CA1048560A

CA1048560A - Railway vehicle suspensions

Info

Publication number: CA1048560A
Application number: CA76267839A
Authority: CA
Inventors: Bernard R. Wing
Original assignee: Dunlop Ltd
Current assignee: Dunlop Ltd
Priority date: 1976-01-08
Filing date: 1976-12-14
Publication date: 1979-02-13
Also published as: SE7700131L; GB1566710A; SE406172B

Abstract

ABSTRACT
A railway vehicle suspension in which a resilient spring member is provided with heating means operable at low ambient temperatures to heat the spring member to a suitable working temperature.

Description

1~48560 This invention relate~ to railway vehicle suspen~ions~
and in particular, though not exclu3ivel~, to elastomeric material suspensions for use at very low ambient temperatures.
- Hitherto vehicle suspensions have not been protected from low temperatures and, in the case of rubber springs the hysteresis losseæ during initial low speed running have been relied on to enable tbe resilient characterlstics of rubber to be improved to a satisfactory level by the consequent temperature ri~e. Compounding of suitable rubber materials is, however, particularly difficult and the advent of high speed rolling stock of greatly improved accelerative capabilities has made effective spring design even more difficult.
An object of the present invention is to provide an ; effective elastomeric material railway vehicle suspen~ion for use in very low ambient temperatures which may operate to the ,. .
required characteristics ;mmediately the vehicle is run.
According to one aspect of the present invention a railway vehicle suspension comprise~ at least one spring member and heating means for said member operable at low ambient temperatures to heat the ~pring material to a suitable working temperature.
Preferably the spring material i~ a resilient ela~tomeric material ~uch as rubber~
~emperature sensors or suspen~ion movement sensors are preferably provided to switch off the heating means when the springs are-in use following which hysteresis losses within the ~pring material provide the required workin~
temperature.
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1~48560 ~he heating means ma;y be external of tbe spring or internal of the spring. Heat transfer may be effected by radiation, conduction or convection from the heating means to the ~priDg material.
Heat insulation may be provided between the spring a~d adja¢ent metal members of the railway vehicle suspension, for examiple a layer or layers of asbestos ba~ed material 9 to minimise heat 108~ to the metal members. Alternatively an air gap may be provided between the spring and metal members of the railwa~ vehicle suspension to avoid significant heat losses to sald metal members. ~hus, for example 9 a small air gap may be provided between facing surfaces o~ the spring and metal members of the suspensioDis except at localised regions of contact at which the spring iR located relative to ~aid metal me~ibers.
Suitable heating means may comprise for exampleO-; (1) Electri¢ally-heated plates ad~acent to or integral !, with one or both end plats~ of a conventional rubber block spring in which the rubber block is bonded between end plates.
(2) Electrical-heating means attacbed to or within one ~ or more metal interleaving plates of a multi-block..
rubber spring.

(3) Ele¢trical-heating by means of passing a current through the spring memberr For a spring member comprising elastomeric material and compounded to - have a suitable electrical resistance the heating ma~
be by passing the current through the ela~tomeric :

~485SO
material

(4) Heating by means of ~ets of warm air directed at tho spring and heated by small heaterR or taken from a .' vehicle exhau~t cooling system or carriage interior.
~he spring if of rubber preferably includes one or more through pa~sages to increase the surface area~

(5) Heating by internal resonance within a spocially compounded elastomer or otber suitable material causing excitation by for example~ ultra~onics9 High Frequenc~ induction or microwavesO
~he electrical power may be provided from a supply ~' common to the vehicle heating system or separatel~. Onl~ a small amount of power, less than a kilowatt per spring may be required~ Preferably the heating means is switched off . .
when the vehicle is used and this may be done by means operated b~ the driver inserting his "ke~" or by sen~ing the vehicle movement ~uch as for example the operation of its generators or movement of the suspensionO Alternativel~
temperature sensors in the spring material may be used to switch the heating means so as to maintain a pre-set minimum I spring temperature~
; In a preferred embodiment of the present invention a railway vehicle suspension compri~e~ two axle boxe~ located .~ one at each end of an axle and each resiliently connected to ;~ 5 a vehicle bogie b~ means of chevron type springs each comprising . .
~ a sandwich of V-shaped metal platesand interleaving layers of ., . rubber~
;. ~he interleaving layers of rubber are formed of a :', , 40 ....
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1~4~560 ruhher compounded to have a suitable electrical resistance and thereby generate heat when an electrical current i8 . passed through the rubber between end metal plates of the springO Thin layers of asbestos are interposed between the end metal plates and the contacted metal surfaces of the axle boxes and bogie to minimise heat losses from the springs and electrically insulate the springs from the bogie.
Operation of the heating of each spring is controlled by means of temperature sensor attached to a~ $nterleaving metal plate of the springD
Whilst the invention ha~ been specifically described in relatio~ to spring members comprising rubber and other : elastomeri¢ materials and is particularly useful in such application~, it is also of use in conjunction with metal springs such as coil springs and leaf springs whose charact-eristics may be adversely affected by low temperature.

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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:-

1. A railway vehicle suspension comprising at least one resilient spring member and heating means for said member operable at low ambient temperatures to heat the spring material to a suitable working temperature.

2. A railway vehicle suspension according to claim 1 wherein heat insulation material is provided between the spring and adjacent metal members of the railway vehicle suspension.

3. A railway vehicle suspension according to claim 1 or claim 2 wherein an air gap is provided between the spring and metal members of the railway vehicle suspension to restrict heat losses to said metal members.

4. A railway vehicle suspension according to claim 1 wherein a temperature sensor is provided to control operation of the heating means.

5. A railway vehicle suspension according to claim 1 wherein a suspension movement sensor is provided to control operation of the heating means.

6. A railway vehicle suspension according to claim 1 wherein the spring member comprises a stack of two or more metal plates interleaved by one or more layers of elastomeric material.

7. A railway vehicle suspension according to claim 6 wherein the heating means comprises one of said metal plates of the spring member, or a metal plate adjacent said spring member, and arranged to be electrically heatable.

6.

8. A railway vehicle suspension according to claim 1 wherein the spring member comprises elastomeric material compounded to have a suitable resistance to enable it to conduct electricity and thereby generate heat.

9. A railway vehicle suspension according to claim 1 wherein the heating means comprises a material which generates heat under ultrasonic, High Frequency induction, or microwave excitation.

10. A railway vehicle suspension according to claim 1 wherein the heating means is operable to direct jets of warm air to the spring member.

11. A railway vehicle suspension according to claim 10 wherein the spring member includes one or more passages through which warm air may flow.