WO2010133863A2

WO2010133863A2 - Power generating system

Info

Publication number: WO2010133863A2
Application number: PCT/GB2010/050798
Authority: WO
Inventors: Stephen Bedford
Original assignee: Ingineered Limited
Priority date: 2009-05-18
Filing date: 2010-05-17
Publication date: 2010-11-25
Also published as: GB0908492D0; WO2010133863A3

Abstract

The present invention relates to a power generating system for attachment to a vehicle, comprising a generator unit; a rotatable ground engaging means adapted to be contactable with a ground surface, the rotatable ground engaging means being coupled to the generator unit through a transmission mechanism; and a rotatable ground engaging means support arrangement. The rotatable ground engaging means is mounted on the rotatable ground engaging means support arrangement and the rotatable ground engaging means support arrangement is configured such that substantially vertical motion of the rotatable ground engaging means is allowable when the rotatable ground engaging means is engaged with a ground surface.

Description

POWER GENERATING SYSTEM

The present invention relates to a power generating system, in particular to a power generating system for attachment to a vehicle.

All vehicles have electrical systems. Typically an engine driven generator provides power which is stored in a battery for when the engine is not running. The electrical system is designed to operate the vehicle, originally simply starting, providing ignition and lights, however modern vehicles use electrical power for many things e.g. engine management, power steering, ABS brakes and stability control, air conditioning, seat position, etc.

As demand for power has increased within the vehicle, so have demands for power to drive auxiliary systems from the vehicle electrical supply.

Whilst all vehicles have some spare electrical capacity, this is often not as much as is required.

This problem is particularly acute on military vehicles, used to transport soldiers, where an increasing number of systems are being fitted for protection from roadside bombs, land mines, or improvised explosive devices (IEDs).

During military operations it has been known for combatants to use explosive devices to restrict enemy movement or delay an enemy force. Movement in warzones can therefore be treacherous.

Roadside bombs can be triggered in a number of ways including pressure, movement, sound, radio frequency, magnetism or vibration. The triggering mechanisms from roadside bombs can thus be defeated by an array of counter-measures, such as rollers, infra-red hot plates, radio jammers and special lighting, but many of these use electrical power. Many of the vehicles in service can not provide enough spare electrical power for all of the counter-measures to be run concurrently from the vehicle engine alone.

There are three approaches currently being employed in the art for dealing with the power requirement for roadside bomb counter-measures.

The first is the use of so called "low power counter-measures" Low power counter measures have the benefit of being more widely deployable to combat simple roadside bombs, however, the bombs are becoming more and more sophisticated and defeating them requires more power. Thus low power counter-measures, while having the benefit of not draining a substantial amount of battery power, are becoming less effective at combating roadside bombs.

The second approach is the use of a diesel generator. Diesel generators can be used to provide auxiliary power, but in many applications they are unsuitable because they require a lot of maintenance, including refuelling. In addition, they are not reliable enough, are heavy and expensive to buy and run. As a result, the use of diesel generators is generally avoided if possible.

The third approach is the upgrading of a vehicle's power system for greater power capacity. Although the power systems are designed to have more spare capacity, there are additional calls from other equipment such that it does not remain spare for long. It is known in the art to use a ground driven wheel to generate power.

An example of such a device is disclosed in GB2156291. GB2156291 discloses a self-regenerating motor built into an electrically driven vehicle in which a wheel, fixed to a retractable trailing arm, is lowered to the ground when the vehicle is in motion in order to recharge the battery.

A different type of device is disclosed in US2007/0051542. US2007/0051542 discloses an electrical power generation and storage device for portable or emergency use. The device uses the wheel axle of a towed vehicle or a drive system of a car to effectuate rotation of the shaft of an alternator in order to produce electric power capable of being stored within a single battery or a series of batteries.

However neither of the devices of GB21576291 or US2007/0051542 are designed for sustained use on uneven terrain where harsher working conditions are imposed on the ground driven wheel.

Nor do either of the devices provide energy to power auxiliary systems as they are both concerned with storage of energy.

There is therefore a need for a lighter, more compact and reliable power generation system which is more adaptable for use on uneven terrain, such as the terrain often encountered by military vehicles.

According to a first aspect of the invention there is provided a power generating system for attachment to a vehicle, comprising a generator unit; a rotatable ground engaging means adapted to be contactable with a ground surface, the rotatable ground engaging means being coupled to the generator unit through a transmission mechanism; and a rotatable ground engaging means support arrangement, the rotatable ground engaging means being mounted on the rotatable ground engaging means support arrangement and the rotatable ground engaging means support arrangement being configured such that substantially vertical motion of the rotatable ground engaging means is allowable when the rotatable ground engaging means is engaged with a ground surface.

