Technical Field

This invention relates to methods and components for powering motor vehicles.

Background

Traditionally motor vehicles are driven by a dedicated motor and gearbox assembly. Each motor and gearbox assembly is specifically designed for each specific vehicle type such that the vehicle has appropriate drive characteristics. For example, nowadays motor vehicles have to be capable of accelerating to reach certain speeds and also be capable of maintaining those speeds in order for them to be suitable to drive on the roads. As a result of a host of different vehicle factors including: size, weight and shape, the motor and gearbox needed to drive each vehicle are often very different. For example, a typical motor needed to drive a minibus with a weight of around 3 tonnes is likely to be less powerful than a motor which is used to drive a heavier lorry with a weight of, for example, 10 tonnes.

Whilst the difference is more obvious in the case where a minibus is compared to a lorry, there is often a significant difference between the motors of relatively similar vehicles.

In addition to the difference between the motors in different vehicles, the gear ratios of the gearboxes are often significantly different. Each gearbox has to be designed to transfer power efficiently from the motor to the wheels and therefore gearboxes often have to be developed in unison with a motor so that they are compatible with one another. Not only does a gearbox have to be designed to work with the motor, the gearbox often has to be designed to provide the desired drive characteristics of the vehicle. For example, a small saloon car may have a 0-60mph acceleration time of 10 seconds, whereas a 4x4 type vehicle may have a 0-60mph acceleration time of 15 seconds. As a result, the gearbox in each vehicle has to be designed accordingly to be capable of powering each vehicle.

According to current methods of manufacture, when a vehicle manufacturer develops a vehicle they often develop a brand new motor and gearbox suitable for driving the vehicle. Whilst sometimes this may involve entirely changing a motor, in some cases the changes are less notable. For example, in the case of combustion engines, the engine capacity may be changed in order to modify the engine's power output. Alternatively, in vehicles which are driven by electric motors, if more power is required to drive the vehicle, typically an electric motor with a higher power output is developed. Whilst the changes in both examples are sometimes small, the motor is nonetheless changed accordingly. Therefore, even among a fleet of different vehicles developed by a single manufacturer, each vehicle will likely have its own unique motor and gearbox, both of which have been designed for each particular type of vehicle. Summary

The present invention aims to improve upon the situation discussed above and when viewed from a first aspect provides a set comprising a plurality of different vehicles, each vehicle in the set comprising at least one universal electric motor and at least one gearbox, wherein at least two of the vehicles are powered by a different number of said universal electric motors.

Thus it will be seen by those skilled in the art that in accordance with the present invention a set comprising a plurality of vehicles can be powered by a single type of universal electric motor. Powering the set of vehicles in this manner means that time and resources need only be spent on developing a single universal motor. This contrasts with prior manufacturing techniques where a design team would have to design a motor for each type of vehicle thus incurring significant design costs.

Additionally developing bespoke motors means that each motor has to be individually tested which in itself is a costly and time consuming process. Therefore, by only using a single type of universal motor according to the present invention, the design and testing costs are significantly reduced. The Applicant has

appreciated for the first time that this is a viable approach.

Implementing the present invention may also significantly reduce manufacturing costs. If only a single type of universal motor is produced in order to power each vehicle in the set, only a single set of manufacturing tooling and assembly lines are required. Another benefit of using a single type of universal motor is that only a single set of ancillary components is required, which further reduces cost. Aside from manufacturing the motors in the first place, motors also have to be maintained post-manufacture. In a fleet of vehicles which all have individually designed motors, as in the prior art approach, separate skill, expertise and spare parts are required to maintain each one. The present invention may help to address this problem as maintenance personnel only have to be equipped to repair the universal motor in order to be able to maintain all vehicles within the set.

Additionally, they only need to stock one type of replacement component for the universal motor rather than a range of components for different motors. The availability of spare components for repairing vehicles is often one of the key factors that inhibits their repair.

A further advantage of the present invention is the use of an electric motor as the universal motor. This is particularly advantageous as scaling up the number of electric motors, depending on the particular vehicle, is easier than scaling up the number of, for example, internal combustion engines. Electric motors are therefore particularly advantageous in the modular approach to powering the vehicles which is employed in accordance with this invention. In addition, electric motors are typically more compact than internal combustion engines and therefore using multiple electric motors on a vehicle demands less space and is thus more feasible than using multiple internal combustion engines.

