JPH1137170A - Equi-velocity universal joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control torque loss and wear in a contact part by reducing sliding resistance in time of the axial movement of a button member. SOLUTION: A rolling means 5 consists of plural needle rollers 5a and a retainer 5b equipped with a pocket holding these needle rollers free of rolling motion. Each needle roller 5a held by this pocket comes into sliding contact with both of a flat outer sides 3a of a button member 3 and an inner side 4b of a wedge member 4. An axial movement to an outer side joint member 1 of the button member 3 is rollingly guided by the rolling means 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant velocity universal joint used for power transmission in automobiles and various industrial machines, and more particularly, to a joint suitable for a steering device of an automobile or the like.

[0002]

2. Description of the Related Art In general, a constant velocity universal joint used for a steering device for controlling a traveling direction of an automobile has a large operating angle and a small rotational backlash (circular backlash). , Small size and light weight, and low cost are required.

[0003] The applicant of the present invention has the above-mentioned characteristics,
In particular, constant velocity universal joints shown in FIG. 3 and constant velocity universal joints shown in FIG. 4 have been developed as constant velocity universal joints particularly suitable for steering devices, and have already been filed (Japanese Patent Application No. 8-274616).
No., Japanese Patent Application No. 7-339378, Japanese Patent Application No. 8-27462.
No. 3). These constant velocity universal joints are common in that gaps between main constituent members such as an outer joint member, an inner joint member, and a button member are reduced by using a preload means to eliminate rattling in the circumferential direction of the joint. However, the configuration of the preload applying means is different. For example, in the configuration shown in FIG. 3, the wedge member 14 interposed between the inclined flat surface 11 a of the outer joint member 11 and the flat outer surface 13 a of the button member 13 is pressed by the coil spring 16 to The thirteen inner spherical surface 13b is pressed against the outer spherical wall surface 12a of the inner joint member 12. In the configuration shown in FIG. 4, the inner joint member 22 is divided into a plurality of parts, and the wedge member 24 interposed between the inclined inner wall surface 22 b of the inner joint member 22 and the inclined outer wall surface 27 a of the shaft 27 is provided. The spherical outer wall surface 22 a of the inner joint member 22 is pressed against the spherical inner side surface 23 b of the button member 23 by being pressed by the coil spring 26.

[0004]

When the joint transmits the rotational torque while maintaining the operating angle, the button member reciprocates in the axial direction with respect to the outer joint member in accordance with the phase change in the rotation direction. In the apparatus provided with such a preload applying means, since the button member is pressed against the outer joint member or the wedge member by the preload, the sliding resistance at the time of moving in the axial direction is increased, and the torque loss and the wear of the contact portion are accelerated. Could be the cause.

An object of the present invention is to reduce the sliding resistance of the button member when it is moved in the axial direction, to suppress torque loss and wear of the contact portion.

[0006]

SUMMARY OF THE INVENTION A constant velocity universal joint according to the present invention has an outer joint member having a regular polygonal hollow hole surrounded by a plurality of flat surfaces, and an outer joint member incorporated in the hollow hole of the outer joint member. An inner joint member having a plurality of spherical outer wall surfaces corresponding to the flat surface of the joint member, and a spherical surface interposed between the outer joint member and the inner joint member and in spherical contact with the spherical outer wall surface of the inner joint member A button member having an inner surface and a flat outer surface on the opposite side, a preload applying means for filling a gap between these components by an elastic pressing force, and a rolling guide for axial movement of the button member with respect to the outer joint member And rolling means.

[0007] As the rolling means, a configuration having a plurality of needle rollers and a retainer having a pocket for rotatably holding the needle rollers can be adopted. Further, the pocket of the retainer of the rolling means can be formed into a shape that can be engaged with both ends of the needle roller and only one in the radial direction.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the constant velocity universal joint according to this embodiment has a hollow outer joint member 1 having, for example, a bottomed cylindrical shape having a hollow hole having a substantially regular hexagonal cross section surrounded by six flat surfaces 1a.
An inner joint member 2 incorporated in a hollow hole of the outer joint member 1, a block-shaped button member 3 interposed between the outer joint member 1 and the inner joint member 2, and a flat surface of the outer joint member 1. Wedge member 4 and rolling means 5 interposed between surface 1a and flat outer surface 3a of button member 3, and elastic means interposed between bottom surface 1b of outer joint member 1 and wedge member 4. For example, the coil spring 6 is a main component. The shaft 7 is connected to the inner joint member 2, or the shaft 7 is integrally formed or joined. Note that a retaining ring 9 is fitted to the inner diameter of the outer joint member 1 at the opening end.

