JP2001193753A - Universal joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a universal joint capable of effectively preventing vibrations and abnormal noise. SOLUTION: Recessed portions 13c, 4c are formed in the inner bottom of a cup 13a of a bearing 13 and in the end face of a shaft diameter portion 4a of a cross shaft 4, respectively. With an elastic member 14 interposed in a space 15 formed by the recessed portions 13c, 4c in an elastically deformed state, a pre-load is applied to the shaft diameter portion 4a in the thrusing and radial directions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cross-shaped universal joint used for, for example, a propulsion shaft or a steering device of an automobile.

[0002]

2. Description of the Related Art Conventionally, in a steering apparatus of an automobile, a cross shaft-shaped universal joint has been used, for example, in order to connect a column shaft and a steering gear to be freely bent. In this universal joint, a bipedal yoke is provided at each end of a pair of shafts, a cup-shaped bearing is fitted into a bearing hole of each yoke, and the shaft diameter portion at the end of the cross shaft is fitted to this bearing. By fitting, a cross shaft is rotatably connected to the yoke. In this universal joint, in order to prevent the cup of the bearing and the shaft diameter of the cross shaft from moving relative to each other in the axial direction, the inner bottom portion of the cup and the end face of the shaft diameter portion opposed to the inner bottom are provided. Between them, a pin made of a synthetic resin is attached (for example, see Japanese Patent Application Laid-Open No. 8-135677).

[0003]

In the above-mentioned conventional universal joint, the thrust load applied to the cruciform shaft is controlled by the pin tightened between the inner bottom of the bearing cup and the end face of the shaft diameter of the cruciform shaft. As a result, it is possible to prevent the cross shaft from rattling in the thrust direction with respect to the bearing, thereby suppressing generation of vibration and abnormal noise. However, since the radial load applied to the cross shaft cannot be received by the pin, the cross shaft is loosened in the radial direction with respect to the bearing. For this reason, there was a problem that generation of vibration and abnormal noise from the universal joint could not be effectively prevented. The present invention has been made in view of the above problems, and has as its object to provide a universal joint that can more effectively prevent generation of vibration and abnormal noise.

[0004]

A universal joint according to the present invention for achieving the above object has a shaft diameter portion at an end of a cross shaft formed by cup-shaped bearings fitted into respective bearing holes of a pair of yokes. In a universal joint that rotatably supports
A recess is formed in each of the inner bottom portion of the bearing cup and the end surface of the shaft diameter portion in a state where the recess faces each other, and an elastic member is interposed in a space formed by each recess in an elastically deformed state. The shaft member is pressurized in the thrust direction and the radial direction by the elastic member (claim 1). According to this universal joint, since the shaft diameter portion is pressed in the thrust direction and the radial direction by the elastic member interposed in the space defined by the concave portion, the cross shaft is moved in the thrust direction and the radial direction with respect to the bearing. It is possible to prevent rattling.

It is preferable that in the universal joint, the elastic member is elastically deformed in the radial direction by decentering one and the other of the concave portions facing each other. In this case, by the radial repulsion of the elastic member, the shaft diameter portion can be easily pressed in the radial direction, and by selecting the amount of eccentricity between one concave portion and the other concave portion, The magnitude of the radial pressing load applied to the radial portion can be set.

[0006]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 2 is a front view showing a universal joint to which the universal joint X of the present invention is applied. This universal joint connects a steering shaft 1 and a column shaft 2 in an automobile steering system, and a universal joint X of the present invention is provided at each end of an intermediate shaft 3 whose length is adjustable. ing. The intermediate shaft 3
A first yoke Y1 and a second yoke Y2 that support the cross shaft 4 of one universal joint X in a pair with each other.
The other end of the intermediate shaft 3 is provided with a third yoke Y3 and a fourth yoke Y4 which form a pair and support the cross shaft 4 of the other universal joint X.

[0007] The second yoke Y2 and the third yoke Y
3 is welded to one end and the other end of the intermediate shaft 3, respectively. Further, the first yoke Y1 is welded to a shaft joint 5, and the steering shaft 1 is attached to the shaft joint 5.
Is clamped at one end. Further, the fourth yoke Y4 is welded to one end of the column shaft 2.

Referring to FIG. 1, opposing arm portions 10 of respective yokes Y1 to Y4 of the universal joint X are provided.
Is formed with a bearing hole 11, into which a cup-shaped bearing 13 is fitted. This bearing 13
The needle rollers 13b are arranged along the inner periphery of the bottomed cylindrical cup 13a.
A shaft diameter portion 4a at the end of the cross shaft 4 is fitted into the inside of b, whereby the cross shaft 4 is connected to each of the yokes Y1 to Y4.
Are rotatably supported with respect to.

At the inner bottom of the cup 13a of each bearing 13,
A recess 13 c is formed, and the shaft diameter portion 4 of the cross shaft 4 is formed.
A concave portion 4c is formed on the end surface of the portion a so as to face the concave portion 13c. The recess 13c of the cup 13a
The shaft diameter portion 4a is provided concentrically with the axis L of the shaft diameter portion 4a.
The concave portion 4c of a is eccentric with respect to the axis L of the shaft diameter portion 4a.