It will be appreciated that all of the universal motors used within each individual vehicle and each vehicle within the set will have the same pre-determined motor characteristics. These motor characteristics may, for example, be: power output, torque, motor shape and mounting points. Therefore, every motor used in the set will be functionally identical. Whilst it may be possible in accordance with the invention to modify slightly the universal motors for some applications, e.g. to attach a mounting bracket, it should be understood that such minor modifications do not prevent such variants constituting a single universal motor.

The person skilled in the art will appreciate that the number of universal motors used to power each particular vehicle will depend on the vehicles characteristics. The number of universal motors may, for example, be influenced by the weight of the vehicle, its shape and/or potential pay-load capacity. Thus in accordance with the present invention, a vehicle that has a larger weight will typically have an increased number of motors in order to power it. Similarly a vehicle that has a shape that is less aerodynamic, and thus requires more power to drive it, will typically also have more universal motors powering it. For example, a lorry with a flat fronted cab will experience significantly more air resistance than, for example, a more aerodynamic-fronted minibus. Ultimately the vehicle characteristics and the number of universal motors powering the vehicle will determine the driving capabilities of the vehicle. For example, if a heavy vehicle is only provided with a single universal motor, and is thus underpowered, it will not be able to accelerate sufficiently quickly or maintain speed. Therefore, the desired drive capabilities of the vehicle in question may also influence the number of universal motors used on a particular vehicle. For example, if a vehicle is intended to be driven for long periods of time at high speeds a higher number of universal motors may be provided which can achieve this with minimal fatigue on each one. It will be appreciated that powering motor vehicles in this modular way makes designing vehicles

considerably simpler. The design team is required simply to determine basic characteristics of the vehicle and then choose an appropriate number of universal motors sufficient to power the vehicle. This significantly reduces the costs involved in designing the motor vehicle. In order for the universal motor to be suitable for use on a range of vehicles it should be compatible with all the vehicles in that range. Thus in a set of

embodiments the universal motor is designed to have a specific shape and mounting points that permit use on a range of different vehicles. This may, for example, involve keeping the physical size of the universal motor as small as possible so that positioning the universal motor is less affected by other features of the vehicle, for example the vehicle chassis. Additionally or alternatively, it may involve providing extra mounting points that are redundant when the universal motor is mounted in some vehicles in the set, but are utilised when used on other vehicles in the set. This would allow the universal motor to be mounted in a range of positions thus further enhancing its ability to function in a range of vehicles in the set.

The positioning of the universal motor on each vehicle in the set will determine how the universal motor powers the vehicle. In a set of embodiments the position of the universal motor(s) depends on the vehicle. For example, a front-heavy vehicle may have multiple universal motors arranged to drive its front axle, whereas a rear- heavy vehicle may have multiple universal motors arranged to drive its rear axle(s). The ability to position the universal motor(s) in a range of positions on a vehicle ensures that the vehicle is appropriately powered. Whilst the universal motor(s) may be arranged to power a particular set of wheels on the vehicle this does not necessarily mean that they are arranged directly near or next to those wheels. For example, a universal motor may be positioned near the rear front of the vehicle, i.e. proximal to the front wheels, however the power from the universal motor may be transferred to the rear wheels of the vehicle. This may also happen in reverse where a universal motor is positioned towards the rear of a vehicle and be arranged to power the front wheels. Furthermore the universal motor(s) may be arranged to power more than one set of wheels on the vehicle. The position of the universal motor(s) on the vehicle may have an impact on the weight distribution of the vehicle, and this is a factor that may be taken into account by the vehicle designer when designing each specific type of vehicle.

As the set of vehicles typically comprises multiple different vehicles which may each be produced in large numbers, it is preferable that the universal motor can be manufactured at a relatively low cost. Advantageously therefore the universal motor is designed so that it is suitable for low cost mass production. This may, for example, involve using standard components that are readily available and can be easily assembled. It may also involve designing the universal motor in such a way that it can be manufactured on an existing production line. These both help to reduce the cost of the universal motor and ensure that it can be produced quickly.