The inner joint member 2 has an integral structure, and its outer peripheral surface has the same number (six in this embodiment) of spherical outer wall surfaces 2a as the flat surfaces 1a of the outer joint member 1 (in the right rotation direction in FIG. 2a1, 2a2,..., 2a6). The spherical outer wall surfaces 2a1, 2a4 are PCD
(The circle at the center where the load is applied: depends on the load conditions using the joint) and a spherical surface having a radius r centered on the intersection O1 of the diagonal line of the hollow hole and the spherical outer wall surface 2a3, 2
a6 is drawn as a spherical surface having a radius r centered on the intersection O2 of the PCD and the diagonal line of the hollow hole, and has a spherical outer wall surface 2a2,
2a5 is drawn as a spherical surface having a radius r whose center is the intersection point O3 between the PCD and the diagonal line of the hollow hole. The three spherical centers O1, O2, O3 are located at equal circumferential positions on the PCD. As described above, since the spherical center of each spherical outer wall surface 2a is offset from the joint center O by a predetermined amount in a predetermined direction, the three spherical outer wall surfaces 2a1, 2a3 located at circumferentially equidistant positions. , 2a5 are deflected in the leftward rotation direction in the figure, and the remaining three spherical outer wall surfaces 2a2, 2a4, 2a6 at the circumferentially equidistant positions are each deflected in the rightward rotation direction in the figure. . Then, the direction of the deflection has a reciprocal relationship between the spherical outer wall surfaces 2a adjacent in the circumferential direction.

The button members 3 are formed in the shape of a vertically long block in the axial direction, and are provided with the same number (six in this embodiment) as the flat surfaces 1 a of the outer joint member 1. The button member 3 includes a flat outer surface 3a formed in a flat shape parallel to the axis, and a spherical inner surface 3b in spherical contact with the spherical outer wall surface 2a of the inner joint member 2. The shape of the button member 3 is not limited to the block shape, but may be another shape, for example, a disk shape.

The wedge member 4 has a block shape that is vertically long in the axial direction, and its outer surface 4a is formed into a tapered surface inclined with respect to the axis, and its inner surface 4b is formed into a flat surface parallel to the axis. The flat surface 1a of the outer joint member 1 is formed in a tapered surface inclined with respect to the axis, and the wedge member 4 has a tapered shape formed between the flat surface 1a of the outer joint member 1 and the rolling means 5. It is interposed in the wedge space. A spring seat 8 is provided at one end of the wedge member 4 (the end on the inner side of the outer joint member).
, One end of the coil spring 6 abuts.

As shown enlarged in FIG. 2, the rolling means 5
Comprises a plurality of needle rollers 5a and a plurality of needle rollers 5a.
And a retainer 5b made of, for example, a steel plate press and having a pocket 5b1 for holding the roller 5 in a freely rolling manner. Pocket 5
The needle roller 5a held by b1 is the button member 3
Rolling contact with both the flat outer surface 3a and the inner surface 4b of the wedge member 4. The wall surface in the direction perpendicular to the axis of the pocket 5b1 is a straight surface 5b2 {FIG. 7A}, and the wall surface in the axial direction is a combined surface of the straight surface 5b3 and the tapered surface 5b4 {FIG. The straight surface 5b3 is located on the inner side (inner diameter side), and the tapered surface 5b4 is located on the outer side (outer diameter side).
Located in. In the longitudinal direction of the needle roller 5a,
The distance between the opposed straight surfaces 5b3 is slightly larger than the entire length of the needle roller 5a, and the distance between the opposed tapered surfaces 5b4 gradually decreases outward,
The conical end of the needle roller 5a is in a state of embracing it. The needle roller 5a is held outward by the tapered surface 5b4 of the retainer 5b, and held inside by the button member 3 (in this type of joint, the button member has a small amount of axial movement, so that the button member The needle roller can be designed so that it does not come off even when the needle roller is moved by the maximum amount in the axial direction.) The retainer 5b is held outward by the wedge member 4, and held inside by the needle roller 5a. Therefore, during rotation of the joint, the needle roller 5a falls off or the retainer 5b
No abnormal operation occurs, and stable joint rotation can be obtained. Further, since the pocket wall surface of the retainer 5b is formed as described above, the production of the retainer 5b is simplified. This is because the pocket wall surface of the retainer 5b has a shape capable of being die-cut, so that the retainer 5b is formed by pressing.
Alternatively, it can be formed from a sintered material.
Therefore, the pocket wall surface of the retainer 5b can be engaged with both ends of the needle roller 5a in one of the radial directions,
In addition, any shape can be used as long as the mold can be cut out, and the shape is not particularly limited to the shape illustrated in FIG. In addition, a flange portion 5b5 for preventing the button member 3 from coming off is integrally provided at both ends in the axial direction of the retainer 5b.

