GB2076936A

GB2076936A - Universal joints

Info

Publication number: GB2076936A
Application number: GB8113653A
Authority: GB
Original assignee: Loehr and Bromkamp GmbH
Current assignee: GKN Driveline Deutschland GmbH
Priority date: 1980-05-28
Filing date: 1981-05-05
Publication date: 1981-12-09
Also published as: IT8105137A0; JPS5712120A; FR2483549A1; ES264804Y; DE3020193A1; IT8106954V0; BR8102561A; ES264804U; IT1205437B

Abstract

A universal joint with an outer member comprises one or a number of groove defining elements 9, Figure 1, held within a supporting component 1 by being moulded or cast therein. The groove defining element 9 or elements are of a wear resistant material such as hardened steel, while the supporting component 1 is of a relatively light material such as an aluminium alloy. As shown, balls 5 roll in inclined grooves 2, 4 in the groove defining element 9 and an inner joint member 3, respectively. Alternatively each groove defining element 14, Figure 4, may form a single groove. <IMAGE>

Description

SPECIFICATION Universal joint This invention relates to universal joints, for torque transmission, of the type comprising an outer joint member affording a cavity within which is disposed an inner joint member, the outer and inner joint members having axially inclined opposed complementary pairs of groove, in each of which pairs of grooves is received a torque transmitting element, such as a ball, to provide for torque transmission between the outer and inner joint members whilst accommodating relative angular displacement between the rotational axes thereof.

In a known type of universal joint, such as disclosed by DE-OS2419236, the outer and inner joint members consist of steel forgings which have been extensively machined throughout. Such machining, particularly in the region of the grooves, must necessarily be within a fine tolerance range and hence this method of production can be expensive. Furthermore, since the highest loads occurring in the outer and inner joint members are in the region of the grooves which receive the torque transmitting balls, the workpiece material must be such that it withstands the highest loads occurring within this region. Consequently, the entire workpiece material has to be made of a hardenable material suitable for such torque transmission.

It is an object of the present invention to provide a universal joint of relatively light weight whilst retaining suitable torque transmission capacity.

According to the invention we provide a universal joint for torque transmission, comprising an outer joint member affording a cavity within which is disposed an inner joint member, the outer and inner joint members having opposed complementary pairs of grooves, in each of which pairs of grooves is received a torque transmitting element, such as a ball, to provide for torque transmission between the outer and inner joint members whilst accommodating relative angular displacement between the rotational axes thereof, wherein the outer joint member comprises one or more elements which define the grooves, said element or elements being of a wear resistant material and secured within a supporting component by being moulded or cast therein; said supporting component being of a lightweight material relative to that of the groove defining elements.

There may be a single groove defining element of annular form, which may be produced as a steel pressing.

The supporting component may be of aluminium or of an aluminium alloy, which is cast around the groove defining element or elements.

There may be a plurality of groove defining elements.

The axes of the grooves may be inclined relative to the rotational axis of the outer joint member. In the type of joint where adjacent grooves are oppositely inclined, this means that a single annular groove defining element is axially secured within the supporting component without any additional securing means.

When individual groove defining elements are circumferentially spaced within the supporting component each individual element may have a protuberance extending outwardly from the outer surface of the element, to ensure that each individual element is securely held within the supporting component.

In accordance with a further feature of the invention, fixing holes may be provided around the supporting component, the fixing holes containing bushes of a material corresponding to that of the groove defining elements, the bushes being cast or moulded integrally within the supporting component.

As an alternative to the supporting component being of aluminium, it could be of a suitable synthetic plastics material, capable of being moulded around the groove defining element or elements. The synthetic plastic material could further contain strengthening elements, such as fibres, to provide adequate supportforthe groove defining element or elements.

One advantage of the present invention is that by using a combination of materials, namely a wearresistant material suitable for torque transmission and a relatively lightweight material suitable for casting or moulding, is that such an arrangement can achieve a considerable reduction in weight when compared to a universal joint composed of a single material, such as a hardenable steel. When there is a single annular groove defining element, dividing errors, which can occur when a number of individual components require accurate location with respect to each other, may be reduced or eliminated.

The invention will now be illustrated byway of example only, with reference to the accompanying drawings in which: Figure 1 shows a front view of a universal joint according to the present invention.

Figure 2 shows part of the joint of Figure 1.

