WO1991018753A1

WO1991018753A1 - A wheel and methods of manufacture of a wheel

Info

Publication number: WO1991018753A1
Application number: PCT/GB1991/000814
Authority: WO
Inventors: Martin Ogilvie
Original assignee: Group Lotus Plc
Priority date: 1990-05-25
Filing date: 1991-05-23
Publication date: 1991-12-12
Also published as: GB9011835D0

Abstract

The present invention relates to a wheel comprising a rim portion (25) which comprises an annular member (18) which has corrugations which extend parallel to the axis of rotation of the wheel. In a preferred embodiment the disc portion (26) of the wheel is corrugated when viewed radially of the wheel. The invention also provides methods by which according to the invention can be made from components (10, 16, 20) at least some of which are made from flat sheets of material, by forming corrugated flat discs of the material and deforming the flat dics to the required shape.

Description

A WHEEL AND METHODS OF MANUFACTURE OF A WHEEL

This invention relates to a wheel and in particular to a wheel for use by a four-wheeled land vehicle. The invention also provides methods by which a wheel according to the invention may be manufactured.

The trend in recent years has been for vehicle stylists to require lower wall-height tyres, in particular for use with sports cars. If the overall diameter of the wheel and tyre combination is to remain comparable with existing wheel and tyre combinations then the diameter of the wheel must be increased to compensate for the decreased tyre height. The increase in wheel diameter has a beneficial effect in that more clearance can be provided around the brakes allowing either more efficient cooling of the brakes and/or larger and more powerful brake assemblies.

The requirement for high stiffness wheels of larger than usual diameter has necessitated a reappraisal of basic wheel design.

It has previously been well known in the art of wheel manufacture that a wheel could be strengthened by "corrugating" the disc portion of the wheel. The portion of a wheel that is referred to as "the. disc portion" for the purposes of this application is that portion of a wheel which extends between the rim portion and the hub portion and can be attached to the hub. By corrugating the disc portion of the wheel such that it consists of alternating troughs and peaks when viewed radially of the wheel, the wheel is given greater stiffness than if the disc portion is fashioned as a flat disc.

The present invention provides a novel wheel comprising a corrugated rim portion. The rim portion of a wheel for the purposes of this specification shall be considered as being that part of a wheel which supports the tyre.

According to the present invention there is provided a wheel comprising a circumferential rim portion to support a tyre which rim portion comprises an annular member which has corrugations which extend parallel to the axis of the wheel.

Preferably the said annular member is a reinforcing member for the tyre supporting rim portion which is located radially inwardly of the rim portion. Preferably the wheel also comprises a disc portion which extends between the rim portion and a hub which disc portion is corrugated when viewed radially of the wheel_s Preferably the wheel is formed from a plurality of components each forming a part of the disc portion and a part of the rim portion. These components are preferably each formed from a single sheet of material and are formed such that the corrugation of the rim portion deepens from the periphery thereof inwardly towards to disc portion and the corrugation of the disc portion deepens radially inwardly from the periphery of the disc portion. Preferably the disc portion comprises a plurality of bolt holes, a part of the interior surface of each of said holes being defined by the corrugation of the disc portion.

Preferably the wheel is made from composite materials.

In a preferred embodiment the disc portion of the wheel is provided with ventilation holes which allow communication between both sides of the wheel. The present invention also provides methods of manufacture of the wheel of the invention and methods of manufacture of components thereof. In a method of the invention the wheel is formed from components' formed by forming corrugated discs from the sheets of material and deforming the discs to the required shape. Preferably the sheets are sheets of fibrous material and when the components are formed they are loaded into a mould into which resin is injected and subsequently cured to bind the components together. The sheets can be formed of fibrous material having resin interwoven with the fibres, in which case the wheel can be formed by loading the components into a mould and heating the mould to cause the resin interwoven in the fibres to soften and to bind the components together.

Preferred embodiments of the present invention shall now be described with reference to the accompanying drawings in which: Fig 1 is a cross-sectional view of one embodiment of one component of a preferred embodiment of the invention, the section being taken in a plane parallel with the axis of rotation of the wheel and showing only one half of the cross-section of the component. The dotted lines show features that would not normally be visible in the cross-section.

Fig 2 is a fragmentary perspective view of the component of the wheel shown in section in Fig 1.

Fig 3 is a cross-sectional view of a component of a preferred embodiment of the invention, the section being taken in a plane parallel with the axis of rotation of the wheel and showing only one half of the cross-section of the component. The dotted lines show features that would not normally be visible in the cross-section.

