GB2110793A

GB2110793A - Vehicle wheel brake disc assembly

Info

Publication number: GB2110793A
Application number: GB08232797A
Authority: GB
Inventors: Alfred Otto; Hans Rocholl; Willi Klein
Original assignee: Bergische Stahl Industrie
Current assignee: Bergische Stahl Industrie
Priority date: 1981-11-17
Filing date: 1982-11-17
Publication date: 1983-06-22
Also published as: ES8307622A1; BE895046A; IT1148668B; DE3145563C2; FR2516618B1; ES517407A0; IT8249488A0; FR2516618A1; DE3145563A1; GB2110793B

Abstract

In an arrangement for securing a brake ring (12) of a partially or fully lined disc brake, particularly for a rail vehicle, against axial displacement relative to the vehicle wheel (11) or hub, wherein brake forces are transmitted from the wheel (11) to the brake ring (12) through strips (13) of the one part - wheel or brake ring - in radial grooves (15) parallel to the axis at the other part, the securing is provided by at least one tensioning sleeve (21) or similar lying radially in bores (20, 24) of both parts. One side of the sleeve (21) is clamped near to the inner or outer circumference (23 or 19) of the brake ring (12) in a radial bore (20) and the other side of the sleeve (21) is clamped in the proximity of the radially oppositely disposed circumference at the wheel (11) or the hub, respectively. The brake ring (12) bears, in about its middle third seen in radial direction, by means of a dog (14) or the like against the wheel (11) or the hub. <IMAGE>

Description

SPECIFICATION A vehicle wheel brake disc assembly The present invention relates to a vehicle wheel brake disc assembly, and has particular reference to the securing of an annular brake disc of a partially or fully lined disc brake, particularly for a rail vehicle, against axial displacement relative to the wheel or wheel hub.

Wheel brake rings generally have the property that they distort to the shape of a plate when heated during braking, this distortion being cancelled on cooling of the brake ring provided it has not deformed plastically or warped through the heating. The greatest degree of deflection or distortion occurs with monobloc brake discs where the longest lever arm is present. In other constructions of this kind, the problem is still generally apparent.

When the fastening of a steel carrier is, for example, at the external diameter of a brake ring and extends from there to the rim of the wheel, then large forces of constraint are transmitted to the fastening elements, which can lead to premature destruction of these elements. When the fastening is at the inner diameter, a relatively large deflection results and additionally a high stressing of the fastening elements, thus of tensioning sleeves, which again can lead to rapid destruction of the same. When tensioning sleeves of that kind are also used to transmit the braking forces, they must be of such a large size that the plate-shaped deflection of the brake ring generates very substantial stresses which rapidly destroy either the eye for the tensioning sleeve or the tensioning sleeve itself.

There is accordingly a need for a brake disc assembly which avoids the disadvantages of the known constructions and separates the transmission of the braking forces from the axial securing of the disc.

According to the present invention there is provided a vehicle wheel brake disc assembly comprising an annular brake disc which is coupled to a wheel or the wheel hub for transmission of braking forces through strip means engaged ir, substantially radially extending groove means and which in a radial cross-section is provided substantially in the central third of its radial extent with means bearing against the wheel or hub, one of the strip means and the groove means being provided at the disc and the other at the wheel or hub, and a radially extending securing element securing the disc against axial displacement relative to the wheel or hub, the securing element being clamped at an end portion thereof in a bore in the disc in the region of one of the inner circumference and the outer circumference of the disc and at another end portion thereof in a bore in the wheel or hub in the region of the respective other circumference of the disc.

In a preferred embodiment, the brake forces are transmitted from the wheel or the hub to a brake ring through strips of the one part wheel or hub, respectively, or brake ring - in radial grooves parallel to the axis at the other part. The ring is secured against axial displacement relative to the wheel or hub by at least one tensioning sleeve or similar extending radially in bores of both parts. One side of the tension sleeve or similar is clamped in near to the inner or outer circumference at the brake ring in a radial bore and the other side of the tensioning sleeve or similar is clamped in in the proximity of the radially oppositely disposed circumference at the wheel or the hub respectively. The brake ring in about its middle third seen in radial direction bears in a direction parallel to the axis by means of a dog or similar against the wheel or the hub respectively.

Advantageously, the tensioning sleeve or similar is constructed to be relatively soft.

Expediently, the bore arranged in the wheel or hub can be provided at an intermediate member.

An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawing, the single figure of which is a schematic radial section of a rail vehicle wheel with a brake disc assembly embodying the invention.

