of a cylindrical surface centered on the bearing center line C.

The annular portion 32 of the slinger 30 is in surface contact with the side surface 56a (of the hem 56b) of the flange 56. The slinger 30 cannot be displaced toward the outer side of the vehicle while the annular portion 32 is in contact with the flange 56. Further, since the slinger 30 is externally fitted to a part of the hub shaft 11 and is held by the hub shaft 11 only by a tense force, when the vehicle travels, the slinger 30 eventually rotates along the hub shaft 11. It may be displaced in the direction and displaced from a predetermined position of the hub axle 11 toward the vehicle inner side.

The slinger 30 has a second cylindrical portion 35 extending toward the vehicle inner side from the radially outer end portion 32a of the annular portion 32. The second cylindrical portion 35 is located radially outside a part of the fourth lip 22 of the sealing member 20. A labyrinth gap is formed between the second cylindrical portion 35 and the fourth lip 22, and in this labyrinth gap, foreign matter such as muddy water infiltrates into the sliding contact portion between the first lip 21a and the slinger 30. It has a function to suppress the operation.

[Concave curved surface]
FIG. 3 shows a cross section including the bearing center line C of the slinger 30 according to the first embodiment. As shown in FIGS. 2 and 3, the slinger 30 has a concave curved surface 33 on the end surface of the cylindrical portion 31a on the vehicle inner side. The concave curved surface 33 is formed in an annular shape by recessing the end surface of the cylindrical portion 31a on the vehicle inner side toward the vehicle outer side over the entire circumference, and is curved in a concave round shape in a cross section including the bearing center line C. The concave curved surface 33 has a curved surface shape that allows surface contact with the ball 13. Further, as shown in FIG. 3, edge portions 37 and 38 are formed at both ends of the concave curved surface 33 in the radial direction.

The concave curved surface 33 is arranged at a position facing the ball 13 in the axial direction. Therefore, the concave curved surface 33 can come into surface contact with the ball 13 when the slinger 30 moves toward the vehicle inner side in the axial direction.

[Radius of curvature of concave surface]
As shown in FIG. 4, the concave curved surface 33 of the present embodiment is formed with a radius of curvature R having a dimension equal to or greater than the radius (D / 2) of the ball 13. In such a configuration, the concave curved surface 33 comes into surface contact with the ball 13, and the contact surface thereof has an elliptical shape. For example, when the end surface of the cylindrical portion 31a on the vehicle inner side is a flat surface, the contact surface between the end surface and the ball 13 has a perfect circular shape, and the contact area is as compared with the case where the contact surface has an elliptical shape. Becomes smaller.

Therefore, in the slinger 30, the contact area between the slinger 30 and the ball 13 is increased by making the concave curved surface 33 face-contact with the ball 13 as compared with the case where the concave curved surface 33 is not provided. As a result, the contact surface pressure between the slinger 30 and the ball 13 is suppressed. In such a slinger 30, by reducing the contact surface pressure with the ball 13, even if the slinger 30 comes into contact with the ball 13, the ball 13 is less likely to be scratched.

As described above, in the slinger 30, the concave curved surface 33 is formed with a radius of curvature equal to or greater than the radius (D / 2) of the ball 13. According to this configuration, the concave curved surface 33 and the ball 13 can be brought into surface contact with each other, and the contact surface pressure between the slinger 30 and the ball 13 can be suppressed.

[Curved surface shape of concave curved surface]
When the slinger 30 walks out to the vehicle inner side and the concave curved surface 33 is in surface contact with the ball 13, the concave curved surface 33 is brought into contact with the ball 13 outside the radial inner end and inside the radial outer end. It is preferable to set the arc shape of the concave curved surface 33. In the slinger 30 of the present embodiment, in a state where the concave curved surface 33 is in contact with the ball 13, it is outside the edge portion 38 at the radial inner end of the concave curved surface 33 and inside the edge portion 37 at the radial outer end. The arc shape of the concave curved surface 33 is set so as to come into contact with the ball 13.

Specifically, as shown in FIGS. 5A and 5B, it is preferable that the curved surface shape of the concave curved surface 33 is set based on the shape of the range in which the slinger 30 in the ball 13 comes into contact. The range in which the cylindrical portion 31a of the ball 13 comes into contact is the range of the arc AB shown in FIG. 5A in the cross section including the bearing center line C. In such a case, as shown in FIG. 5B, the center of curvature Y is set on the straight line L passing through the midpoint P of the arc AB and the center X of the ball 13 in the cross section including the bearing center line C. It is preferable that the arc drawn from the center of curvature Y to the radius of curvature R (R ≧ D / 2) is the curved shape of the concave curved surface 33. According to this configuration, the edge portions 37, 38 existing at both ends in the radial direction of the concave curved surface 33 do not come into contact with the ball 13, and the concave curved surface 33 and the ball 13 can be surely brought into surface contact with each other. This makes it possible to reliably suppress the contact surface pressure between the slinger 30 and the ball 13. The center of curvature Y of the concave curved surface 33 is most preferably on the straight line L, but it is sufficient if the edges 37 and 38 do not come into contact with the ball 13, and the center of curvature Y is set in the vicinity of the straight line L. May be good.

