JPH03255226A - Constant velocity joint - Google Patents

Abstract

PURPOSE:To prevent an inward member from being locked by making the curvature center of the axial central part of an inward member outer periphery surface offset toward the outside in the diametrical direction from the curvature center of the inner periphery surface of a cage so as to make the curvature center of an axial end apart from the end in an axial and diametrical direction. CONSTITUTION:An inward member 11 is spline-engaged with one end of a driven shaft 20 to form the center 13 of an outer periphery surface 12 at a curved surface which uses a point 02 on a line intersecting in perpendicular to an axial line as a curvature center and in an end 14, a point 03 which is offset by (a), (b) from a point 01 on an axial center is formed out of a curvature center. A cage 30 is fitted to the inner periphery of an outward member 21 to that it may slide, and the curvature center of a protruding spherical surface 31 in a fitted part is taken as 04. The inward member 11 and the outward member 21 are provided with a ball groove 15, and an interpositioning ball 33 transmits torque. The inward member 11 and a surface opposing to the cage 30 come into contact with each other first at an end whose inclination angle is large, so locking of the inward member 11 against the cage 30 is difficult to generate and slide resistance is reduced.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a constant velocity joint.

<Prior art> Utility Model Publication No. 63-2665 and Utility Model Publication No. 611436
No. 5 discloses that the outer peripheral surface of the inner member 1 is formed with an arbitrary point on the axis as the center of curvature, as shown in FIG.
The inner circumferential surface of is made into a cylindrical surface with an arbitrary length in the axial direction at its center, and by connecting both sides of this cylindrical surface with partial curved surfaces,
A device in which an axial gap is formed between the cage 2 and the inner member 1 is disclosed.

In the above-mentioned structure, by providing the axial clearance on both sides of the central part, the inner member 1 and the cage 2 can move relative to each other even when axial vibration is input, so that the sliding inside the constant velocity jigo point is prevented. Can reduce resistance.

<Problems to be Solved by the Invention> However, as shown in FIG. 4, the above-mentioned axial clearance is shorter at the center than at both ends.

Therefore, when the inner member moves relative to the cage,
The opposing surfaces of the cage and inner member initially contact at a central portion where the axial distance is small. Moreover, since the angle of inclination of the inner circumferential surface of the cage with respect to the axis of the inner member is smaller at this central part than at both ends, the inner member locks against the cage, and when this lock occurs, the slide inside the joint There was a problem of increased resistance.

<Means for Solving the Problems> The present invention has been made to solve the above-mentioned problems, and the present invention is made by dividing the outer circumferential surface of the inner member into a center portion and an end portion other than the center portion in the axial direction. The center of curvature forming the central portion is a point offset radially outward from the center of curvature forming the inner circumferential surface of the cage, and the center of curvature forming the end portion forms the inner circumferential surface of the cage. A point offset from the center of curvature in the axial and radial directions in the direction away from the end, and an axial gap is provided between the cage and the inner member that gradually decreases from the center to the end. It is.

<Operation> With the above-described configuration, when axial vibration is input, the inner member moves relative to the cage. At this time, since the axial gap between the opposing surfaces of the inner member and the cage is smaller at the ends than at the center, the opposing surfaces first come into contact at the ends, and the cage at this end Since the inner circumferential surface of the cage has a larger inclination angle with respect to the axis than the central portion, it becomes difficult for the inner member to lock onto the cage. Therefore, the sliding resistance within the joint is reduced.

<Example> Embodiments of the present invention will be described below based on the drawings.

1 and 2, reference numeral 10 indicates a driven shaft, and an inner member 11 is splined to one end of the driven shaft 10. As shown in FIG.

As shown in FIG. 2, a central portion 13 having an axial length of X on the outer peripheral surface 12 of the inner member 11 intersects with an arbitrary point 01 on the axis of the driven shaft 10 perpendicularly to the axis. It is formed by a curved surface whose center of curvature is an arbitrary point 02 on the line. The end portions 14 of the outer circumferential surface 12 of the inner member 11 excluding the central portion 13 are respectively axially and radially a from the point 01.

It is formed with the center of curvature at point 03 offset by b. The center of curvature of the left end in FIG. 2 is point 03, which is farther away from the left end with respect to point 01, and the center of curvature of the right end is point 05, which is farther away from the right end with respect to point 01. . The outer circumferential surface 12 of the inner member 11 has a plurality of (six) ball grooves 15 formed on the circumference along the axial direction.

