Field of the Invention

The invention relates to electrically powered wheels for vehicles.

The term "vehicle" is to be interpreted broadly and may include any land, air, ice, snow and water going vehicle which is driven at least partially by a wheel or outer ring propelled turbine. In particular, the term "vehicle" includes bikes, motorbikes, automobiles, off-road vehicles, trains, planes, all quad bikes or 2 to 8 wheelers (on or off road) and aircraft of any kind.

Background to the Invention

The conventional wheel envelope is designed to accommodate a spinning shaft to drive the rotation. It also accommodates separate mechanically actuated braking systems. The invention seeks to address a variety of problems present in such conventional systems. The following is a list of several of these problems:

• The requirement of providing a spinning shaft;

• The limits of the conventional steering mechanism;

• Systems which are primarily internal combustion driven;

• The problems of having a separate electrical motor and a wheel; • Excessive vehicle weight due to unnecessary components employed in power generation, braking and/or complex control systems;

• Problems associated with the control of multiple driving wheels; and

• Problems associated with excessive mechanical wear in drive train, gear boxes (manual or automatic) and chain and sprocket mechanisms for example.

These various problems are addressed by certain aspects of the invention which will be described in detail in the following sections. Further problems may also be deduced from the technical effects and features referred to in the description which follows.

Summary of the Invention

In a first broad independent aspect, the invention provides an electrically powered wheel for vehicles comprising an outer ring forming a rotor and an inner portion forming a stator; said outer ring being configured to drive the rotation of the tyre when fitted to said wheel and incorporating an arrangement of magnetic material or being constituted of magnetic material; said inner portion incorporating a powered conductive arrangement with a plurality of distinct winding portions; a connection for connecting said wheel to a controller which varies the mode of the powering of said distinct winding portions; whereby dependent upon the magnetic relationship between said magnetic material and said plurality of distinct winding portions, rotation of said outer ring is achieved, in use, whilst the inner portion remains static; wherein said wheel is configured to support the load of the vehicle.

This configuration is particularly advantageous because it allows the electric motor of the wheel to be integrated within the envelope of a wheel. It also allows the components of the wheel to support the load of a vehicle. Due to the close integration of the electric motor into the wheel envelope, it reduces the drive components when compared to those required to drive a conventional spinning shaft. In addition, this configuration also reduces friction. The close integration of the stator and rotor within the wheel envelope also allows for efficient transmission of power into usable drive torque. The wheel suggested may also be bi-directional, have variable speed and be configured as a sealed power unit. Furthermore, the wheel may be self-braking with its strong electric motor slowing revolutions to maintain control of speed at all times. Motor torque may be employed as the brake. Furthermore, when incorporated into a vehicle the wheel may be employed to improve aerodynamics when compared to the traditional "open car wheel arch" such a vehicle may also have improved aerodynamics since it may have flat sides, a flat undertray for smooth underfloor airflow and down force and a reduced spinning wheel portion.

When appropriate control is employed, improvements in the electronic traction may be achieved for optimal grip during acceleration and/or during braking. The wheel may also operate in conjunction with a remote variable speed control which the driver may employ directly.

In a subsidiary aspect, the invention provides an outer ring which rests essentially magnetically on the inner portion. This configuration avoids the requirement for additional bearings and therefore further reduces the components required.

In a further subsidiary aspect, said outer ring incorporates an outer annular portion about which magnetic material in the form of magnets is disposed, a radially extending web and a rotary boss; and wherein said inner portion incorporates a stator portion, a stator holder and a stationery boss for engagement with one or more bearings for supporting said rotary boss. This configuration provides a particularly advantageous distribution of forces in the wheel.

In a further subsidiary aspect, said inner portion comprises one or more vehicle load bearing members extending across said inner portion and incorporates an attachment to a linkage member extending radially upwards; whereby said wheel may be secured radially to a vehicle. This configuration is particularly advantageous because it would allow the motor vehicle to have greater manoeuvrability for parking and cornering. In one embodiment, it may take the form of a multi-directional castor. In this configuration it may have 360° manoeuvrability. It also allows the steering mechanism to be provided away from the crash or underside damage location.

In a further subsidiary aspect, said linkage member is configured to carry current to said inner ring. This provides for a particularly compact composition as the linkage member has dual functionality. In one embodiment of the invention it is preferred that most if not all elements of the wheel have a duality of function as a structural and/or a motor component. The linkage arm may take the form of a fork to carry battery power to a hub.

In a further subsidiary aspect, said outer ring incorporates vehicle load bearing members in the form of a plurality of tubes containing magnetic material. This configuration is particularly advantageous because it allows the outer ring to be both load bearing and of magnetic material in a particularly compact form.

