GB2052653A

GB2052653A - Rail Vehicle Disc Brake Arrangement

Info

Publication number: GB2052653A
Application number: GB8017025A
Authority: GB
Original assignee: Sab Industri AB
Current assignee: Sab Industri AB
Priority date: 1979-05-23
Filing date: 1980-05-22
Publication date: 1981-01-28
Also published as: DE3019597A1; BR8003213A; SE7904523L; JPS55156764A; IT8022093A0; IT1131611B; FR2457205A1

Abstract

A rail vehicle disc brake arrangement comprises a brake disc (14) extending radially inwardly from a rail vehicle wheel rim (2,3,5,8,9) and a disc brake actuator means (19-22) arranged on an axle box (11) for the wheel shaft (10) so as to be substantially within the boundaries of the wheel. <IMAGE>

Description

SPECIFICATION Rail Vehicle Disc Brake Arrangement This invention relates to a rail vehicle disc brake arrangememt.

A normal, prior art disc brake arrangement for a rail vehicle comprises a pneumatically or hydraulically operated disc brake calliper or the like suspended from the vehicle underframe or bogie and co-operating either with a separate brake disc attached to a wheel shaft or with brake discs arranged on both sides of the web of a vehicle wheel (between the rim and the hub thereof).

Such arrangements have several disadvantages, such as being space consuming, complex, heavy and expensive. Besides, and more important, severe difficulties may arise if, during brake operation, the braked wheel set moves vertically and/or axially.

The present invention aims to avoid these and other disadvantages. According to the invention, there is provided a rail vehicle disc brake arrangement, in which a brake disc extends substantially radially inwardly from the rim of a rail vehicle wheel, at a predetermined distance from the web of the wheel, and a disc brake actuator means for braking engagement with both sides of the disc is mounted on an axle box or the like for a shaft of the wheel.

By means of the arrangement according to the invention, it is possible not only to eliminate the usual disc brake rigging, but the mounting of the actuator means on the axle box will also have the very advantageous effect that the whole brake arrangement will move in different directions together with the wheel set.

If the wheel rim, in a manner known per se, comprises a wheel tyre, two rubber elements together forming an open V, two wedge rings, and screw joints keeping the different wheel rim parts together as a resilient and noise reducing unit, the brake disc may be attached to the wedge rings.

In particular, the brake disc or rather an attachment ring thereon may be clamped between the two wedge rings by the screw joints.

A particularly compact and protected arrangement is obtained, if the disc brake actuator means is mounted on a mounting bracket, attached to the axle box, and is arranged substantially within the boundaries of the wheel, whose web is outwardly curved for increasing the available space within the wheel.

The disc brake actuator means may well be of the type frictionally engaging the brake disc, preferably a fluid operated actuator, but also an eddy-current means or other means for nonfrictional engagement with the brake disc is conceivable.

The invention will now be described in further detail with reference to the drawing which is a perspective view of a rail vehicle wheel with one embodiment of a disc brake arrangement according to the invention with some parts cut away for the sake of clarity.

A rail vehicle wheel may, as shown in the drawing, consist of the following parts: a flanged wheel tyre 2 (for co-operation with a rail 1), two flat rubber elements 3 (together forming an open V), a wheel centre 4 (comprising a first wedge ring 5, a web 6 and a hub 7), a second wedge ring 8, and screw joints 9 extending axially through and holding the two wedge rings 5 and 8 and thus the whole wheel together.

The wheel hub 7 is heat shrunk or otherwise attached to a shaft 10, which isjournalled in an axle box or journal box 11. This axle box 11 is resiliently suspended, for example by means of rubber springs 12, from a vehicle underframe or bogie 13 for example.

A circular brake disc 14 is, by means of an attachment ring 15, joined to the brake disc 14 by means of heat expansion means 1 6 attached to the wheel and the brake disc 14 extends radially inwardly from the wheel rim consisting of the parts 2, 3, 5 and 8. The attachment ring 1 5 is clamped between the two wedge rings 5 and 8 by means of screw joints 9, which thus have the dual purpose of keeping the wheel rim parts together and attaching the brake disc 14 in a nonrotatable and torque transmitting way.

The mounting of the wheel is very simple: the wheel centre 4 may be placed horizontally on its web 6, and the wheel tyre 2 is placed thereon with one of the rubber elements 3 therebetween.

