JP2502770Y2 - Wheel bearing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a wheel bearing device used for a wheel bearing of an automobile, a drive pinion shaft bearing, or the like.

[Conventional technology]

FIG. 3 shows a conventional bearing device for a non-driving side wheel of an automobile.

As shown in the figure, this bearing device includes a hub 32 having a wheel mounting portion protruding outward from an outer ring 30 fixed to a fixing member such as a vehicle body, and an inner ring fitted to the tip of the hub 32. An inner member 31 composed of 33 is inserted, and two rows of ball guide grooves 34, 35 are formed on the opposing surfaces of the outer ring 30 and the inner member 31 at axial distances. , 35 with a large number of balls 36, 37 incorporated therein.

In the above structure, the wheel is attached to the attachment portion of the hub 32 with the bolt 38, and the hub 32 is attached to the outer ring via the balls 36 and 37.
It will be cantilevered to 30.

[Problems to be solved by the device]

By the way, in the above-mentioned conventional bearing device, both balls 36 and 37 having the same diameter are used mainly from the viewpoint of workability, and the positions of the balls 36 and 37 are aligned with the center of the load between the balls. However, in the structure in which the inner member 31 is supported in a cantilever manner as described above, the load center often deviates in the axial direction from the center position between both balls. (Usually, the center of the load approaches the inner ball 36 that serves as a fulcrum for cantilever support, and a larger load is applied than the outer ball 37.) Therefore, in the above bearing device, a large load is close to the center of the load. However, there is a drawback that the ball to which the bearing is worn wears in a short period of time and the durability of the ball determines the durability of the bearing device at a low level.

In order to deal with such a drawback, conventionally, a structure has been adopted in which the distance between both ball guide grooves is expanded to reduce the ratio of the distance from the load center, thereby reducing the unbalanced load applied to the ball on the high load side. However, in this structure, the hub
Since the total length of 32 becomes long, there is a problem that the weight of the bearing device increases.

Therefore, an object of the present invention is to provide a double row ball bearing device in which the durability of the ball on the high load side is improved without increasing the size of the bearing device.

[Means for solving the problem]

In order to solve the above-mentioned problems, the present invention uses a ball, which is axially spaced from each other and is incorporated into two rows of inner and outer ball guide grooves, on the opposing surfaces of an outer ring and an inner member inserted therein. A pair of angular ball bearing units that rotatably connect the outer ring and the inner member to each other, and a wheel bearing device having a flange portion for mounting a wheel at one end of the angular ball bearing unit, wherein The ball diameter on the side away from the flange is larger than the other ball diameter.

[Action]

In the above structure, since the ball diameter is increased, the load resistance of the ball on the side away from the flange portion is increased and the durability life of the ball is extended. Therefore, the durability of the bearing device is improved as a whole.

〔Example〕

FIG. 1 shows an embodiment in which the present invention is applied to a bearing of a non-driving side wheel.

As shown in the figure, the inner member 2 inserted into the outer ring 1 is composed of a hub 3 and an inner ring 5 fitted to a shaft portion 4 at the tip of the hub 3. It is fixed to the hub 3 by a nut 6 screwed into the tip of the. A flange portion 39 for mounting a wheel is provided on the outer end of the hub 3.

The outer peripheral surface of the hub 3 and the outer peripheral surface of the inner ring 5 are formed with two rows of ball guide grooves 7b and 8b axially spaced from each other, while the inner peripheral surface of the outer ring 1 is formed with the ball guide grooves. Ball guide grooves 7a and 8a are formed corresponding to 7b and 8b, respectively.

Of these ball guide grooves, the guide surfaces of the inner guide grooves 7a and 7b that are to be mounted on the automobile are the guide surfaces of the other guide grooves 8a and 8b.
On the other hand, a curved surface having a large radius of curvature is formed so that a ball having a large diameter can be guided.

