An eaxle

Abstract

An eAxle for a multi-axle vehicle is described. The eAxle is configured in an over the shoulder arrangement wherein a motor and transmission of the eAxle are provided to a first side of a differential, power to the differential being delivered by a pinion that is coupled to the differential from a second opposing side of the differential.

Description

[0001] An eAxle

[0002] Field of the Invention

[0003] The present invention is related to electric axles, commonly termed eAxles. The invention more particularly relates to eAxles that can be incorporated into off-road vehicles.

[0004] Background

[0005] An eAxle, or electric axle, is an integrated unit used in electric and hybrid vehicles that combines an electric motor, transmission, and power electronics into a single compact module. The primary function of the eAxle is to deliver power from the electric motor to the vehicle's wheels, thus propelling the vehicle. Unlike traditional internal combustion engine (ICE) powertrains, which require a complex system including gears, axles, and differentials, the eAxle simplifies the drivetrain by integrating these components. This integration results in a more efficient, compact, and lighter system that is crucial for optimizing the performance and range of Electric Vehicles (EVs).

[0006] At the core of the eAxle is an electric motor, which converts electrical energy stored in the vehicle's battery into mechanical energy to drive the wheels. The electric motor's efficiency, high torque at zero and low speeds, and instant torque delivery make it ideal for vehicle propulsion. The motor is typically connected to a transmission system that includes reduction gears to convert the high rotational speed of the motor to a suitable speed for the wheels. This gearing ensures that the motor operates within its optimal efficiency range while providing the necessary torque to the wheels for various driving conditions, from city driving to highway cruising to off-road terrain.

[0007] Power electronics play a crucial role in managing the flow of electricity between the direct current, DC, supply, such as a battery and the electric motor. These components, including inverters and controllers, convert direct current (DC) from the battery into alternating current (AC) required by the motor. They also handle the reverse process during regenerative braking, where the motor acts as a generator to convert kinetic energy back into electrical energy, recharging the battery. This regenerative braking capability enhances the vehicle's overall efficiency and extends its driving range by recovering energy that would otherwise be lost as heat during braking.

[0008] Another critical component of the eAxle is the differential, which allows the wheels to rotate at different speeds, especially important when the vehicle is turning. The differential ensures smooth and stable handling by compensating for the differences in wheel speed, thus enhancing the vehicle's stability and drivability. Some advanced eAxles incorporate torque vectoring, where the power sent to each wheel can be independently controlled, providing improved handling and traction control, especially in performance and All-Wheel-Drive (AWD) vehicles.

[0009] One of the main features of the eAxle is its compact and lightweight design, which integrates multiple functions into a single unit, saving space and reducing the vehicle's overall weight. This compactness allows for more flexible vehicle design and easier integration into different types of electric and hybrid vehicles. Additionally, the eAxles modularity means it can be adapted for various vehicle configurations, including frontwheel drive, rear-wheel drive, and all-wheel drive setups. This adaptability, combined with the efficiency and performance benefits, makes the eAxle a key technology in the advancement of electric mobility. In addition, the use of eAxles in an all-wheel-drive vehicle eliminates the need for a transfer case and the need for a mechanical connection between the axles, from the axles to a transfer case and from a transfer case to the powerpack. This reduces complexity of the vehicle design, increases the flexibility of the vehicle driveline layout, increases available space within the vehicle and lowers the centre of gravity, improving stability.

[0010] Despite these advantages of conventional eAxles, there continue to be challenges in incorporating eAxles into all vehicle types, particularly those that are intended for offroad or heavy-duty applications. The provision of the motor on the underside of the vehicle means that it may be exposed during usage, and this particularly becomes an issue in environments where vehicle clearance from the ground may vary. Evidently a smaller motor and other components may reduce the actual size of the eAxle but this may reduce the available power that can be delivered from the eAxle which can be problematic, particularly in these environments where power can be a critical factor in performance.

[0011] There therefore continues to exist a need for improved eAxles. Summary

[0012] These and other needs are addressed by a vehicle comprising an eAxle in accordance with the present teaching. Accordingly there is provided a vehicle as detailed in claim 1. Advantageous features are described in the dependent claims.

