JP2007002942A - Tripod type constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the effective ranges of an operating angle and a maximum operating angle while maintaining the basic performance of a constant velocity universal joint. <P>SOLUTION: This tripod type constant velocity universal joint comprises an outside joint member 10 having, on its inner periphery, three track grooves 18 in the axial direction and having roller guide faces 15 formed on the opposite side walls of the track grooves 18, a spider 20 having a boss 22 and three trunnion journals 26 radially projected from the circumferentially equally spaced positions of the boss 22, and rollers 30 rotatably supported around the trunnion journals 26 and stored in the track grooves 18 of the outside joint member 10. The inner peripheral surface of the outside joint member 10 comprises the large inner diameter r2 of track groove portions and a small inner diameter r1 between the adjacent track grooves. The small inner diameter r1 at the inlet side is formed larger than at the depth side, or the track grooves 18 at the inlet side are formed shallower than at the depth side. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a tripod type constant velocity universal joint used for a drive shaft of an automobile, although not limited thereto.

  6 shows a longitudinal section of the tripod type constant velocity universal joint, and FIG. 7 is an end view of the outer joint member in FIG. As shown in the figure, the tripod type constant velocity universal joint includes an outer joint member 10 having three track grooves 14 in the axial direction on the inner periphery and having roller guide surfaces 15 formed on opposite side walls of each track groove 14. The spider 20 having three trunnion journals 26 projecting radially from the circumferentially equally divided positions of the bosses 22 and the bosses 22 and rotatable around each trunnion journal 26 via a plurality of rolling elements 34 And a roller 30 accommodated in the track groove 14 of the outer joint member 10. A spline hole 24 is formed in the boss 22, and is connected to the spline shaft portion of the shaft 2 so as to be able to transmit torque, and is prevented from coming off by a retaining ring 28. As shown in FIG. 7, on the inner peripheral surface of the outer joint member 10, a small inner diameter portion 16 having a small inner diameter r1 and a large inner diameter portion 18 having a large inner diameter r2 appear alternately in the circumferential direction.

The diversification of automobiles is progressing, including the rise of SUVs (Sports Utility Vehicles). Along with this, needs such as expansion of the operating angle (θ: FIG. 6) of the constant velocity universal joint, expansion of the effective range of the maximum operating angle, and the like are increasing. In the tripod type constant velocity universal joint, the maximum operating angle at the time of slide-in, that is, when the spider 20 is on the back side of the outer joint member 10, is limited by interference between the shaft 2 and the small inner diameter r1 of the outer joint member 10. The Therefore, conventionally, a chamfer is provided at the entrance of the small inner diameter portion 16 of the outer joint member 10 (see FIG. 6). As shown in FIGS. 6 and 7, the depth of the track groove 14 and the small inner diameter r1 were uniform in the axial direction.
JP 2000-320563 A JP 2001-330048 A

  The larger the outer ring small inner diameter, the more advantageous is the interference of the shaft. However, increasing the outer ring small inner diameter leads to a decrease in the depth of the track which is the roller guide groove. Furthermore, reducing the depth of the track means that the load capacity of the constant velocity universal joint is reduced. Therefore, it was not easy in design to increase the small inner diameter of the outer ring and increase the maximum operating angle.

  The main object of the present invention is to expand the effective range of the operating angle and the maximum operating angle while maintaining the basic performance of the constant velocity universal joint.

The tripod type constant velocity universal joint of this invention is
An outer joint member having three track grooves in the axial direction on the inner periphery and having a roller guide surface formed on opposite side walls of each track groove;
A spider having a boss and three trunnion journals projecting radially from a circumferentially equal position of the boss;
A roller that is rotatable around each trunnion journal via a plurality of rolling elements, and is housed in a track groove of the outer joint member;
The inner peripheral surface of the outer joint member has a large inner diameter of the track groove portion and a small inner diameter between adjacent track grooves, and has a smaller inner diameter on the entrance side than the back side of the outer joint member. Is.

The tripod constant velocity universal joint of the present invention is
An outer joint member having three track grooves in the axial direction on the inner periphery and having a roller guide surface formed on opposite side walls of each track groove;
A spider having a boss and three trunnion journals projecting radially from a circumferentially equal position of the boss;
A roller that is rotatable around each trunnion journal via a plurality of rolling elements, and is housed in a track groove of the outer joint member;
The inner peripheral surface of the outer joint member has a large inner diameter of the track groove portion and a small inner diameter between adjacent track grooves, and the track groove on the entrance side is shallower than the back side of the outer joint member. Is.

  The tripod type constant velocity universal joint, when used as an outboard joint of a drive shaft, transmits the engine power to the tire while sliding in the axial direction in order to absorb the vertical movement and turning movement of the wheel. What is to be done is the axially central portion of the outer joint member. That is, the track depth can be made shallower on the entrance side where the load is not so much compared with the central portion where the load is mainly received. This invention pays attention to this point, and only the small inner diameter on the inlet side is enlarged to avoid interference with the shaft, and the working angle (θ) and the effective range of the maximum working angle are widened. Note that the invention of claim 1 is defined from the small inner diameter, and the invention of claim 2 is defined from the track groove depth.

  Embodiments of the present invention will be described below with reference to the drawings. As a tripod type constant velocity universal joint, a so-called single-storey type (see Japanese Patent Application Laid-Open No. 2001-330048) in which one roller is attached to one trunnion journal, and a so-called one-story type in which two rollers are attached. A two-story type (see Japanese Patent Application Laid-Open No. 2000-320563) is known, but the present invention can be applied to any tripod type constant velocity universal joint regardless of the type. Hereinafter, the case of the two-story type will be described as an example.