Figure 3 shows a groove defining element according to the invention, and Figure 4 shows an alternative embodiment of an individual groove defining element according to the invention.

Referring to Figure 1, a universal joint comprises an annular outer joint member 1 affording a generally cylindrical cavity, within the inner surface of which are arranged circumferentially spaced, axially inclined grooves 2. An annular inner joint member 3 is provided within the cyiindrical cavity of the outer joint member 1 and is keyed for rotation with a drive shaft (not illustrated) via its centre bore. Circumferentially spaced around the inner joint member 3 are further grooves 4 each of which faces one of the grooves 2 in the outer joint member. Each of the grooves 4 is axially inclined with respect to the axis of rotation of the inner joint member 3 in a sense opposite to the inclination of its facing groove 2.

Between each of the pairs of complementary grooves 2 and 4, is located one of a number of torque transmitting balis 5, held in place at the intersection of the axes of the complementary grooves. An annular cage 6 is disposed between the outer joint member 1 and the inner joint member 3 and contains window slots 7 which hold the balls 5 in the angle-bisecting plane between the rotational axes of the outer joint member 1 and the inner joint member 3. The outer joint member 1 is also provided with circumferentially spaced holes 8 which extend axially through the member 1 to allow fixing of this member to a flange or the like forming part of a vehicie or machine.

The grooves 2 are defined by an annular groove defining element 9 which is of hard wearing material, eg. steel having a hardened surface. The element 9 is cast or moulded within a supporting component 10 and, by virtue of the opposite inclination of each groove 2 with respect to an adjacent groove 2, the element 9 is locked within the component 10. The supporting component 10 is of a relatively lightweight material such as an aluminium alloy or a suitable plastics material.

Referring to Figure 2, the joint outer member here shown has the circumferentially spaced holes 8 provided with tubular bushes 11 of material identical to that of the annular element 9, the bushes 11 providing adequate reinforcement for torque trans- mission.

In Figure 3 is shown the annular element 9 in which the opposite axial inclination of adjacent pairs of grooves 2 can again be clearly seen.

In an alternative embodiment, as shown in Figure 4, the each groove 2 may be defined by the arcuate part-cylindrical section 12 of an individual groove defining element 14. The elements 14 are spaced circumferentially around the inner surface of the supporting component 10 or the outer surface of the innerjoint member 3. Each element 14 is provided with a rectangular protuberance 13 which restrains the element 14from movement when moulded or cast into the supporting component 10 or inner joint member 3. It will be seen that the element 14 corresponds in principle to a single groove defining part of the annular element 9 of Figures 1 - 3.

It is envisaged that the principle of providing a pre-formed groove defining element or elements which is or are subsequently cast or moulded into a supporting component is applicable to further types of known joints having grooves and is not limited to the type of joint hereinbefore described.

Claims

1. Auniversal jointfortorque transmission, comprising an outer joint member affording a cavity within which is disposed an inner joint member, the outer and inner joint members having opposed complementary pairs of grooves, in each of which pairs of grooves is received a torque transmitting element, such as a ball, to provide for torque transmission between the outer and inner joint members whilst accommodating relative angular displacement between the rotational axes thereof, wherein the outer joint member comprises one or more elements which define the grooves, said element or elements being of a wear resistant material and secured within a supporting component by being moulded or cast therein; of a wear resistant material and said supporting component being of a lightweight material relative to that of the groove defining elements.

2. A universal joint according to Claim 1 wherein there is single groove defining element of annular form.

3. A universal joint according to Claim 2 in which the groove defining element is a steel pressing.

4. A universal joint according to any preceding claim in which the supporting component is of an aluminium alloy which is cast around the groove defining element or elements.

5. A universal joint according to any preceding claim in which the axis of each groove is inclined relative to the rotational axis of the outer joint member.

6. A universal joint according to Claim 1 comprising a plurality of individual groove defining elements, each of which has a protuberance which, when cast or moulded within the supporting component, extends into the component such that the groove defining element is securely held in place.

7. A universal joint according to any preceding claim in which bushes of material identical to that of the groove defining element or elements are provided in holes in the supporting component, for fixing the supporting component to a torque trans mittingflange orthe like.

8. A universal joint according to Claim 5 wherein the axes of adjacent grooves are oppositely inclined.

9. A universal joint substantially as herein described with reference to and as shown in Figures 1, 2, 3, or as modified with reference to Figure 4, of the accompanying drawings.