JP2002089584A - Spider universal joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spider universal joint preventing localized load to prevent its service life from decreasing by keeping the raceway of a bearing case and the axis of a trunnion parallel to each other. SOLUTION: The spider universal joint includes a trunnion, a bearing case of approximately U-shaped cross section fitted over the end face of the trunnion, a needle roller interposed between the trunnion and each side face of the bearing case, and a yoke for fitting and supporting the outer surface of the bearing case in a bearing hole. The outer surface 2b of the bearing case 2 is in the form of a projecting spherical surface and the inner surface 6a of the bearing hole 6 in the yoke 5 is in the form of a recessed spherical surface. The bearing case 2 is spherically fitted over the inner surface 6a of the bearing hole 6 in the yoke 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cross joint that is used for automobiles and various industrial machines.

[0002]

2. Description of the Related Art As shown in FIGS. 3 and 4, a conventional cross-shaft universal joint has four trunnions 30 which are circumferentially arranged at regular intervals of 90 degrees, and cover the end faces 30a of the trunnions 30. Bearing case 31 having a substantially U-shaped cross-section fitted to the trunnion 30 and both side surfaces 3 of the bearing case 31
It has a needle roller 32 interposed between 1a and 30b, and a yoke 34 for fitting and supporting the outer surface 31b of the bearing case 31 to the inner surface 35a of the bearing hole 35. A roller bearing 33 is formed by the bearing case 31 and the needle rollers 32.

[0003]

In this conventional cross-shaft universal joint, the load distribution of the bearing 33 is not uniform in the axial direction (axial direction of the trunnion 30). ), The surface pressure of the track on the tip side of the trunnion 30 becomes larger than the surface pressure of the track on the base side of the trunnion 30, so that damage such as track separation is likely to occur on the tip side of the trunnion 30. This peeling or the like may occur more largely due to a difference in rigidity between the yoke 34 and the trunnion 30.

[0004] Since this unbalanced load changes with torque,
From the beginning, it is conceivable to design the shape, clearance, rigidity, etc. in consideration of the unbalanced load, but even if this is done, it is effective under compatible torque conditions, but the life will be shortened under other torque conditions. There's a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cross joint that prevents the occurrence of an unbalanced load and prevents the life of the cross shaft from being shortened by always keeping the raceway of the bearing case and the axis of the trunnion parallel. .

[0006]

Means for Solving the Problems As means for solving the above-mentioned problems, the invention of claim 1 comprises a trunnion, a bearing case having a substantially U-shaped cross section fitted to cover the end face of the trunnion, a trunnion and a bearing case. In a cross-shaft universal joint having a needle roller interposed between both side surfaces and a yoke that fits and supports the outer surface of the bearing case in the bearing hole, the outer surface of the bearing case is formed into a convex spherical shape, The inner surface of the bearing hole of the yoke has a concave spherical shape, and the inner surface of the bearing hole of the bearing case and the yoke is spherically fitted.

According to a second aspect of the present invention, a separate ring is fitted and fixed to one of upper and lower portions in the axial direction of the inner surface of the bearing hole of the yoke, and the inner surface of the ring is recessed in the inner surface of the bearing hole. It is characterized in that it is formed as a concave spherical surface constituting a part of the spherical surface.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. The cross shaft universal joint is basically
A trunnion 1, a bearing case 2 having a substantially U-shaped cross section fitted so as to cover an end surface 1a of the trunnion 1, and a trunnion 1
A needle roller 3 interposed between the outer raceway surface 1a of the bearing case 2 and the inner raceway surface 2a of the bearing case 2, and an integral yoke 5 for fittingly supporting the outer surface 2b of the bearing case 2 in the bearing hole 6. You. A bearing 4 for supporting the trunnion 1 in the bearing hole 6 of the yoke 5 is formed by the needle rollers 3 of the bearing case 2.