[0013] Brief Description of the Drawings

[0014] Figure 1 is a section through an eAxle in accordance with the present teaching

[0015] Figure 2A is a view from along the longitudinal axis of the eAxle of Figure 1 of the planetary assembly module.

[0016] Figure 2B is a section along the line B-B of Figure 2A.

[0017] Figure 3 is a view from above of the eAxle of Figure 1 showing additional detail of ancillary equipment that can be mounted to the eAxle.

[0018] Figures 4A and 4B show details of a parking brake that can be coupled to the eAxle of the present teaching.

[0019] Figure 4C is an example of a pump and parking brake combination that can be coupled to the eAxle of the present teaching.

[0020] Figure 4D shows another configuration of an eAxle of the present teaching with a pump provided at the ground level.

[0021] Figure 4E is a detail of portion of an eAxle in accordance with the present teaching which is configured to be used with ancillary assemblies.

[0022] Figure 4F is a detail of a modification to the the embodiment of Figure 4E so as to provide direct power to the ancillary module.

[0023] Figure 5 is a schematic showing the planetary assembly and axle module.

[0024] Figure 6 is a view from along the longitudinal axis showing the coupling of the eAxle of Figure 1 to a suspension.

[0025] Figures 7A and 7B show a mounting of the eAxle within a mounting cradle.

[0026] Figure 8 is a schematic showing an exemplary 8X8 wheel vehicle with each of the sets of wheels provided with an independent eAxle, in accordance with the present teaching. Figure 9 is a schematic showing an exemplary 8X8 wheel vehicle with each of the sets of wheels provided with an independent eAxle, in accordance with an alternative configuration per the present teaching.

[0027] Figure 10 shows typical tyre sizes and approach angle of an eAxle when provided in accordance with the present teaching

[0028] Figure 11 is an example of a multi-axis vehicle incorporating individual eAxles per the present teaching.

[0029] Detailed Description of the Drawings

[0030] Figure 1 shows an example of an eAxle 100 in accordance with the present teaching. The eAxle 100 comprises an electric motor 105 which is configured to provide power. The motor 105 is coupled to a planetary multi-speed transmission 110 arranged in a planetary assembly.

[0031] It will be understood that the number of speeds provided by the transmission 110 will vary according to the desired usage of the eAxle but at least two, and in this exemplary embodiment three, speeds are provided. It will be understood that the motor can be configured to change its direction to effect a reverse drive motion- there is no need therefore for a reverse gear. As will be understood by those of ordinary skill planetary transmissions are highly efficient, versatile, and compact gear systems capable of providing multiple gear ratios and distributing loads effectively. Their design allows for high torque transmission with both smooth shifting and efficient operation in a variety of applications.

[0032] The planetary assembly 110 is coupled to an axle module 120 which includes components which are configured to transfer the motion conveyed by the drive shaft to the wheels that are coupled to the axle. These components include a set of drop gears 121, 122; a pinion 123 and crownwheel 124 and a differential 125. In this exemplary configuration the pinion 123 and crownwheel 124 is a bevelled pinion 123 and crownwheel 124, but other embodiments could equally adopt other configurations such as a hypoid pinion. The bevelled pinion may advantageously offer less friction and therefore is more efficient than other pinion orientations and it may also offer advantages in regenerative braking.

[0033] As is evident from Figure 1 , the eAxle is configured such that the motor 105 and transmission 110 are located on the first side of the differential and the pinion is meshed to a crownwheel which is fixed to the differential at a second opposite side. The transmission 110 is coupled to the pinion via the set of the drop gears in what is defined as an-over- the-shoulder configuration. Within the context of the present teaching the phrase “over the shoulder” will be understood as defining a configuration whereby the output shaft 108a from the planetary 110 passes above the differential 125, into a pair of drop gears which drive a bevel pinion back into the crownwheel 124 and back to the differential 125 to effect rotation of the differential 125.

[0034] As can be seen from Figure 1, and in more detail from inspection of Figures 2A and 2B the planetary assembly 110 in this embodiment is configured to provide a three-gear transmission and hence includes first 111, second 112, and third 113 gear clutches. Selective activation of these gear clutches can effectively change the gearing of the transmission and will change the speed of rotation of the planetary output shaft 108b, 208. The assembly includes both inboard 205 and outboard 206 sun gears, inboard 202 and outboard 204 planetary assemblies, and inboard 207A and outboard 207B ring assemblies.

