JPS5941049B2 - universal joint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to universal joints, and more particularly to axial internal constant velocity universal joints.

In particular, the present invention provides a hollow outer member and an inner member with a plurality of pairs of grooves extending longitudinally oppositely, each engaging between a pair of grooves in the inner and outer members, and a torque transmitter disposed movably along said groove to permit angular and axial movement; and an opening disposed between said inner and outer members in which said ball is received. and a ball cage operative to assist in maintaining said balls in the bisector plane, giving the joint constant speed ratio characteristics (hereinafter referred to as known joints). Related to quick adjustable joints.

The disadvantage of known universal joints is that when one joint shaft enters the other joint shaft, the balls do not rotate in the initial stage but slide (skid), making it difficult for the two shafts to fit into each other smoothly. It is at the point of being blocked.

To overcome this drawback, in known universal joints the cage is mounted so that it freely follows the rotational movement of the torque transmitter during plunging without restraining the cage from moving axially with either the inner or outer joint members. It has been proposed to impart axial movement to the cage relative to the inner and outer joint members.

For example, this type of constant velocity universal joint is also shown in British Patent No. 11566.26 (Japanese Patent No. 697259).

The universal joint has a guide member mounted for axial movement on the inner member and to which the cage is mounted for angular movement.

This guide member has a convex partial spherical surface on its outer periphery in order to perform the angular movement on the outer curved end of the cage that abuts the inner surface of the cylindrical hole of the outer member or a member fixed thereto. The partially spherical surface has centers of curvature spaced apart from each other by equal distances toward the ends from the axial center position of the guide member.

In all the embodiments described and illustrated in GB 1 156 626, the guide member is axially movable relative to the inner member to prevent sliding of the ball over substantially the entire range of permissible axial movement. .

The disadvantages of conventional devices of this type must be taken into account in various design considerations in conjunction with configurations that allow axial movement of the cage relative to the inner and outer members of the joint over virtually the entire range of permissible axial movement. It was about imposing restrictions.

The object of the invention is to provide an improved form of universal joint which at least minimizes this disadvantage.

According to the invention, the cage is provided with a convex partially spherical outer surface engaging the surface of the cylindrical hole of the outer member or a member fixed to this member and a guide member attached to the inner member or a member fixed to this member. a concave part-shaped inner surface engaging a complementary convex part-spherical surface, and the part-spherical surface of the cage has a center of curvature offset by an equal amount on opposite sides of the joint center along the joint axis; Furthermore, said guide member is capable of displacing the torque transmitter within the grooves of the inner and outer members over a distance of a very short fraction of the total allowable axial movement relative to the inner member or to a member fixed thereto. To provide a plunge-type constant velocity universal joint that allows permissible axial movement over a short distance.

The cage, the torque transmitter, and the inner member are movable in the axial direction of the outer member by sliding contact between the cylindrical hole of the outer member or a member fixed thereto and the convex partially spherical outer surface of the cage, thereby allowing the joint to protrude. During a part of the permissible axial (plunge) motion, the guide member and the cage move relative to the inner member in the axial direction, and the ball also moves along with this.The high sliding movement is prevented and the inner member moves. To roll along.

The guide member may be axially movable relative to the inner member or a member fixed thereto to a sufficient extent to prevent sliding of the ball over a small portion of the permissible plunge movement of the joint.

Preferably, the structure is such that the ball is prevented from sliding only at the beginning of the plunge motion.

Accordingly, in a preferred arrangement, a relatively small axial movement of the guide member relative to the inner member, i.e. only a small stroke compared to that required to prevent sliding of the ball over the entire range of permissible plunging movement. is secured, so 5 is good.

The present invention is based on the fact that it is actually most effective to prevent the ball from sliding at the initial stage of the plunge motion, and the present invention is designed to prevent the ball from sliding over substantially the entire range of the permissible plunge motion. The structure is based on the conclusion that not only is it unnecessary, but it also imposes many restrictions on the design.

In general joints that do not prevent the balls from sliding,
Since the ball is forced to slide within the groove between the inner member and the outer member at the start of the thrusting motion, the frictional resistance generated by such sliding causes the ball to seize.

However, in the joint according to the present invention, such seizure does not occur because the ball is prevented from sliding at the start of the plunge motion.

When designing a universal joint, the designer must specify the desired form of the joint,
Its desired torque transmission capacity, its desired articulation angle and its processing dimensions must be considered.

In contrast to known joints in which sliding of the ball is prevented over virtually the entire range of permissible plunging movement, the joint according to the invention is designed by providing means to prevent sliding of the ball at least at the beginning of the plunging movement. Ru.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

The plunge-type constant velocity universal joint shown in the figure basically consists of an inner member 10 and a hollow outer member 11 surrounding the inner member.
and a torque transmitting top 12 operatively connected to both members.

Inner member 10 has a cylindrical bore formed with splines 13 for engagement with the splined end of a drive shaft inserted into the bore.

The inner member includes a flat cylindrical portion 14 and a portion 15 adjacent thereto and of a larger outer diameter.

The enlarged diameter portion 15 defines six axially straight grooves, one of which is indicated at 16, which grooves are equally spaced locally in the inner member.

The outer member 11 is inserted into the side wall 17 and the hole defining a cylindrical hole forming six straight axially extending grooves, one of which is indicated by the reference numeral 18, each positioned opposite the groove of the inner member. an end wall 19 having a protrusion 20 defining a cylindrical bore formed with splines 21 for engagement with the splined end of the drive shaft, the inner end of the splined bore having an insert 22 Closed by.

Balls 12 are engaged within and between a pair of opposing grooves 16, 18, respectively, so that the balls act to transmit torque between inner and outer members 10 and 11 while Permits associated angular and axial (plunge) movements.

