WO1991013787A1

WO1991013787A1 - Wheelset for rail vehicle

Info

Publication number: WO1991013787A1
Application number: PCT/CA1991/000082
Authority: WO
Inventors: Steven P. Lapp; Peter E. Timan
Original assignee: Utdc Inc.
Priority date: 1990-03-15
Filing date: 1991-03-14
Publication date: 1991-09-19
Also published as: AU7448291A

Abstract

A wheelset for a transit vehicle comprises a stationary axle tube (36) connected to the vehicle with hubs (44) formed at each end. A conical wheel (60) is mounted on each hub (44) and the wheels are interconnected for conjoint rotation by a torque tube (74) extending through the axle tube (36).

Description

WHEELSET FOR RAIL VEHICLE

The present invention relates to wheelsets for rail vehicles.

Wheels used on rail vehicles conventionally have a conical tread that runs along the rails with the wheels interconnected by a solid axle. The conicity of the wheels provides different rolling radiuses for each wheel as it negotiates a curve and thus allows the wheelset to adopt a position in which each wheel is rotating at the same rate while travelling a different distance.

The axle on which the wheel is mounted conventionally rotates within bearing assemblies located at the corners of the truck used to support the vehicle. The axle therefore has to transmit torque between the two wheels but more significantly accommodate the vertical loads imposed upon the wheels. Because the axle is rotating, the reversing dynamic loads are imposed upon the axle which requires it to be stiff and therefore heavy. The use of rail vehicles in mass transit applications has resulted in the need for a compact light weight vehicle that may be produced economically. The large axle assemblies required for conventional axles are unsatisfactory as they increase the unsprung mass of the vehicle and its overall weight. Free-wheeling axles have been proposed in which one wheel may rotate independently of the other but in this arrangement the self-centering action of the coned wheelset is lost, resulting in high flange contact and rapid wear of the individual wheels. There is therefore a need for a lightweight robust axle that still permits the conjoint rotation of coned wheels.

Accordingly, the present invention provides a wheelset for a rail vehicle comprising an axle tube

SUBSTITUTE SHEET having a hub disposed at opposite ends, a wheel having a conical tread rotatably mounted on said hub by bearings and a torque transmitting tube extending through said axle tube and being connected to each of said wheels whereby conjoint rotation of said wheels is provided. The axle tube may be utilized to connect pivotally the wheelset to the vehicle through pivotal connections intermediate the ends of the axle tube.

It is preferred that the torque tube and wheel are interconnected by a radially-extending disk.

An embodiment of the invention will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a diagrammatic representation of a transit system;

Figure 2 is a view on the line 2-2 of Figure 1; and

- Figure 3 is a view on the line 3-3 of Figure 1.

Referring therefore to Figure 1, a transit system 10 comprises a pair of transit vehicles 12 interconnected by an articulated joint 14. Each of the vehicles 12 is substantially identical in construction and only one will therefore be described in detail. The transit vehicle 12 has a body 16 supported on a pair of trucks 18. The trucks 18 are maintained in longitudinally spaced relationship by a chassis 20 extending beneath the body 16. As can best be seen in Figure 2, each of the trucks 18 is connected to the body 16 by a turntable 22 that permits rotation about a generally-vertical axis V-V. Turntable 22 comprises an outer race 24 connected to the body 16 and an inner race 26 connected to a horizontal support member 28. Ball bearings 30 are located between the races 26, 28 to accommodate rotation between the inner and outer races. The laterally extending outer ends of the support 28 are connected to inclined suspension, members

SUBSTITUTE SHEET 32 formed from elastomeric cylinders. The suspension members 32 extend between inclined mounting plates 34, one of which is rigidly secured to one end of an axle tube 36. As may best be seen in Figure 3, the axle tube 36 includes a pair of cylindrical bosses 38 that are journaled in bushes 40 located within bores 42 in the chassis 20. The axle tube 36 may thus rotate about the vertical axis V-V relative to the chassis 20 which is coincident with the axis of rotation of the turntable 22. The axle tube 36 is of square cross-section and has a hub 44 welded at each end. Each of the hubs 44 is of similar construction and therefore only one will be described in detail. The hub 44 has a cylindrical outer surface"46 with a radially-extending flange 48 at the inner end. The outer end of the surface 46 is screw-threaded as indicated at 50.

