JPH0331856Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

This invention relates to a constant velocity universal joint mainly applied to a front wheel drive automatic type, and particularly to a tripod type constant velocity universal joint.

[Prior art and its problems]

As a conventional constant velocity universal joint of this type, for example, as shown in FIG. A radial leg shaft 4 is provided protruding from 3, and a spherical roller 5 is fitted to the outside of each leg shaft 4 so as to be rotatable and slidable in the axial direction.
It is known that the spherical roller 5 is engaged with roller guide surfaces 6 on both sides of the track groove 2. In the tripod type constant velocity universal joint described above, considering the case where the rotational force is transmitted in a state where the outer ring 1 and the tripod member 3 take an operating angle, each spherical roller 5
The roller guide surface 6 of the cylindrical track groove 2 and the roller guide surface 6 of the cylindrical track groove 2 are oblique to each other as shown in FIGS. 6 and 7, and the spherical roller 5 cannot be caused to roll correctly. That is, while the spherical roller 5 tries to roll in the direction shown by arrow A in FIG.
is cylindrical and parallel to the axis of the outer ring 1, so the spherical roller 5 moves while being restrained by the track groove 2. As a result, sliding occurs between the roller guide surface 6 of the track groove 2 and the spherical roller 5, generating heat, and this slipping further induces a thrust force in the axial direction, causing vibration. FIG. 8 is a graph showing the relationship between the phase angle of the joint and the induced thrust force. The mechanism of generation of this induced thrust force will be explained with reference to FIG. FIG. 5 shows the positional relationship of each member when rotating force is transmitted with the outer ring 1 and the tripod member 3 assuming an operating angle. When the joint rotates, the leg shaft 4 of the tripod member 3
The spherical roller 5 fitted to the outer ring roller guide surface 6
It repeats reciprocating motion in the axial direction of the outer ring while being restrained by. At this time, each of the three spherical rollers 5 moves from point P to P', from point Q to point Q', and from point R to point
Each slides toward R', then changes direction to the opposite direction, and makes one reciprocation on the roller guide surface 6 with one rotation of the joint. A thrust force is induced in the axial direction by the contact force that naturally acts as a power transmission joint between the roller guide surface 6 and the spherical roller 5 that move in this manner. The direction and magnitude of the thrust force generated by each spherical roller 5 when the joint rotates varies depending on the rotational phase, and as shown in FIG. , and one spherical roller 5 induces a pulling and compressing thrust force in the right direction, respectively. As shown in Fig. 8, the total thrust force generated by the three spherical rollers 5 fluctuates in the forward and reverse directions with three cycles due to one joint, and the large amplitude of the fluctuations causes This causes various vibration problems. To solve the above problem, a tripod type constant velocity universal joint has already been proposed, in which the roller is composed of an inner ring and an outer ring, and the outer ring is guided parallel to the axis of the outer ring. Kosho 57
−13210). However, in this tripod type constant velocity universal joint, in order to guide the outer ring parallel to the axis of the outer ring, the outer ring is slidably guided on the end face of the outer ring, so the smoothness of this guide part, the heat generation, and the end face of the outer ring There is still room for improvement in the forming and processing of the track grooves on the outer ring that comes into contact with the outer ring.

【the purpose】

The technical objective of this invention is to solve the problems of the conventional tripod type constant velocity universal joint and prevent the generation of vibration by reducing the thrust force induced in the universal joint.

[Means to solve the problem]

In order to solve the above problems, this invention consists of a roller that is rotatably inserted into the leg shaft of the tripod member and slidably in the axial direction of the leg shaft, consisting of an inner ring and an outer ring, The inner ring and the outer ring are in spherical contact, and the outer circumferential surface of the outer ring in a longitudinal section is formed with a smaller curvature than the outer diameter of the outer ring, and the outer circumferential surface of the outer ring and the roller guide surface are They are in contact at a point.

[Effect]

The constant velocity universal joint with the above configuration allows the outer ring that makes up the roller to maintain its posture smoothly, generates less heat, and has good durability.The outer ring is aligned correctly in the direction of the track groove formed in the axial direction of the outer ring. By rolling, the sliding resistance can be reduced and the thrust force induced in the joint can be reduced.