Whilst the vehicles in the set may comprise small vehicles, such as cars, the invention may be particularly well suited to larger vehicles, such as buses and lorries. Therefore, in a set of embodiments the universal motor is capable of powering 0.5 tonnes to 6 tonnes, e.g. 3 to 5 tonnes or e.g. 4 tonnes. A motor capable of powering such weights is advantageous as the weights are not so large that the universal motor has to be excessively large, but not so small that a large number of universal motors are required to power some vehicles. It should be appreciated that the weights stated above are the maximum weight that the universal motor is able to power. For example, if a vehicle weighs 2 tonnes, it would only require a single universal motor, whereas a vehicle that weighs 10 tonnes may require three universal motors.

The weight that a universal motor is said to be capable of powering is understood to be a nominal weight set by the manufacturer of the universal motor e.g. 4,000kg. It should be appreciated that whilst the universal motor may be capable of powering such a nominal weight, in certain circumstances the universal motor may be used to power more or less weight. It will further be appreciated that a universal motor used to power less weight than its nominal rating will be able to accelerate the vehicle faster, of course depending on other factors. A universal motor may also be used to power more weight than its nominal rating where acceleration is of low importance.

In a set of embodiments, the universal motor has a continuous power output between 40-80 kW, e.g. 50-80 kW, e.g. 50-60 kW or e.g. 55 kW. In a set of embodiments the universal motor has a peak power output between 40-1 OOkW, e.g. 60-90 kW, e.g. 70-80 kW or e.g. 78kW. A universal motor with a power output in this general range is particularly suitable for use in driving motor vehicles as it has a sufficiently high power to drive a significant weight yet still has a low enough power output such that it will not excessively drain its power supply. Additionally or alternatively, in another set of embodiments the universal motor has a continuous torque of 200-400 Nm, e.g. 200-300 Nm, e.g. 230-270 Nm or e.g. 250 Nm. In a set of embodiments the universal motor has a peak torque of between 200-500 Nm, e.g. 250-350 Nm or e.g. 300 Nm. A torque in this range is useful as it can be used to drive a range of vehicles, e.g. from small cars to articulated lorries.

In order to drive the vehicles appropriately, different vehicles in the set may have different arrangements of the universal motors relative to the wheels. On some vehicles a universal motor may be positioned to drive each axle of the vehicle, whereas on other vehicles a universal motor may be dedicated to driving a single wheel and thus on one axle there may be two universal motors. The arrangement of the universal motors is largely dependent on the vehicle characteristics and it will be appreciated that there are a large number of permutations of how the universal motors can be arranged. The number of permutations is further increased by the fact that some vehicles will have more than two sets of wheels. ln a set of embodiments the gearbox in each vehicle in the set is chosen from a sub-set of no more than three gearboxes. In a further set of embodiments each gearbox in the sub-set has an identical casing. In another set of embodiments, each gearbox comprises a set of common internal components, the majority of which are identical to the common internal components in each of the other gearboxes within the sub-set. The Applicant has appreciated that as a single universal motor is used to power all of the vehicles in the set, it is not necessary to design a gearbox individually for each type of vehicle. However the Applicant has appreciated that some vehicles may require different gearboxes in order for the vehicle to be suitably driven. By providing no more than three different gearboxes, an appropriate gearbox can be chosen for each vehicle. As for the universal motor,

advantageously the three gearboxes are designed to be suitable for low cost mass production. Thus in a preferred set of embodiments only a single universal motor and three gearboxes have to be manufactured in order to power and drive a large range of vehicles. Additionally, by using a common casing for each gearbox and using a common set of internal components, the cost of manufacturing the gearboxes can be reduced.

In a set of embodiments one of the gearboxes has a gear ratio of 9:1 , another has a gear ratio of 14:1 and the other gearbox has a gear ration of 19:1 . These gear ratios are advantageous as they are suitable for a wide range of vehicles.

In an alternative set of embodiments the gearbox in each vehicle in the set is chosen from a sub-set of two gearboxes. In such a set of embodiments one of the gearboxes in the sub-set has a gear ratio of 9:1 , 14:1 or 19:1 and the other gearbox in the sub-set has a different gear ratio from the same set of 9:1 , 14:1 or 19:1 .

In a further alternative set of embodiments a single type of gearbox is used in every vehicle in the set. In such a set of embodiments the gearbox has a gear ratio of 9:1 , 14:1 or 19:1 .

