JPH04228925A - Constant velocity universal joint - Google Patents

Abstract

PURPOSE:To increase the strength of a guide groove for balls rolling therein. CONSTITUTION:A first guide groove 20 at the closed side of an outer joint member 10 is formed as a closed side first guide groove 22 having the center of curvature at a point (b) offset radially outward from an intersection (a) between an axial line l1 and a joint center surface l2, and the first groove 22 is deepened, thereby preventing a ball 13 from stranding and cutting a groove edge. Furthermore, a second guide groove 23 at the open side of the outer joint member 10 has an open side second guide groove 25 having the center of curvature at a point (d) offset radially outward further from a point (c) offset toward the closed side from the intersection (a) along an axial line l1, and the wall thickness of the groove 25 is increased, thereby improving the durability of an inner joint member 11.

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.

0002

2. Description of the Related Art FIG. 3 shows a general BJ type constant velocity universal joint. This constant velocity universal joint includes an outer joint member 1 which is cup-shaped and has a spherical surface on the inner periphery, and has six first guide grooves 5 that extend in an arc shape in the axial direction and are arranged at equal intervals on the circumference, and The inner joint member 2 has a spherical surface, extends in an arc shape in the axial direction, and has the same number of second guide grooves 7 corresponding to the first guide grooves 5, and is fitted into both the outer and inner joint members 1 and 2. The ball 4 is held in a ball holding window 3a of the cage 3 and engaged with the first guide groove 5 and the second guide groove 7.

The center of curvature of the first guide groove 5 is a point A on the axis L3 offset toward the opening side of the outer joint member 1 from the intersection O between the joint center plane L4 passing through the center of the ball 4 and the axis L3. It is formed as. Further, the second guide groove 7
is formed with a point B on the axis L3 offset from the intersection O toward the back side of the outer joint member 1 by a distance equal to the distance between the intersection O and the point A as the center of curvature.

Furthermore, the inner spherical surface 6 of the outer joint member 1 between the first guide groove 5 and the inner joint member between the second guide groove 7 and the second guide groove 7 are The outer spherical surfaces 8 of No. 2 are each formed with the point O as the center of curvature.

[0005]

As described above, the center of curvature A forming the first guide groove 5 of the outer joint member 1 is
This is a point offset toward the opening side from the center of curvature O forming the inner spherical surface 6 of the outer joint member 1. Due to the difference in the radius of curvature between the center of curvature point A and the point O, the first guide groove 5 is formed to have a shallow depth on the inner side of the outer joint member 1. Therefore, when the outer joint member 1 and the inner joint member 2 have a relative angle and the ball 4 is positioned at the back side of the outer joint member 1 and transmits rotational torque, the load applied from the ball 4 causes the There is a risk that the edge portion of the first guide groove 5 may be chipped.

Furthermore, the center of curvature B forming the second guide groove 7 of the inner joint member 2 is a point offset to the back side from the center of curvature O forming the outer spherical surface 8 of the inner joint member 2. Due to the difference in the radius of curvature between the curvature center point B and the point O, the inner joint member 2 has a thinner wall thickness in the radial direction on the opening side of the outer joint member 1. Therefore, when the outer joint member 1 and the inner joint member 2 have a relative angle and the ball 4 is positioned on the opening side of the outer joint member 1 and transmits rotational torque, the load applied from the ball 4 causes the outer joint member to move outward. There is a possibility that the inner joint member 2 on the opening side of the inner joint member 1 may be damaged.

[0007]

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and the first guide groove extending from the joint center surface to the opening side of the outer joint member is formed in the shaft. The first guide groove on the opening side is formed with the center of curvature at the intersection of the axis and the joint center plane, and the first guide groove from the joint center plane to the back side of the outer joint member is the first guide groove on the opening side. The first one on the back side with the center of curvature at a point offset radially outward from the center of curvature forming the guide groove.
The second guide groove, which is formed as a guide groove and extends from the joint center surface to the back side of the outer joint member, extends from the center of curvature forming the opening-side first guide groove to the outer joint member on the axis of the shaft. The second guide groove on the back side is formed with the center of curvature at a point offset to the back side of the member, and the second guide groove from the joint center surface to the opening side of the outer joint member is the second guide groove on the back side. The second guide groove on the opening side is formed with the center of curvature at a point offset radially outward from the center of curvature of the groove.

