WO1999032307A1

WO1999032307A1 - Noise reduction for wheels

Info

Publication number: WO1999032307A1
Application number: PCT/AU1998/001027
Authority: WO
Inventors: John Gemmell Padgett
Original assignee: 3M Australia Pty Ltd
Current assignee: 3M Australia Pty Ltd
Priority date: 1997-12-19
Filing date: 1998-12-11
Publication date: 1999-07-01
Anticipated expiration: 2000-06-19
Also published as: AUPP101697A0

Abstract

A noise reduction or damping apparatus (10) for use with a wheel (50), the wheel (50) including a hub (51) and an outer rim (52) with a junction region (53) between the hub (51) and rim (52), the rim (52) includes an axially projecting flange (54) having an outer bearing surface (56), an inner surface (55) and a free end face (57), the apparatus (10) including a generally annular shaped body (12) having an inner edge portion and an outer edge portion, the annular shaped body (12) when in the fitted position, being securable to the inner surface (55) of the flange (54) of the rim (52).

Description

NOISE REDUCTION FOR WHEELS

This invention relates generally to noise reduction or damping for wheels and more particularly, but not exclusively for railway carriage wheels.

In recent years, the noise generated by the wheels or bogies of railway carriages during operation has become a serious environmental problem.

Apart from providing sound barriers at appropriate locations, one traditional solution has been to provide a steel ring which is fitted into a slot in the wheel rim. One issue to install the ring the wheel must be machined which can cause other problems related to stress relief etc. Another proposal has been to provide a cover formed of a laminate of a polymer and aluminium which overlies the wheel hub. The major disadvantage of these arrangements is that the railway vehicle wheels have to be removed from the carriage in order for the devices to be fitted or can only be fitted to wheels prior to them being fitted to the vehicle.

It is an object of the present invention to provide an arrangement which alleviates one or more of the aforementioned problems.

The noise reduction or damping apparatus according to the invention is suitable for use with wheels of the type which include a hub and an outer rim with a junction region between the hub and rim. The rim includes at least one axially projecting flange having an outer bearing surface, an inner surface and a free end face. For example, the wheel rim may have one axially projecting flange projecting to one side of the hub. In another arrangement the wheel rim may have two axially projecting flanges projecting to opposite sides of the hub.

According to one aspect of the present invention there is provided a noise reduction or damping apparatus suitable for use with a wheel, the wheel including a hub and an outer rim, the rim includes an axially projecting flange having an outer bearing surface, an inner surface and a free end face, the apparatus including a generally annular shaped body having a inner edge portion and an outer edge portion, the annular shaped body when in the fitted position, being securable to the inner surface of the flange of the rim.

In one preferred embodiment, there is a junction region between the hub and rim and, when the annular shaped body is in the fitted position the inner edge portion of the body is disposed in the region of the junction between the wheel hub and the wheel rim.

When in the fitted position the outer edge portion of the body may terminate generally at or extend beyond the free end face of the flange of the wheel.

In a preferred form of the invention, the inner edge portion of the annular shaped body is disposed in the region of the junction between the wheel hub and the wheel rim and the outer edge portion terminates generally at or extends beyond the free end face of the wheel.

In one preferred form of the invention, the annular shaped body is in the form of a ring like element which extends around the inner surface of the flange of the wheel rim when in the fitted position.

The ring like element may in one form include a metal strip or band which in use is secured to the inner surface of the wheel rim flange. One preferred metal which can be used is aluminum although it will be appreciated that other metals may be suitable.

In another form of the invention, the ring like element includes a flexible band which in use is secured to the inner surface of the wheel rim. Preferably, the band is formed of a a visco elastic material and more preferably a visco elastic polymer. There may further be provided a layer of pressure sensitive material on at least one side of the flange or incorporated into the structure of the band itself. The pressure sensitive material may for example be in the form of fast curing pressure sensitive adhesive. For example, the material may be a tape or film such as that sold under the trade mark Scotch 4959 NHB. In another form of the invention, the ring like element may be in the form of a laminated structure which includes an inner layer of visco elastic material such as for example, that described above, and an outer constraining layer of metal such as aluminium. In one preferred form the outer layer extends outwardly from the free end face of the rim when in the fitted position. It has been found preferable that the extended portion is about 2 to 3mm although it may be more or less. Preferably, the thickness of each layer is about 1 to 3mm thick.