This arrangement provides a power generation system which is more adaptable for use on uneven terrain. This is because torque from the other forces acting on the support arrangement can be isolated due to the fact that the rotatable ground engaging means support arrangement is configured so as to allow substantially vertical motion of the rotatable ground engaging means when the rotatable ground engaging means is engaged with a ground surface.

In addition, the configuration of the rotatable ground engaging means support arrangement in accordance with the invention allows predominately the same movement of the rotatable ground engaging means going forwards as going backwards than if the rotatable ground engaging means was mounted on the rotatable ground engaging means support arrangement in such a way that prevented substantially vertical motion of the ground engaging means when engaged with a ground surface.

In embodiments of the invention, the power generation system further comprises a multi-part linkage assembly adapted to link the rotatable ground engaging means to a vehicle. The multi-part linkage assembly gives the rotatable ground engaging means greater manoeuvrability relative to the vehicle than a single part linkage as known in the art.

In addition, the amount of vibration transmitted to the components of the power generator system by the rotatable ground engaging means is greatly reduced using the multi-part linkage than a single part linkage as known in the art. As a result the damping requirements for the power generation system are reduced and the life span of the generator components of the power generator system increased.

The generator unit may be any suitable system for transmitting energy.

In embodiments of the invention, the generator unit comprises an alternator. The alternator permits the conversion of mechanical energy generated by the rotatable ground engaging means into an alternating current electrical energy in order to power the auxiliary systems of a vehicle.

Alternatively, or in addition, the generator unit may comprise an air compressor or a hydraulic pump.

The transmission mechanism is adapted to provide the required angular velocity output to the generator unit from the angular velocity input provided by the rotatable ground engaging means.

In various embodiments of the invention, the transmission mechanism is adapted to provide a higher angular velocity output to the generator unit than the angular velocity input provided by the rotatable ground engaging means. In various em bod i merits of the invention, the transmission mechanism is adapted to provide the same angular velocity output to the generator unit as the angular velocity input provided by the rotatable ground engaging means.

In various embodiments of the invention, the transmission mechanism is adapted to provide a variable angular velocity output to the generator when compared to the angular velocity input provided by the ground engaging means.

The transmission mechanism may comprise any suitable transmission device adapted to transfer mechanical energy from the rotatable ground engaging means to the generator unit. Examples of suitable transmission devices include, but are not limited to, a pulley assembly, a chain drive assembly or a gear assembly.

The transmission mechanism may comprise a single type of transmission device or a combination of different transmission devices.

In preferred embodiments of the invention, where the transmission mechanism is adapted to provide a higher angular velocity output to the generator unit than the angular velocity input generated by the rotatable ground engaging means, the transmission mechanism comprises a pulley assembly, a chain drive assembly and a gear assembly.

The pulley assembly is ideally a belt and pulley system arrangement known in the art, and is configured to provide the required input/output angular velocity ratio. The gear assembly ideally comprises a plurality of intermeshing gears arranged with each other such that the gear assembly provides the required input/output angular velocity ratio.

The chain drive assembly is configured to provide the required input/output angular velocity ratio. The chain drive assembly ideally comprises an oil immersed chain.

A benefit of using an oil immersed chain is that the oil acts as a lubricant as well as a coolant thus reducing the maintenance required when compared to a non-oil immersed chain.

In embodiments of the invention, the power generation system is adapted to be moveable between an operating position wherein the rotatable ground engaging means is engageable with a ground surface and a stowed position wherein the rotatable ground engaging means is not engageable with the ground surface.

This means that the power generating system of the invention can be deployed as and when auxiliary power is required thus extending the working life of the system as it not constantly in an operating position even when auxiliary power is not required.

In various embodiments of the invention, the power generating system further comprises a frame for housing the generator unit.

In certain embodiments, the frame may also facilitate the connection of the power generating system to a vehicle. Connection of the frame to a vehicle may be done by any suitable means known in the art. In preferred embodiments of the invention, the frame is releasably connectable to a mounting plate attached to the vehicle.

In preferred embodiments of the invention comprising the multi-part linkage assembly, the multi-part linkage assembly comprises four linked sections arranged such that they define a four bar linkage type arrangement.

The provision of a four bar linkage type arrangement further facilitates the manoeuvrability of the rotatable ground engaging means over uneven terrain.

In addition, the four bar linkage type arrangement facilitates the movement of the power generation system between the operating position and the stowed position.

In various embodiments of the invention comprising four linked sections, the four linked sections comprise a multi-part arm and a connecting arm.

In embodiments of the invention, the rotatable ground engaging means support arrangement is in the form of a wheel support arrangement. In preferred embodiments of the invention, the rotatable ground engaging means support arrangement comprises a stem having a first end onto which a rotatable ground engaging means is mountable.