[0035] In addition to those features identified above, Figure 2A and Figure 2B provide further detail on the components that are found in the planetary assembly. Figure 2A is a view along the line A’-A of Figure 1, whereas Figure 2B is a section along the line B-B of Figure 2A. Many of the components and their functionality will be familiar to those of ordinary skill and are listed below in Table 1.

[0036] Table 1

[0037] The geared output from the planetary assembly is coupled via the planetary output shaft 208, 108a via first 121 and second 122 drop gears to engage with the pinion 123. The pinion is coupled via a crownwheel 124 into the differential 125. In this way, the rotation of the planetary output shaft 108a about a first axis, the axis A-A’, is transferred through the drop gears 121 , 122 to the pinion 123 which is rotatable about a second axis, the axis C-C’. It will be appreciated in this embodiment that the pinion will effectively rotate in an opposite direction to that of the output shaft 108a- which is different to a conventional arrangement where the two are typically arranged along a common longitudinal axis and rotate in the same direction. This opposite direction is however consistent with the fact that the “forward direction” rotation of the output shaft 108a is anticipated to cause a corresponding “forward direction” rotation of the differential. It will be appreciated however that by introducing additional sets of drop gears that the rotation can be caused to be in the same direction- although this may result in a less compact assembly. As the pinion is coupled to the differential in an opposing direction to that of the rotation of the output shaft, it is appropriate for it to rotate in an opposite direction as that rotation causes a corresponding rotation of the differential 125 via the meshed coupling between the pinion 123, the crownwheel 124 and the differential 125.

[0038] It will be appreciated that the use of a crownwheel 124 is advantageous in that it facilitates a reverse driving arrangement which can allow for regenerative braking which is useful in providing power back to the battery that powers the motor during braking activities. Effectively during a braking action, the crownwheel 124 will rotate in in the same direction to that which it adopts during a driving direction, but torque is exerted in the opposite direction by the motor translated through the drop gears, shaft and transmission. The motor in this braking mode functions as a generator which effects a re-charging of the battery. This can then effect a re-charging of the battery (not shown) which provides the power to the motor. It will be seen that the plane of rotation of the pinion 123 is parallel to, but below the plane of rotation of the output shaft 108a. Each of the pinion 123 and output shaft 108a are effectively rotating in tandem but one below the other, effectively they are arranged in parallel. This allows for an assembly that is more compact than if they were serially aligned. It will be understood that the terms above and below are relative terms but are considered relative to the terrain on which the vehicle is travelling such that the plane of rotation of the pinion is closer to the ground than the plane of rotation of the output shaft.

[0039] In addition to the advantages that are attributed to the compact nature of the assembly, the location of the pinion in a different plane to that of the output shaft makes it an independently assembly for coupling to ancillary assemblies 130. These can include parking brakes and the like.

[0040] Figure 3 is a top view showing the eAxle of Figure 1 with further details of an exemplary ancillary module 130 coupled to the differential. In this arrangement, and more detail is provided in Figures 4A and 4B, an ancillary parking brake 400 is directly coupled to the axle module within which the differential 125 is located. The ancillary module 130 is provided on an opposite site of the axle module 120 to the planetary assembly and electric motor. The axle module 130 effectively has a motor proximal portion 301 and a motor distal portion 302. As the over-the-shoulder coupling provides the drive coupling from the motor to the differential, it is possible to have access directly to the differential from the motor distal portion 302. It is therefore possible to directly couple a parking brake to the eAxle, something that heretofore was problematic given the available space available in traditional arrangements. It will be appreciated that having the availability to have a separate parking brake for each eAxle is advantageous, as each eAxle provides independent power to its respective set of wheels and the capacity to independently secure at the point of the eAxle improves the security of stopping.