The set of motor vehicles could include any vehicle that is capable of being driven by a motor. For example, a non-exhaustive list of possible vehicles may include: buggies, cars, motorbikes, minibuses, vans, buses, trucks, pickups, recreational vehicles (RVs), motorhomes, sports utility vehicles (SUVs) and lorries. Advantageously, the motor vehicles may comprise commercial vehicles. Within the present specification, the term "commercial vehicle" is intended to comprise a lorry and/or a bus. Whilst it will be appreciated that set of vehicles could comprise a large number of different types of vehicles, in a set of embodiments the set of motor vehicles comprises buses and/or lorries. Buses and lorries, defined as "commercial vehicles" above, are particularly well suited to being powered in accordance with the present invention as often there is sufficient space on vehicles of this type to provide additional universal motors and gearboxes to power them. This is not always the case with smaller vehicles such as cars where space is more

constrained.

In accordance with the invention, at least one of the vehicles will have at least two universal motors. As a result of the fact that at least one of vehicles will be powered by multiple universal motors it is important that the universal motors can be used to power the vehicle in a coordinated fashion. For example, if a vehicle is driven by two motors on its rear axle, it is important that both motors power the vehicle uniformly as otherwise one of the rear wheel may be caused to rotate at a different speed and thus detrimentally affect the drive of the vehicle. Therefore, in a set of embodiments at least the vehicle(s) in the set with a plurality of universal motors comprise(s) a control system for controlling the universal motors in order to coordinate their operation. In a set of embodiments such a control system is incorporated into each universal motor and arranged to communicate with each other control system. Alternatively a separate control unit may be provided elsewhere on the vehicle to control the universal motor(s) on that vehicle.

The set of vehicles could be powered solely by the universal electric motors, but this is not essential and so one or more of the vehicles may be further powered by other means. Thus in a set of embodiments at least one vehicle in the set is powered, in addition to the universal electric motor, by an additional power unit. The additional power unit would typically have different characteristics to the universal motor e.g. a different power output. Whilst the additional power unit may also be an electric motor, in a set of embodiments the additional motor is an internal combustion engine, which may be connected to and configured to drive an electrical generator; in other words one or more of the vehicles may be hybrid vehicles. Hybrid vehicles have a host of advantages which are well known in the art e.g. extended driving range. These embodiments may be particularly advantageous where it is desired that a number of vehicles in the set are powered solely by the universal motors, with specific vehicles which have certain required characteristics also being supplemented with additional power units.

The Applicant has further appreciated that it is advantageous to share other significant mechanical components between vehicles in the set. Thus in a set of embodiments at least two vehicles in the set comprise at least one further identical mechanical component. In a set of embodiments the further identical component is a suspension component. The Applicant has appreciated that suspension system components are typically a significant component of the cost of a vehicle and thus by reducing the number of suspension components needing to be manufactured across the set of vehicles, the overall cost of manufacture can be significantly reduced.

When viewed from a second aspect, the present invention provides a method of manufacturing a vehicles from a set of modular components, wherein the modular components comprise a universal motor capable of moving a pre-determined weight of a vehicle and no more than three gearboxes each with a different gear ratio; the method comprising: choosing an appropriate number of universal motors necessary to drive the vehicle and choosing an appropriate gearbox or gearboxes to drive the vehicle.

Using a universal motor and gearbox assembly to power a range of different vehicles provides many advantages as previously discussed. The advantage of the reduction in time spent designing and manufacturing the vehicle can further be enhanced by incorporating the universal motor and a gearbox into a single axle assembly that can be used on a range of vehicles. This is considered novel and inventive in its own right and thus when viewed from a third aspect the present invention provides a self-contained universal axle assembly for a vehicle, the axle assembly comprising at least one axle, two wheels mounted to the at least one axle, at least one universal motor for driving the wheels and at least one gearbox. The axle assembly may advantageously comprise a frame and a suspension assembly supporting the wheels, such that the axle assembly comprises a modular combined suspension and drivetrain sub-assembly. The person skilled in the art will appreciate that the axle assembly discussed above can be used to power a motor vehicle. In a set of embodiments the universal axle is designed to power a specific weight. This is ultimately determined by the number of universal motors provided on the universal axle. The person skilled in the art will therefore appreciate that a vehicle that weighs 7.5 tonnes can be powered by two universal axles which are each suitable for powering a weight of 4 tonnes or powered by a single universal axle suitable for powering a weight of 8 tonnes. This is particularly advantageous as even less effort is required to design and