As described above, in the slinger 30, the concave curved surface 33 contacts the ball 13 outside the radial inner end and inside the radial outer end of the concave curved surface 33. According to this configuration, since the edge portions 37, 38 existing at both ends of the concave curved surface 33 in the radial direction do not come into contact with the ball 13, the concave curved surface 33 and the ball 13 can be surely brought into surface contact with each other. It is possible to reliably suppress the contact surface pressure between the slinger 30 and the ball 13.

[Position of concave curved surface]
As shown in FIG. 6A, the position of forming the concave curved surface 33 in the slinger 30 is aligned with the shape of the contact portion of the concave curved surface 33 in the ball 13, and the concave curved surface 33 is formed by moving it inward in the radial direction of the cylindrical portion 31a. Alternatively, as shown in FIG. 6B, the concave curved surface 33 may be formed by moving it toward the radial outer side of the cylindrical portion 31a, or as shown in FIG. 6C, it may be concave in the radial center of the cylindrical portion 31a. The curved surface 33 may be formed. Further, the end surface of the cylindrical portion 31a may be provided with a flat surface portion radially outside the edge portions 37 and 38.

As described above, the wheel bearing device 10 has a hub shaft 11 having a flange 56 on which wheels are mounted on the vehicle outer side (one side in the axial direction) and an outer ring provided on the radial outer side of the hub shaft 11. 12, a plurality of balls 13 provided between the hub shaft 11 and the outer ring 12, a cage 14 for holding the plurality of balls 13, an annular seal member 20 attached to the outer ring 12, and a hub. It is provided with an annular slinger 30 that is fitted and attached to the shaft 11 so that the seal member 20 slides into contact with the shaft 11. The slinger 30 has an annular portion 32 extending in the radial direction and a tubular portion 31 extending from the annular portion 32 to the vehicle inner side (the other side in the axial direction), and has a tubular portion 31 on the vehicle inner side of the tubular portion 31. A concave curved surface 33 that is concave and curved toward the outer side of the vehicle and can come into contact with the ball 13 is formed on the entire circumference of the end surface.

According to the wheel bearing device 10, when the slinger 30 moves from a predetermined position of the hub shaft 11 to the vehicle inner side, the ball 13 can be brought into surface contact with the concave curved surface 33 of the slinger 30. As a result, the contact surface pressure between the slinger 30 and the ball 13 can be suppressed, and even if the slinger 30 walks out, it is possible to suppress the ball 13 from being scratched.

[Slinger according to the second embodiment]
7 and 8 show the slinger 39 according to the second embodiment. FIG. 7 is a cross-sectional view including the bearing center line C of the slinger 39 according to the second embodiment. The slinger 39 is different from the slinger 30 of the first embodiment in that it has a heterogeneous portion 34 at the end of the cylindrical portion 31a on the vehicle inner side, and the other parts are the same as those of the first embodiment. It is common with the configuration of the slinger 30.

[Heterogeneous part]
The slinger 39 shown in FIG. 7 has a heterogeneous portion 34 at the end of the cylindrical portion 31a on the vehicle inner side. The heterogeneous portion 34 is a portion made of a material different from the material of the slinger 39 (SUS430 in this embodiment). The heterogeneous portion 34 is fixed to the end portion of the cylindrical portion 31a on the vehicle inner side by a method described later. As the material constituting the heterogeneous portion 34, a material having a hardness lower than that of the ball 13 can be used. As the material constituting the heterogeneous portion 34, synthetic resin, rubber, metal (for example, aluminum) or the like having a hardness lower than that of the ball 13 can be used. Then, in the slinger 39, a concave curved surface 33 is formed at an end portion of the heterogeneous portion 34 on the vehicle inner side.

[Method of forming heterogeneous part]
When the material constituting the heterogeneous portion 34 is a synthetic resin, the heterogeneous portion 34 can be provided in the cylindrical portion 31a by injection molding (insert molding). Further, when the material constituting the heterogeneous portion 34 is rubber, the heterogeneous portion 34 can be provided in the cylindrical portion 31a by vulcanization adhesion. When the material constituting the heterogeneous portion 34 is a dissimilar metal such as aluminum, the heterogeneous portion 34 can be provided on the cylindrical portion 31a by adhesion using an adhesive.

When the material constituting the heterogeneous portion 34 is a resin (synthetic resin, rubber, etc.), a slinger 39 having the heterogeneous portion 34 is generally used for providing a resin portion on a metal part such as insert molding or vulcanization adhesion. It can be easily manufactured by a conventional method. Further, when the foreign portion 34 is made of a resin, if the resin contains a lubricating material, the ball 13 can be prevented from being scratched when the slinger 39 comes into contact with the ball 13, and the ball 13 can be prevented from being scratched. It is possible to improve the lubrication state.