Fig 4 is a fragmentary perspective view of the component shown in section in Fig 3.

Fig 5 is a cross-sectional view showing a preferred embodiment of the invention comprising the components shown in Figs 1 and 3. The cross-section is not instantaneous and is taken in a plane parallel with the axis of rotation of the wheel and showing only one half of the cross-section.

Figs 6 to 9 are cross-sections along the line A-A in Fig 5, showing different methods of forming bolt holes according to the invention.

A preferred embodiment of the invention shall now be described, with reference to Figs 1 to 5. The wheel is formed in components. A cross-section of the first component 10 can be seen in Fig 1. This section shows only half of the component and is taken parallel to the axis of rotation of the wheel. The disc portion of the component is corrugated. Fig 1 shows a peak 11 with a hole 12, a trough 13 and an annular member 14 with a rim 15. A perspective fragmentary view of the first component can be seen in Fig 2.

A second component 16 is shown in cross-section in Fig 3. This component has a disc portion 7 and an annular member 18. The annular member 18 and the disc portion section 17 are of a configuration such that they match exactly at a line designated B-B in Fig 3. In a preferred embodiment the component 16 is manufactured such that the annular member 18 and the disc portion section 17 are formed together. The component 16 also has a rim 19. A fragmentary perspective view of the second component 16 can be seen in Fig 4.

During assembly of the wheel the two components 10 and 16 are attached together, component 16 overlaying component 10. The two components 10 and 16 are each manufactured with holes 12 that align when the component 16 is attached to component 10. The assembled wheel can be seen in Fig 5.

A third component 20 is shown in Fig 5. The component 20 is in .fact a corrugated cylinder of special cross-section. When the wheel is assembled it is attached to both component 10 and component 16. The component 20 has two rims 21 and 22. Rim 21 is attached to rim 15 of the first component when the wheel is assembled. Rim 22 is attached to the rim 19 of the second component, when the wheel is assembled. The two rims 21 and 22 facilitate the mounting of a tyre on the rim portion of the wheel. In a preferred embodiment reinforcing sections 23 and 24, as shown in Fig 5, are attached to the wheel to ease the mounting of a tyre on the rim portion of the wheel. When the preferred embodiment of the invention is assembled as shown in Fig 5 there is provided a wheel with a rim portion, designated generally as 25 in the figure and a disc portion, designated generally as 26. The rim portion 25 comprises the corrugated annular member 18 of the component 16, the annular member 14 of the component 10, the third component 20 and the reinforcement sections 23 and 24. The corrugated part of the rim portion of the wheel is provided by the corrugated annular member 18 and the component 20. The corrugated disc portion of the wheel 26 comprises the disc portions of both the first component 10 and the second component 16. The corrugations of the two components 10 and 16 provide the wheel with a high degree of stiffness The corrugated nature of the rim portion 25 provides the wheel with considerably improved stiffness in comparison with conventional wheels. This is obviously advantageous since deformation of the wheel is limited when forces are applied to it, for instance when it is attached to a land vehicle cornering at speed or when it is attached to a vehicle passing over perturbations in a road.

Holes 12 are provided in the disc portion of the wheel as shown in Figs 1 and 3. These holes are preferably provided on one side of a corrugation of the disc portion of each component. The holes aid ventilation of the braking assembly situated behind the wheel when the wheel is in use, thus improving the operational characteristics of the braking assembly.

Each of the components 10 and 16 are formed from single sheets of material. The corrugation of the rim portion 25 deepens from the periphery thereof inwardly towards to the disc portion 25 of the wheel. The corrugation of the disc portion 26 deepens radially inwardly. The deepening of the corrugation of the rim portion 25 and the disc portion 26 is a necessary result of manufacturing the components from single sheets and has an advantageous effect in that the stiffness of the wheel is increased towards the hub, this being beneficial since greater stiffness is provided where it is needed most. Generally the components 10 and 16 are formed in two stages. First sheets of material are processed to form corrugated discs with corrugations that deepen towards the centre. The corrugated discs are then extruded to the required shape.

The wheel comprises additionally a plurality of bolt holes, numbered 25 in Fig 5. The bolt holes are formed such that part of the walls of the bolt holes are formed from the corrugation of the disc portion 26 of the wheel, and different ways of forming these holes are shown in Figs 6, 7, 8 and 9.

In Fig. 6 the bolt hole 27 is formed by attaching a sleeve 28 between the two adjacent corrugations of the corrugated disc portion 26 of the wheel. Fig. 7 shows an alternative positioning of the sleeve 28 with respect to the corrugations.