In embodiments of the invention comprising the four linked sections having a multi-part arm and a connecting arm, the stem is attached to the frame by the multi-part arm and the connecting arm such that when the rotatable ground engaging means is engaged with a level ground surface, the multi- part arm and the connecting arm are in a substantially horizontal orientation.

By mounting the rotatable ground engaging means on a stem in such a manner allows substantially vertical motion of the rotatable ground engaging means when the rotatable ground engaging means is engaged with a ground surface. This facilitates the isolation of the torque from the other forces acting on the rotatable ground engaging means support arrangement. In addition, it allows predominately the same movement going forwards as going backwards than if the rotatable ground engaging means was mounted on a diagonal oriented stem.

In various embodiments of the invention the rotatable ground engaging means support arrangement comprises a substantially vertical slider assembly.

This allows substantially vertical motion of the rotatable ground engaging means when the rotatable ground engaging means is engaged with a ground surface.

In various embodiments of the invention, the power generating system further comprises a deflector plate connected to the multi-part linkage assembly and positioned such that, in use, it is located in advance of the path of the rotatable ground engaging means.

There will be occasions where a vehicle will encounter an obstacle be it a rock, a curb or a step. In order for a rotatable ground engaging means to climb the obstacle, the radius of the rotatable ground engaging means must be greater than the height of the obstacle. If this is not the case the obstacle will impede further movement of the rotatable ground engaging means in the required direction.

By having a deflector plate positioned such that, in use, it is located in advance of the path of the rotatable ground engaging means the deflector plate will engage the obstacle before the rotatable ground engaging means. As the deflector plate is connected to the multi-part linkage assembly which is linked to the rotatable ground engaging means, the deflector plate as it travels across the obstacle will cause the rotatable ground engaging means to be lifted off the ground surface thus facilitating the traversing of the rotatable ground engaging means over the obstacle.

The deflector plate may be made of any suitable material which will remain substantially rigid when it comes into contact with an obstacle. For example, the deflector plate may be made from a material such as steel or fibre glass.

In preferred embodiments of the invention, the rotatable ground engaging means is in the form of a wheel and tyre arrangement.

In various embodiments of the invention, the power generating system further comprises an operator control unit.

This allows a user to control and monitor the battery condition and to be informed of any faults.

According to a second aspect of the invention there is provided a power generating system for attachment to a vehicle, comprising a generator unit; a rotatable ground engaging means adapted to be in contact with a ground surface, the rotatable ground engaging means being coupled to the generator unit through a transmission mechanism; wherein the rotatable ground engaging means is installed in a swivel caster frame having an inclined caster adaptor at the free end thereof.

The power generating devices known in the art are generally designed with the ground driven rotatable ground engaging means configured for the situation where a vehicle to which is attached is moving forwards. As such use when the vehicle is reversing is somewhat problematic as the ground driven rotatable ground engaging means is not designed to work in these conditions.

This issue is overcome by a power generating system according to the second aspect of the invention.

As known in the art, by means of a swivel caster frame, a caster is mounted on a pivot, such that the rotatable ground engaging means will automatically swivel, aligning itself to the direction in which it is moving.

Due to the fact that the caster frame has an inclined caster adaptor, the caster will be connected such that when the rotatable ground engaging means is moving forward in use it will engage with the ground. When the direction of the rotatable ground engaging means changes, due to the nature of the caster to automatically swivel to align itself to the direction in which it is moving, the swivelling of the caster will result in the rotatable ground engaging means being lifted off the ground or a spring force biasing the rotatable ground engaging means to the ground greatly reduced. As the rotatable ground engaging means is no longer in contact with the ground or due to the spring force being greatly reduced, the problems associated with reversing are overcome. The adaptor may be a mounting plate or connecting pin as known in the art.

In preferred embodiments of the invention, the caster adaptor is inclined at angle between 5 to 30 degrees. More specifically, the caster adaptor is inclined at a substantially 15 degree angle.

According to a third aspect of the invention there is provided a roller assembly comprising a roller adapted to engage with a ground surface; a roller frame adapted to be connected to a vehicle, the roller being coupled to the roller frame; and a power generating system according to the first or second aspect of the invention.

In various embodiments of the invention, the roller assembly is a mine clearing roller assembly.

In preferred embodiments of the invention the power generating system is connected to the roller frame.

In various embodiments of the invention, the roller defines the rotatable ground engaging means of the power generating system.

Preferably the roller assembly comprises a plurality of rollers adapted to engage with a ground surface.

It will be understood that some of the features of various embodiments of the first and second aspects of the invention may be equally applicable to other embodiments of the invention. Throughout the description and claims of this specification, the words "comprise" and "contain" and variations of the words, for example "comprising" and "comprises", means "including but not limited to", and is not intended to (and does not) exclude other components, integers or steps.

Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

The invention will now be described, by way of non limiting example, with reference being made to the accompanying drawings in which:

Figure 1 is a perspective view of a first embodiment of a power generating system according to a first aspect of the invention;

Figure 2 is a side view of the power generating system of Figure 1 ;

Figure 3 is a perspective view of the power generation system of Figure 1 taken from a different angle;

Figure 4 is a schematic view of the power generating system of Figure 1 attached to a vehicle;

Figure 5 is a schematic view of the power generating system of Figure 1 attached to a vehicle in a stowed position; Figure 6 is a schematic view of an embodiment of a transmission mechanism of the power generating system of the invention;

Figure 7 is a perspective view of a second embodiment of a power generating system according to a first aspect of the invention;

Figure 8 is a schematic view of a third embodiment of a power generating system according to a first aspect of the invention;

Figure 9 is a schematic view of a power generating system according to a first embodiment of a second aspect of the invention;

Figure 10 is a schematic view showing the workings of the caster according to the first embodiment of the second aspect of the invention;

Figure 11 is a schematic view of a power generating system according to a second embodiment of the aspect of the invention;

Figure 12 is a perspective view of a first embodiment of a roller assembly according to a third aspect of the invention; and

Figure 13 is a perspective view of a second embodiment of a roller assembly according to the third aspect of the invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood that the drawings and detailed description thereof are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the scope of the invention as defined by the appended claims.

Further, although the invention will be described in terms of specific embodiments, it will be understood that various elements of the specific embodiments of the invention will be applicable to all embodiments disclosed herein.

Referring to Figures 1 to 5, a power generating system (10) for attachment to a vehicle (24) according to a first aspect of the invention is shown.

The power generating system (10) comprises a generator unit (12); a rotatable ground engaging means (14) adapted, in use, to be in contact with a ground surface (40); a rotatable ground engaging means support arrangement (21 ) onto which the rotatable ground engaging means (14) is mounted; and a multi-part linkage assembly linking the generator unit (12) to the rotatable ground engaging means (14).

The generator unit (12) comprises an alternator (18) which is housed in a frame (20) adapted to be attached to a vehicle (24). The alternator (18) is similar to one known in the art and will therefore not be described in any great detail. It will be readily understood that the size of the alternator (18) will be dependent on the auxiliary power requirements of the vehicle (24).

The frame (20) is releasably attached to the vehicle (24) via a mounting plate (44) which is secured to a vehicle attachment bracket (25) of the vehicle (24). The mounting plate (44) is secured to the vehicle attachment bracket (25) by welding, although it may be secured to the vehicle attachment bracket (25) by any other suitable means. In the embodiment shown, the mounting plate (44) is substantially triangular in shape, although it should be understood that the shape and size of the mounting plate (44) may vary depending on the type of vehicle to which it is to be attached to.

The frame comprises a pair of first hooks (48) located on the sides of the frame (20) and a pair of second hooks (46) positioned centrally on the frame (20).

In the embodiment shown, the first hooks (48) are fixed on the sides of the frame (20) and are engageable with the base of the substantially triangular mounting plate (44). The first hooks (48) are located in such a manner that once engaged with the mounting plate (44), they react to transverse, longitudinal and upward forces acting on the frame (20).

The second hooks (46) are pivotally mounted on the frame (20) and are engageable with the top of the substantially triangular mounting plate (44). The second hooks (46) are located in such a manner that once engaged with the mounting plate (44), they react to longitudinal and upward forces acting on the frame (22).

The rotatable ground engaging means (14) is in the form of a wheel and tyre arrangement known in the art. In preferred embodiments of the invention, the wheel and tyre arrangement is in the form of a wheel with a pneumatic tyre fitted around the wheel. The wheel and tyre arrangement may however be any alternative arrangement known in the art.

Henceforth, reference to the term "wheel" is taken to mean a wheel and tyre arrangement. The rotatable ground engaging means support arrangement (21 ) is in the form of a wheel support arrangement. The wheel (14) is mounted on an end of the wheel support arrangement (21 ) which in the embodiment shown is in the form of a stem (22). The wheel support arrangement (21 ) is configured such that substantially vertical motion of the wheel (14) is allowed when the wheel (14) is engaged with the ground surface (40).

A first end of a multi-part arm (16) is rotatably connected to an end of the stem (22) opposite to that which the wheel is mounted. A second end of the multi-part arm (16) is rotatably connected to the frame (20). In the embodiment shown, the multi-part arm (16) comprises three parts (16a, 16b, 16c).