The outer surface 2b of the bearing case 2 is formed in a convex spherical shape, and the inner surface 6a of the bearing hole 6 of the yoke 5 is formed in a concave spherical shape.
The inner surface 6a of the bearing hole 6 is fitted with the above-mentioned uneven spherical surface. By this uneven spherical surface fitting, the bearing case 2 and the yoke 5
Are capable of self-centering. That is, since the track 2a of the bearing case 2 and the axis of the trunnion 1 are always parallel in response to the load variation acting on the bearing 4, the bearing 4 is not subjected to an eccentric load and is even (arrow). Becomes

The concave spherical surface 6a of the yoke 5 corresponding to the convex spherical surface 2b of the bearing case 2 has the following configuration. The lower half portion 60a of the concave spherical surface 6a is directly formed on the inner diameter portion of the yoke 5 in the axial direction, and the outer diameter portion of the axial direction has a stepped peripheral surface portion 5a whose inner diameter is increased in the radial direction and parallel to the axis of the bearing hole 6. It has been. A separate ring body 7 which is a part of the yoke 5 is fitted to the stepped peripheral portion 5a, and is fixed by a retaining ring 8 fixed to an end of the yoke 5 so as not to come off in the axial direction. . The inner side surface 7a of the ring body 7 has a concave spherical surface 60 constituting the upper half of the concave spherical surface 6a of the yoke 5.
b is formed. That is, the convex spherical surface 2b of the bearing case 2 is supported by the concave spherical surface 60a of the lower half of the yoke 5 and the concave spherical surface 60b of the ring body 7 that forms a part of the yoke 5. With this configuration, the yoke 5 and the ring 7
The processing of the concave spherical surfaces 60a and 60b is easy.

However, when considering the reduction of the number of parts for ease of workability, the ring body 7 may be omitted and the upper and lower concave spherical surfaces 60a and 60b may be formed on the yoke 5 itself.

FIG. 2 shows another embodiment of the present invention. In the embodiment of FIG. 1, the bearing hole 6 of the yoke 5 is formed so as to be axially penetrated by the integral yoke, but in FIG. 2, the yoke 5 is divided into a yoke main body 50 and a lid 51 in the radial direction. And integrated with bolts 9
Are formed. This structure is well known in the art. A radially inner half of the concave spherical surface 6a is formed on the inner surface of the bearing hole 6 on the yoke body 50 side, and an outer half of the concave spherical surface 6a is formed on the inner surface of the bearing hole 6 of the lid 51. Have been. Other configurations are the same as those in FIG. With this configuration, the processing of the concave spherical surface 6a is facilitated and the ring body 7 of FIG. 1 is not required.

[0013]

According to the cross shaft universal joint of the present invention, since the yoke and the bearing case are fitted into the concave and convex spherical surfaces, the bearing case and the yoke can be self-aligned, and the load on the bearing can be reduced. Correspondingly, the orbit of the bearing case and the axis of the trunnion are always parallel. Therefore, an unbalanced load does not act on the bearing, and a reduction in life is prevented.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a cross shaft universal joint according to an embodiment of the present invention.

FIGS. 2A and 2B are another embodiment of the present invention, wherein FIG. 2A is a plan view and FIG. 2B is a partial cross-sectional view taken along a line II of FIG. Is a partial sectional view of the front.

FIG. 3 is a sectional view of a conventional cross shaft universal joint.

FIG. 4 is an enlarged view of a main part of FIG. 3;

[Explanation of symbols]

 Reference Signs List 1 trunnion 2 bearing case 2b outer surface (convex spherical surface) 3 needle roller 4 bearing 5 yoke 6 bearing hole 6a inner surface (concave spherical surface) 7 ring

Claims (2)

[Claims] 1. A trunnion, a bearing case having a substantially U-shaped cross-section fitted so as to cover an end face of the trunnion, a needle roller interposed between both side surfaces of the trunnion and the bearing case, and an outer surface of the bearing case. A universal joint having a yoke that fits and supports the bearing case in the bearing hole, the outer surface of the bearing case has a convex spherical shape, the inner surface of the bearing hole of the yoke has a concave spherical shape, and the inner surface of the bearing case and the yoke have a bearing hole. A cross shaft universal joint characterized by having a spherical surface fitting. 2. A separate annular body is fitted and fixed to one of upper and lower portions in the axial direction of the inner surface of the bearing hole of the yoke, and the inner surface of the annular body forms a part of a concave spherical surface of the inner surface of the bearing hole. The universal joint according to claim 1, wherein the joint is formed as a concave spherical surface.