manufacture a vehicle. According to this aspect of the invention, the manufacturer simply determines the weight of the vehicle and then provides an appropriate number of universal axles suitable for powering the vehicle. As such, this, and the previously-described advantages, provide a system for scalable production of motor vehicles. The system is scalable in the sense that vehicles of different

specifications, particularly weight and load capacity, can be manufactured from a limited set of drivetrain components, particularly from a single universal electric motor and one of no more than three gearboxes. A desired vehicle specification, for example, selected by a customer, may first be provided. This may comprise a desired vehicle weight or load carrying capacity, or vehicle length. The total weight of that vehicle may be then determined, including a maximum loaded weight of the vehicle. A combination of a universal single specification electric motor, and up to three different gearbox configurations, may be known which may be capable of propelling a given vehicle weight. The number of universal motors and specific gearbox configuration may then be determined based on the selected vehicle specification. The scalable solution may comprise providing a modular axle subassembly including one or two of the universal motors driving the wheels through one or two gearboxes respectively, and the provision of an appropriate number of these universal axle subassemblies for mounting to a vehicle chassis. In a set of embodiments multiple different universal axles may be developed, each with a different number of universal motors. Whilst the term universal axle is used, in some embodiments it is not necessarily intended to cover an axle that is suitable for all vehicles, instead it is intended to cover an axle that is universal across a set range of vehicles. This range may for example be determined by the weight of the vehicles. Developing multiple universal axles is advantageous as it means that each vehicle can be powered by at least one of the universal axles. There may, for example, be three different universal axles each with different universal motor arrangements, e.g. one with a universal motor arranged to drive both wheels, one with two universal motors to drive both wheels together and one with two universal motors each driving each wheel individually. Of course, the Applicant appreciates that there may be some examples where more universal motors are used e.g. three universal motors.

In a set of embodiments the gearbox used on the universal axle is chosen dependent on a desired weight range which the universal axle is suitable for. For example, if the universal axle is designed to power vehicles which have a weight of between 3-10 tonnes, one specific gearbox may be used; whereas a different universal axle suitable for vehicles of a weight of 10-20 tonnes may have a different gearbox.

At least two vehicles in the set may comprise a universal axle assembly comprising a modular combined suspension and drivetrain sub-assembly, comprising a frame, at least one universal electric motor and at least one gearbox. The method may comprise assembling the or each universal motor and the or each chosen gearbox into a universal axle assembly comprising a frame, the or each chosen universal electric motor and the or each chosen gearbox, at least one axle connected to the or each gearbox and two wheels mounted to the at least one axle.

The method may further comprise mounting the universal axle assembly to a vehicle chassis.

Mounting the universal axle assembly to a vehicle chassis may comprise connecting the frame of the universal axle assembly to the vehicle chassis.

The method may comprise a method of manufacturing a commercial vehicle, wherein mounting the universal axle assembly to the vehicle chassis may comprise mounting the universal axle assembly to a commercial vehicle chassis comprising a pair of spaced chassis rails which extend along a majority of the length of the vehicle.

The method may comprise determining the appropriate number of universal motors based on at least one factor comprising one or more of an intended vehicle size, an intended vehicle weight and an intended vehicle load-carrying capacity.

The method may comprise determining the or each appropriate gearbox based on at least one factor comprising one or more of an intended vehicle size, an intended vehicle weight and an intended vehicle load-carrying capacity.

The method may comprise a method of scalable production of a range of electric motor vehicles of different weight or load-carrying capacity, further comprising a step of receiving a specification of a vehicle to be manufactured, the specification comprising a vehicle weight, and determining the appropriate number of universal motors based on the received vehicle weight specification and the predetermined weight that each universal motor is capable of moving, and the universal motor power.

The method may comprise producing a plurality of universal axle assemblies in accordance with the received vehicle specification and determined number of universal motors and gearboxes. The production of universal axle assemblies may occur in a first location, and the method may further comprise transporting the or each universal axle assembly to a separate, second location, remote from the first location, and mounting the or each universal axle assembly to a vehicle chassis at the second location.

A universal axle assembly for a vehicle, the axle assembly comprising at least one axle, two wheels mounted to the at least one axle, at least one universal motor for driving the wheels and at least one gearbox.