[0041] As shown in Figures 4A and 4B the parking brake 400 comprises a brake disc 420 which can be engaged by a brake calliper 410. In this embodiment a spring applied hydraulic release parking brake is provided. Application of a force through a spring engages the calliper onto the disc and a hydraulic feed is used to release the calliper.. If the disc is coupled to the pinion 123 (as shown in Figure 1) that can cause a corresponding restriction in the rotation of the pinion and consequently the differential. As referenced above, this effectively provides a possibility to have a parking brake at the differential - and in the event of a multi-axle vehicle allows for multiple parking brakes- each provided at a corresponding axle. It will be appreciated that this feature allows for parking braking at the individual eAxle level. Since there is no mechanical connection between eAxles, it is not possible to implement parking braking on the driveline or transfer case as with a conventional mechanical driveline. Hence a parking brake on the axle is required, especially for parking on large gradients.

[0042] Figure 4C is an example of another type of ancillary equipment that can be coupled to the eAxle. In this arrangement a pump 430 is provided to assist in scenarios where vehicle hydraulic system failures are encountered. This can be particularly problematic in the context of powered steering where hydraulics are used to provide power assisted steering. In the event of failure of the primary hydraulic systems, a backup pump such as the pump 430 is particularly advantageous in that it can be used to provide an alternative or secondary source of hydraulic fluid, powered from the rotation of the wheels. In the event of vehicle breakdown, a towing of the vehicle will cause rotation of the wheels which will provide power for the pump. The pump can then provide a source of pressurised hydraulic fluid that can be coupled into other vehicle modules such as the hydraulic steering system.

[0043] In the arrangement of Figure 4C, the ancillary pump is mounted in combination with the parking brake 400- effectively first and second sets of modular functional components are mounted in combination with one another. Selective controls can be provided so as to independently operate one of the modular functional components or the other. In the event that a parking brake and steering fluid secondary pump are provided, it is unlikely that the brake will be applied whilst at the same time that assisted steering is being provided. However, certain scenarios may require the operation of the two concurrently.

[0044] It will be appreciated that this embodiment advantageously provides and enables the mounting of a power take off, PTO, in tandem with an eAxle which is fitted with a parking brake. In this example the PTO is useable to provide power for a ground-driven Emergency Steering Pump, it can be used for constant-flow hydraulic pumps which are only required to operate when the vehicle is moving. Advantageously, this arrangement can provide lubrication from the main eAxle oil volume without the need for external piping passing over / near the brake disc 420.

[0045] Other scenarios, such as that envisaged in the embodiment of Figure 3, may only provide one type of modular functional component- such as the brake Figure 3, or as will be shown with reference to Figure 4D, a pump.

[0046] The embodiment of Figure 4D differs from that of Figure 4C, not only in fact that it includes a pump but no brake, but also in the arrangement of Figure 4C actuation of the pump is responsive to a rotation of the wheels, whereas in the embodiment of Figure 4D the pump can be powered directly from the electrical motor.

[0047] In this embodiment, which exemplifies a further modification of an eAxle in accordance with the present teaching, a power take off, PTO, is provided which has the capability of running heavy hydraulic pumps or other equipment independently of the drive to ground. In this embodiment the drive is de-coupled from the road wheels in one (or more) axles which are not fitted with parking brakes, while the drive is still directed to wheels on at least one other axle. The decoupled eAxle, which is no longer providing active drive to the wheels on its axle, is then configured such that its motor 105 will supply full electric motor power to the PTO, while other axles provide mobility. This will facilitate running auxiliary equipment while the vehicle can be either stationary or moving. Such a system can then be used in a variety of specialist or municipal vehicles, such as Fire Tenders (to run water pumps etc) or Refuse Compactor / Collection truck where hydraulic pumps can be run independently of vehicle speed.

[0048] Per the arrangement of for example Figures 1-3, power to the differential 125 is provided through the transmission to a pinion 123 that is coupled to the differential 125. The output shaft 108a is coupled to the pinion 123 via a drop gear arrangement 121,122. This is shown in more detail in Figure 4E.

[0049] As shown in Figure 4F, it is possible to disconnect the output shaft 108a from the pinion 123 and then providing an output shaft extension 108c which is coupled to the output shaft 108a, it is possible to provide a drive shaft external of the eAxle. This output shaft 108c will rotate with rotation of the output shaft 108a and can be used to provide power directly to ancillary modules such as the pump 430- not shown in Figure 4F. It will be appreciated that this mode of operation represents a second mode of operation of the eAxle- a mode where the pinion is decoupled from the motor., the first mode of operation being where the pinion is coupled to the motor. In the second mode, the motor provides a source of power for other ancillary equipment that can be mounted to the eAxle- such as the exemplified pump or parking brake.