[0008]

According to the present invention, a deep first guide groove is formed on the deep side of the first guide groove. Therefore,
The outer joint member and the inner joint member have a relative angle,
Even when the ball is positioned in the first guide groove on the back side and transmits rotational torque, the ball will not ride on the first guide groove on the back side and the edge portion of the groove will not be chipped.

Further, an opening-side second guide groove is formed on the opening side of the second guide groove, and the inner joint member has a thick wall. Therefore, even when the outer joint member and the inner joint member have a relative angle and the ball is located on the opening side of the second guide groove to transmit rotational torque, the load from the ball causes the inner joint member to The joint member will not be damaged. Further, the opening side of the outer joint member is formed thicker by the opening first guide groove, and the inner joint member further has a thicker wall thickness formed by the inner second guide groove. Therefore, when transmitting rotational torque at an angle between two axes, even when the ball engages between the first opening guide groove and the second guide groove on the back side,
The outer joint member and the inner joint member are not damaged by the load of the ball.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings. Reference numeral 30 in FIG. 1 indicates a driven shaft, and one end of this driven shaft 30 has an open cup-shaped outer joint member 10.
are connected, and the inner peripheral surface 43 of this outer joint member 10
is formed into a concave spherical surface whose center of curvature is an arbitrary point c on the axis L1 of the driven shaft 30. This inner peripheral surface 43
Six first guide grooves 20 (described later) extending in the axial direction are formed at equal angular intervals in the circumferential direction.

Reference numeral 31 designates a drive shaft, and a short cylindrical inner joint member 11 is splined to one end of the drive shaft. The center of curvature forming the outer circumferential surface 41 of this inner joint member 11 is offset from the point c on the axis L1 toward the opening side, and is at the intersection a of the axis L1 and a joint center plane L2 passing through the center of the ball 13, which will be described later. The outer circumferential surface 41 of the inner joint member 11 is formed into a convex spherical surface due to this center point a of curvature. Further, six second guide grooves 23 corresponding to the first guide grooves 20 are formed on the outer circumferential surface 41 at equal angular intervals in the circumferential direction.

A cage 12 is fitted between the inner peripheral surface 43 of the outer joint member 10 and the outer peripheral surface 41 of the inner joint member 11. The outer circumferential surface 42 of the cage 12 has approximately the same curvature as the inner circumferential surface 43 of the outer joint member 10, and the inner circumferential surface 40 of the cage 12 has approximately the same curvature as the outer circumferential surface 41 of the inner joint member 11. It is formed. Also cage 12
There are six ball holding windows 1 at equal angular intervals along the circumference.
5 is formed, and the ball 13 is rotatably held in this ball holding window 15.

The first guide groove 20 includes an opening-side first guide groove 21 formed toward the opening side from the joint center surface L2, and a back-side first guide groove 21 formed toward the back side from the joint center surface L2. It is composed of a guide groove 22. The opening-side first guide groove 21 is formed with the center of curvature at the intersection a between the axis L1 and the joint center plane L2, and the back-side first guide groove 22 is offset radially outward from the point a by a predetermined distance. point b
It is formed with the center of curvature at. Note that the opening-side first guide groove 21 and the back-side first guide groove 22 are connected smoothly so that the rolling of the ball 13 is not hindered.

The second guide groove 23 includes an opening-side second guide groove 25 formed toward the opening side from the joint center surface L2, and a back-side second guide groove 25 formed toward the back side from the joint center surface L2. It is composed of a guide groove 24. The opening-side second guide groove 25 is formed with a center of curvature at a point c offset from the point a by a predetermined distance toward the rear side on the axis Ll. The second inner guide groove 24 is formed with its center of curvature at a point d that is offset radially outward by a predetermined distance from the point c. In addition, the opening side second guide groove 25 and the back side second guide groove 24 are connected smoothly so that the rolling of the ball 13 is not hindered.