In the space 15 formed by the recess 13c of the cup 13a and the recess 4c of the shaft diameter portion 4a,
A disk-shaped elastic member 14 made of a synthetic resin such as PPS is interposed. The elastic member 14 is elastically contracted in the direction of the axis L in the space 15, and the repulsive force applies a preload to the shaft diameter portion 4 a of the cross shaft 4 in the direction along the axis L (thrust direction). Loading. Further, the elastic member 14 is elastically deformed in the direction orthogonal to the axis L in the space 15 due to the eccentricity of the one concave portion 13c and the other concave portion 4c. The axis L with respect to the shaft diameter portion 4a of the shaft 4
A preload is applied in a direction (radial direction) orthogonal to (see FIG. 3). In order to appropriately apply the preload in the thrust direction and the radial direction, it is preferable to use the elastic member 14 having a hardness of JIS-A90 or more. The gap between the opening of the cup 13a and the shaft diameter portion 4a is closed by a seal ring 16.

As described above, in the universal joint X,
Since the preload is applied to the shaft diameter portion 4a of the cross shaft 4 in the thrust direction and the radial direction by the elastic member 14, the cross shaft 4 is prevented from rattling with respect to the bearing 13 in both the thrust direction and the radial direction. can do. For this reason, generation of vibration and abnormal noise from the universal joint X can be effectively prevented. Also, one concave portion 1
3c and the other concave portion 4c are eccentric to form the elastic member 1
Since the preload is applied in the axial radial direction to the shaft diameter portion 4a of the cross shaft 4 by elastically deforming the preload 4 in the radial direction, the preload can be easily applied.
Moreover, the magnitude of the preload in the radial direction is different from that of the one recess 1.
It is determined by the amount of eccentricity between 3c and the other concave portion 4c.
A preload of a desired magnitude can be applied to the shaft diameter portion 4a only by appropriately selecting the eccentric amount. For this reason, it becomes easy to set the preload for the shaft diameter portion 4a.

In the universal joint X, the concave portion 13c of the cup 13a and the concave portion 4c of the shaft diameter portion 4a are provided concentrically, and in a space 15 formed by the concave portions 13c, 4c,
The elastic member 14 may be elastically deformed into a drum shape, and the inner diameter of the recess 4a may be pressed in the vicinity of the central portion in the axial direction to press the shaft diameter portion 4a in the thrust direction and the radial direction (FIG. 4). In this case, the shaft diameter portion 4a
Is pressed in all directions in the radial direction. The universal joint of the present invention is not only a universal joint of the steering device, but also a propulsion shaft of an automobile.
It is also suitably applied as a universal joint in other rotating bodies.

[0013]

As described above, according to the universal joint according to the first aspect, the elastic member interposed between the cup of the bearing and the axial diameter portion of the cross shaft causes the axial diameter portion to be in the thrust direction and the radial direction. Since the pressure is applied in the direction, it is possible to prevent the cross shaft from rattling in the thrust direction and the radial direction with respect to the bearing. For this reason, generation of vibration and abnormal noise from the universal joint can be more effectively prevented.

According to the universal joint according to the second aspect, the axial diameter portion can be easily pressed in the radial direction by the radial repulsive force of the elastic member, and the one concave portion and the other concave portion facing each other can be pressed. By selecting the amount of eccentricity with the concave portion, a preload having a desired magnitude can be applied to the shaft diameter portion, so that it is easy to set the pressurizing load applied to the shaft diameter portion.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing an embodiment of a universal joint of the present invention.

FIG. 2 is a front view of a universal joint to which the universal joint of the present invention is applied.

FIG. 3 is an enlarged sectional view of a main part of the universal joint.

FIG. 4 is an enlarged sectional view of a main part showing another embodiment.

[Explanation of symbols]

 Reference Signs List 4 cross shaft 4a shaft diameter portion 4c recess 11 bearing hole 13 bearing 13a cup 13c recess 14 elastic member 15 space X universal joint Y1 to Y4 yoke

Continued on the front page F term (reference) 3J012 AB06 AB07 BB01 CB03 FB11 3J101 AA14 AA24 AA42 AA62 AA72 BA54 BA56 BA77 EA31 EA77 FA01 FA41 GA14

Claims (2)

[Claims] 1. A universal joint wherein a shaft diameter portion at an end of a cross shaft is rotatably supported by cup-shaped bearings fitted in respective bearing holes of a pair of yokes. In each of the bottom and the end face of the shaft diameter portion, a concave portion is formed in a state of being opposed to each other, and an elastic member is interposed in a space defined by each concave portion in an elastically deformed state. A universal joint wherein a shaft diameter portion is pressed in a thrust direction and a radial direction. 2. The universal joint according to claim 1, wherein said elastic member is elastically deformed in a radial direction by eccentrically arranging one and the other of the concave portions facing each other.