GB2114267A

GB2114267A - Universal joints

Info

Publication number: GB2114267A
Application number: GB08302239A
Authority: GB
Inventors: Klaus Ehrlenspiel; Jochen Balken; Thomas John
Original assignee: Uni Cardan AG
Current assignee: GKN Driveline International GmbH
Priority date: 1982-01-30
Filing date: 1983-01-27
Publication date: 1983-08-17
Also published as: FR2520822A1; DE3203139C2; GB2114267B; IT8306921V0; DE3203139A1; JPS58134229A; GB8302239D0

Abstract

A universal joint for connecting to shafts, comprises a yoke 2 connected to one of the shafts 1 and supporting between its limbs 3 a coupler 10, swivelable about an axis perpendicular to the rotational axis of the shaft. The coupler defines a recess 11 with opposed parallel side faces, which receive a cylindrical member 13 connected to the other shaft 12. The cylindrical surface of the member fits closely between the parallel opposed walls of the recess in the coupler. A ball and socket 16, 17 may be provided for centring the joint. <IMAGE>

Description

SPECIFICATION Universal joint This invention relates to a universal joint for torque transmission between two rotary ele ments.

The most common type of universal joint in the Hookes joint, comprising two yokes provided on the rotary elements, the yokes being connected by a cruciform coupling member.

The arms of the cruciform coupling member are usually received in the yokes with the intermediary of needle roller bearings, which renders the joint relatively expensive. Further, the simple Hookes joint is not capable of dealing with large angles of articulation between the rotary elements.

It is also known to transmit torque between two rotary elements by a box shaped receiving member provided at the end of one element, in which engages a suitably shaped block on the other element. However, this is not suitable for connecting elements whose rotary axes are not aligned.

It is the object of the present invention to provide a universal joint which is relatively economical and yet which permits large angles of articulation.

According to the invention, we provide a universal joint for torque transmission between two rotary elements, comprising a yoke member connected or adapted to be connected to one of said elements, a coupler supported by said yoke member for swiveling about an axis perpendicular to the rotational axis of said one element and defining a recess with opposed faces parallel to said swiveling axis, and a cylindrical member connected or adapted to be connected to said other element with its axis transverse to the rotary axis thereof, and engaging in said recess with its cylindrical surface between said opposed faces thereof.

By virtue of the arrangement of the swivelable coupler, and the cylindrical member engaging therein in a form fitting manner between the opposed walls thereof, relatively large angles of articulation are obtainable.

When rotating, the parts are able to adjust themselves in such a way that synchronization between the two rotary elements is achieved.

The invention will now be described by way of example with reference to the accompanying drawings, of which: Figure 1 is a perspective view of a joint according to the invention, with its main parts separated; Figure 2 is a longitudinal section through the joint of Fig. 1; Figure 3 is a longitudinal section through the joint, in a plane at right angles to the section plane of Fig. 2.

The illustrated universal joint comprises a yoke member 2 connected to a rotary shaft member 1, the yoke having spaced parallel limbs 3, 4 provided with aligned bores 5, 6 respectively. These bores 5, 6 receive pins 7, 8, by which a coupler 10 is supported in the yokes for swiveling about an axis 9 perpendicular to the rotational axis of shaft element 1.

The pins 7, 8 may be firmly connected to the coupler 10 and receive for pivotal movement in the bores 5, 6 of the yoke limbs, or they may be firmly connected to the yoke limbs and be pivotal in apertures in the coupler 10.

To reduce friction, a rolling element bearing may be associated with each of the pins 7, 8.

The coupler 10 is made of sheet metal or the like, and is in the general form of a box defining a recess 11 with opposed side walls parallel to the swiveling axis of the coupler.

Received in the recess 11 is a cylindrical member 1 3 provided on shaft element 12, the axis of member 1 3 extending transversely relative to the rotary axis of shaft element 1 2.

The cylindrical surface 14 of member 1 3 fits closely between the opposed walls of recess 11 which are parallel to the swiveling axis 9 of the coupler.