The part (16c) of the multi-part arm (16) connected to the frame (20) is substantially U-shaped having a crossbar (36) and two parallel branches (38) extending therefrom, the free end of the branches defining the second end of the multi-part arm (16).

The wheel (14) is coupled to the generator unit (12) through a transmission mechanism (not shown in Figures 1 to 5) which is housed within the stem (22).

Referring to Figure 6, a preferred arrangement of the transmission mechanism of the invention is shown. The transmission mechanism comprises a staged transmission arrangement which includes a gear assembly (26), a chain drive assembly (not shown) and a pulley assembly section (30). The gear assembly (26) comprises a plurality of intermeshing gears arranged with each other. The gear assembly (26) is connected to an axle (42) of the wheel (14) and has an input/output ratio of 1 :3.3.

The chain drive assembly comprises an oil immersed chain having an end thereof connected to the gear assembly (26). The input of the chain drive assembly is connected to the output of the gear assembly, and the chain drive assembly has an input/output ratio of 1 :1.5.

The pulley assembly (30) comprises a first pulley wheel, a second pulley wheel (29) and a belt (31 ) arranged in a belt and pulley system arrangement known in the art.

The first pulley wheel is attached to the alternator and the second pulley (29) is attached to the stem (22). The second pulley wheel is connected to the output of the drive chain, and the pulley assembly (30) is configured to have an input/output ratio of 1 :2.4.

The free end of the branches (38) are pivotable about the drive axis of the alternator (18) so that the belt length of the belt (31 ) of the pulley assembly (30) is fixed with respect to the movement of the multi-part arm (16).

The combined ratios of the gear assembly (26), the chain drive assembly and the pulley assembly (30) thus gives the transmission mechanism an input/output ratio of around 1 :12.

The power generating system (10) further comprises a connecting arm (32) having a first end rotatably connected to the stem (22) and a second end rotatably connected to the frame (20). The multi-part linkage assembly connecting the generator unit (12) to the wheel (14) is defined by the stem (22), the multi-part arm (16), the connecting arm (32) and the frame (20). The components of the multi-part linkage are arranged such that they define a four bar linkage type arrangement.

The pivot points of the four bar linkage type arrangement are located at the first end of the connecting arm (32), the second end of the connecting arm (32), the first end of the multi-part arm (16), and the second end of the multi-part arm (16).

The stem (22) is attached to the frame (20) by the multi-part arm (16) and the connecting arm (32) such that when the wheel (14) is engaged with a level ground surface (40), the multi-part arm (16) and the connecting arm (32) are in a substantially horizontal orientation as best seen in Figure 2. That is to say that a line running through the connecting arm pivot points is parallel to a line running through the multi-part arm pivot points.

A damper (34) is positioned between the generator unit (12) and the wheel (14). In the embodiment shown, damper (34) is in the form of a spring (not shown in the Figures for clarity) and shock absorber arrangement known in the art. The shock absorber is a hydraulic shock absorber with a coil spring over it having a first end rotatably connected to the frame (20) and a second end rotatably connected to the first end of the multi-part arm (16).

The power generation system (10) is moveable between a stowed position (as shown in Figures 5) and an operating position wherein the wheel (14) is engageable with a ground surface (40). Referring to Figure 7, a second embodiment of a power generating system according to the first aspect of the invention is shown (same reference numerals have been used for the same features to that the first embodiment for ease of reference). The power generating system (10') according to the second embodiment is similar to that of the first embodiment described above with the exception that the multi-part arm (16') comprises two parts (16a¹, 16b') rather than three parts.

Referring to Figure 8, a third embodiment of a power generating system (50) according to the first aspect of the invention is shown. The third embodiment is similar to that of the first and second embodiment of the first aspect of the invention and same reference numerals have been used for the same features for ease of reference.

The difference between the third embodiment and that of the first and second embodiments is that the third embodiment further comprises a deflector plate (52).

The deflector plate (52) is connected to the multi-part linkage assembly and positioned on the crossbar (36) such that, in use, it is located in advance of the path of the wheel (14).

The deflector plate (52) is made from suitable material which will remain substantially rigid when it comes into contact with an obstacle such as steel.

When the deflector plate (52) comes into contact with an obstacle, and as it travels across the obstacle, it will deflect upwards. This will cause the multi-part linkage to move in the direction of the deflector (52) which will cause the wheel to be lifted off and out of contact the ground surface (40) in order to facilitate the traversing of the wheel over the obstacle.

In a fourth embodiment of a power generating system according to the first aspect of the invention (not shown), the wheel support arrangement comprises a substantially vertical slider assembly instead of a stem. As in the previously described embodiments, the wheel support arrangement is configured such that substantially vertical motion of the wheel is allowed when the wheel is engaged with the ground surface.