In addition, in the guide groove provided in the outer ring 1, the inner guide groove
7a is arranged on the outer diameter side of the outer guide groove 8a, and when the balls 9 and 10 constituting the angular ball bearing unit are incorporated in the respective guide grooves, the balls 9 and 10 and the hub 3 and the inner ring 5 are The inscribed circles are set to have the same diameter.

Also, in this embodiment, the inner guide groove 7a
Is formed in a portion where the wall thickness is increased directly below the mounting flange 11 provided on the outer periphery of the outer ring 1, thereby eliminating the thinning of the outer ring wall thickness due to the large diameter of the guide groove 7a, and increasing the rigidity. To prevent the decline of.

The ball guide grooves 7a, 7b and the ball guide grooves 8a, 8b are assembled with a large number of balls 9, 10 held by cages 12, 13, respectively. It is set larger than the diameter of the outer ball 10.

This increase in ball diameter is determined according to the amount of deviation of the load center with respect to the center position between the balls 9 and 10, that is, the difference in the load applied to each ball 9 and 10, and for example, in a standard bearing. Select a bearing that is one rank above or two ranks above.

In the bearing device of the embodiment having the above structure, the hub 3 to which the wheel is attached is supported in a cantilever manner, so that even if a large load is applied to the inner ball 9, the diameter of the ball 9 is increased and the load bearing capacity is increased. Since it is large, the wear of the balls 9 is suppressed as compared with the conventional structure, and the life is extended. Therefore, the life of the bearing device is no longer determined by the life of the balls 9, and the durability of the device can be improved.

Further, in the structure of the above-mentioned embodiment, the load bearing capacity is improved by increasing the diameter of the ball as compared with the conventional structure. Therefore, by shortening the distance between both balls 9 and 10, the bearing device can be made compact. Can be planned.

FIG. 2 shows an example in which the present invention is applied to a bearing of a driving wheel.

The major structural difference between this example and the embodiment of FIG. 1 is that an insertion hole 28 into which a drive shaft such as a constant velocity joint is inserted is formed inside the hub 21, and the inner ring 22 is connected to the hub 21. It is at the point where it is press-fitted into the groove 23 at the tip.

Other structures, namely balls in inner ball guide groove 24
The same applies to the structure in which the diameter of 26 is made larger than the diameter of the ball 27 of the outer ball guide groove 25 so that the cantilever-supported load is received by the large diameter ball 26.

[Effect of device]

As described above, according to the present invention, since the diameter of the ball in the inner ball guide groove to which a high load is applied is made larger than the diameter of the ball in the outer ball guide groove, the load bearing capacity is increased, so that Wear can be prevented and the durability of the bearing device can be improved.

Further, in the above structure, since it is only necessary to slightly increase the ball diameter, it is not necessary to upsize the outer ring and the inner member, and there is an advantage that the bearing device can be made compact.

[Brief description of drawings]

FIG. 1 is a partial vertical sectional view showing an embodiment according to the present invention, FIG. 2 is a sectional view showing another embodiment, and FIG. 3 is a partial vertical sectional view showing a conventional example. 1, 20 ... Outer ring, 2 ... Inner member, 3, 21 ... Hub,
5,22 …… Inner ring, 7a, 7b, 8a, 8b, 24,25 …… Ball guide groove, 9,10,26,27 …… Ball.

Claims (1)

(57) [Scope of utility model registration request] Claim: What is claimed is: 1. An outer ring and an inner member are mounted on the facing surface of an outer ring and an inner member inserted through the inner ring through balls incorporated in two rows of ball guide grooves inside and outside with a distance in the axial direction. A pair of angular ball bearing units that are rotatably connected to each other is formed, and in a wheel bearing device having a flange portion for attaching a wheel to one end of the angular ball bearing unit, on a side remote from the flange portion of the angular ball bearing unit. A bearing device for a wheel, wherein a ball diameter is made larger than the other ball diameter.