A pair of tapered roller bearings 52 are located cm the outer surface 46 and maintained in spaced relationship from the flange 48 by means of a spacer 54. The bearings 52 are held on the hub 44 by means of a nut 56 received on the screw thread 50 which acts through a spacer 58 to locate the bearings.

The bearings 52 support a wheel 60 that has a stepped bore 62 to receive the bearings 52. The periphery of the wheel 60 is formed with a frustoconical tread 64 and a radially extending flange 66 at its inside. The flange 66 and tread 64 are of a standard configuration suitable for running along a standard profile rail 68 forming a track for the vehicle 12. The wheel 60 is freely rotatable about the hub

44 by virtue of the bearings 52 and is retained on the hub by means of a retaining ring 70. Seals 72 are located on opposite sides of bearings 52 and engage the periphery of spacers 54,58 to seal the cavity. The wheels 60 are interconnected by a torque tube 74 that is located on the interior of the axle tube 36 and has a pair of bosses 76 at opposite ends. The

SUBSTITUTE SHEET bosses 76 project laterally beyond the outer end of the hub 44 to be aligned with the outer face of the retaining ring 70. An annular disk 78 extends between the boss 76 and the retaining ring 70 and is attached to the boss and wheel 60 by bolts 80,82 respectively. The load from the bolts 80,82 is distributed by means of an annular pad 84 and cylindrical plug 86.

The support 28 and axle tube 36 are maintained in vertical alignment by means of a draglink assembly 88 that extends from the mounting member to the axle tube 36. Draglink assembly 88 includes a horizontal draglink 90 extending between a pair of vertical projections 92,94 extending from the axle tube 36 and support 28 respectively. Pitch movement between the support 28 and axle tube 36 is also accomodated by means of a roll bar assembly 96 having opposite ends offset to opposite sides of the axle tube 36 and its intermediate portion secured to the support member 28. In this manner, elevation of one wheel 60 relative to the support 28 will induce a torsional loading in the roll bar 96 to control the rolling movements between the wheels and the body.

Longitudinal loads imposed by acceleration and deceleration are transferred from the body 16 to the chassis 20 by a longitudinal link 98 having ball joints at opposite ends to accomodate vertical and lateral movement of the body 16 on the chassis 20.

In operation, therefore, the vertical loads of the vehicle 12 are transmitted through the turntable 22 and support 28 into the suspension members 32 and to the outer extremities of the axle tube 36. The axle tube 36 is stationary and therefore is not subjected to the rotating bending loads of a solid axle. The bearings 52 permit rotation of the wheels 60 about the hubs 44 but are interconnected through the tube 74 and disks 78. Therefore, upon the wheels negotiating a curved track, the conicity of the treads 64 will enable the wheelset formed between the wheels and axle tube 36 to adopt a position relative to the rails 68 in which each wheel is rotating at the same angular velocity whilst avoiding contact of the flanges 66 with the track 68. The tube 74 is only subjected to the differential torque between the two wheels rather than the bending loads induced by the weight of the vehicle and may therefore be of relatively thin wall construction to reduce the mass of the tube.

SUBSTITUTE SHEET

Claims

We claim:

1. A wheelset for a rail vehicle comprising an axle tube having a hub disposed at opposite ends, a wheel having a conical tread rotatably mounted on said hub by bearings and a torque transmitting tube extending through said axle tube and being connected to each of said wheels whereby conjoint rotation of said wheels is provided.

2. A wheelset according to claim 1 wherein said axle tube includes pivotal connections intermediate its ends for connection to a chassis to permit rotation about a vertical steering axis.

3. A wheelset according to claim l wherein said axle tube includes suspension mounting brackets at spaced locations.

4. A wheelset according to claim 1 wherein said wheel is connected to said torque tube by a disk extending radially outwardly from said tube to said wheel.

5. A wheelset according to claim 1 wherein said axle tube is non-circular in cross section.

6. A wheelset according to claim 5 wherein said axle tube is square in cross section.