JPH11170805A - Bearing device for wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing device for a wheel, with which a bearing part can be formed compactly as a whole, in which a pre-load can stably be applied, and which can reduce the space (for the bearing), compared with the former one. SOLUTION: A hub 2, which is installed on the wheel side, forms both a flange part 2a, by which hub 2 is attached to the wheel, and a cylindrical part 2b, which serves as an inner ring for a bearing part and which is provided with a plural rows of race ways for balls. The hub 2 is fitted with pressure to an equal velocity joint outer ring 1 and welded along the joining part. A part of the end part on the inner periphery side of an outer ring 4, which constitutes the bearing part, is provided with a ball retaining groove 4d. In addition, in order to give a preload (to the bearing), rings 8, 9 are press-fitted into a plural places on the inner peripheral side of the cylindrical part of the hub 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel bearing device disposed between a drive shaft (axle) and a drive wheel, and more particularly to a compact overall structure by reducing the diameter of a bearing portion. The present invention relates to a wheel bearing device capable of applying a predetermined preload to a bearing portion.

[0002]

2. Description of the Related Art A rotational torque transmitted from a propeller shaft via a differential gear is further transmitted from a drive shaft to wheels. A wheel bearing device as shown in FIG. 3 is provided between the drive shaft and the wheels. Such a conventional wheel bearing device includes a hub 2 having a flange portion 22a connected to a constant velocity joint outer ring 21 at an end of a drive shaft and attached to a wheel side.
2, an outer ring 24 fixed to the vehicle body, balls 23a and 23b disposed between the hub 22 and the outer ring 24,
, And the like.

[0003]

In the conventional wheel bearing device having the above structure, as can be seen from FIG.
The second cylindrical portion 22b constitutes a part of the outer race 21 of the constant velocity joint and is also the inner race of the wheel bearing device, and has substantially the same diameter. When assembling the outer ring 24, the ball 23a, and the like, it is necessary to assemble from the end of the cylindrical portion 22b of the hub 22. That is, when assembling, there is a problem that the inner diameter of the outer ring 24 fixed to the vehicle body side becomes larger than the outer diameter of the cylindrical portion 22b of the hub 22 or the outer diameter of the constant velocity joint outer ring 21, so that the entire diameter becomes large.

The hub 22 is mounted on the wheel side, and rotational torque is transmitted from the constant velocity joint outer ring 21 side. A wheel bearing device having a diameter substantially equal to the cylindrical portion 22b of the hub 22 is provided. The rotational moment of inertia is also inevitably large, which adversely affects the steering system such as operation delay. Further, in the conventional wheel bearing device having the above configuration,
When applying a preload, there is also a problem that it is difficult to obtain a stable and constant preload.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to make the bearing portion compact as a whole and to apply preload stably. It is an object of the present invention to provide a wheel bearing device that can be reduced in size.

[0006]

That is, the present invention provides a constant velocity joint outer ring (1) for solving the above-mentioned problems.
A hub (2) attached to the wheel side; an outer ring (4) attached to the vehicle body side to form a bearing; and a double-row ball disposed between the hub (2) and the outer ring (4). (3
a, 3b), the wheel bearing device comprising:
The hub (2) has a flange portion (2a) for mounting to a wheel and a cylindrical portion (2b) which is provided with a double row of raceways for the balls and serves as an inner ring of a bearing portion. 2b)
The end (2c) is press-fitted to the constant velocity joint outer ring (1) and welded along the end of the fitting portion, and a part of the inner peripheral end of the outer ring (4) is balled. The groove (4d) is provided.

Also, rings (8, 9) are press-fitted at a plurality of locations on the inner peripheral side of the cylindrical portion (2b) of the hub (2).

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a partial sectional view in the axial direction of a wheel bearing device according to the present invention.
The wheel bearing device comprises a constant velocity joint outer ring 1 which is a part of a drive shaft, a hub 2 attached to wheels (not shown), an outer ring 4 attached to a vehicle body (not shown), and the hub. 2 and balls 3a and 3b disposed between the outer ring 4 and the outer ring 4. The outer ring 4 is formed with a flange portion 4a for mounting on the vehicle body side.
Reference numerals 5 and 6 denote sealing members.

The hub 2 has a flange portion 2a for mounting to a wheel, and a cylindrical portion 2b serving as an inner ring of a bearing portion of the wheel bearing device. And an inner diameter portion of an end 1a of the constant velocity joint outer ring 1 on the hub 2 side;
The outer diameter portion of the end portion 2c of the cylindrical portion 2b on the constant velocity joint outer ring 1 side is processed so that they are press-fitted (tight fit). Ends 1 of these constant velocity joint outer rings 1
The inner diameter portion of a and the outer diameter portion of the end 2c of the hub 2 are press-fitted and then welded (for example, electron beam welding) along the joint. The ball 3 is provided on the outer peripheral surface of the hub 2.
Track surfaces 2d and 2e for arranging a and 3b are formed, and track surfaces 4b and 4c are also formed on the inner peripheral surface of the outer ring 4. With the above configuration, both the outer diameter of the cylindrical portion 2c of the hub 2 and the inner diameter of the outer ring 4 are the same as those of the constant velocity joint outer ring 1
Can be formed smaller than the diameter.