The brake disc 14 is positioned with its attachment ring 1 5 on the first wedge ring 5 of the wheel centre 4. The second wedge ring 8 and the remaining rubber element 3 is put in position on the brake disc attachment ring 1 5 and the remainder of the wheel, whereupon the screw joints 9 are applied and fastened. The resilient wheel with its brake disc is now complete and ready for use.

The dismounting of the wheel for the replacement of wornout parts, such as the wheel tyre 2, the rubber elements 3 or the brake disc 14, is of course just as simple.

In the embodiment shown in the drawing the wheel is of the rubber resilient type, where the brake disc 14 is integrated in a natural way. It is however important to note that a brake disc of any kind (having heat expansion means of any kind or not) may be attached in any way so as to extend substantially radially inwardly from a wheel rim, be it resilient or not.

As appears from the drawing the web 6 is not straight but outwardly curved, which gives certain advantages as regards the strength and running properties but more important makes it possible to arrange a disc brake actuator in an extremely advantageous position to be described below.

On the axle box 11 a mounting bracket 1 7 is attached by means of screws 18. A so-called floating disc brake cailiper 19 is axially movably arranged in the bracket 1 7. A brake actuator 20 is mounted in the calliper 1 9. A first brake pad 21 is attached to the push rod of the actuator 20 and a second brake pad 22 is mounted on the floating calliper 1 9.

The actuator 20 may be of the type applying a brake force on the brake pad 21 at the admission of hydraulic brake fluid under pressure through a brake line 23 from a suitable source (not shown) on the vehicle. The actuator 20 may equally well be of the spring brake type, i.e. the brake force is created by a strong spring therein, which is normally held back in an unapplied position by the brake fluid pressure applied through the line 23 and which thus will accomplish an emergency and parking brake function. The actuator 20 may if desired contain a conventional slack adjuster of any kind.

The arrangement with the floating calliper 19 will enable the wheel and its shaft aiso to move, axially to a certain extent during a brake operation.

It is again important to note that the arrangement with the hydraulically operated, mechanical disc brake 1 9-23 is shown only by way of example and that any other braking means mounted on the axle box 11, co-operating with the brake disc 14 and substantially contained within the boundaries of the wheel itself may be used. A pneumatically operated disc brake is clearly conceivable, but the use of an eddycurrent braking means mounted on the axle box and non-frictionally co-operating with the brake disc is a viable alternative.

Other modifications are possible with the scope of the appended claims, and the embodiment shown and described above is only one example of the inventive idea to accomplish an extremely compact and reliable disc brake arrangement substantially within the boundaries of the wheel, which may be resilient.

Claims

1. A rail vehicle disc brake arrangement, in which a brake disc extends substantially radially inwardly from the rim of a rail vehicle wheel, at a predetermined distance from the web of the wheel, and a disc brake actuator means for braking engagement with both sides of the disc is mounted on an axle box or the like for a shaft of the wheel.

2. A disc brake arrangement according to claim 1 , wherein the wheel rim comprises a wheel tyre, two rubber elements together forming an open V, two wedge rings and screw joints holding the different wheel rim parts together as a resilient and noise reducjng unit, and wherein the brake disc is attached to the wedge rings.

3. A disc brake arrangement according to claim 2, wherein the brake disc is provided with an attachment ring which is clamped between the two wedge rings by the screw joints.

4. A disc brake arrangement according to any preceding claim, wherein the disc brake actuator means is mounted on a mounting bracket attached to the axle box.

5. A disc brake arrangement according to any preceding claim, wherein the disc brake actuator means is arranged substantially within the boundaries of the wheel whose web is outwardly curved for increasing the available space within the wheel.

6. A disc brake arrangement according to anypreceding claim, wherein the disc brake actuator means is of the type frictionally engaging the brake disc.

7. A disc brake arrangement according to claim 6, wherein the disc brake actuator means is fluid operated.

8. A disc brake arrangement according to any one of claims 1 to 5, wherein the disc brake actuator means is of the type non-frictionally engaging the brake disc.

9. A disc brake arrangement according to claim 8, wherein the disc brake actuator means is operated by eddy-current means.

10. A rail vehicle disc brake arrangement substantially as described herein with reference to the drawings.