In another form of the invention, the annular shaped member may comprise a plurality of spaced apart segments arranged on the inner surface of the ring to define a ring like structure.

According to yet another aspect of the present invention there is provided a method of installing a noise reduction or damping apparatus on a wheel the wheel including a hub and an outer rim, the rim including an axially projecting flange having an outer bearing surface, an inner surface and a free end face, the method including the steps of

(a) providing damping or noise reduction apparatus, which includes a strip, the strip including an outer surface between opposed end portions, the outer surface having thereon an adhesive and a removable cover liner overlying the adhesive; (b) forming the strip into a generally ring like configuration which generally conforms to the periphery of the inner surface of the flange of the wheel;

(c) locating the strip in its ring like configuration in position with the cover liner thereof in abutment with the inner surface of the wheel flange, and

(d) removing the cover liner so that the adhesive abuts the inner surface of the wheel flange.

Preferably, the cover liner is slit so that a portion thereof forms at least one tab which when the strip is located in position according to step (c) above the or each tab is exposed, and the cover liner is removed according to step (d) above by pulling on the or each exposed tab. Preferably, the strip is provided in an indefinite length and is cut to form the ring like configuration. Preferably, the free ends of the strip forming the ring like configuration are operatively connected together.

Preferred embodiments of the invention will be hereinbefore described with reference to the accompanying drawings.

Figure 1 is a schematic partial side elevation of a wheel including noise reduction or damping apparatus according to the present invention;

Figure 2 is a comparative graph tracing noise intensity against time between a wheel having noise reduction or damping apparatus according to the present invention fitted and a wheel with no such apparatus fitted;

Figure 3 is a further comparative graph tracing noise intensity against frequency between a wheel having noise reduction or damping apparatus according to the present invention fitted and a wheel with no such apparatus fitted;

Figures 4a to 4d illustrate steps in the method of installation.

Referring to Figure 1 of the drawings there is shown a wheel generally indicated at

50 which includes a hub portion 51 and an outer peripheral rim 52, the rim merging with the hub at a junction region 53. The rim includes a flange 54 having an inner surface 55 and an outer surface 56 and a free end face 57.

The noise reduction apparatus according to the invention generally indicated at 10 comprises a ring like element 12 in the form of a laminate having an inner strip or band of visco elastic material 14 and an outer strip or band of aluminium 16. The inner band 14 includes pressure sensitive layers 17 and 18 for securing the laminates together as well as securing the band 14 to the inner surface 55 of the wheel rim flange 54. The outer laminate of aluminium projects beyond the free end face of the wheel flange by a distance W.

Referring to Figure 2 there is shown a graph comparing the performance characteristics of a wheel having fitted thereon apparatus according to the present invention (Graph A) and the same wheel without such apparatus (Graph B).

The graphs are a measure of noise intensity against time. In both cases there are three cycles shown. It can be seen from Graph A that the noise intensity dissipates very quickly whereas in Graph B there is a much longer resonance time.

Figure 3 is a graph of comparison between a train having wheels fitted with apparatus according to the present invention and one without. As can be readily seen there is a significant reduction in frequencies above 2000hz which represent those which cause pain to the human ear.

A preferred method of installation of apparatus according to a preferred embodiment will hereinafter be described with reference to Figures 4a to 4d. The particular form of apparatus includes a laminated strip 30 including a layer of aluminium 31 , a layer of pressure sensitive adhesive material 32 and a cover liner 33 overlying the pressure sensitive layer 32.

The first step in the procedure is to prepare the wheel rim flange to which the apparatus is to be attached. This may involve washing the region using a detergent and warm water and thereafter drying the surface. If necessary a light abrasion may be necessary to remove heavy oxide contamination.