In a further subsidiary aspect, said outer ring incorporates a plurality of slots for housing said magnetic material. This configuration is also particularly advantageous in order to provide a load bearing structure and protection for the magnets or the magnetic material portions.

In a further subsidiary aspect, said outer ring incorporates a load bearing portion which is formed from a material selected from the group comprising: composite thermo-setting material, Kevlar, carbon fibre and nickel plated iron. These various materials provide advantageous structural properties which allow the outer ring to provide both a load bearing function and a magnetic function.

In a further subsidiary aspect, said outer ring incorporates vehicle load bearing members which are formed in a honeycomb configuration with the webs of the honeycomb configuration extending substantially in a radial direction. This configuration allows for advantageous weight and strength ratios whilst providing an advantageous housing for the magnetic material when the magnetic material is provided in one embodiment of this configuration within the honeycombs.

In a further subsidiary aspect, said magnetic material forms a plurality of distinct elongate magnets which are disposed at an angle from the radius of said wheel and/or at an angle from the axis of rotation. This configuration is particularly advantageous because it improves the efficiency of the generation of rotation in the primary direction of rotation.

In a further subsidiary aspect, the longitudinal axis of said distinct winding portions is located at an angle from the radius of said wheel. This configuration is also particularly advantageous in order to improve the efficiency of the generation of rotation in the primary rotary direction.

In a further subsidiary aspect, one or more abutment surfaces are provided acting between said outer ring and said inner portion to constrain radial and/or lateral relative movement between said outer ring and said inner portion. This configuration secures the relative position of the inner portion and the outer ring for advantageous operation.

In a second broad independent aspect, the invention provides a vehicle incorporating one or more electrically powered wheels according to any of the preceding aspects.

Brief Description of the Figures

Figure 1 is a representation of an electrically powered wheel according to various embodiments of the invention.

Figure 2 is a representation of a further embodiment of the invention where the electrically powered wheel is of a so-called "multi-directional caster style".

Figure 3 shows an exploded view in perspective of a further embodiment of an electrically powered wheel.

Figure 4 shows an exploded and perspective view of an electrically powered wheel of the kind shown in Figure 3 with an alternative arrangement of magnetic portions.

Figure 5 shows a cross-sectional view of the embodiment of either Figure 3 or Figure 4.

Figure 6 shows a perspective view of the rotor and stator of an electrically powered wheel where the rotor incorporates a honeycomb configuration.

Figure 7 shows a rotor and stator arrangement in cross-sectional view in accordance with a further embodiment of the invention.

Figure 8 shows a further embodiment of the invention in cross-sectional view. Detailed Description of the Figures

Figure 1 shows an electrically powered wheel for vehicles generally referenced 1 with an outer ring 2 forming a rotor 2 and an inner portion 3 forming a stator. The outer ring is equipped with a number of distinct magnets such as magnet 4. Each one of the magnets is tilted relative to the radius of the wheel as shown. In this configuration, the positive end of the magnet points towards the inner portion 3 whilst the negative end of the magnet points towards the outside of the wheel. By charging the magnets negatively on the outside, this will have the additional benefit of repulsing the typically negatively charged metallic compounds which may be found in proximity to a wheel in use. The inner portion incorporates a number of distinct winding portions such as winding portion 5. Winding portion 5 is shown as acting primarily radially. Alternatively the winding portions may be angled as for example shown by winding portions 6 and 7. The individual winding portions are in effect flared outwards and forwards in the direction of rotation of the wheel. The winding portions may incorporate copper flux which in order to further improve performance may be coated with a nickel coating. As shown in the Figure, the magnets are angled whilst the cable ends may also be angled. The magnetic material may be a band of magnetic material or an annular magnet with distinct poles located at distinct positions about the circumference of the outer ring. Arrows such as arrow 8 show the intended direction of rotation in this embodiment of the invention. As previously mentioned, an appropriate mode of powering of the distinct winding portions may achieve rotation either in the direction shown or the opposite direction which allows the motor wheel to be bi-directional.

The inner portion may be secured via bolt holes such as bolt hole 9 to a connector, or directly to the chassis of a vehicle. The electrical connection to the various distinct winding portions may be provided through the central axis 10 of the wheel. Located remotely from the wheel there may be provided a controller which may simply constitute primarily of a transformer in order to vary the amount of power to the wheel in order to vary the speed.

The embodiment of Figure 1 shows the primary components of an electrically powered wheel. An appropriate casing (not shown) would be provided about the outer ring to allow the fitting of a tyre. A protective cover (not shown) would also be provided to protect the various components from the surrounding environment. This may be provided for example by a sealed disc.