Referring now to the drawing, there is shown one side of a wheel 11 for a rail vehicle, at which at brake ring 1 2 is fastened.

The ring 1 2 is provided in about its middle (seen in radial direction) with a strip 13, which continues into a dog 1 4. The strip 1 3 is clamped in a clamping groove 1 5 extending in length radially outwards and in depth parallel to the axis. The groove 1 5 is provided in an intermediate member 16, which can have any desired shape, for example, that of a segment, etc. The intermediate member 1 6 is fastened by screws 1 7 to a hub portion 1 8 of the wheel.

A tensioning sleeve 21, for example a split sleeve, which is secured by a spline or pin 22 or the like against radial movement, is clamped in a double bore 20 near the outer circumference 1 9 of the brake ring 1 2. On the other side, the sleeve 21 is clamped near the inner circumference 23 in a bore 24 of the intermediate member 1 6. Since the sleeve 21 penetrates a bore or recess 25 in the strip 1 3 clamped in the groove 15, the bore or recess 25 is enlarged to such an extent that the sleeve 21, even on distortion of the brake ring, cannot bear against the walls of the bore or recess 25.In the region of the intermediate member 16, whether this is a ring or a segment, the ring 1 2 is provided at its inner side with a recess 26 in order to prevent the brake ring 12, in the event of distortion, from coming into contact in this region with the member 16.

The tensioning sleeve 21, several of which can be present, prevents movement of the brake ring 1 2 parallel to its axis and relative to the wheel 11. The sleeve 21 does not, however, have to transmit braking forces, because these are transmitted by the couple of strip 1 3 and groove 1 5. If the braking ring becomes warm or even hot in consequence of heating during braking, it may distort approximately in such a manner that, in radial direction, it moves away from the wheel at the outer circumference 1 9 and towards the wheel at the inner circumference 23, the movement taking place about the contact surface 27 between the dog 14 and adjoining part of the wheel 11.Due to the relatively great distance between the two clamping points of the sleeve 21 represented by the bores 20 and 24, the sleeve is bent only to a small extent and survives this stress without damage.

Modifications, which result in the same effect, are of course feasible. For example, the two clamping points of the tensioning sleeve can be inter-changed so that the clamping point at the wheel lies in the proximity of the outer circumference 1 9 of the brake ring 1 2 and the clamping point at the brake ring approximately at the inner circumference 23.

The clamping point represented by the double bore 20 in the described embodiment can be provided by a single bore or recess or can be constructed in other manner appropriate to the requirements.

In addition, the intermediate member need not be arranged at the hub of the wheel, but could be provided at the rim of the wheel.

In place of the tensioning sleeve 21, any other similarly acting element can be used, for example a tensioning pin or the like.

The securing against axial displacement can also be provided at a different place rather than at or in a clamping groove, although the groove is the best location.

It is also possible to arrange two brake rings 1 2 on one hub, wherein both brake rings bear at the rear side by a dog 14.

The embodiment hereinbefore described has the advantage that the deflection or distortion of the brake ring is restricted to a minimum, whereby it is ensured that permanent deformation does not occur. This results in the further advantage that the gap between brake lining and brake ring surface can be kept as small as possible, which in turn reduces the braking response time. Moreover, the minimised distortion signifies reduced stress in the brake ring and theregby reduced risk of cracking.

Claims

1. A vehicle wheel brake disc assembly comprising an annular brake disc which is coupled to a wheel or the wheel hub for transmission of braking forces through strip means engaged in substantially radially extending groove means and which in a radial cross-section is provided substantially in the central third of its radial extent with means bearing against the wheel or hub, one of the strip means and the groove means being provided at the disc and the other at the wheel or hub, and a radially extending securing element securing the disc against axial displacement relative to the wheel or hub, the securing element being clamped at an end portion thereof in a bore in the disc in the region of one of the inner circumference and the outer circumference of the disc and at another end portion thereof in a bore in the wheel or hub in the region of the respective other circumference of the disc.

2. An assembly as claimed in claim 1, wherein the securing element comprises a tensioning sleeve.

3. An assembly as claimed in claim 2, wherein the sleeve is constructed to accept a limited amount of deformation.

4. An assembly as claimed in any one of the preceding claims, wherein the wheel or hub comprises a mounting member, the bore in the wheel or hub being provided in the mounting member.

5. An assembly as claimed in claim 4, wherein the disc is provided with a recess at side thereof facing the mounting member so as to permit distortion of the disc towards the member.

6. An assembly substantially as hereinbefore described with reference to the accompanying drawing.