For centring the shaft elements 1, 12, to ensure that their rotational axes intersect, the end of shaft element 1 has been provided with a ball 16. This engages in a part spherical recess 1 7 provided in the cylindrical member 13.

In Figs. 2 and 3 of the drawings, the centre of curvature of ball 1 6 and recess 1 7 is indicated at 18. The swiveling axis 9 of the coupler 10 is axially offset by a distance a from this centre of curvature. The central axis of the cylindrical member 1 3 is indicated at 15, and this is axially off-set from the centre of curvature 1 8 by the same distance a, but in the axially opposite direction. It would be possible for the directions of offset of the axes 9 and 1 5 to be exchanged.

To increase the possible angle of articulation of the joint, parts of the cylindrical member 1 3 and coupler 10 are rounded and recessed. For example, the cylindrical element 1 3 has a frusto-conical surface, or part spherical surface of larger radius of curvature, surrounding the part-spherical recess 1 3. Similarly the coupler 10 is shaped to provide clearance under large articulation angles.

Possible detailed design changes to the joint according to the invention are, for example, that the ball 1 6 may be provided on the end of shaft element 1 2 and the surface in which it engages provided on the end of a component associated with shaft element 1.

In certain applications, if the shaft elements are held in fixed relationship to one another, no centring means may be necessary in the joint.

It would be possible for the cylindrical member 1 3 to be provided with roller bearing elements which engage the opposed faces 11 of the coupler. Suitably inter-engaging ele ments may be provided to hold the cylindrical member 13 within the coupler 10, to prevent the joint from coming apart when it is not installed.

Further, it will be appreciated that when we refer to a cylindrical member it need not be completely of cylindrical form but merely requires part-cylindrical or other surface portions to provide the necessary close engagement between the walls of recess 11 during articulation relative thereto.

As an alternative means of centring the two shaft elements relative to one another, it would be possible for them to be provided with inter-engaging part-spherical components which surround the joint.

Claims

1. A universal joint for torque transmission between two rotary elements, comprising a yoke member connected or adapted to be connected to one of said elements, a coupler supported by said yoke member for swiveling about an axis perpendicular to the rotational axis of said one element and defining a recess with opposed faces parallel to said swiveling axis, and a cylindrical member connected or adapted to be connected to said other element with its axis transverse to the rotary axis thereof, and engaging in said recess with its cylindrical surface between said opposed faces thereof.

2. A univeral joint according to claim 1 wherein said coupler is swivelable between spaced parallel limbs of said yoke member, supported therein by rotary bearings.

3. A universal joint according to claim 2 wherein said bearings comprise pins fixed to said coupler and rotatably engaging in bores in said yoke limbs.

4. A universal joint according to claim 2 wherein said bearings comprise pins fixed to said yoke limbs and rotatably engaging in bores in said coupler.

5. A universal joint according to any one of claims 2 to 4 incorporating rolling element bearings to support said coupler.

6. A universal joint according to any one of the preceding claims wherein said cylindrical member is provided with roller bearings which engage said opposed faces of said coupler recess.

7. A universal joint according to any one of the preceding claims wherein there is provided centring means comprising a ball member associated with one of said rotary elements and a socket associated with the other of said rotary elements.

8. A universal joint according to claim 7 wherein said socket is provided in said cylindrical member.

9. A universal joint according to claim 7 or claim 8 wherein said swivel axis of said coupler is axially offset relative to the centre of curvature of said centring ball and socket.

10. A universal joint according to any one of claim 7 to 9 wherein the central axis of said cylindrical member is axially offset relative to the centre of curvature of said centring ball and socket.

11. A universal joint according to claim 9 or claim 10, wherein said swivel axis and central axis of said cylindrical member are axially offset by the same amount on opposite sides of the centre of curvature of said centring ball and socket.

12. A universal joint according to any one of claims 1 to 11 further comprising means for retaining said cylindrical member within said coupler.

13. A universal joint according to any one of claims 1 to 6 wherein said rotary elements are provided with co-operating spherical elements extending over the joint.

14. A universal joint substantially as hereinbefore described with reference to the accompanying drawings.