The ball 12 has a convex partially spherical outer surface 25 that engages the surface of the cylindrical bore of the outer member 11 and a concave portion that engages a complementary convex partially spherical surface on a guide ring 27 attached to the inner member 10. It is placed within the opening 23 of the cage 24, which has a spherical inner surface 26.

The inner surface 26 of the cage is arranged by axially arranged inner and outer members on the axis of the joint and towards one end of the joint such that the center of the joint, i.e. the plane containing the ball center, intersects the axis of the joint. has a center of curvature that is moved from a point to

The outer surface 25 of the cage has a center of curvature that is likewise located on the axis of the joint but offset from the center of the joint by an equal distance in the opposite direction.

This off-center arrangement ensures that the center of the articulating ball 12 of the joint is always kept in the bisector plane of the joint, thereby providing the constant velocity ratio characteristics of the C-joint.

The guide ring 21 has a continuous annular portion 28 integrally formed with a flat cylindrical bore slidably engaged with the flat cylindrical portion 14 of the inner member 10 and a larger inner diameter than said annular portion 28 and a larger inner diameter of the inner member. It consists of an annular section 29 surrounding the grooved section 15, the ring section 29 having six equally spaced slots 30 extending axially from the inner end of said section for accommodating the balls 12. is forming.

The inner end surface of the slot 30 has a partially spherical shape with the center of curvature at the center of the ball so as to match the ball.

The convex part of the guide ring has a spherical outer surface that forms the two parts of the ring 2
8 and 29.

The guide ring 21 has a ring part 28 and an inner member part 1.
4 is slightly axially movable relative to the inner member 10 by the sliding engagement between the ring and the shoulder formed between the two parts 28 and 29 of the ring and the inner member. It is restricted in one direction by abutment with a shoulder formed between adjacent parts 14 and 15 and in the opposite direction by abutment with a retaining ring 31 fixed around the outer end face of the ring and the inner member. .

The guide ring 27 is arranged in the relative axial direction (
It is axially movable in relation to the inner member so as to prevent the ball 12 from sliding in the grooves 16 and 18 of the inner and outer members only at the beginning of the movement (plunging).

Therefore, at the beginning of the plunging movement, the cage is free to move axially relative to the inner member (and also relative to the outer member) and is moved relative to the inner member so that no sliding of the balls in the groove occurs. and becomes movable.

Ball sliding may occur during the remainder of the plunging motion, but this is negligible with respect to the effective natural functioning of the joint.

A sealing element 32 is connected between the inner member 10 and the outer member 11 at the outer end of the joint.

The inner end of the hole in the inner member 10 is connected to the insert 22 in the outer member.
It is closed by an elastically deformable element 33 arranged to cooperate with the inner member to limit the range of axial movement of the inner member relative to the outer member in one direction.

Element 33 is secured to the inner member by a retaining ring 34.

As is clear from the embodiment of the universal joint according to the present invention described above, the universal joint according to the present invention is different from the conventional universal joint in which the torque transmitter can roll over the entire range of axial movement. In comparison, a major feature is that although the same level of smooth axial movement is possible when the joint enters, it is relatively easy to design and manufacture.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the plunger constant velocity universal joint according to the present invention, FIG. 2 is an end view of the guide ring of the joint, and FIG. 3 is a view of the guide ring taken along line A-A in FIG. FIG. Explanation of symbols, 10... Inner member, 11...
...Outer member, 12...Torque transmitter, 13.
... Spline, 14 ... Cylindrical part, 1
5... part, 16, 18... groove, 17
...Side wall, 19...End wall, 20...
...Protrusion, 21... Spline, 22...
...Insert, 23...Opening, 24...
... Cage, 25 ... Convex partial spherical surface, 2
6... Concave partial spherical surface, 27... Guide ring, 28.29... Annular portion, 30...
...Slot, 31...Retaining ring, 32...
...Sealing element, 33... Elastic deformation element, 34.
...Retaining ring.

Claims (1)

[Scope of Claims] 1. A hollow outer member and an inner member having a plurality of pairs of grooves extending oppositely in the longitudinal direction, each of which engages with the grooves of the inner and outer members and between the pair of grooves; forming an opening arranged between the inner and outer members and a torque transmitting top movable along the groove to allow relative angular and axial movement between the members and in which the ball is received; a ball cage mounted on the inner member or a member affixed to the inner member for axial movement relative to the inner member; a convex partially spherical outer surface that engages a surface of the cylindrical bore of the guide member; and a concave partially spherical inner surface that engages a complementary convex partially spherical surface on the guide member; the shaped surface has a center of curvature offset by an equal amount on opposite sides of the joint center along the joint axis, whereby the cage is operative to assist in maintaining the ball in the bisector plane of the joint; In a universal joint that provides a constant velocity ratio characteristic of the joint, the cage is axially movable relative to the outer member and the guide member allows torque transmission over a limited range of part of the axial movement. A universal joint according to claim 1, wherein the universal joint is axially movable relative to the inner member or to a member fixed thereto for rotation within grooves of the inner and outer members. 2 said guide ring comprises a first continuous annular portion integrally formed with a flat cylindrical hole slidably engaging a flat cylindrical portion of said inner member at one end of said groove; a portion of the inner member adjacent to the first portion and having an outer diameter greater than the diameter of the first portion; a second annular portion enclosing a spherical outer surface of the convex portion of the ring that engages the cage; The universal joint according to claim 1, characterized in that it is formed to provide a. 3 a shoulder formed between said two portions of said guide ring such that a shoulder formed between said adjacent portions of said inner member limits axial movement of said guide ring relative to said inner member in one direction; Claim 2, characterized in that such movement in the opposite direction is limited by means, for example a retaining ring, provided on the continuous annular part of the ring remote from its shoulder. , universal joint.