GB2182294A

GB2182294A - A wheel set for a rail vehicle

Info

Publication number: GB2182294A
Application number: GB08621820A
Authority: GB
Inventors: Alfred Uttner
Original assignee: Messerschmitt Bolkow Blohm AG
Current assignee: Airbus Defence and Space GmbH
Priority date: 1985-10-31
Filing date: 1986-09-10
Publication date: 1987-05-13
Also published as: DE3538779C1; FR2591538B1; FR2591538A1; IT8621960A0; GB2182294B; IT1197500B; JPS62103203A; GB8621820D0

Abstract

Wheels 2, 3 are secured fixed on respective parts 4, 5 of a two-part axle 1. The parts 4, 5 are independently rotatable but are mutually non-displaceable by reason of the interpolation of radial bearings 6, which absorb axial forces from the two wheels 2, 3 in an axle region in which the one axle part 4 penetrates by way of its end 4.1 into the other axle part 5 which is of hollow-cylindrical form as at 5.1 at least towards the middle of the wheel set. For achieving differential rotation of the wheels 2, 3 the two axle parts 4, 5 are couplable by way of a coupling 10, two coupling parts 10.1 and 10.2 of which define a working gap 10.3, concentric to the axle 1, for a magnetisable powder. The hollow-cylindrical axle part end 5.1 is designed as a housing of the outer part 10.1 of the coupling 10, or as the outer part 5.1/10.1 thereof and the inner part 10.2 of the coupling 10 is fixed firmly on the shaft end 4.1. <IMAGE>

Description

SPECIFICATION A wheel set for a rail vehicle This invention concernsa wheel setfora railvehicle.

The invention is more particularly concerned with a wheel set as aforesaid which comprises wheels fixedly mounted upon a two part axle and having profiled running surfaces or rims, with one wheel associated with each axle part respectively, in which the two axle parts on the one hand are adapted to be independently rotatable but mutually nondisplaceable, by the interpolation of a radial bearing which absorbs axial forces ofthe two wheels, in an axle region in which one axle part penetrates by an end thereof into the other axle part which is of hollow-cylindrical form at least towards the middle ofthe wheel set, and on the other hand, for achievement of differential rotational speeds of the wheels, are mechanically connected by way of a coupling or clutch comprising two parts which define a working gap, concentric to the axle, for a magnetisable powder.

In the case of such a wheel set in accordance with a prior proposal, bearings intended for the support of the coupling or clutch are subject to relatively slight stressing because they, like the radial bearings between the two parts, run only atthe differential rotational speed of the wheels or ofthe parts, as permitted by the magnetic powder coupling or clutch. In this connection, however, the proposed positioning of the coupling or of both coupling parts at the outer periphery ofthe hollow-cylindrical axle ends necessitates a torsionally stiff connection element for the transmission oftorque between the outer part of the coupling and the associated axle part, which connection element has to be flexurally relatively soft, in orderto preclude changes in the working gap ofthe coupling as a result of axle deformations.The necessaryco-ordination ofthe bending orflexural stiffness ofthe axle under static and dynamic loading makes this connection element a critical component ofthe wheel set.

The problem underlying the invention is, therefore, to construct a wheel set ofthe kind mentioned at the introduction hereof in such a way that such a flexurally-soft, torsionally-stiff connection element between the coupling outer part and the associated axle part can be dispensed with.

This problem is solved by providing forthe hollow cylindrical axle part end to be designed as a housing ofthe outer part of the coupling orclutch or as the outer part thereof, and for the inner part ofthe coupling or clutch to be arranged so asto be firmly seated on its respective shaft part end.

With appropriate enlargement of the radial distance between the hollow-cylindrical axle part end andthe end ofthe othershaft part,this is usable, through the supporting action of a radial bearing (preferably in an embodiment in accordance with claim 2) as a basis, practicallyfreefrom axle deformation,forthe inner partofthe coupling or clutch and in this way one obtains, atthe same time,forthe outer part thereof, a positioning possibility which economises on the flexurally-soft connection el ement.In this respect, the radial bearing, associated with the root of the shaft end (inthemannerchar- acterised in claim 3) is at the same time usable as supporting bearing forthe outer part ofthe coupling or clutch i.e. compared with the prior proposed wheel set, separate supporting bearings forthe coupling or clutch can be completely dispensed with.

The invention will be described further, by way of example, with reference to the accompanying draw ing in which the single figure is a part-sectional elev ation of a preferred exemplified embodiment of the wheel set of the invention.

As shown, the illustrated wheel set comprises wheels 2 and 3 fixed firmly or securely to respective parts of a two part axle 1. The wheels 2,3 of course, have profiled running surfaces or rims. In the middle of the figure, two alternative possibilities for coupling the associated axle parts 4 and 5, making up the axle 1,areshownschematically.

Upon the wheel set travelling along a track, the wheels 2 and 3 need to be partially decouplablefrom one another, but must nevertheless remain mutually non-displaceable. Forthis, on the one hand the one axle part 4 penetrates by way of its end 4.1 into the otheraxle part5which is ofhollow-cylindrical form at least towards the middle of the wheel set, with the interpolation of two radial bearings 6 consisting for exampleofone roller bearing each,there being one such radial bearing 6 arranged each at the end orex- tremity of the shaft end 4.1 and at the root of the shaft end 4.1.