In the slinger 39 provided with the foreign portion 34 shown in FIG. 7, when the slinger 39 walks out to the vehicle inner side, the ball 13 comes into surface contact with the concave curved surface 33 formed on the foreign portion 34. Since the heterogeneous portion 34 has a lower hardness than the ball 13, when the ball 13 comes into surface contact with the concave curved surface 33, the heterogeneous portion 34 on the slinger 39 side is worn. As a result, it is possible to reliably prevent the ball 13 from being scratched.

[Shape of heterogeneous part]
As shown in FIG. 7, in the slinger 39, the inner diameter of the heterogeneous portion 34 is made larger than the inner diameter of the cylindrical portion 31a, and the stepped portion 36 is provided on the inner side in the radial direction of the heterogeneous portion 34. Therefore, when the mounting portion 29 is press-fitted into the cylindrical portion 31a, the foreign portion 34 can be separated from the mounting portion 29, whereby unnecessary force is not applied to the foreign portion 34. As a result, when the slinger 39 is press-fitted into the mounting portion 29, unnecessary force acts on the foreign portion 34 to prevent the foreign portion 34 from being damaged (for example, disengaged).

As shown in FIG. 8A, in the slinger 39, the concave portion 31c is formed on the end surface of the cylindrical portion 31a on the vehicle inner side, and the convex portion 34a that can be fitted into the concave portion 31c on the end surface of the heterogeneous portion 34 on the vehicle outer side. Is forming. Then, the foreign portion 34 is fixed to the cylindrical portion 31a in a state where the convex portion 34a is fitted into the concave portion 31c. In such a configuration, when a radial force acts on the foreign portion 34, the convex portion 34a can be locked by the concave portion 31c, so that the foreign portion 34 is less likely to come off from the cylindrical portion 31a. Further, in such a configuration, the adhesive area between the cylindrical portion 31a and the foreign portion 34 can be increased as compared with the case where the concave portion 31c and the convex portion 34a are not provided, so that the foreign portion 34 is more difficult to come off. be able to. The concave-convex structure provided to prevent the foreign portion 34 from coming off from the cylindrical portion 31a may be a structure as shown in FIG. 8B.

In the structure shown in FIG. 8B, the uneven portion 31d is formed on the end surface of the cylindrical portion 31a on the vehicle inner side, and the uneven portion 34b is formed on the end surface of the heterogeneous portion 34 on the vehicle inner side. Then, the heterogeneous portion 34 is fixed to the cylindrical portion 31a in a state where the uneven portion 31d and the uneven portion 34b are fitted together. In such a configuration, the adhesive area between the cylindrical portion 31a and the heterogeneous portion 34 can be increased, and when a radial force acts on the heterogeneous portion 34, the uneven portion 34b is locked by the uneven portion 31d. Therefore, it is possible to make the foreign portion 34 more difficult to come off.

As described above, the slinger 39 has a heterogeneous portion 34 made of a material having a hardness lower than that of the ball 13 at the end portion of the tubular portion 31 on the vehicle inner side, and a concave curved surface 33 is formed on the heterogeneous portion 34. Has been done. According to this configuration, when the slinger 39 comes into contact with the ball 13, the slinger 39 side can be worn. As a result, it is possible to more reliably prevent the ball 13 from being scratched by contact with the slinger 39.

The embodiments disclosed as described above are exemplary in all respects and are not restrictive. That is, the wheel bearing device of the present invention is not limited to the illustrated form, and may be another form within the scope of the present invention.

10: Wheel bearing device 11: Hub shaft 12: Outer ring 13: Ball 14: Cage 20: Seal member 30: Slinger (first embodiment) 31: Cylindrical portion 32: Annulus portion 33: Concave curved surface 34: Foreign portion 39: Slinger (second embodiment)
56: Flange R: Radius of curvature (of concave curved surface 33) D: Diameter (of ball 13)

Claims (4)

A hub shaft with a flange on one side in the axial direction to which the wheel is mounted,
An outer ring provided on the radial outer side of the hub axle and
A plurality of balls provided between the hub shaft and the outer ring, and
The cage that holds the plurality of balls and
An annular seal member attached to one side of the outer ring in the axial direction,
An annular slinger that is fitted onto the hub shaft and attached to the other side of the flange in the axial direction, and the sealing member slides into contact with the slinger.
Equipped with
The slinger has an annular portion extending in the radial direction and a ring portion extending in the radial direction.
It has a tubular portion extending from the annular portion to the other side in the axial direction, and has.
A wheel bearing device in which a concave curved surface that is recessed and curved in one side in the axial direction and can be surface-contacted with the jade is formed on the entire circumference of the end surface on the other side in the axial direction of the cylinder portion. The concave curved surface is
The wheel bearing device according to claim 1, which is formed with a radius of curvature equal to or greater than the radius of the ball. The concave curved surface is
The wheel bearing device according to claim 2, wherein the concave curved surface is in contact with the jade outside the inner end in the radial direction and inside the outer end in the radial direction. The slinger is
Claims 1 to 3 have a heterogeneous portion made of a material having a hardness lower than that of the ball at the other end of the tubular portion in the axial direction, and the concave curved surface is formed on the heterogeneous portion. The wheel bearing device according to any one of the above.

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