Figure 2 shows a second embodiment of the invention in the form of an electrically powered wheel 1 1 with an outer ring 12 forming a rotor and an inner portion 13 forming a stator. Instead of providing a conventional axially extending linkage member to a vehicle, a radially extending linkage member 14 is provided. In practice a first and a second member may be provided on opposite sides of the wheel which would form a fork. By rotating the linkage member greater manoeuvrability of the wheel may be achieved for parking and cornering.

The control and operation of the wheel may be of the kind described with reference to Figure 1. The potential rotation of the outer ring is indicated by a plurality of arrows such as arrow 15.

Figure 3 shows an electrically powered wheel generally referenced 16. The wheel comprises a rim 17 onto which a pneumatic tyre may be secured. The pneumatic tyre may have the additional benefit of acting as an electrical insulator for the electrically powered wheel. A flange 18 is provided with a number of holes 19 through which bolts 20 may be placed to secure outer ring 21 which will rotate together with the wheel rim. The inner portion 22 is designed to be secured to a vehicle linkage member (not shown) by bolt holes 23. Outer ring 21 incorporates an annular portion 24 and a radially extending web 25 where bolt holes 26 are provided. In addition, a boss 27 projects axially from the web 25. Boss 27 rotates together with the outer ring and is therefore referred to as a rotary boss. Rotary boss 27 is sized and configured to fit within the stationary boss 28 of the inner portion 22. A pair of roller bearings 29 and 30 is located inside stationary boss 28. These support the rotation of outer ring 21 as rotary boss 27 rests on the inner diameters of the bearings. Located on the outer surface of boss 28, the inner portion is provided with a plurality of distinct winding portions such as winding portion 31 located at regular intervals about the circumference of a holder 32. A plurality of distinct magnets 33 are provided at regular intervals about the inner diameter of the annular portion 24 of the outer ring. A connection (not shown) for connecting the wheels to a controller may be provided. The controller may incorporate a transformer to vary the mode of the powering of the distinct winding portions. Dependent upon the magnetic relationship between the magnetic material and the plurality of distinct winding portions, rotation of the outer ring is achieved, in use, whilst the inner portion remains static.

In Figure 4 a plurality of magnets or magnetic portions 34 are shown located about the inner diameter of the annular portion. By contrast to the magnetic portions of Figure 3, these are angled relative to the axis of the wheel.

Figure 5 shows the components of Figure 3 in an assembled form. Identical numerical references have been employed as those used in Figure 3.

Figure 6 shows a wheel generally referenced 35 with an outer ring 36 and an inner portion 37. The outer ring is formed of a plurality of radially extending webs which together form a plurality of hexagonal cells. The invention also envisages alternative cellular structures such as triangular and/or rectangular cells. Within the cells magnetic material may be provided in order to allow the outer ring to be rotated about the inner portion. A plurality of winding portions such as portion 38 may be provided about the circumference. In this embodiment, the outer ring rests essentially magnetically on the inner portion. There are no central boss and bearing arrangements. In other words the junction between the outer ring and the inner portion is a magnetic bearing. In this context, in order to prevent the outer ring from inadvertently moving from the inner portion, Figures 7 and 8 show the provision of abutment surfaces to constrain the lateral displacement of the outer ring relative to the inner portion.

In Figure 7 the outer ring 39 incorporates inwardly projecting flanges 40 and 41. In Figure 8, a rail is provided as part of the inner portion. Rail 42 projects radially outwards and into a groove 43 provided circumferentially in the outer ring. Further embodiments may be envisaged where the rail is provided as part of the outer ring and the corresponding groove is provided in the inner portion. Similarly with regard to Figure 7 flanges may be provided as part of the inner portion in order to constrain the relative lateral movement. Further Descriptive Aspects

An embodiment of the invention envisages an electric wheel where all components are totally integrated. The rubber tyre may be used as an electrical insulator.

The spindle may be fixed on both sides and may remain stationary whilst the whole wheel revolves around the charged shaft with a brushless direct drive or direct current (DC) design. Instead of a spinning shaft as in the prior art, the wheel body may rotate around the spindle.

The electrical components of the wheel may be protected by fixed discs, which may also provide a dirt, dust and water proof seal to the wheel.

The motor wheel may be bi-directional, have variable speed and be a sealed power unit.

The vehicle equipped with electro-magnetic wheel of the kind envisaged may have no further moving parts to drive the vehicle.

The wheel may be self-braking with the electric motor designed to slow down revolutions and/or to maintain the control of speed at all times. Motor torque may act as the main brake.

The wheel may be either unidirectional or of a so-called "multi-directional caster style". This may provide 360° manoeuvrability for parking and cornering. The steering mechanism may be located away from crash or underside damage.