[0050] This decoupling or disconnect between the output shaft 108a and the pinion 123 can be achieved in a number of different ways. For example, as shown in Figure 4F a bearing 435 can be fitted adjacent the drop gears 121 fitting a bearing (orange) into the Drop Pinion, and having dog clutch 440 that is slideable on the output shaft 108a, it is possible to use the clutch to engage or disengage the output shaft 108a from the pinion 135 and as such the drive will not be transmitted to the wheels unless the clutch 440 is engaged. It will be appreciated that a dog clutch arrangement is an exemplary configuration and other means can be used to cause the shaft 108a to engage or disengage from ultimately driving the wheels that are coupled to the differential 135.

[0051] Figure 5 shows in schematic a geartrain schematic for operation of an eAxle 100 which heretofore have been described with reference to specific assembly configurations The Outboard sun So is permanently connected to the motor 105 via the input shaft 108b. The inboard ring Ri and outboard carrier Coare permanently connected to each other and to the output pinion. The outboard ring Roand inboard carrier Ci are permanently connected to each other. Brake X when engaged will lock the outboard ring Ro / inboard carrier Cl to the housing, engaging 1st Gear. Brake Y when engaged will lock the inboard sun SI to the housing, engaging 2nd Gear Clutch A when engaged will clutch the input shaft to the inboard sun SI, engaging 3rd Gear.

[0052] Figure 6 shows a mounting of an eAxle in accordance with the present invention on a sprung suspension 600. It will be understood that this schematic simplifies the mounting arrangement in the chassis components of the vehicle are not visible. The suspension is mounted either to a cradle or directly to the chassis. The eAxle is mounted either to the same cradle or to the chassis. It will be appreciated however that the chassis will sit above the eAxle, which is mounted to the chassis..

[0053] Axle halfshafts 605 are inserted into the differential 125. The connection may involve splines that fit into matching grooves, ensuring that torque is efficiently transferred from the differential to the axle shafts 605. Wheel hubs 610, which house the bearings and provide the mounting point for the wheels, are coupled to the ends of the axle shafts 605 such that torque can be delivered from the differential to the wheels. This connection is typically secured with nuts or bolts. The wheel hubs can be also mounted to a suspension 615 that allows the movement of the wheels in a vertical direction. This exemplary arrangement is a hydraulic suspension but other types such as a spring and damper suspension could equally be used. A double wishbone suspension 620 operates in cooperation with the suspension 615 to enhance the performance and isolate the wheel motion from the actual forces that may otherwise be transmitted into the eAxle. The dual suspension absorbs significant forces and the frequency of the forces is dampened so that the forces experienced by the eAxle are greatly diminished. Given that the sets of wheels that each eAxle is coupled to may independently move relative to each other sets of wheel (and in the example of Figures 8 and 9 there are four sets that can independently move as the vehicle traverses the terrain on which it is driven) this decoupling of the eAxle from the movement of the wheels is particularly advantageous. As referenced above, whilst not explicitly shown it will be understood that the eAxle is coupled to the vehicle chassis. This provides a stable base for the axle and ensures proper alignment with the wheels. Figures 7A and 7B shows an example of a mounting bracket or cradle 700 that can be used to support the eAxle 100 when it is mounted to a chassis. It will be appreciated that as the eAxle 100 is provided on the underside of the vehicle it could be exposed to the terrain that that vehicle is travelling. Particularly on uneven surfaces such as will be encountered in off-road situations there is a risk that exposed components could be damaged during the movement of the vehicle. This risk can be mitigated by putting the eAxle 100 into a protective cradle 700. The cradle will typically adopt a U-shaped orientation with a base 715 extending under the body of the eAxle and protecting it from contact with the ground or other obstacles encountered by the vehicle. The base 715 is provided at a distance defined by the height of the side walls 705 which typically have at least one opening 720 to allow access of the axle shafts to the differential. The cradle 700 is coupled to the chassis through the mating of a mating surface 705 with a corresponding surface of the chassis (not shown). This can be secured through one or more mounting nuts or the like.

[0054] As was referenced above, an eAxle per the present invention provides independent power to each set of wheels that it is coupled to. In multi-wheel configuration this can be particularly advantageous in that multiple sets of wheels can be individually and independently powered and controlled.