The slider assembly comprises a first cylindrical member and a second cylindrical member having a cavity adapted to telescopically receive the first cylindrical member therein. The wheel is mounted on a first end of the first cylindrical member and a second end thereof is located within the cavity of the second cylindrical member.

Two stop plates are positioned spaced apart from one another on an outer circumference of the second cylindrical member and the slider assembly further comprises a compression coil spring interposed and retained between the stop plates.

The stop plates are retained in substantially the same location on the outer circumference of the second cylindrical member. This may be achieved by having the stop plates integrally formed with the second cylindrical member or secured to the second cylindrical member by means which allow the stop plates to counteract the spring force acting on the stop plates due to the coil spring.

The slider assembly facilitates the manoeuvrability of the wheel over uneven terrain by allowing substantially vertical motion of the wheel when the wheel is engaged with the ground surface due to the telescopic arrangement of the cylindrical members.

Referring to Figures 9 and 10, a first embodiment of a power generating system (100) for attachment to a vehicle according to a second aspect of the invention is shown. The power generating system (100) is similar to that of the first aspect of the invention and same reference numerals have been used for the same features to that the first aspect of the invention for ease of reference. Reference numerals for similar features to that of the first aspect of the invention have been increased by 100 for ease of reference, for example the stem which was referred to with reference numeral 22 in the first aspect will have a reference numeral 122.

In the embodiment shown, the power generating system (100), as in the first aspect of the invention comprises a generator unit; a wheel (114) adapted to be in contact with a ground surface (140), the wheel (114) being coupled to the generator unit through a transmission mechanism; a wheel support arrangement (121 ) onto which the wheel (114) is mounted; and a multi-part linkage assembly linking the generator unit to the wheel (114). These features in common with the first aspect of the invention will not be described in any further detail.

Unlike in the first aspect of the invention, the wheel (114) is installed in a swivel caster frame (102) having an inclined caster adaptor (104) at the non-wheel engaging end thereof.

The term "caster" will be used henceforth to refer to the wheel (114) and the caster frame (102) when connected to each other. The caster is connected to the wheel support arrangement, which in the embodiment shown is in the form of a stem (122), via the caster adaptor (104) and as a result of the inclination of the caster adaptor (104) will be inclined at an angle (θ). In embodiments of the invention, the stem (122) is inclined at an angle of approximately 15 degrees.

The caster is mounted on a pivot (not shown), such that the wheel (114) will automatically swivel, aligning itself to the direction in which it is moving.

Due to the fact that the caster frame has an inclined caster adaptor (104), the caster will be connected such that when the wheel (114) is moving forward in use (as best seen in Figure 10a) it will engage with the ground (140). When the direction of the wheel changes, due to the nature of the caster to automatically swivel to align itself to the direction in which it is moving, the swivelling of the caster will result in the wheel (114) being lifted off the ground (140) (as best seen in Figure 10b).

Referring to Figure 11 , a second embodiment of a power generating system (200) for attachment to a vehicle according to the second aspect of the invention is shown. Reference numerals for similar features to that of the first embodiment of the second aspect of the invention have been increased by 100 for ease of reference, for example the caster frame which was referred to with reference numeral 102 in the first embodiment will have a reference numeral 202.

The power generating system (200) comprises a generator unit; a wheel (214) adapted to be in contact with a ground surface (240), the wheel (214) being coupled to the generator unit through a transmission mechanism; and a wheel support arrangement onto which the wheel (214) is mounted.

As in the first embodiment of the second aspect of the invention, the wheel (214) is installed in a swivel caster frame (202). The caster frame (202) may have an inclined caster adaptor as in the first embodiment or an uninclined caster adaptor. In the embodiment shown, the caster frame (202) comprises an uninclined caster adaptor (204).

The wheel support arrangement comprises a substantially vertical slider assembly (205) and as in the previously described embodiments, the wheel support arrangement is configured such that substantially vertical motion of the wheel (214) is allowed when the wheel (214) is engaged with the ground surface (240).

The slider assembly (205) comprises a first cylindrical member (206) and a second cylindrical member (207) having a cavity (211 ) adapted to telescopically receive the first cylindrical member (206) therein. A first end of the first cylindrical member (206) is coupled to an end of the caster adaptor (204) and a second end thereof is located within the cavity (211 ) of the second cylindrical member (207).

A stop plate (217) is positioned on an outer circumference of the second cylindrical member (207) and the slider assembly (205) further comprises a compression coil spring (208) interposed and retained between the caster adaptor (204) and the stop plate (217).

The stop plate (217) is retained in substantially the same location on the outer circumference of the second cylindrical member (207). This may be achieved by having the stop plate (217) integrally formed with the second cylindrical member (207) or secured to the second cylindrical member by means which allow the stop plate (217) to counteract the spring force acting on the stop plate (217) due to the coil spring (208).

