GB2121895A

GB2121895A - A wheel and brake disc assembly

Info

Publication number: GB2121895A
Application number: GB08310787A
Authority: GB
Inventors: Willi Klein; Hans Rocholl
Original assignee: Bergische Stahl Industrie
Current assignee: Bergische Stahl Industrie
Priority date: 1982-04-24
Filing date: 1983-04-21
Publication date: 1984-01-04
Also published as: IT1164894B; BE896551A; DK177183D0; NL8301428A; GB8310787D0; DE3215357A1; IT8348147A0; DE3215357C2; GB2121895B; ATA141183A; AT392450B; FR2525714A1; DK177183A

Abstract

A rail vehicle wheel and brake disc assembly comprises fastening elements (25) arranged laterally at a wheel (27) and around the wheel axis, and fastening dogs (15) arranged parallel to the axis on an annular brake disc (11, 12), each fastening element (25) having two radial surfaces (26) which are parellel with the wheel axis and between which a respective one of the fastening dogs is clamped. Radially extending ribs (13) for the formation of cooling air channels are provided on a rear side of the brake disc. The disc has an even number of the fastening dogs (15) and is in two halves with the dividing plane (16), in which the wheel axis lies, passing through two fastening dogs (15) disposed diametrically opposite to each other. <IMAGE>

Description

SPECIFICATION A wheel and brake disc assembly The present invention relates to a wheel and brake disc assembly, especially an assembly for a rail vehicle.

A clamping attachment of brake discs to rail vehicle wheels is known from, for example DE 20 47 513. It is also known, for example from DE 20 62 407, to provide a divided annular brake disc, wherein the dividing plane, which contains the wheel axis, passes through clamping grooves in the brake disc and the clamping force between the clamping grooves and guide strips or fastening dogs arranged at the hub is exerted through screws which bridge over the dividing plane of the disc and connect the disc halves together. It is obvious that these screws must be designed to be quite large, which increases the unsprung mass of the rail vehicle and entails the disadvantage that, due to continuous heating and cooling in use, damage to the screws can occur, which endangers the interconnection of the disc halves.

According to the present invention there is provided a wheel and brake disc assembly comprising a wheel provided with a plurality of laterally arranged fastening means spaced apart around the wheel axis, and an annular brake disc provided with an even number of fastening dogs each projecting from the disc in a direction generally parallel to the wheel axis and each clamped between two substantially radial surfaces of a respective one of the fastening means, the disc being divided in plane passing through the wheel axis and through two diametrically opposite ones of the fastening dogs.

In a preferred embodiment, fastening elements are arranged laterally at the wheel and around the wheel axis and fastening dogs parallel to the axis are provided at the annular brake disc, each fastening element having two radial surfaces, which are parallel with the wheel axis and between which a respective one of the fastening dogs is clamped, and axially extending ribs for the formation of cooling air channels being provided on the rear side of the brake disc. The disc has an even number of fastening dogs and the dividing plane, in which the wheel axis must lie, passes through two fastening dogs disposed opposite to the other.

Advantageously, each brake disc half in the dividing plane has a fastening dog half extending inwardly parallel to the wheel axis and both halves, lying against each other, are clamped in a clamping groove in the wheel or in an intermediate place.

Expediently, the clamping groove is provided in a box-like frame member fastened to the wheel disc.

Such an assembly embodying the present invention may have the advantage that the two disc halves can be pressed into the clamping grooves and also removed. During pressing out of a brake disc on a rail vehicle axle between the wheels, the fact that the disc falls apart into two parts after being pressed out considerably simplifies its removal. Similarly, a new brake disc can be pressed on, so that an exchange of worn or damaged discs is possible without problems. On the other hand, there are no disadvantages associated with this arrangement, because after pressing on of the two brake disc halves they are connected by the clamping force into one unit, which provides a structure equivalent to a onepiece brake disc.

An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a rear view of parts of two annular brake disc halves, laid against each other, in a wheel and brake disc assembly embodying the invention; Fig. 2 is an end view, in direction of arrow X, of the parts of the brake disc halves of Fig. 1; Fig. 3 is a rear view of the parts of the brake disc halves and part of a wheel showing fastening means clamping the brake disc halves; and Fig. 4 is a cross-section along the line IV--IV of Fig. 3.

Referring now to the drawings, there is shown in Figs. 1 and 2 part of an annular brake disc which is divided into two halves 11 and 12 each provided on a rear side thereof with ribs 13, every second one of which carries a supporting dog 14 at about its centre in the radial direction of the disc. Each disc half 11 and 12 is provided at each dividing zone with a respective fastening dog half 15, the two dog halves 1 5 at each dividing zone together forming a fastening dog which can be clamped in a clamping groove.Each dog half 1 5 possesses, in about its middle seen in radial direction, a respective dog 1 6a which extends into the dividing gap 1 6 and has only a small height, because the spacing of the two disc halves in the dividing plane is determined thereby and must not be too large or else the wear of the brake linings will be excessive. Conversely, a certain gap must be present between the disc halves, for reasons of manufacturing tolerances and thermal expansion during braking. Moreover, each dog half 1 5 is provided on a side facing the disc of a wheel 27 (Figs. 3 and 4) with a dog 17, by means of which the brake disc bears against the wheel disc.Each disc half 11 and 12 also has a respective eye 20 near each of the outer circumference 1 8 and the inner circumference 19, the eyes 20 being disposed one after the other in radial direction so that the bores present in the eyes 20 are aligned with each other. Provided in the two dog halves 1 5 and extending approximately tangentially are two bores 21, which are aligned with each other and engaged in which is a centring bolt 22 bridging over the dividing gap 16. A radial groove 23 is provided in each dividing surface of the disc halves.