Reference numeral 20 denotes a drive shaft, and a cylindrical outer member 21 is formed at one end of this drive shaft 20, and an inner peripheral surface 22 of this outer member 21 corresponds to each ball groove 15 of the inner member 11. A plurality of ball grooves 23 are formed.

30 is a cage interposed between the inner and outer members 11.21. The outer circumferential surface of this cage 30 has a frustoconical shape with a partially convex spherical surface 31 that slidably fits into the inner circumferential surface 22 of the outer member 21, and the center of curvature forming this partially convex spherical surface 31 is as described above. A point 04 is located on the axis of the driven shaft 10 and is spaced a certain distance from the point 01.

The inner peripheral surface 32 of the cage 30 is formed with the center of curvature 01 as the center of curvature, and is formed into a concave spherical surface corresponding to the outer peripheral surface 12 of the inner member 11. Further, a plurality (six) of ball holding windows 34 for holding torque transmitting balls 33 are formed in the cage 30 at equal angular intervals on the circumference.

In addition, since the inner member 11 in the central portion 13 is formed so as to be smoothly connected to the end portion 14 at the center of curvature 02, the inner member 11 can be smoothly angled with respect to the cage 30.

With the above configuration, an axial gap is formed between the outer peripheral surface 12 of the inner member 11 and the inner peripheral surface 32 of the cage 30, as shown in FIG. The axial clearance gradually becomes smaller toward the end 14, and cl < c2 < c3 < c4 < c5
The relationship becomes (1). Therefore, when axial vibration is input from the driven shaft 10, the inner member 11 moves relative to the cage 30 in the axial direction, but the outer circumferential surface 12 of the inner member 11 and the inner circumferential surface 32 of the cage 30 Contact above (
Due to the relationship 1), this occurs first on the end 14 side. End 1
Since the inner circumferential surface of the cage 30 on the 4th side is more inclined with respect to the axis of the inner member 11 than the inner circumferential surface of the cage 30 on the central part 3, the locking of the inner member 110 to the cage 30 is difficult. This reduces the sliding resistance within the constant velocity joint.

<Effects of the Invention> As described above, according to the present invention, when axial vibration is input, the opposing surfaces of the inner member and the cage first come into contact at the ends with a large inclination angle with respect to the axis. , the inner member is less likely to lock against the cage, and sliding resistance within the joint is reduced.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a constant velocity joint showing an embodiment of the present invention, Fig. 2 is a view showing the relationship between the inner member and the cage, and Fig. 3 is the outer and inner parts of the inner member and the cage in Fig. 2. FIG. 4, an enlarged view of the main parts showing the relationship between the circumferential surfaces, shows a conventional constant velocity joint. DESCRIPTION OF SYMBOLS 10... Drive shaft, 11... Inner member, 12... Outer peripheral surface, 13... Center part, 14... End part, 15.23
... Ball groove, 20 ... Driven shaft, 30 ... Cage, 32 ... Inner peripheral surface, 33 ... Pole.

Claims (1)

[Claims] (1) An inner member provided on one of two intersecting axes and having a ball groove extending in the axial direction on the outer circumferential surface thereof, and an inner member provided on the other side and having an inner circumferential surface corresponding to the outer circumferential surface of the inner member and whose inner circumferential surface extends in the axial direction. an outer member having a cylindrical shape and having a ball groove on its inner peripheral surface;
A plurality of torque transmitting balls arranged between the ball grooves, and a ball that is fitted between the inner and outer members and has an arbitrary point on the axis as the center of curvature of the inner circumferential surface and for holding the balls. In a constant velocity joint comprising a cage having a plurality of ball holding windows on the circumference, the outer circumferential surface of the inner member is divided in the axial direction into a central part and an end part other than the central part, and the central part is divided into a central part and an end part other than the central part. The center of curvature that forms the center of curvature is a point that is offset in the radial direction from the center of curvature that forms the inner peripheral surface of this cage so that it is smaller than the radius of curvature of the cage, and the center of curvature that forms the end portion is a point that is smaller than the radius of curvature of the cage. A point offset in the axial and radial directions from the center of curvature forming the surface in the direction away from the end, and an axial gap that gradually decreases from the center to the end between the cage and the inner member. A constant velocity joint characterized by the provision of a constant velocity joint.