As shown in Figure 4a, the laminated strip 30 is laid flat and a slit 34 formed in the cover liner 33 generally midway between the free ends 36 and 37 of the strip 30. A primer such as 3M Primer 94 is applied to the wheel rim flange surface and allowed to dry. The ends of the cover liner 33 formed by the slit are folded back to form gripping tabs 38 and 39. With the cover liner 33 still in place the strip 30 is formed into a ring as shown in

Figure 4b which will be sized by for example, marking with a pencil 48 to fit snugly against the flange surface 55 of the flange 54 of the wheel rim 52. Any excess strip can be removed by cutting. The strip is then located in place against the flange surface 55 with the tabs 38

5 and 39 of the cover liner exposed.

The strip 30 is then locked in position using a keeper 42 or the like. Location of the keeper 42 is effected using circlip pliers 44, the ends of which are locatable within holes 45 and 46 in the strip 30. The pliers force the strip into a position where the free ends 36 and 10 37 can be located within the slots 46 and 47 of the keeper. Release of the ends by the pliers causes the ends to be urged towards one another. The liner 33 is then removed by pulling on tabs 38 and 39 and the pressure sensitive adhesive layer is pressed against the flange surface.

15 Finally, it is to be understood that various alterations, modifications and/or additions may be incorporated into the various constructions and arrangements of parts without departing from the spirit or ambit of the invention.

Claims

CLAIMS :

1. A noise reduction or damping apparatus suitable for use with a wheel, the wheel including a hub and an outer rim, the rim includes an axially projecting flange having an outer bearing surface, an inner surface and a free end face, the apparatus including a generally annular shaped body having a inner edge portion and an outer edge portion, the annular shaped body when in the fitted position, being securable to the inner surface of the flange of the rim.

2. Apparatus according to claim 1 wherein there is a junction region between the hub and rim of the wheel and, when in the fitted position said inner edge portion of said body is disposed in the region of the junction between the wheel hub and the wheel rim.

3. Apparatus according to claim 1 or claim 2 wherein when in the fitted position said outer edge portion of said body terminates generally at or extending beyond the free end face of the wheel.

4. Apparatus according to any preceding claims wherein, the annular shaped body is in the form of a ring like element which, in the fitted position extends around the inner surface of the wheel rim when in the fitted position.

5. Apparatus according to claim 4 wherein said ring like element includes a metal strip or band which, in the fitted position is secured to the inner surface of the wheel rim flange.

6. Apparatus according to claim 4 wherein said ring like element includes a flexible polymeric band which in use is secured to the inner surface of the wheel rim.

7. Apparatus according to claim 5 or claim 6 wherein the ring like element is formed of viscoelastic material.

8. Apparatus according to claim 4 wherein, the ring like element includes a laminated structure which includes an inner layer of visco elastic material, and an outer constraining layer of metal.

5 9. Apparatus according to claim 8 wherein the outer layer extends outwardly from the free end face of the rim when in the fitted position.

10. Apparatus according to any one of claims 4 to 8 wherein the annular shaped member includes a plurality of spaced apart segments arranged on the inner surface of the ring to

10 define a ring like structure.

11. Apparatus according to any preceding claim including an adhesive for securing the body to the rim.

15 12. Apparatus according to claim 11 wherein the adhesive is pressure sensitive.

13. Apparatus according to claim 11 including a pressure sensitive adhesive layer.

14. A method of installing a noise reduction or damping apparatus on a wheel the wheel 20 including a hub and an outer rim, the rim including an axially projecting flange having an outer bearing surface, an inner surface and a free end face, the method including the steps of (a) providing damping or noise reduction apparatus, which includes a strip, the strip including an outer surface between opposed end portions, the outer surface having thereon an adhesive and a removable cover liner overlying the adhesive; 25 (b) forming the strip into a generally ring like configuration which generally conforms to the periphery of the inner surface of the flange of the wheel;

(d) removing the cover liner so that the adhesive abuts the inner surface of the 30 wheel flange.

15. A method according to claim 14 wherein said cover liner is slit so that a portion thereof forms at least one tab which when the strip is located in position according to step (c) the or each tab is exposed, and said cover liner is removed according to step (d) by pulling on the or each exposed tab.

16. A method according to claim 14 or 15 wherein said strip is provided in an indefinite length and is cut to form the ring like configuration.

17. A method according to any preceding claim wherein the free ends of said strip forming the ring like configuration are operatively connected together.