GB2173277A

GB2173277A - Vehicle suspension arrangement

Info

Publication number: GB2173277A
Application number: GB08506808A
Authority: GB
Inventors: Jucker Zelo Nicolaisen
Original assignee: Silentbloc Ltd
Current assignee: Silentbloc Ltd
Priority date: 1985-03-15
Filing date: 1985-03-15
Publication date: 1986-10-08
Also published as: GB8506808D0

Abstract

In a vehicle suspension arrangement a resilient member 13 is located between the chassis 11 and the axle bearing 12. The resilient member is made of rubber and can either be spherical or cylindrical. In its undeformed state the resilient member has a circular cross-section in a plane which is other than perpendicular to the direction of loading. It is attached to the chassis and axle bearing by means of metal plates 14, 15 or strips. If cylindrical, the resilient member can have convex or concave axial faces. <IMAGE>

Description

SPECIFICATION Vehicle suspension arrangement The present invention relates to vehicle suspension arrangements, in particular, for commercial vehicles and railway rolling stock.

Vehicle axles are flexibly attached to the vehicle frame or chassis by means of springs.

The springs may be of metal or rubber or may be air springs, and may be attached to the vehicle frame via axle bearings and a subframe or bogey.

A desired characteristic of such springs is that they exhibit a constant natural frequency, regardless of the load applied. Thus the quality of the load will then remain unaltered whether the vehicle is empty or fully loaded.

This has previously thought to be difficult to achieve using rubber springs without resorting to complicated (and therefore costly) profiles while complex control systems are required in the case of all springs.

It is therefore an object of the present invention to provide a simple, inexpensive spring design for a vehicle suspension arrangement which exhibits a substantially constant natural frequency over a load range corresponding to at least normal working conditions.

According to the invention, there is provided a vehicle suspension arrangement comprising an axle bearing component, a chassis component and a resilient member located between these two components, the resilient member having a circular cross-section in its undeformed state in a plane which is other than perpendicular to the direction of loading in use.

The axle bearing component may be the axle bearing itself or some other component attached to the bearing. The chassis component may be the vehicle frame, the chassis itself, or a subframe or a bogey.

The resilient member is preferably made of rubber, either natural or synthetic. It may take the form of a sphere or a circular cylinder, preferably one in which the axial dimension is less than the diameter, and is therefore in the form of a thick disc. The cylinder may alternatively have convex or concave axial faces, but in all variants, it is preferably symmetrical.

The resilient member may be fastened to the axle bearing and chassis components by means of metal discs or strips bonded to the rubber, or alternatively, they may be mechanically trapped. Depending upon the suspension design, two or four units comprising a rubber member and metal fixings are preferably used to support each axle, and these may be installed at an angle, e.g. to increase the stiffness in a transverse direction.

It has been found that in an arrangement according to the invention, the stiffness varies exponentially with load, with the result that a generally constant natural frequency is shown.

The invention may be carried into practice in various ways and some embodiments will now be described by way of example with reference to the accompanying drawings, in which: Figures 1 and 2 are respectively front and side elevations of a resilient member in accordance with one embodiment of the present invention; Figures 3 and 4 are views similar to Figs. 1 and 2, showing a second embodiment; Figures 5 and 6 are views similar to Figs. 1 and 2, showing a third embodiment; Figures 7 and 8 are views similar to Figs. 1 and 2, showing a fourth embodiment, and; Figure 9 is a typical graph showing the way in which deflection varies with load, and the way in which the natural frequency varies with deflection, for an embodiment similar to that shown in Fig. 1.

Figs. 1 and 2 show one suspension unit for a single axle on railway rolling stock. In use two or four such units would be employed per axle. The unit comprises a chassis component 11, a bearing component 12 and a resilient or spring member 13 fastened to these two components by means of metal discs 14,15 which are bonded to the spring member 13 and which are welded or bolted to the components 11,12. The spring member 13 is made from a synthetic rubber material.

In use, the unit is orientated so that the load is applied perpendicularly downwards as shown in Fig. 1. As can be seen from Fig. 9, the deflection (curve A) is generally exponential with the result that the natural frequency (curve B) is generally constant.

In the embodiment shown in Figs. 3 and 4, a short, cylindrical rubber spring member 33 is fastened to the chassis and bearing components 11,12. In this case, the fastening is by means of metal strips 34,35 which are bonded to the spring member 33 and welded or bolted to the components 11,12. The strips 34,35 are located along the cylindrical surface of the spring member 33, at diametrically opposite positions.

In use, the unit is orientated so that the load acts in a line through the two strips 34,35.

The embodiment shown in Figs. 5 and 6 is similar to that shown in Figs. 3 and 4, but in this case, the cylindrical spring member 53 has convex end faces 56,57. The embodiment shown in Figs. 7 and 8 is also similar but in this case the end faces 76,77 of the resilient member 73 are concave.

In general, the configuration shown in Figs.

1 and 2 would offer the greatest resistance to deflection, followed by that shown in Figs. 5 and 6, then that shown in Figs. 3 and 4, with the embodiment shown in Figs. 7 and 8 offering the least resistance.

Claims

1. A vehicle suspension arrangement comprising an axle bearing component, a chassis component and a resilient member located between these two components, the resilient member having a circular cross-section in its undeformed state in a plane which is other than perpendicular to the direction of loading in use.

2. A vehicle suspension arrangement as claimed in claim 1 in which the resilient member is made of natural or synthetic rubber.

3. A vehicle suspension arrangement as claimed in claim 1 or claim 2 in which the resilient member is in the form of a sphere.

4. A vehicle suspension arrangement as claimed in claim 1 or claim 2 in which the resilient member is a circular cylinder in which the axial dimension is less than the diameter.

5. A vehicle suspension arrangement as claimed in claim 4 in which the cylinder has convex axial faces.

6. A vehicle suspension arrangement as claimed in claim 4 in which the cylinder has concave axial faces.

7. A vehicle suspension arrangement as claimed in any preceding claim in which the resilient member is symmetrical.

8. A vehicle suspension arrangement as claimed in any preceding claim in which the resilient member is fastened to the axle bearing the component and the chassis component by means of metal members bonded to the resilient member.

9. A vehicle suspension arrangement as claimed in any preceding claim in which the axle bearing component comprises the axle bearing itself and the chassis component comprises the chassis itself.

10. A vehicle suspension arrangement constructed and arranged substantially as herein specifically described with reference to and as shown in Figs. 1 and 2, Figs. 3 and 4, Figs. 5 and 6, or Figs. 7 and 8 of the accompanying drawings.