[0055] Figure 8 is plan view from above of an 8X8 configuration 800. Four sets of wheels 805, 810, 815, 820 are provided. Each set has its own eAxle 100, and the eAxles are orientated such that the motors 105 of each eAxle is pointed in the same direction - in this example the front of the vehicle is at 835 and the rear at 830.

[0056] In this arrangement, the motor component of the eAxle is therefore located rearwardly such that it may be at least partially protected from inadvertent contact with items on the terrain with which the vehicle is driving over. However, given the fact that each eAxle is independently mounted to its respective set of wheels, other configurations are equally possible. For example, as shown in Figure 9, two sets of wheels 905, 910 are each provided. Within each set the eAxles are orientated in the same direction- however in this configuration the two sets mirror one another- such that in a mid-region 920 of the vehicle, a larger space between individual axles may be provided. It will be appreciated that this additional space can be usefully employed to locate ancillary equipment at the eAxle. Each of the eAxles provide independent power to the wheels connected to that eAxle. As was discussed above, ancillary equipment can be provided on individual ones of a multi-eAxle drive train. Also the additional space that can be provided between individual eAxles can usefully accommodate steering equipment or the like. It will be appreciated that this flexibility in the layout of the drive line is important - you can arrange the e axles in sets and change the orientation of one set relative to the other depending on the use case for the actual vehicle. As also shown in figure 9, the eAxle is available in two configurations, one with the motor at the front of the eAxle, and the other with the motor at the rear. This significantly improves the flexibility of driveline layouts compared with conventional eAxles which are available configured at the front of the axle only.

[0057] It will be appreciated that this example of an 8X8 vehicle is just that, an example. The use of an eAxle in accordance with the present invention can be advantageously deployed in any multi-axle configuration- 4X4, 6X6 etc. The ability to provide power specific to each axle within the constraint of a multi-axle drive train is particularly advantageous in off-road vehicles and the like, where the requirements for localised power of heavy torque- which is ideally provided by an electric motor coupled to a multi geared transmission is particularly useful. There is effectively no limit on the number of wheels that be driven using a plurality of eAxles in accordance with the present teaching. Each eAxle can be configured to provide independent power to its respective set of wheels, this localised provision of power may advantageously allow multiple sets of wheels in specific vehicle configurations. Individual ones of the sets may be coupled to a steering arrangement, and indeed multiple variations in steering configurations may be accommodated. Given that the power for the wheel is not centred in a single location - such as in a conventional combustion engine- the distribution of weight along the length of the vehicle may also be improved.

[0058] Whilst the specific dimensions are not limiting within the context of the present teaching, it will also be appreciated that the compact nature of the eAxle configuration that is provided in accordance with the present teaching means that its overall length is less than comparable prior art eAxles. The compact nature of the component parts when assembled allows a mounting of the eAxle on a chassis of a vehicle that requires approximately 450mm ground clearance, as would typically be provided by mounting to wheels with 20-inch (508mm) rims- such as those required by 365 / 85 R20 tyres- and yet maintain approximately 45 degrees approach angle when considered from the front of the vehicle when travelling forwardly, or the departure angle when considered from the perspective of the rear of the vehicle.

[0059] It will be appreciated that the eAxle of the present teaching can be deployed as a modular component of a heavy-duty driveline with an integrated independent suspension system. An eAxle per the present teaching is not specific to series-hybrid drivelines or the like as it can be used with any fuel source that produces the required DC link voltage. Each eAxle module advantageously provides independent power and torque control at each axle. The compact nature of the eAxle which is provided by the over the shoulder configuration provides a compact design for ease of packaging and installation due to the high-power density motor. Given that each eAxle is fully independent of each other eAxle there is enhanced flexibility of layout of the drive line. For example, multiple alternative and configurable motor locations (front or rear of the differential as viewed relative to the front or rear of the vehicle) can be deployed for improved packaging. The eAxle includes an electrical motor but this motor is compatible with any fuel source that can be used to generate electricity at the appropriate voltage level.

