Structure for tripod constant velocity joint and method of assembling roller assembly

Abstract

Disclosed herein are a structure for a tripod constant velocity joint and a method of assembling a roller assembly, which maintain the structural stability of the tripod constant velocity joint, and minimize the frictional force between a trunnion and a track, thus remarkably reducing the generation of axial force, therefore ensuring the stable operation and durability of the constant velocity joint. The structure for the tripod constant velocity joint includes an inner roller and an outer roller provided between a track of a housing and a trunnion of a spider. A roller groove is formed on a central portion of an outer surface of the outer roller in a circumferential direction of the outer roller. Further, a plurality of recesses is formed on a surface of the trunnion to reduce a contact area with the inner roller.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view showing a structure for a tripod constant velocity joint, according to the present invention;

FIG. 2 is a sectional view showing a housing and a spider of FIG. 1, in an assembled state;

FIG. 3 is an enlarged view showing a part of FIG. 2;

FIG. 3 a is an alternative to the view of FIG. 3 and illustrating a curved inner roller;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 2;

FIG. 5 a is a plan view showing an inner roller, according to the present invention;

FIG. 5 b is a sectional view taken along line Z-Z of FIG. 5a;

FIG. 5 c is an enlarged sectional view showing portion F of FIG. 5b;

FIG. 5 d is a sectional view taken along line V-V of FIG. 5a;

FIG. 6 is a view showing a structure of a trunnion, according to the present invention;

FIG. 7 is a sectional view taken along line VI-VI of FIG. 6;

FIG. 8 is a sectional view taken along line VII-VII of FIG. 6;

FIG. 9 is a sectional view taken along line VIII-VIII of FIG. 6;

FIG. 10 is a side view showing the spider of FIG. 1; and

FIGS. 11 a to 11c are views showing the method of assembling a roller assembly, according to the present invention.

Claims

1. A structure for a tripod constant velocity joint, comprising: an inner roller and an outer roller provided between a track of a housing and a trunnion of a spider;a roller groove formed on a central portion of an outer surface of the outer roller in a circumferential direction of the outer roller; anda plurality of recesses formed on a surface of the trunnion to reduce a contact area with the inner roller.

2. The structure for the tripod constant velocity joint as set forth in claim 1, wherein a pair of locking steps is provided on a lower end of an inner circumferential surface of the inner roller in such a way as to form a predetermined angle in a circumferential direction and to face each other.

3. The structure for the tripod constant velocity joint as set forth in claim 1, wherein the roller groove of the outer roller is defined by a junction of two arc parts which are formed on opposite sides of a division line that divides the outer roller into two parts on a section perpendicular to a rotating central axis, and a radius center of each of the arc parts is located on a line segment connecting a contact point between the arc part and the track to the division line in such a way as to perpendicularly extend from the contact point.

4. The structure for the tripod constant velocity joint as set forth in claim 1, wherein each of the recesses of the trunnion is formed between a wide angle part and a narrow angle part, the wide angle part being formed in a rotating direction of the trunnion on a section contacting a pitch circle of the trunnion, and the narrow angle part being formed in a direction perpendicular to the rotating direction of the trunnion and being narrower than the wide angle part, and the wide angle part and the narrow angle part are formed at the same rotation radius from a central axis of the trunnion.

5. The structure for the tripod constant velocity joint as set forth in claim 4, wherein a ratio between an angle of the wide angle part and an angle between two neighboring recesses positioned on opposite-sides of the wide angle part is from 0.80 to 1.08.

6. The structure for the tripod constant velocity joint as set forth in claim 1, wherein the trunnion has a section having a shape of an ellipse whose major axis is formed in a rotating direction.

7. The structure for the tripod constant velocity joint as set forth in claim 1, wherein a predetermined portion of the trunnion, formed by rotating about an axis perpendicular to the rotating central axis of the trunnion, is rounded.

8. A method of assembling a roller assembly of a tripod constant velocity joint, comprising the steps of: making one of locking steps, provided on a lower end of the inner roller to face each other, contact a predetermined portion where an upper end of a neck part of a trunnion meets a spherical surface, while the roller assembly is inclined at a predetermined angle;fitting the roller assembly by rotating the roller assembly about a point where the locking step contacts the portion where the upper end of the neck part meets the spherical surface; andapplying a predetermined force to force-fit the roller assembly, when a remaining one of the steps is stopped by a spherical surface of the trunnion.

9. The structure for the tripod constant velocity joint as set forth in claim 1, wherein the inner roller includes a constant radius.

10. The structure for the tripod constant velocity joint as set forth in claim 1, wherein the inner roller is defined by a varying radius.