【Example】

Embodiments of this invention will be described below with reference to the accompanying drawings. 1 and 2, the outer ring 10 has a first shaft 11 integrally provided at the closed end as in the conventional case, and three track grooves 12 in the axial direction on the inner circumferential surface.
are formed at 120 degree intervals around the central axis. Each track groove 12 has two roller guide surfaces 13 on both sides. Tripod member 1 inserted into the outer ring 10
5 is engaged with a serration 17 formed at one end of the second shaft 16, and is connected to a stepped portion 18 and a clip 1.
9 to prevent it from coming off. This tripod member 15 has three leg shafts 20, and a roller consisting of an inner ring 21 and an outer ring 22 is fitted around the leg shafts 20 via rolling elements 23. The rolling element 23 includes a spacer 24 and a guide ring 25.
It is held in the axial direction of the leg shaft 20 by a clip 26 via. Note that the outer diameters of the spacer 24 and the guide ring 25 are formed to be slightly smaller than the inner diameter of the inner ring 21, so that movement of the inner ring 21 in the axial direction of the leg shaft 20 is not hindered. A spherical outer circumferential surface 27 is formed on the outer circumference of the inner ring 21, a spherical inner circumferential surface 28 is formed on the inner circumference of the outer ring 22, and both the inner and outer rings 21 and 22 are in spherical contact. are doing. Note that the spherical inner circumferential surface 28 is provided with a notch for assembling the inner ring 21, although not shown. The outer circumferential surface 29 of the outer ring 22 contacts the roller guide surface 13 of the outer ring 10. FIG. 4 illustrates this. The inner ring 21 and the outer ring 22 are in contact with each other at a spherical outer peripheral surface 27 and a spherical inner peripheral surface 28, and the radius of curvature of this spherical surface is R4. This allows the inner ring 21 to tilt freely relative to the outer ring 22. Outer peripheral surface 29 in longitudinal section of outer ring 22
is formed with a smaller curvature than the outer diameter of the outer ring 22, that is, the radius of curvature R1 of the outer peripheral surface of the outer ring 22 is smaller than the radius R2 of the outer ring 22. The roller guide surface 13 is composed of two arcuate surfaces 30 and 31 having a radius of curvature R3 slightly larger than R1, and the outer ring 22 is in contact with the roller guide surface 13 at two points A and B. Due to the above relationship, the outer ring 22 is held in a posture parallel to the axis of the outer ring 10 by the roller guide surface 13. Radius of curvature R1 of the outer peripheral surface 29 of the outer ring 22
Considering the posture holding force of the outer ring 22 and the contact force between the outer ring 22 and the roller guide surface 13, it is desirable that the radius R2 of the outer ring 22 be approximately 30 to 50% of the radius R2 of the outer ring 22. The contact angle θ with the roller guide surface 13 is preferably about 15 to 25 degrees. FIG. 3 shows the joint at its working angle, with the inner ring 21 tilted relative to the outer ring 22, and the inner ring 21 moving on rolling elements 23 radially outward of the joint. . outer ring 22
is guided by the roller guide surface 13 in parallel to the axis of the outer ring 10. Therefore, outer ring 2
2 rolls correctly on the roller guide surface 13.

【effect】

With the above configuration, the following effects are achieved. (b) The outer ring is smoothly held in position by the roller guide surface, which has good durability, and the outer ring rolls correctly in the axial direction of the roller guide surface, resulting in low slip resistance and low heat generation. Vibration caused by induced thrust force can be reduced. (b) There is no need to provide a guide shoulder for maintaining the posture of the outer ring in the track groove of the outer ring, making it easy to form the outer ring. (c) The inner ring and outer ring have a simple shape, are easy to process, and are inexpensive.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional side view showing an embodiment of the constant velocity universal joint according to this invention, Fig. 2 is a cross-sectional view of the same as above, and Fig. 3 is a vertical cross-sectional side view when the joint assumes an operating angle. , FIG. 4 is an enlarged view of the main parts of the constant velocity universal joint according to the present invention, FIG. 5 is an explanatory diagram of the operation of the conventional joint, FIG. 6 is a longitudinal side view showing the conventional joint, and FIG.
This figure is a perspective view showing the rolling state of the spherical roller same as above, and FIG. 8 is a graph showing the combined induced thrust force in each leg axis. 10... Outer ring, 12... Track groove, 13...
Roller guide surface, 15...Tripod member, 21...
...Inner ring, 22...Outer ring.

Claims (1)

[Scope of utility model registration request] Three track grooves are formed in the outer ring in the axial direction, a tripod member is inserted inside the outer ring, and a roller is rotatably mounted on the three leg shafts of the tripod member and slides in the axial direction of the leg shafts. In a constant velocity universal joint in which the roller is freely inserted and inserted into the roller guide surface in the outer ring axial direction of the track groove, the roller is composed of an inner ring and an outer ring, and the inner ring and the outer ring have a spherical surface. and the outer circumferential surface of the outer ring in a longitudinal section is formed with a smaller curvature than the outer diameter of the outer ring, and the outer circumferential surface of the outer ring and the roller guide surface are brought into contact at two points. constant velocity universal joint.