  First, as shown in FIGS. 1 and 2, the tripod constant velocity universal joint includes an outer joint member 10 connected to one of the two shafts to be coupled (not shown), and the other rotary shaft. The main components are a spider 20 connected to the (shaft 2) and a roller assembly 30 as a torque transmission element interposed between the two.

  The outer joint member 10 is cup-shaped, and three track grooves 14 are formed at equal positions in the circumferential direction on the inner peripheral surface. Each track groove 14 extends in the axial direction of the outer joint member 10, and a roller guide surface 15 is formed on the opposite side wall. The cross section (FIG. 2) of the outer joint member 10 has a flower crown shape in which a small inner diameter portion 16 having a radius r1 and a large inner diameter portion 18 having a radius r2 appearing alternately in the circumferential direction are connected by a roller guide surface 15. Yes. The roller guide surface 15 extends parallel to the axis of the outer joint member 10, and the cross-sectional shape thereof is a Gothic arch shape.

  The spider 20 includes a boss 22 having a spline (or serration; the same applies hereinafter) hole 24 and three trunnion journals 26 protruding radially from a circumferentially equal position of the boss 22. In this embodiment, the cross section of each trunnion journal 26 has a substantially elliptical shape whose major axis is orthogonal to the axial direction of the joint. A spline shaft portion of the shaft 2 is inserted into the spline hole 24 and is prevented from coming off by a retaining ring 28.

  A roller assembly 30 is disposed on the outer periphery of each trunnion journal 26. The roller assembly 30 includes an outer roller 32 and an inner roller 36 that are rotatable relative to each other via a plurality of rolling elements 34. Here, the rolling elements 34 are needle rollers, and the cylindrical inner peripheral surface of the outer roller and the cylindrical outer peripheral surface of the inner roller 36 are raceways on which the needle rollers roll. The inner roller 36 and the rolling element 34 are prevented from coming off by a washer 38 attached to a ring groove formed on the inner peripheral surface of the outer roller 32.

  The generatrix shape of the inner peripheral surface of the inner roller 36 is a curve having a convex central portion in the axial direction. Therefore, the inner roller 36 and thus the roller assembly 30 can rotate, swing, and move in the axial direction with respect to the trunnion journal 26.

  The outer peripheral surface of the outer roller 32 is a part of a spherical surface, that is, a partial spherical surface, and is in angular contact with the roller guide surface 15. By making an angular contact between the roller and the roller guide surface, the posture of the roller is further stabilized, and the roller can roll on the roller guide surface with less resistance. As another embodiment, the roller and the roller guide surface may form a circular contact.

  As shown in FIGS. 1 and 3, the small inner diameter r <b> 1 of the outer joint member 10 becomes relatively larger than other portions as it goes toward the end face 12. The broken line in FIG. 1 shows the small inner diameter portion of the conventional outer joint member. From FIG. 1, it can be seen that the portion that interferes with the shaft 2 moves backward and the operating angle (θ) increases as compared with the conventional case.

  In the modified example shown in FIG. 4, the small inner diameter r1 is gradually increased toward the end face 12 in the case of FIG. 3, whereas the small inner diameter r1 is increased linearly toward the end face 12 side. Is.

  In the modification shown in FIG. 5, the small inner diameter r1 is gradually increased in FIGS. 3 and 4, whereas the small inner diameter r1 is changed stepwise.

A longitudinal sectional view of a tripod type constant velocity universal joint showing an embodiment End view of the outer joint member in FIG. 1 is a longitudinal sectional view of the outer joint member in FIG. Longitudinal sectional view of an outer joint member similar to FIG. Longitudinal sectional view of an outer joint member similar to FIG. 3 showing another modification Longitudinal section of tripod type constant velocity universal joint showing conventional technology End view of the outer joint member in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Outer joint member 12 End surface 14 Track groove 15 Roller guide surface 16 Small inner diameter part 18 Large inner diameter part 20 Spider 22 Boss 24 Spline hole 26 Trunnion journal 28 Retaining ring 30 Roller assembly 32 Outer roller 34 Rolling element 36 Inner Laura 38 washer

Claims (2)

An outer joint member having three track grooves in the axial direction on the inner periphery and having a roller guide surface formed on opposite side walls of each track groove;
A spider having a boss and three trunnion journals projecting radially from a circumferentially equal position of the boss;
A roller that is rotatable around each trunnion journal via a plurality of rolling elements, and is housed in a track groove of the outer joint member;
Tripod type constant velocity with the inner surface of the outer joint member having a large inner diameter of the track groove portion and a small inner diameter between adjacent track grooves, with the small inner diameter of the inlet side larger than the back side of the outer joint member Universal joint. An outer joint member having three track grooves in the axial direction on the inner periphery and having a roller guide surface formed on opposite side walls of each track groove;
A spider having a boss and three trunnion journals projecting radially from a circumferentially equal position of the boss;
A roller that is rotatable around each trunnion journal via a plurality of rolling elements, and is housed in a track groove of the outer joint member;
Tripod type constant velocity with the inner peripheral surface of the outer joint member having a large inner diameter of the track groove portion and a small inner diameter between adjacent track grooves, with the track groove on the entrance side being shallower than the back side of the outer joint member Universal joint.

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