FIG. 2A shows the outer race 1 of the constant velocity joint.
FIG. 2B is a partial cross-sectional view of the hub 2 and the outer ring 4 before the hub 2 is press-fitted with FIG. 2, and FIG. 2B is a view taken along the line XX of FIG. 2A. Balls 3a and 3b are arranged between the cylindrical portion 2b of the hub 2 and the outer ring 4. In the wheel bearing device of the present invention, the rigidity of the hub 2 is maintained and the number of parts is reduced. Therefore, an inner ring member having a raceway surface formed on the outer peripheral side of the hub 2 is not separately provided. Therefore, the ball 3b particularly arranged on the outer ring 1 side of the constant velocity joint has the hub 2
Cannot be arranged on the raceway surfaces 2e and 4c between the cylindrical portion 2b and the outer race 4. Therefore, a groove 4d for inserting balls is provided in a part of the inner peripheral end of the outer race 4. Thereby, the ball 3b can be arranged between the hub 2 and the outer ring 4. Reference numeral 7 denotes a retainer, but the ball 3b does not fall apart even if the ball insertion groove 4d is provided in a part of the inner peripheral end of the outer ring 4 in this way.

As described above, in this wheel bearing device, the cylindrical portion 2b of the hub 2 and the outer ring 4 attached to the vehicle body are provided.
Between the raceway surfaces 2d, 4b and 2e, 4c
a and 3b are arranged, and these track surfaces 2d, 4b and 2
Since a thrust load is applied to e and 4c and the balls 3a and 3b, a preload must be applied. However, in this state, these raceway surfaces 2d, 4b and 2e, 4c and balls 3a, 3
No preload can be applied between b. Therefore, FIG.
Alternatively, as shown in FIG. 2 (A), the protrusions 2f, 2g around the circumference are provided at two locations on the inner peripheral side of the cylindrical portion 2b of the hub 2, that is, at or near the positions where the balls 3a, 3b are arranged. Is formed and the surface is cut, and rings 8 and 9 are press-fitted therein. By press-fitting the rings 8, 9, a certain preload can be applied to the raceway surfaces 2d, 4b and 2e, 4c and the balls 3a, 3b.

With the wheel bearing device of the present invention configured as described above, the outer diameter of the hub 2 and the inner diameter of the outer ring 4 constituting the bearing portion are made smaller than the outer ring 1 of the constant velocity joint. It becomes possible. Further, the constant velocity joint can be the same as the conventional one, and there is no need to change the space. By making the outer diameter of the hub 2 and the inner diameter of the outer race 4 smaller than that of the constant velocity joint outer race 1, the moment of inertia can be reduced, and the braking function can be improved. Further, the influence of gyro moment caused by the inclination of the wheel shaft or the change of the running angle can be reduced. In addition, since it is possible to apply a preload to the bearing portion by the rings 8 and 9, the rigidity of the bearing portion of the wheel bearing device can be increased.

[0013]

As described in detail above, the wheel of the present invention
According to the bearing device for a vehicle, since the diameter of the bearing portion of the hub and the outer ring can be made smaller than the diameter of the outer ring of the constant velocity joint, it is possible to make the whole compact.
In addition, a stable preload can be applied to the bearing portion, so that the rigidity of the bearing portion can be increased.
In addition, the life of the bearing can be extended.

[Brief description of the drawings]

FIG. 1 is a partial sectional view in the axial direction of a wheel bearing device of the present invention.

FIG. 2 (A) is a partial cross-sectional view of a hub and an outer ring of a constant velocity joint constituting a bearing device for a wheel of the present invention before being press-fitted to the outer ring, and FIG. (B) shows FIG.
It is an XX arrow line view of (A).

FIG. 3 is a partial sectional view of a conventional wheel bearing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Constant-velocity joint outer ring 2 Hub 2b Hub cylindrical part 2c 3a, 3b 4 Outer ring 8, 9 ring

Claims (2)

[Claims] 1. A constant velocity joint outer ring, a hub attached to a wheel side, an outer ring attached to a vehicle body to form a bearing portion, and a double row of balls arranged between the hub and the outer ring. In the wheel bearing device provided, the hub is provided with a flange portion for attaching to a wheel and a double-row raceway surface for the balls, and a cylindrical portion serving as an inner ring of the bearing portion is formed. The end portion is press-fitted with the outer ring of the constant velocity joint and welded along the end portion of the fitting portion, and a part of the inner peripheral side end portion of the outer ring is provided with a ball insertion groove. Bearing device for a wheel. 2. The wheel bearing device according to claim 1, wherein rings are press-fitted at a plurality of positions on the inner peripheral side of the cylindrical portion of the hub.