The slider assembly (205) facilitates the manoeuvrability of the wheel (214) over uneven terrain by allowing substantially vertical motion of the wheel (214) when the wheel (214) is engaged with the ground surface (240) due to the telescopic arrangement of the cylindrical members (206, 207).

The power generating system (200) further comprises attaching means for attaching the power generating system (200) to a vehicle or trailer. In the embodiment shown, the attaching means is in the form of a mounting bracket (209) attached to the second cylindrical member (207) although the attaching means may be in similar to the means previously described for attaching the previously described embodiments to a vehicle or any suitable form known in the art.

The generator unit comprises a low speed hydraulic pump (215) connected to the wheel and plurality of hydraulic hoses (213) in fluid communication with the generator unit and the vehicle.

The transmission mechanism (not shown) is of a form known in the art for transferring rotational energy through the movement of the wheel (214) to the pump (215).

The pump (215) is actuated by the rotation of the wheel (214) via the transmission mechanism as known in the art and the hydraulic power generated by the hydraulic pump (215) is transferred to the vehicle via the hoses (213).

Referring to Figure 12, a first embodiment of a roller assembly (300) according to a third aspect of the invention is shown.

The roller assembly (300) comprises a plurality of rollers (360) adapted to engage with a ground surface and a roller frame (362) adapted to be connected to a vehicle (not shown).

The roller assembly (300) is shown in the form of a mine clearing roller assembly.

The roller frame and the rollers may be of various different designs and configurations as known in the art for mine clearing roller assemblies and will therefore not be described in any great detail.

The rollers (360) are coupled to the roller frame (362), and the number of rollers (360) and the position of the rollers (360) on the frame will be dependent on the intended use and requirements of the roller assembly (300).

In the embodiment shown, the roller assembly (300) comprises twelve rollers (360).

The roller assembly (300) further comprises a power generating system according to a first aspect or second aspect of the invention. In the embodiment shown, the power generating system is one in accordance with the first aspect of the invention. The power generated by the power generating system can be utilised to put weight on the rollers such that, in operation as a mine clearing roller assembly, the roller assembly (300) applies a ground pressure higher than that exerted by the vehicle.

Referring to Figure 13, a second embodiment of a roller assembly (400) according to a third aspect of the invention is shown (same reference numerals have been used for the same features to that the first embodiment for ease of reference).

The roller assembly (400) according to the second embodiment is similar to that of the first embodiment described above with the exception that the ground engaging means of the power generator system is defined by a roller (414) of the roller assembly.

The other components of the power generator system have been omitted from Figure 13 for clarity.

While the embodiments of the invention have been described as being attachable to a vehicle, it would be readily understood that they can be attached or mounted to a trailed or carrier implement which, itself, is attached to the vehicle.

Further modifications and improvements may be added without departing from the scope of the invention herein described.

Claims

1. A power generating system for attachment to a vehicle, comprising a generator unit; a rotatable ground engaging means adapted to be contactable with a ground surface, the rotatable ground engaging means being coupled to the generator unit through a transmission mechanism; and a rotatable ground engaging means support arrangement, the rotatable ground engaging means being mounted on the rotatable ground engaging means support arrangement and the rotatable ground engaging means support arrangement being configured such that substantially vertical motion of the rotatable ground engaging means is allowable when the rotatable ground engaging means is engaged with a ground surface.

2. A power generating system according to claim 1 further comprising a multi-part linkage assembly adapted to link the rotatable ground engaging means to a vehicle.

3. A power generating system according to claim 1 wherein the generator unit comprises a system for transmitting energy.

4. A power generating system according to claim 2 wherein the generator unit comprises an alternator.

5. A power generating system according to claim 2 or claim 3 wherein the generator unit comprises an air compressor.

6. A power generating system according to claim 2 or claim 3 wherein the generator unit comprises a hydraulic pump.

7. A power generating system according to any one of the preceding claims wherein the transmission mechanism is adapted to provide an angular velocity output to the generator unit from the angular velocity input provided by the rotatable ground engaging means.

8. A power generating system according to claim 6 wherein the transmission mechanism is adapted to provide a higher angular velocity output to the generator unit than the angular velocity input provided by the rotatable ground engaging means.

9. A power generating system according to claim 6 wherein the transmission mechanism is adapted to provide the same angular velocity output to the generator unit as the angular velocity input provided by the rotatable ground engaging means.

10. A power generating system according to claim 6 wherein the transmission mechanism is adapted to provide a variable angular velocity output to the generator when compared to the angular velocity input provided by the ground engaging means.

