AU722808B2

AU722808B2 - Wheel noise reduction

Info

Publication number: AU722808B2
Application number: AU57830/98A
Authority: AU
Inventors: Kenneth Sydney Hoskins
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-01-31
Filing date: 1998-01-26
Publication date: 2000-08-10
Anticipated expiration: 2018-01-26
Also published as: CA2278719A1; WO1998033666A1; EP0956210A1; CN1246094A; AU5783098A; JP2001510418A

Description

WO 98/33666 PCTINZ98/00003 -1- WHEEL NOISE REDUCTION FIELD OF INVENTION The invention relates to wheel noise reduction.

BACKGROUND

At present with modern vehicles which can travel at relatively high speeds over modern roads with smooth and quietly running engines, one of the few remaining problems to be overcome is the question of road noise.

Road noise is understood to be created by vibrations transmitted from road surface to the cab of a motor vehicle. Varying different types and quality of road surface create different levels of vibration and noise which ideally should be reduced if not eliminated.

The applicant understands that the source of this noise is created by the tyre acting in much the same fashion as a stereo speaker cone when it vibrates in and out.

The applicant considers the action of a vehicle tyre moving over each and every bump on a road surface causes the same effect and sound. These impact movements of the tyre surface invade the internal pressurised air space of the tyre to be converted into a myriad of sound waves amplified into shock waves. by the high pressure of the inflated tyre. The magnitude of these shock waves are increased or decreased according to vehicle speed and the condition of the road. The shock waves hammer and ricochet with considerable force around the interior surface of the tyre and the exposed areas of a wheel rim which is normally constructed from steel or another metal alloy. The vibrations are then transmitted through the wheel rims, discs, wheel bearings and suspension culminating in an irritating noise in the vehicle cab. The irritating noise not only spoils radio listening but can affect people susceptible to headaches.

k(I -2- One attempt to eliminate this problem is for car manufacturers to heavily pad the interior body panels. This adds markedly to manufacturing cost.

It is an object of the present invention to overcome or ameliorate at least some of the disadvantages of the prior art, or to provide a useful alternative.

DISCLOSURE OF THE INVENTION According to a broadest aspect of the invention there is provided a noise isolation barrier in a road wheel assembly for a motor vehicle with pneumatic tyres in which: the isolation barrier is made from any suitable noise absorbing/deadening material eeoc manufactured to exacting safety specifications as far as width and thickness; the isolation barrier is placed between two steel or other material rings or plates, e

V,

which can constitute a road wheel rim and/or a wheel hub assembly, such that it completely isolates the wheel rim from the wheel hub assembly.

Preferable the barrier is made from a solid synthetic or natural rubber or plastics material which is an extremely poor medium for transmitting vibrations.

oleo Preferably the barrier is a specially prepared durable rubber extruded and vulcanised between two steel or other metal rings or plates.

Preferably the invention can be incorporated into a new wheel or as a modification to an existing wheel which should in no way affect the balance of the wheel.

WO 98/33666 PCT/NZ98/00003 -3- Examples of the invention will now be described with reference to the accompanying drawings: DESCRIPTION OF THE DRAWINGS Figure 1 shows diagrammatically a cross-section through part of an example of wheel assembly incorporating the present invention; Figure 2 shows a cross-section through an alternative construction of wheel assembly incorporating the present invention; Figure 3 shows a part section through yet another alternative construction of wheel assembly showing the actual size of a 15 inch wheel rim incorporating the present invention; and Figure 4 shows a part section through a construction of wheel assembly for a cast aluminium alloy wheel.

DESCRIPTION OF THE PREFERRED EXAMPLES All the examples of the invention will be described with reference to a standard wheel assembly for a vehicle, the wheel assembly has a tyre 6 to be mounted relative to a wheel bearing 1. The wheel bearing 1 is linked in known manner via a metal disc 2 portion of the wheel assembly which would normally have associated therewith an annular rim 3.

In the first example shown in Figure 1 the annular rim 3 has sandwiched between it and a wheel rim 5 an annular strip of durable natural/synthetic rubber 4. The WO 98/33666 PCT/NZ98/00003 -4rubber strip 4 is vulcanised to both the wheel rim 5 and the rim 3. The tyre 6 is fitted in the normal way to the wheel rim In the second example shown in Figure 2 the wheel is constructed with two discs which are joined together by a vulcanised rubber plate 4.

In the third example in Figure 3 a part section through a 15 inch wheel is shown.

