WO2000005118A1

WO2000005118A1 - A wheel for railway vehicles or similar with a flange provided with an anti-derailment edge

Info

Publication number: WO2000005118A1
Application number: PCT/EP1999/005048
Authority: WO
Inventors: Alberto Lucarelli
Original assignee: Istituto Finanziario Di Sviluppo Immobiliare S.P.A.
Priority date: 1998-07-24
Filing date: 1999-07-15
Publication date: 2000-02-03
Also published as: AU4911499A; ITMI981708A1; IT1301852B1; ITMI981708A0

Abstract

A wheel (1) for railway vehicles or similar includes a flange (5) with an operative edge made of a concave part (6) which rests on and follows the lateral convex edge (7) of the top of the rail (8) and of a convex part (9) which extends radially outwards from this concave part (6) and flanks, without touching, the side to the rail. The flange (5) comprises an additional edge (10) too that further extends outwards and sideways from this convex part (9) so as to be situated at a greater distance from the side of the rail than said convex part (9).

Description

A WHEEL FOR RAILWAY VEHICLES OR SIMILAR WITH A FLANGE PROVIDED WITH AN ANTI-DERAILMENT EDGE

DESCRIPTION 5 This invention concerns with a wheel for railway vehicles or similar with a rolling rib provided with an anti-derailment edge.

The ever higher increase of the speed of trains, in particular of trains for passengers named trains at high speed, has made more and more frequent and diffuse the risk of derailment of trains.

10 These ones have actually had the largest modifications of technologic development, for more and more powerful engines and more and more comfortable passenger trains, while analogous technologies did not develop at the same time for rails and rolling profiles of the train wheels, conceived identical to those of trains that run at a very inferior speed.

15 With regard to wheels, it is well known that these ones present a rolling rib that has an operative edge formed by a concave part which rests on and follows accurately the lateral convex edge of the rail top and by a convex part that extends radially outwards from this concave part and flanks without touching the rail side to guarantee the maintenance of the wheel in the 0 correct position of lateral engagement with the rail also in case of lateral skidding.

If, as a consequence of a high speed of running of the train, the lateral skidding is over a certain value, the present rolling rib is not able to hold back in the correct position the wheel anymore and so the derailment of the

25 train could occur.

Anyway we cannot think to resolve this problem by increasing the height of the convex part of the operative edge of the wheel because in case of transversal position of the wheel in comparison with the railway, the eventual oversized edge would increase the effect of derailment for the well-

30 known "lever effect" exerted by reaction with the side of the railway. The object of the present invention is to realize a wheel for trains that reduces the risk of derailment of trains in any conditions of use.

Another object of the present invention is to realise a wheel with these above-said characteristics that in a normal operative condition does not reduce the grade of connections of the wheel to the railway and so does not have an influence on the driving power of the locomotives.

Another object of the present invention is to realise a wheel for trains which does not cause modifications to the present railways.

A further object of the present invention is to realise a wheel for trains which is of easy applicability to the present trains, does not involve additional costs and does meet the present technological constraints.

According to the invention, these intents are overtaken by a wheel presenting a rolling rib with an operative edge which consists of a concave part which rests and follows the lateral convex edge of the top of the railway and of a convex part which extends radially outwards from this concave part and flanks, without touching, the side of the rail, characterised in that this rolling rib includes also an additional rolling edge extending subsequently outwards and sideways in comparison with this convex part so as to be situated at a greater distance from the side of the rail than said convex part. In this way the additional rolling edge does not influence the normal operative conduct of the wheel at all, does not modificate the present railways, determinates an extremely cheap additional cost and also is able to work in state of emergency in a strong lateral skidding of the wheel to keep this one in connections with the railway and to prevent the derailment of the train.

In conclusion, the wheel according to the invention has now two rolling edges, the first one normally operative and the second one for reserve ready to work in a state of emergency, exclusively.

The characteristics of the present invention will be made more evident by the following detailed description of an embodiment thereof, which is illustrated by way of not limitative example in the enclosed drawings, in which:

Fig. 1 shows a wheel according to this invention in diametrical section and with the central part removed to simplify the design; Fig. 2 shows a quarter of the wheel according to Fig. 1 in sideview with transversal section;

Fig. 3 shows in diametrical section a couple of wheels according to this invention, belonging to the same train, in normal conditions of engagement with a couple of railways; Fig. 4 shows in diametrical section the same couple of wheels in lateral skidding conditions of the vehicle.

In Figs. 1 and 2 a wheel is shown according to the invention, indicated as a whole with number 1, which is made by a thin central web 2 and by a thick peripherical rim 3 opportunely shaped. In particular the peripherical rim 3 shows a rolling profile on the railway, which beginning from a support plane line 4 develops in a lateral rolling rib 5.

The latter has an operative edge formed by a concave part 6 destined for resting on the lateral convex edge 7 of the railway 8 and following partially the development of the same (fig. 3) and by a convex part 9 extending radially outwards from the concave part 6 and flanking without touching the side of the railway (fig. 3) to assure, in normal operative conditions, the maintenance of the wheel in the correct position of lateral engagement with the railway. As mentioned above, this operative condition is represented in figure 3, which shows two wheels of the same train in engagement with corresponding rails of a rolling railway.

The rolling rib 5 comprises also an additional rolling edge 10 which further extends outwards and sideways from the convex part 9 so as to be at a greater distance from the side of the railway than the convex part (fig. 3). As proved in figure 3, in normal operative conditions, the additional edge 10 does not touch the railway and so it does not influence the work of the wheel.

In case of strong lateral skidding of the train, on the contrary, the additional edge of one of the two wheels of the vehicle starts to operate with the side of the corresponding railway so to keep the wheel, and therefore the vehicle to which it is part of, in its working location and thus to prevent the derailment of the train.

The size of the rolling rib of the wheel according to this invention may obviously change according to the diameter of the wheel itself. For information only, it is possible to state exactly that in a wheel with a diameter comprised between 760 mm. and 1000 mm., the inclination of the internal face 11 of the additional edge 10 with respect to the horizontal resting line of the wheel on the railway is preferably equal to about 80°.

Claims

CLAIMS 1. A wheel for railway vehicles or similar including a rolling rib (5) with an operative edge formed by a concave part (6) which rests on and follows the lateral convex edge (7) of the rail top (8) and by a convex part (9) that extends radially outwards from this concave part (6) and flanks, without touching, the side of the rail, characterised in that said rolling rib (5) has an additional rolling edge (10) too that further extends outwards and sideways from this convex part (9) so as to be situated at a greater distance from the side of the rail than said convex part (9). 2. A wheel according to claim 1, characterised in that said additional edge (10) has an internal face (11) about inclined 80° as to the horizontal resting line (4) of the wheel on the railway.