11. A power generating system according to any one of the preceding claims wherein the transmission mechanism comprises a transmission device adapted to transfer mechanical energy from the rotatable ground engaging means to the generator unit.

12. A power generating system according to claim 11 wherein the transmission device comprises a pulley assembly.

13. A power generating system according to claim 11 or 12 wherein the transmission device comprises a chain drive assembly.

14. A power generating system according to any one of claims 11 to 13 wherein the transmission device comprises a gear assembly.

15. A power generating system according to claim 12 or any claim dependent from claim 12, wherein the pulley assembly is a belt and pulley system arrangement configured to provide the required input/output angular velocity ratio.

16. A power generating system according to claim 13 or any claim dependent from claim 13, wherein the chain drive assembly is configured to provide the required input/output angular velocity ratio.

17. A power generating system according to claim 13 or any claim dependent from claim 13, wherein the chain drive assembly comprises an oil immersed chain.

18. A power generating system according to claim 14 wherein the gear assembly comprises a plurality of intermeshing gears arranged with each other such that the gear assembly provides the required input/output angular velocity ratio.

19. A power generating system according to any one of the preceding claims wherein the power generation system is adapted to be moveable between an operating position wherein the rotatable ground engaging means is engageable with a ground surface and a stowed position wherein the rotatable ground engaging means is not engageable with the ground surface.

20. A power generating system according to any one of the preceding claims further comprising a frame for housing the generator unit.

21. A power generating system according to claim 20 wherein the frame is releasably connectable to a mounting plate attached to the vehicle.

22. A power generating system according to claim 2 or any claim dependent from claim 2, wherein the multi-part linkage assembly comprises four linked sections arranged such that they define a four bar linkage type arrangement.

23. A power generating system according to claim 22 wherein the four linked sections comprise a multi-part arm and a connecting arm.

24. A power generating system according to any one of the preceding claims wherein the rotatable ground engaging means arrangement is in the form of a wheel support arrangement.

25. A power generating system according to any one of the preceding claims wherein the rotatable ground engaging means support arrangement comprises a stem having a first end onto which a rotatable ground engaging means is mountable.

26. A power generating system according to claim 25 when dependent on claims 23, wherein the stem is attached to the frame by the multi-part arm and the connecting arm such that when the rotatable ground engaging means is engaged with a level ground surface, the multi-part arm and the connecting arm are in a substantially horizontal orientation.

27. A power generating system according to anyone of the preceding claims wherein the wheel support arrangement comprises a substantially vertical slider assembly.

28. A power generating system according to claim 2 or any claim dependent from claim 2, further comprising a deflector plate connected to the multi-part linkage assembly and positioned such that, in use, it is located in advance of the path of the rotatable ground engaging means.

29. A power generating system according to claim 28 wherein the deflector plate comprises a rigid material.

30. A power generating system according to claim 29 wherein the rigid material comprises steel.

31. A power generating system according to claim 29 wherein the rigid material comprises fibre glass.

32. A power generating system according to any one of the preceding claims wherein the rotatable ground engaging means is in the form of a wheel and tyre arrangement.

33. A power generating system according to any one of the preceding claims further comprising an operator control unit.

34. A power generating system for attachment to a vehicle, comprising a generator unit; a rotatable ground engaging means adapted to be in contact with a ground surface, the rotatable ground engaging means being coupled to the generator unit through a transmission mechanism; wherein the rotatable ground engaging means is installed in a swivel caster frame having an inclined caster adaptor at the free end thereof.

35. A power generating system according to claim 34 further comprising a caster mounted on a pivot configured such that the rotatable ground engaging means will automatically swivel, aligning itself to the direction in which it is moving.

36. A power generating system according to claim 34 or claim 35 wherein the caster adaptor comprises a mounting plate.

37. A power generating system according to claim 34 or claim 35 wherein the caster adaptor comprises a connecting pin.

38. A power generating system according to any one of claims 34 to 37 wherein the caster adaptor is inclined at angle between 5 to 30 degrees.

39. A power generating system according to claim 38 wherein the caster adaptor is inclined at a substantially 15 degree angle.

40. A roller assembly comprising a roller adapted to engage with a ground surface; a roller frame adapted to be connected to a vehicle, the roller being coupled to the roller frame; and a power generating system according to any one of the preceding claims.

41. A roller assembly according to claim 40 wherein the roller assembly is a mine clearing roller assembly.

42. A roller assembly according to claim 40 or 41 wherein the power generating system is connected to the roller frame.

43. A roller assembly according to claim 40 or 41 wherein the roller defines the rotatable ground engaging means of the power generating system.

44. A roller assembly according to any one of claims 40 to 43 wherein the mine clearing roller assembly comprises a plurality of rollers adapted to engage with a ground surface.