The arrangement of the divided brake disc on the wheel 27 is apparent from Figs. 3 and 4. The two dog halves 15, firmly engaging each other by the dogs 1 6a, are clamped in a box-like opening 24 of a member 25 by means of surfaces 26 of the member, the surfaces 26 extending substantially radially and parallel to the wheel axis.

By this means the brake disc is fastened to the wheel, because the member 25 is fastened by screws 28 and fit pins or similar to the rim of the wheel 27. Since the dividing plane of the brake disc passes through two diametrically opposite fastening dogs and the clamping surfaces 26 not only retain the disc halves 11 and 1 2 but also press them together, there results a unit in which the halves can displace only in radial direction relative to each other or individually relative to the member 25, for example due to heating arising during braking and distortion connected therewith.

However, as relative displacement of the two halves of the brake disc is to be avoided as far as possible, two centring bolts 22 are arranged in the mutually aligned bores 21 of the disc halves in such a manner that the bolts extend substantially tangentially and bridge over the dividing gap.

The member 25 is provided at both sides with laterally extending projections 30, which in radial direction are each disposed medially between the eyes 20 of a respective pair of eyes, so that the radial bore in the projection 30 is aligned with the bores in the eyes 20. A tightening sleeve 31 or, for example, a similarly effective pin extends radially in all three bores. The sleeve 31 is secured against radial displacement by split pins or similar arranged externally of the eyes 20. Each disc half 11 and 12 is secured against displacement parallel to the wheel axis by the sleeves 31.Due to the fact that each projection 30 is disposed approximately medially between the eyes 20 of the associated pair, a certain degree of resilience in a direction parallel to the wheel axis is provided, whereby the disc halves 11 and 1 2 can, during braking, bear against the wheel disc by means of the dogs 17 of the dog halves 15 and the dogs 14 of the ribs 13. In order that the brake disc can have the greatest possible diameter, the disc is recessed in the region of each of the screws 28 to provide a semi-circular depression 32.

Of course, other constructions are possible in which the clamping groove is not provided by a box-like opening, but has another kind of shape. In addition, the fastening dogs can be of a different shape and other centring measures, which have the same effect, can be used in place of the centring pins. Thus, for example, it is feasible for each half of the fastening dogs 1 5 to be constructed in the manner of a groove and key, not only in radial direction, but also in direction parallel to the axis.

Moreover, in the region of the dog halves small protrusions 33 can be provided to determine how deeply the dog halves are pressed into the member 25.

Claims

1. A wheel and brake disc assembly comprising a wheel provided with a plurality of laterally arranged fastening means spaced apart around the wheel axis, and an annular brake disc provided with an even number of fastening dogs each projecting from the disc in a direction generally parallel to the wheel axis and each clamped between two substantially radial surfaces of a respective one of the fastening means, the disc being divided in plane passing through the wheel axis and through two diametrically opposite ones of the fastening dogs.

2. An assembly as claimed in claim 1, wherein each half of the -brake disc is provided with a respective half of each of'the two dogs through which the dividing plane passes, the two halves of each divided dog extending from the disc halves towards the wheel and being clamped against each other in a clamping groove defined by the respective fastening means.

3. An assembly as claimed in claim 2, wherein the clamping groove of each fastening means is provided by a respective groove in the wheel.

4. An assembly as claimed in claim 4, wherein the clamping groove of each fastening means is provided in a respective intermediate member secured to the wheel.

5. An assembly as claimed in claim 4, wherein each intermediate member comprises a generally box-shaped frame, the respective clamping groove being provided by the space enclosed by the frame.

6. An assembly as claimed in any one of claims 3 to 6, wherein the two halves of each divided dog are located relative to each other by two centring pins extending over the division therebetween.

7. An assembly as claimed in any one of the preceding claims, wherein each half of each of the two divided dogs is provided in a substantially central region thereof with abutment means to abut the abutment means of the respective other dog half.

8. An assembly as claimed in any one of the preceding claims, wherein each half of each of the two divided dogs is provided with support means to bear against the wheel.

9. An assembly as claimed in any one of the preceding claims, wherein the brake disc is provided on a side thereof facing the wheel with a plurality of substantially radially extending ribs defining cooling air channels.

10. An assembly as claimed in claim 2, wherein at least every second one of the ribs is provided with a supporting member to bear against the wheel.

11. An assembly as claimed in either claim 4 or claim 5, wherein each of the intermediate members is provided with lateral apertured projections and the brake disc is provided at a side thereof facing the wheel with a respective pair of apertured lugs arranged one on each side of each lateral projection on a radius of the disc, each lateral projection being connected to the respective pair of lugs by means of a connecting eiement engaged in the apertures of the projections and lugs and secured against displacement radially of the disc.

12. An assembly as claimed in claim 11, wherein the lugs of each pair are disposed adjacent to the inner circumference and the outer circumference of the disc respectively and the associated lateral projection is disposed substantially medially between the lugs.

1 3. An assembly as claimed in any one of the preceding claims, wherein the wheel is a rail vehicle wheel.

14. A wheel and brake disc assembly substantially as hereinbefore described with .

reference to the accompanying drawings.