The two radial bea rings 6 are so mutually placed thattheyare ableto absorb axial forces ofthetwo wheels 2 and 3 by way of the independently rotatable axle parts 4 or 5 respectively. This is ensured by a so-called thrust ring 7 on the one hand and a socalled thrust disc 8 on the other hand, which, in an axiallyfree manner, brace the two radial bearings6 with an interposed spacer sleeve 9, on the shaft end 4.1. In this connection, the thrust ring 7 positioned at the root of the shaft end 4.1. is connected (by way of a closure disc 12) to the hollow-cylindrical axle part end 5.1, and the thrust disc8 is connected to the shaft end 4.1.

On the other hand, a connection can be established between the two axles parts 4 and 5 by way of a mag netic powder coupling or clutch 10. In the case ofthe magnetic powder coupling construction illustrated above the longitudinal axis ofthe wheel set, the hollow-cylindrical axle part end 5.1 forms the housing fora separate coupling outer part 10.1 made of magnetisable material.On the other hand, in the case ofthe alternative construction ofthe magnetic pow dercoupling or clutch 10 illustrated below the longitudinal axis ofthewheel set,the axle partend 5.1 serves also as the outer part 10.1 ofthe coupling or clutch 10, in which case the relevant axle part end5 may consist entirely of a magnetisable steel (for ex- ample St 50 or25 CrMo5V).

In both cases, the inner part 10.2, provided with an energising coil 11, of the magnetic powder coupling or clutch 10 is arranged so as to be seated firmly on the shaft end 4.1 or the spacer sleeve 9, that (apart from the magnetic powder coupling orclutch 10) no further connection means is necessaryforthe trans- mission of torquf between the two axle parts 4 and 5.

Moreover, because it is possible to support the hollow-cylindrical axle part end 5.1 byway ofthe closure disc 12 ofthe coupling or clutch lOon the radial bearing 6 associated with the root of the shaft end 4.1, an additional economy can be achieved in that a separate supporting bearing forthe coupling outer part 10.1 is not needed. Finally,thearrange- ment of the inner part 10.2 between the two radial bearings 6, in otherwordsin an axle partregion which is quasi-flexurally-stiff even under dynamic loading, ensures that axle deformations cannot, in practice, have any significant effect on working gap 10.3 ofthecoupling or clutch 10.

Moreover, the magnetic powder coupling or clutch 10 is effective in known manner, i.e. a magnetic powder (not shown) in the working gap 10.3 is magnetis ablebytheenergisingcoil 11 in such a way that a chain-like formation of magnetic powder particles between the inner and outer parts 10.2 and 10.1 arises to lead to afriction-locking connection thereof (byway ofthe magnetic powder) to result in torque transmission. In this respect, by appropriately con trolling the current ofthe energising coil 11,slippage ofthe magnetic powder coupling or clutch 10 is adjustable and variable.

It is self-evident that in relation to the mounting of the axle parts 4 and 5 by way ofthe two radial bearings 6, the orientation thereof so as to be oppositely effective in the axial direction is compulsory oniy insofarthatthey must absorb axial forces from the wheels 2 and 3. Thus, forthis purpose, equally, two mutually opposed radial bearings 6 can be arranged solely atthe root ofthe shaft end 4.1 sothatthe bearing 6 at the extremity of the shaft end 4.1 needs onlyto be effective in relation to radial loads.

Claims

1. Awheel set, for a rail vehicle, comprising wheelsfixedly mounted upon atwo-part axle and having profiled running surfaces or rims, with one wheel associated with each axle part respectively, in which thetwo axle parts on the one hand are adapted to be independently rotatable but mutually nondisplaceable, by the interpolation of a radial bearing which absorbs axial forces ofthe two wheels, in an axle region in which one axle part penetrates by an end thereof into the other axle partwhich is of hollow-cylindrical form at leasttowards the middle ofthe wheel set and on the other hand, forthe achievement of differential rotational speeds of the wheels, are mechanically connected byway of a coupling or clutch comprising two parts which define a working gap, concentric to the axle, for a magnetisable powder, characterised in that the hollowcylindrical axle part end is designed as a housing of the outer part ofthe coupling or clutch or as the outer partthereof, and the inner part ofthe coupling or clutch is arranged so as to be firmly seated on the respective shaft part end.

2. Awheel set as claimed in claim 1 having its shaft end mounted, at its end and at its root, relative to the hollow-cylindrical axle part end by bearings and characterised in that the inner part of the coupling or clutch is arranged centrally between the two bearings.

3. Awheel set as claimed in claim 2, characterised in that the hollow-cylindrical axle partend is supported, by way of a closure disc of the coupling or clutch, on the bearing disposed at the root of the shaft end.

4. A wheel set, for a rail vehicle, substantially as hereinbefore described with reference to and as illus- trated in the accompanying drawing.