The wheel is constructed from a 15 inch wheel rim 5 and a modified rim 3. The rim 3 is a cut-down and compressed 15 inch rim with both side walls (not shown) originally attached at 8 and 9 removed. The rim 3 is welded to a ledge section 10 on the periphery of the disc 2.

In the fourth example shown in Figure 4 the wheel is constructed from two parts, namely a central hub section 11 and a wheel rim 12. The hub section 11 has a profile suitable for attachment to a wheel hub (not shown) by way of studs which are aligned with holes (not shown) on centre lines 13 (only one of which can be seen) in disc portion 14.

The wheel rim 12 is profiled to have a pneumatic tyre (not shown) fitted and the external profile may of any suitable construction and shape which is cast from the same or similar metal alloy material as the section 11. The section 11 and rim 12 are held together by rubber 15 which is vulcanised to the parts.

The wheel assembly is formed by placing the hub section 11 and wheel rim 12 in position in or on a jig/mechanism so that under heat and pressure the rubber is forced into the space therebetween to be vulcanised to the surfaces 16 and 17 respectively of the hub section 11 and wheel rim 12.

WO 98/33666 PCT/NZ98/00003 In practice operating stresses would expose the noise barrier formed by the rubber 4 to driving, braking, cornering and weight supporting forces. The most effective position in the wheel assembly for this noise barrier would seem to be as close as possible to the noise source. In the examples the barrier is farthermost away from the hub has been chosen for as little stress as possible and that is between the wheel rim and the wheel disc. The applicant is confident that the forces can be taken care of in the strength of the vulcanising contact between the rubber barrier and the wheel rims.

Bearing in mind the quality of modern vulcanising, the applicant considers this will be satisfactory. However, strict quality control measures are essential.

There are other advantages to having this rubber bushing built into motor vehicle wheels apart from the major advantage of muting pneumatic tyre noise entering the vehicle cab. The rubber is an added shock absorbent assisting in taking impact stress off the wheel assemblies, suspensions and also serves to increase the life of the wheel bearings. It should help to protect the vehicle transmission from shock through the mechanical drive to the road. It will also assist in automatically keeping the wheels in balance and giving a smoother ride. The applicant believes it will transform the ride of a standard car into a more luxurious model.

Prior to extruding the rubber between the two parts of the rim it will be necessary to have a special jig manufactured to set the rim and disc assembles in correct concentric positions and also to arrange for correct location between the hub and rim.

Where in the aforegoing description mechanical equivalents are available it is to be appreciated that they can be substituted for the named components.

WO 98/33666 PCTINZ9800003 -6- Thus by this invention there is provided a wheel noise reduction assembly.

Particular examples of the invention have been described and it is envisaged that improvements and modifications can take place with departing from the scope of the appended claims.

Claims

1. A noise isolation barrier in a road wheel assembly for a motor vehicle with pneumatic tyres in, which: the isolation barrier is made from any suitable noise absorbing/deadening material manufactured to exacting safety specifications as far as width and thickness; the isolation barrier is placed between two steel or other material rings or plates, which can constitute a road wheel rim and/or a wheel hub assembly, such that it completely isolates the wheel rim from the wheel hub assembly.

2. A noise isolation barrier in a road wheel assembly as claimed in claim 1 wherein the barrier is made from a solid synthetic or natural rubber or plastics material which is an extremely poor medium for transmitting vibrations.

3. A noise isolation barrier in a road wheel assembly as claimed in claim 1 or claim 2 wherein the barrier is a specially prepared durable rubber extruded and vulcanised between the two steel or other metal rings or plates.

4. A noise isolation barrier as claimed in any of the preceding claims incorporated into a new wheel or as a modification to an existing wheel which should in no way affect the balance of the wheel. A noise isolation barrier in a road wheel assembly as claimed in any one of the preceding claims wherein the barrier is an annular strip of durable natural/ synthetic rubber sandwiched between an annular rim and a wheel rim.

LU VT AMENDED SHEET PENAU -8-

6. A noise isolation barrier in a road wheel assembly as claimed in claim 5 wherein the rubber strip is vulcanised to both the wheel rim and the rim.

7. A noise isolation barrier in a road wheel assembly as claimed in claim 4 wherein the wheel is constructed with two discs which are joined together by a vulcanised rubber plate which acts as the barrier.

8. A noise isolation barrier in a road wheel assembly substantially as herein described with reference to the accompanying drawings. DATED this 13th Day of March, 2000 KENNETH SYDNEY HOSKINS Attorney: STUART M SMIT Fellow Institute of Patent Attorneys of Austtl of BALDWIN SHELSTON WATERS i!w. ~21 TJT C)