The frame of the universal axle assembly may be configured to be mounted to the vehicle chassis to secure the axle assembly to the vehicle chassis. The present invention also provides a vehicle comprising a chassis and at least one universal axle assembly as described above mounted to the chassis.

The vehicle may comprise at least two universal axle assemblies mounted to the chassis, and the frame of the universal axle assembly may be connected to the vehicle chassis, and may comprise the sole connection between the universal axle assembly and the chassis.

The vehicle may comprise a commercial vehicle, and the commercial vehicle chassis to which the or each universal axle assembly is mounted may comprise a pair of spaced chassis rails which extend along a majority of the length of the vehicle.

The vehicle may further comprise any feature of a vehicle of the set described above.

The present invention also provides a set of universal axles as described above, comprising multiple different universal axles, each with a different number of universal motors.

The set may comprise three different universal axles, each with different universal motor arrangements. One universal axle may comprise a universal motor arranged to drive both wheels, and one universal axle may comprise two universal motors to drive both wheels together. One universal axle may comprise two universal motors each driving each wheel individually.

Brief Description of the Drawings

Certain embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Fig. 1 shows a schematic view of a vehicle platform manufactured according to prior art techniques;

Fig. 2 shows a schematic view of a platform of a different vehicle to that of Fig. 1 also manufactured according to prior art techniques; Fig. 3 shows a schematic view of a vehicle platform in accordance with the present invention;

Fig. 4 shows a schematic view of a different vehicle platform to Fig. 3 in accordance with the present invention;

Fig. 5 shows a schematic view of a vehicle platform in accordance with the present invention which is similar in size to Fig. 4 but has different vehicle characteristics; Fig. 6 shows a schematic view of a different vehicle platform in accordance with the present invention;

Fig. 7 shows a schematic view of another different platform in accordance with the present invention wherein there is a double rear wheel

Fig. 8 shows a schematic view of a platform with a larger wheelbase than previous platforms also manufactured in accordance with the present invention

Fig. 9 shows a schematic view of a platform with three axles which is manufactured in accordance with the present invention.

Fig. 10 shows a schematic of a platform with three axles, similar to the platform of Fig. 9, but with a larger weight;

Fig. 1 1 shows a perspective view of a universal axle in accordance with the third aspect of the present invention; and

Fig. 12 shows a perspective view of a vehicle chassis with two universal axles of Fig. 1 1 mounted to the vehicle chassis.

Detailed Description

In order to visually represent different vehicles in the following Figures, vehicle platforms are used. The vehicle platforms illustrate the main drive components of a vehicle, i.e. the motor(s), gearbox(es), wheels and axles. It should be understood that each schematic diagram used in this application is merely representative of a vehicle platform appropriate for certain maximum authorised mass (MAM), also known as gross vehicle weight (GVW). The MAM is the weight of a vehicle that can be carried safely when driven on the road. The illustrative platform does not represent the vehicle as a whole and is just used a visual representation of the key components relevant to this invention.

Figures 1 and 2 show schematic diagrams of vehicle platforms manufactured according to prior art manufacturing techniques. Figure 1 shows a schematic of a vehicle platform of a specific MAM. The platform seen in Figure 1 has two sets of wheels 2, 3, the front wheels 2 are connected by a front axle 4 and the rear wheels 3 are connected by a rear axle 6. The platform of Figure 1 has a motor 8 and gearbox 10 arranged to drive the rear axle 6 of the platform. Figure 2 depicts a different platform which has a larger wheel span and larger MAM than the platform of Figure 1 . Similarly to the platform of Figure 1 , the platform has four wheels 2, 3, a front axle 4 and a rear axle 6. However, as this platform has a larger MAM than that of Figure 1 , the platform requires more power and thus a larger motor 12 and different gearbox 6 are provided to drive the platform. These two Figures illustrate how prior art manufacturing techniques require an individual motor and gearbox to be developed for each different vehicle platform.

Figure 3 shows a schematic diagram of a platform for a vehicle according to an embodiment of the present invention. Similarly to the platforms according to prior art manufacturing techniques, the platform has four wheels 2, 3, a front axle 4 and rear axle 6. The platform shown in this Figure is suitable for a MAM of, for example, 3 tonnes. This platform is driven by a single universal motor 16 and a gearbox 1 . This platform illustrates the simplest possible platform in a set of vehicles in accordance with the invention. In this case the universal motor 16 is used to drive the rear axle 6 and subsequently both rear wheels 3.