[0060] As referenced above, the eAxle of the present teaching is particularly advantageously deployed in a multi-axle vehicle. Figures 8 and 9 provided examples of an 8X8 configuration with four axles, each provided with their own eAxle per the present teaching. Figure 11 shows another deployment, that being a 6X6 configuration 1100. Again the same reference numerals will be used for components already discussed. Three sets 1105, 1110, 1115 of wheels are provided, each set mounted on a respective eAxle 100. In this example, two of the sets 1110, 1115 are coupled to a steering wheel 1120 and rotation of the steering wheel 1120 causes a corresponding steering of these coupled sets. It will be understood that this is an example of the flexibility that can be provided by incorporating eAxles per the present teaching into a multi-axle vehicle configuration.

[0061] It will be appreciated that exemplary arrangements of an eAxle in accordance with the present teaching have been described. The eAxle can be advantageously deployed in a multi-axle vehicle, such that independent power can be provided to each of a plurality of sets of wheels. In a multi-axle configuration, one or more eAxles can be utilised in a non-drive configuration whilst others of the axles are providing power to the wheels. Ancillary equipment may be powered from an eAxle either passively- through rotation of the wheels or actively through a decoupling of the axle differential from the output shaft and the use of the output shaft to provide a power take off mechanism. Modifications and changes may be made without departing from the scope of the present teaching.

Claims

Claims1. A multi-axle vehicle comprising a plurality of eAxles, each eAxle being coupled to a respective set of wheels of the multi-axle vehicle, each eAxle providing independent power to its respective set of wheels, each eAxle comprising: a motor; a planetary multi speed transmission; a set of drop gears; a differential; a pinion; and wherein the eAxle is configured such that the motor and transmission are located on a first side of the differential and the pinion is meshed to a crownwheel which is fixed to the differential at a second opposite side, and wherein the transmission is coupled to the pinion via the set of the drop gears in an over the shoulder configuration, wherein the over the shoulder configuration defines an arrangement whereby an output shaft from the planetary transmission passes above the differential, the output shaft being coupled to a set of drop gears which are coupled to the pinion to effect a driving of the differential.

2. The vehicle of claim 1, wherein the multi speed transmission is a three forward speed transmission.

3. The vehicle of claim 1 or 2 wherein a geared output from the planetary transmission is coupled via the output shaft via first and second drop gears to engage with the pinion, the pinion being coupled via the crownwheel into the differential such that rotation of the planetary output shaft about a first axis is transferred through the drop gears to the pinion which is rotatable about a second axis.

4. The vehicle of claim 3 wherein the pinion operatively rotates in an opposite direction to that of the output shaft.

5. The vehicle of claim 3 wherein a plane of rotation of the pinion is parallel to, but below a plane of rotation of the output shaft.

6. The vehicle of any preceding claim wherein at least one of the eAxles comprises a parking brake.

7. The vehicle e of claim 6 wherein the parking brake is located at the second opposite side of the differential to the location of the motor and transmission, the parking brake being configured, on actuation, to cause a restriction in rotation of the pinion.

8. The vehicle of any preceding claim wherein at least one of the eAxles further comprises a pump, the pump being located at the second opposite side of the differential to the location of the motor and transmission.

9. The vehicle of claim 8 wherein the pump is configured to provide a source of pressurised hydraulic fluid for assisted steering.

10. The vehicle of claim 8 or 9 wherein actuation of the pump is in response to movement of the wheels.

11. The vehicle of claim 8 wherein the pump is coupled to, and driven directly from, the motor.

12. The vehicle of any preceding claim further being operable in a first mode wherein the pinion is coupled to the motor, and a second mode wherein the pinion is decoupled from the motor, and wherein in the second mode ancillary power driven equipment may be driven directly from the motor.

13. The vehicle of any preceding claim configured such that during braking, the crownwheel is configured to rotate in the same direction to that which it adopts during driving, but torque is exerted in the opposite direction, so as to effect a regenerative braking mode and provide power to a battery that provides power to the motor.

14. The vehicle of any preceding claim wherein a plurality of sets of wheels are coupled to a common steering.

15. The vehicle of any preceding claim, wherein individual eAxles are orientated in an opposite direction to other eAxles.

16. The vehicle of any preceding claim, wherein the respective sets of wheels are each coupled to an independent suspension, the suspension decoupling the respective eAxle of each set from movement of the wheels.

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