Fig. 8 shows how a bolt hole 27 can be created in the corrugated disc portion 26 by the addition of supplementary material 29 thereto. Fig. 9 shows how a bolt hole 27 can be formed by bonding metal inserts 30 and 31 to two adjacent corrugations of the corrugated disc portion 26 of the wheel.

It should be noted that the component 20 and the reinforcing sections 23 and 24 of the preferred embodiments described above are not essential features of the invention and it is envisaged that a wheel could be made according the invention with just the two components 10 and 16. Alternatively it is not envisaged that a component such as component 20 with corrugation parallel to the axial direction of the wheel could be attached to an uncorrugated disc portion to form a wheel according to the invention. The essential feature of a wheel according to the invention is a rim portion having corrugations which extend parallel to the axis of rotation of the wheel. Parallel in this sense is not meant to be a definite qualification but a general indication; it will be appreciated that from the drawings that the "parallel" corrugations of the specific embodiment have surfaces which approach nearer the axis of rotation of the wheel in a direction axial of the wheel moving from the rim inwards.

The wheel is preferably made out of composite materials, since these materials are both light, strong and exhibit beneficial stiffness qualities. The nature of the wheel facilitates the use of composite material.

The sectional proportions of the wheel are preferably chosen so as to provide a wheel made out of material of a constant thickness. This can be achieved whilst retaining a high degree of stiffness. This is especially important when manufacturing a wheel from composite materials using woven fabrics. The design of the wheel enables this composites to be used in a manner such that the wheel retains the desired stiffness. The wheel of the invention can also be made in an alternative manner when the wheel is made from composite materials. In such a case, the components of the wheel described above would each be formed from sheets of fibrous material. All the components would then be loaded into a single mould and the mould then injected with resin. In this way the wheel would be formed as a complete entity, without the need for separate sheets to be attached together. This method could be used for all types of injection resin systems, such as thermosetting or thermoplastic types.

A third method of manufacture of the wheel is also envisaged by the applicant, in which third method the components would„be formed from fibrous sheets already coated or interwoven with resin matrix film/fibres. The components are loaded together in a mould and the whole then cured to form an integral wheel.

A wheel according to the invention may have a deep rim without sacrificing stiffness whilst retaining a light structure.

Claims

CLAIMS :

1. A wheel comprising a circumferential rim portion to support a tyre which rim portion comprises an annular member which has corrugations which extend parallel to the axis of the wheel.

2. A wheel as claimed in claim 1 comprising a tyre supporting rim portion and wherein the said annular member is a reinforcing member of the rim portion which is located radially inwardly of the rim.

3. A wheel as claimed in any one of the previous claims wherein the corrugations of the rim portion deepen axially from the periphery of the rim portion toward the disc portion.

4. A wheel as claimed in any one of the preceding claims comprises a disc portion which extends between the rim portion and a hub which disc portion is corrugated when viewed radially of the wheel.

5. A wheel as claimed in claim 3 which comprises a plurality of components each forming a part of the disc portion and a part of the rim portion.

6. A wheel as claimed in claim 4 wherein each of said components is formed from a single sheet of material.

7. A wheel as claimed in any one of the claims 4, 5 or 6 wherein the corrugations of the disc portion deepen radially inwardly from the periphery of the disc portion.

8. A wheel as claimed in claim 7 wherein the disc portion additionally comprises a plurality of bolt holes, part of the interior surface each of said bolt holes being defined by the corrugation of the disc portion.

9. A wheel as claimed in any one of the preceding cliams having ventilation holes in the disc portion to allow communication between both sides of the wheel.

10. A wheel as claimed in any one of the preceding claims made from composite material.

11. A method of manufacturing a component of the wheel as claimed in claim 4 comprising the steps off- forming a corrugated disc from a flat sheet of material, and deforming the corrugated disc to the required shape.

12. A method as claimed in claim 11 wherein the flat sheets of materials are sheets of fibrous materials.

13. A method of manufacture of a wheel from components manufactured by the method of claim 12 which comprises the steps of loading the components into a mould, injecting resin into the mould, curing the resin to bind the components together and ? the mould.

14. A method as claimed in claim 11 wherein the sheet of fibrous material have resin interwoven with the fibres.

15. A method of manufacture of a wheel formed from components made from the method of claim 14 comprises - li ¬

the steps of loading the components into a mould, heating the mould to cause the resin interwoven in the fibres to soften and to bind the components together and removing the wheel from the mould.