Figure 4 shows a different platform in a set of vehicles in accordance with the present invention. This platform represents a vehicle with a MAM of, for example, 5 tonnes. Whilst the platform is shown to have a larger wheelbase, this may not always be the case, and it is only the case in this Figure to illustrate a difference from the platform of Figure 3. This platform has two universal motors 16 and two gearboxes 18. One universal motor 16 and gearbox 18 are used to drive the wheels 2 on the front axle 4 and the other universal motor 16 and gearbox are used to drive the wheels 3 on the rear axle 6. Figure 5 shows another, different platform to that of Figures 3 and 4, which has a similar size and MAM to the platform of Figure 4 but has a different weight distribution. As the platform has a similar MAM to the platform of Figure 4, it requires the same number of universal motors 16 to power it.

However, due to the difference in weight distribution, the two universal motors 16 and gearboxes 18 are positioned on the rear axle 6. Each universal motor 16 is then used to power each rear wheel 3. Whilst in the example shown the platform is driven from the rear wheels 3, in some instances a platform may be driven from the front wheels 2 to provide different drive characteristics, for example providing different acceleration characteristics.

Figure 6 shows another, different platform with a MAM of, for example, 10 tonnes. As the platform has an increased MAM, in order for it to have sufficient power to enable it to be driven appropriately, it requires power to be provided to all four wheels 2, 3. Therefore, the platform is provided with three universal motors 16 each driving a gearbox 18. In the example shown, the platform has two universal motors 16 arranged to drive each of the rear wheels 3 and a single universal motor 16 arranged to drive both of the front wheels 2. It will be appreciated that this arrangement could be reversed in a different platform where more power is required at the front wheels 2.

Figure 7 shows another, different platform with a MAM of, for example, 12 tonnes. In this example the platform also has a double rear wheel 3. In this case four rear wheels 3 are provided to support the vehicle when a large load is applied and transferred directly through the rear wheels 3. Due to the double rear wheel, the platform requires more power to drive the rear wheels 3. Similarly to the platform seen in Figure 6, this platform also utilises two universal motors 16 to drive the rear wheels 3 and a single universal motor 16 to drive the front wheels 2. This arrangement helps to ensure sufficient power is transferred to the rear wheels 3.

Figure 8 shows a larger vehicle platform e.g. that of a large lorry. Here the wheel span is larger than the wheel span seen in the platforms of earlier Figures. Typically a larger wheel span means that the platform will support a larger MAM. Therefore four universal motors 16 are used to power the platform. Another difference from the platforms of earlier Figures is that a second, different, gearbox is used to transfer power from the universal motor 16 to the wheels 2, 3. As the platform represents a vehicle with a large MAM, a gearbox 20 with a different gear ratio better suited for larger vehicles is advantageous.

Figure 9 shows the platform of a similarly large vehicle to that of Figure 8, and has a MAM of, for example, 20 tonnes. This platform has six wheels 2, 3, 21 positioned on three axles 4, 6, 22. Each of the axles 4, 6, 22 is powered by a single universal motor 16 and a gearbox 20. Figure 10 illustrates a platform with a similar wheel arrangement to that of Figure 9, however it has a larger MAM of, for example, 25 tonnes. As a result of the increased MAM, significantly more universal motors 16 are required to power the vehicle. It can be seen in the Figure that two universal motors 16 and gearboxes 20 are arranged to drive each axle 4, 6, 22.

In examples where multiple universal motors 16 are arranged to drive two wheels 2, 3, 21 on a single axle, it will be appreciated that the universal motors 16 may be arranged to drive the axle and thus both of the wheels 2 in a coordinated fashion. Alternatively the universal motors 16 may be arranged each to drive a single wheel individually.

Whilst in the Figures the universal motors and gearboxes are depicted close to the axle or wheel they are intended to power, this does not necessarily represent their actual position on the vehicle. For example, a universal motor arranged to power the rear wheels may, on some vehicles, actually be positioned near the front of the vehicle and the power may be transferred to the rear wheels and vice versa.