The outer surface 4a of the wedge member 4 is taperedly fitted with the flat surface 1a of the outer joint member 1, and the inner surface 4b is in contact with the needle roller 5a. And the coil spring 6
Each wedge member 4 is elastically pressed to one side in the axial direction {reduction side of the wedge (opening side of the outer joint member)} by the elastic force of (1). As a result, the wedge member 4 is pressed inward by the flat surface 1a of the outer joint member 1, so that the button member 3 is pressed inward via the rolling means 5, and as a result, the button member 3 and the inner joint member 2 The gap between them is narrowed, and there is no backlash in the circumferential direction.

On the other hand, when the joint transmits the rotational torque while maintaining the operating angle, the button member 3 reciprocates in the axial direction with the phase change in the rotational direction, and the axial movement is performed by the rolling means 5. Therefore, the sliding resistance of the button member 3 is reduced as compared with the conventional configuration, and accordingly, torque loss and wear of the sliding portion are suppressed.

When assembling, the coil spring 6
And the wedge member 4 is retracted to the inner side of the outer joint member 1 so that the inner joint member 2, the button member 3, and the rolling means 5 are spaced apart from each other.
And can be easily assembled. Then, when the compression of the coil spring 6 is released after the incorporation, the gap between the constituent members is reduced as described above, and the circumferential joint is eliminated in the entire joint.

Further, in this embodiment, the wedge member 5 is pressed toward the opening of the outer joint member 1, but the wedge member 5 is pressed in the opposite direction (toward the inner joint member) to apply a preload. It is also possible to

Further, in this embodiment, an axial wedge mechanism is used as the preload applying means, but a circumferential wedge mechanism may be used. Alternatively, FIG.
It is also possible to employ a wedge mechanism as exemplified in FIG. In this case, the rolling means is interposed between the flat surface of the outer joint member and the flat outer surface of the button member.

[0019]

According to the present invention, since there is provided a preload applying means for filling the gap between the constituent members with an elastic pressing force, it is possible to prevent rattling of the joint in the circumferential direction, and at the same time, to prevent the button from being loosened. Since the rolling means for rolling and guiding the axial movement of the member with respect to the outer joint member is provided, the sliding resistance of the button member is reduced as compared with the conventional configuration, and torque loss and wear of the sliding portion are suppressed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view (FIG. A) and a transverse sectional view (FIG. B) showing an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view (FIG. A) and a transverse sectional view (FIG. B) showing a rolling means.

FIG. 3 is a longitudinal sectional view showing a conventional constant velocity universal joint (FIG. A);
It is a cross-sectional view (FIG. B).

FIG. 4 is a longitudinal sectional view showing a conventional constant velocity universal joint (FIG. A);
It is a cross-sectional view (FIG. B).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer joint member 1a Flat surface 2 Inner joint member 2a Spherical outer wall surface 3 Button member 3a Flat outer surface 3b Spherical inner surface 5 Rolling means 5a Needle roller 5b Cage

Claims (3)

[Claims] 1. An outer joint member having a regular polygonal hollow hole surrounded by a plurality of flat surfaces, and a plurality of spherical outer surfaces incorporated in the hollow hole of the outer joint member and corresponding to the flat surface of the outer joint member. An inner joint member having a wall surface, a spherical inner surface interposed between the outer joint member and the inner joint member, and a spherical outer surface that is in spherical contact with the spherical outer wall surface of the inner joint member and a flat outer surface opposite to the spherical inner surface. A button member having the same, a preload applying means for filling a gap between these components by an elastic pressing force, and a rolling means for rolling and guiding the axial movement of the button member with respect to the outer joint member. Speed universal joint. 2. The constant velocity universal joint according to claim 1, wherein said rolling means has a plurality of needle rollers and a retainer having a pocket for rotatably holding the needle rollers. 3. The constant velocity universal joint according to claim 2, wherein the pocket of the retainer has a shape capable of engaging only with one end of the needle roller in the radial direction.