In certain embodiments, standard tyres may be fitted with wider tyres for good traction for on/off road vehicles (two-wheel drive motorbikes, cars two/four/six wheel drive) or on road with thinner standard tyres for less rolling resistance and less unsprung weight, depending on economy or speed. In a two-wheel drive embodiment, fixed electrically driven rear wheels, or caster wheels, can assist steering wheels to corner and park. The traditional "open car wheel arch" may be avoided, thus improving aerodynamics, with the option of access obtained by removing a panel or via the vehicle's underneath, or from the inside of the car only, to increase security and to avoid outside removal. Vehicle aerodynamics may be enhanced by flat sides and reduced spinning wheel.

Instead of just locating an electric motor in a wheel and then adding the weight of a wheel, the invention envisages in one embodiment fully integrating and hence lowering the overall unsprung weight. The weight may be saved by avoiding additional brake equipment, hubs and shafts.

The tyre may act to dampen vibration to the wheel but also may transmit power to the ground for maximum traction for acceleration and for braking purposes. By employing electronic traction control, optimal grip for acceleration and braking is maximised.

Direct power may be available from the wheel. Control of electric power may be by batteries, and by a remote variable speed control operated directly by the driver. It will reduce tyre wear and fewer components may reduce the overall costs to vehicle of braking, traction control, ABS, limited slip differential, anti-wheelie device and electronics.

The wheels may incorporate self-contained motors with their elements being potentially of dual function (acting as structural and motor components). Force may be adapted to carry battery power to the hub.

The proportions of the inner portions and the outer moving ring may be varied for optimum power/transfer of energy. Particularly advantageous proportions may be 2/3 inner portion and 1/3 outer ring or less.

The width of the wheel may also be increased dependent upon the density of the material and the desired spread of weight required for a particular application.

Circles of electric cable may be employed to form the inner and outer rings. Neodymium iron boron or samarium cobalt may be provided as the magnetic material. These may be provided in circular tubes but these may also be particulate in the structural members. These may also incorporate nickel coating.

Alternatively the magnetic material may be constituted of mumetal and/or permalloy. Alternatively, the magnetic material may be selected from the group comprising Kevlar, composite material, carbon fibre, nickel coated iron, wrought iron etc.

These may be provided in a honeycomb. Alternatively these may be provided as a fan of cables.

A structural web may be provided to transport electromagnetic fields to magnets.

Power cables may radiate from the hub at two or four points towards the rim at say 90°.

A disk may be provided to enclose the wheels so that only the outer edge and the tyre move.

T lock principle and/or pipe in tyre may be provided in order to minimise damage from a total flat.

A two-wheeled drive electric motor powered bike is envisaged with applications for on and off-road designs. Electric wheel motors may be situated in the front and rear of the bike in order to share the maximum power available from the batteries which may be of lithium- ion.

Power may be provided in this embodiment to both wheels to maximise traction, reduce wheel spin and convert all available power into usable drive torque. The balance of the power, between front and rear, may be adjusted to suit conditions and create maximum grip for the tyres. The bike may be pulled from the front wheel forwards and pushed at the same time from behind so that optimal power is delivered to maximise thrust using all tyre points of contact with the ground. In this embodiment, each wheel may be motor wheels of the self powered design that may only require power from a battery such as a lithium-ion battery to the fixed spindle to allow the electro-magnetic wheel to rotate around its fixed axis. There may be no other moving parts inside for the driving of the motor cycle.

The wheels may be used to provide braking for the front and rear and to control speed to avoid locking up and the drifting of either wheel. The maximum traction function may assist braking performance and be more powerful than conventional brakes' designs.

Anti-lock braking and traction control may be provided for maximum adhesion to whatever surface conditions prevail with manual override for competition use.

In one embodiment, there may be no drive train required or chain and sprockets.

It is envisaged that for off-road use, this embodiment will allow superior performance in k/W power terms. For on-road performance, superior traction and drive may provide improvements to cornering, braking and acceleration.

Mechanical drive systems to the front wheel may be avoided. The motor wheel design will reduce the need for any additional weight which would otherwise be necessary when incorporating an alternative braking system or when incorporating mechanical drive components to the wheel.

This embodiment also avoids the loss of power from a motor to the wheel since it is fully integrated into the wheel with no further friction on mechanics or losses through a drive train, chain, gears and additional shafts. There may be no variable performance from heat/cold. The absence of fuel tanks, exhausts, injection systems, filter systems and two or four stroke petrol or diesel engines, considerably reduces the components necessary and therefore their weight. The whole design of the motorbike may be built to higher specifications around the rider's centre of gravity to maximise safety (for rider and pillion) aerodynamics (for all on-road use) handling and performance - especially with the matched two wheel drive power and braking advantages.