The operation will be described below based on the above configuration. The drive shaft 31 and the driven shaft 30 make a large relative angle, and the first guide groove 22 on the back side of the first guide groove 20
When the ball 13 is located in the rear first guide groove 22 to transmit rotational torque, the ball 13 rides up from the rear first guide groove 22 because the groove depth of the rear first guide groove 22 is deep. The edge portion of the end of the first guide groove 22 on the back side will not be chipped due to the load of 13.

Furthermore, the driving shaft 31 and the driven shaft 3
0 takes a large relative angle, and when the ball is positioned in the opening-side second guide groove 25 of the second guide groove 23 and transmits rotational torque, the inner joint member 1 in which the opening-side second guide groove 25 is formed.
Since the wall thickness of the inner joint member 11 is thick, the inner joint member 11
Since the strength of the inner joint member 11 is maintained, the load of the balls 13 will not damage the inner joint member 11.

[0017]

As explained above, in the constant velocity universal joint of the present invention, the first guide groove on the inner side is formed from the center surface of the joint to the inner side of the outer joint member. Because the groove is formed deep by this first guide groove on the back side,
When the ball is located in the first guide groove on the back side and the outer joint member and the inner joint member have a relative angle and transmit rotational torque, the ball rides on the first guide groove on the back side and the edge of the groove Since no portion is chipped, the strength of the outer joint member is improved.

[0018] Further, from the joint center surface to the opening side of the outer joint member, a second opening-side guide groove is formed, the groove depth of which is shallower than in the past. The wall thickness of the inner joint member in the area where the opening-side second guide groove is located is thicker than in the past, so the outer joint member and the inner joint member have a relative angle, and the opening side When the balls are positioned in the side second guide grooves to transmit rotational torque, the inner joint member is not damaged by the load from the balls, so the strength of the inner joint member is improved. Moreover, the opening side of the outer joint member is formed with the same wall thickness as the conventional one due to the opening first guide groove, and the back side of the inner joint member is formed with the same thickness as the conventional one due to the second inner guide groove. Because of the thickness of the ball, when transmitting rotational torque at an angle between two axes, the ball engages between the first opening guide groove and the second guide groove on the back side. However, the outer joint member and the inner joint member are not damaged by the load of the ball.

[Brief explanation of the drawing]

FIG. 1 is an overall view of a constant velocity universal joint showing an embodiment of the present invention.

FIG. 2 is an enlarged view of the main part of FIG. 1;

FIG. 3 is an enlarged view of main parts of a conventional constant velocity universal joint.

[Explanation of symbols]

10 Outer joint member 11 Inner joint member 12 Cage 13 Ball 20 First guide groove 21 Opening side first guide groove 22 First guide groove on the back side 23 Second guide groove 24 Second guide groove on the back side 25 Opening side second guide groove 30 Driven shaft 31 Drive shaft L1 axis line L2 Joint center plane

Claims (1)

[Claims] 1. An outer joint member that is provided on one of two mutually intersecting shafts, has a cup shape with one end open, has a spherical surface on the inner periphery, and has a plurality of first guide grooves extending in an arc shape in the axial direction; an inner joint member provided on the other of the two shafts and having a spherical surface on the outer periphery and having second guide grooves extending in an arc shape in the axial direction and having the same number of second guide grooves corresponding to the first guide grooves; and both the inner and outer joint members. A constant velocity universal joint is provided with a cage fitted into the cage, and a ball held in a ball holding window of the cage and engaged with the first guide groove and the second guide groove. The first guide groove extending from the opening side of the outer joint member is formed as an opening side first guide groove having a center of curvature at the intersection of the axis of the shaft and the joint center plane, and extends from the joint center plane to the outer joint member. The first guide groove extending toward the back side of the member is formed as a first guide groove on the back side with a center of curvature offset to the outside in the radial direction from the center of curvature forming the first guide groove on the opening side. The second guide groove extending from the central plane to the back side of the outer joint member is offset from the center of curvature forming the opening-side first guide groove to the back side of the outer joint member on the axis of the shaft. is formed as a second guide groove on the back side with a curvature center at 1. A constant velocity universal joint, characterized in that the second guide groove on the opening side is formed with the center of curvature at a point offset from .