Additionally, whilst the platforms shown only illustrate vehicles with two different gearboxes it is appreciated that a third, different gearbox may be used with the universal motor in accordance with the present invention.

Figure 1 1 shows an example of a universal axle or universal axle assembly 24 in accordance with an aspect of the present invention. The universal axle 24 has a frame 26 and two wheels 28. A universal motor 16 and gearbox 18 are mounted to the frame 26 and arranged to drive the wheels 28. The universal axle 24 also has incorporated suspension 30 that is appropriate for a pre-determined weight. The suspension 30 is mounted to the frame 26 and supports the wheels 28. An axle 32 extends from each side of the gearbox 18 to a respective wheel 28 to drive the wheels 28. The universal axle 24 forms a modular component or modular subassembly and can be used on a variety of vehicles. For example one of these universal axles could replace each axle on a typical lorry.

Fig. 12 shows a conventional lorry chassis 34 with two universal axles 24 of the present invention mounted thereto. The reference numerals of features of the universal axle 24 shown in Figure 1 1 remain the same as shown in Fig. 12 and description thereof will not be repeated. The lorry chassis 34 comprises a pair of spaced parallel chassis rails 36, which extend along the entire length of the vehicle, although may extend at least along a majority of the length of the vehicle. First and second high voltage battery packs 38, 40 are also mounted to the chassis 34 to power the universal motors 16 in each universal axle 24. A range extender unit 42 is also provided to provide additional electrical power if necessary. The range extender unit 42 may comprise an internal combustion engine coupled to a generator.

The chassis 34 and universal axle 24 assembly of Fig. 12 shows a universal axle 24 being mounted at both the front and rear of the chassis 34, such that the resulting lorry would be four wheel drive. In an alternative embodiment, a universal axle 24 may only be provided on the front or the rear of the chassis 34, to drive only the front or rear wheels. Advantageously, the universal axles 24 may be pre-assembled as respective modular suspension/drivetrain sub-assemblies and subsequently fitted to a conventional commercial vehicle chassis 34, as shown in Fig. 12, in a subsequent vehicle assembly step. This ability to pre-assemble the universal modular axle subassemblies 24 facilitates a more flexible vehicle construction process, where, for example, the universal axles 24 may be pre-assembled as respective modular subassemblies in a first location, and may be packaged and transported to a separate vehicle assembly plant where they are fitted to a vehicle chassis 34. Also, such the universal axles 24 may be fitted to a range of different existing vehicle chassis', such as lorry chassis', to provide different load specification vehicles as a final product, yet utilising a common universal axle across all of the different vehicles. This enables a manufacturing process by which pure electric, or hybrid electric commercial vehicles may be simply and cost-effectively manufactured without the need to redesign from scratch the vehicle chassis. Instead, the universal axles 24 can be mounted to existing commercial vehicle chassis instead of assembling the vehicle using a conventional powertrain.

Whilst the universal axle 24 of Figure 1 1 is shown with a single universal motor 16 and gearbox 18, it is appreciated that an alternative universal axle may be provided with two universal motors 16 arranged to drive both of the wheels attached to the universal axle. Such a universal axle would be appropriate for powering larger vehicles. Producing the two universal axles as discussed would enable a vehicle manufacturer to simply choose the appropriate universal axle for the vehicle they are producing. For instance they may utilise the universal axle 24 for the front axle of a vehicle and use an alternative universal axle with two universal motors on the rear axle. This is just one example of how the universal axles could be arranged on a vehicle with only two axles. It will be appreciated that there is potentially a large number of vehicles with a large number of different axle layouts that could be produced.

From Figures 5, 6, 7, 8, and 10 and the their respective passages of description above, it will appreciated that embodiments of vehicle may include one universal motor to drive each individual wheel, in which embodiments each wheel is connected to each gearbox by its own respective axle. Alternatively, in other embodiments, both wheels at the front or rear of a vehicle are connected to a common axle which is connected to a single gearbox and driven by a single universal motor. As such, it will be appreciated that a single universal axle 24 of the invention may comprise a single axle to which two wheels are attached, or, in the case of each wheel being powered by its own universal motor, two axles, one connected to each wheel.

Whilst the examples given in this application largely relate to vehicles with a larger MAM such as lorries or buses it is envisaged that this invention could be used on any type of vehicle including non-commercial vehicles such as cars.