Drive assembly

Abstract

The invention discloses a drive assembly for a vehicle. The drive assembly includes a central hub having an axis of rotation; the in-wheel motor comprises a stator and a rotor; and a rim assembly comprising an inboard circumferential portion and an outboard circumferential portion disposed adjacent to each other along the axis of rotation, each portion comprising a rim portion for carrying a respective tire, where the rim assembly is coupled to a hub. The in-wheel motor is disposed outside the hub and coupled to the hub. The invention further discloses a vehicle comprising the driving assembly.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to UK Patent Application No. 2209889.1 filed on July 5, 2022, which is hereby incorporated by reference in its entirety. Technical Field

[0002] The present disclosure relates to a drive assembly for a vehicle. In particular, the drive assembly is used for a truck, such as a flatbed truck, a box truck, a tractor, etc., or for an active trailer. The present application also discloses a vehicle including the drive assembly. Background Art

[0003] Electric machines, including motors and generators, are used in a wide range of applications. However, concerns about our reliance on fossil fuel-based internal combustion engines and the pollution they cause are increasing political and commercial pressure to expand the use of electric machines into new applications and to extend their use in existing applications. Electric machines are increasingly used in transportation, such as electric cars, motorcycles, ships, and aircraft. They are also used in energy production, such as generators in wind turbines.

[0004] Another possible application for the motor is in trucks, such as flatbed trucks. Since flatbed trucks typically have a two-wheel arrangement, their wheel hubs differ significantly from those of electric vehicles and motorcycles. Therefore, in-wheel motor drive assemblies for such vehicles typically require significant modifications to the standard wheel hubs used for such trucks.

[0005] However, any modification to a standard wheel hub may limit the economic integration of an in-wheel motor. Therefore, the inventors have recognized a need for a drive assembly having a dual rim assembly and an in-wheel motor that requires minimal or no structural modification to a standard wheel hub and minimal or no structural modification to a brake system and axle body. Summary of the invention

[0006] The embodiments described herein provide a drive assembly for a vehicle and a vehicle comprising a drive assembly as defined in the appended independent claims, to which reference should now be made. Preferred or advantageous features of the disclosure are listed in the dependent claims.

[0007] In a first aspect, the present disclosure provides a drive assembly for a vehicle. The drive assembly includes: a central wheel hub having a rotation axis; an in-wheel motor including a stator and a rotor; and a rim assembly including an inner circumferential portion and an outer circumferential portion, the inner circumferential portion and the outer circumferential portion being disposed adjacent to each other along the rotation axis, each portion including a rim portion for carrying a corresponding tire. The rim assembly is coupled to the wheel hub, and the in-wheel motor is disposed outside the wheel hub and coupled to the wheel hub.

[0008] Advantageously, by providing a rim assembly coupled to a wheel hub and an in-wheel motor disposed outside the wheel hub and coupled to the wheel hub, a drive assembly with an in-wheel motor may be provided, wherein the in-wheel motor may be combined with a standard wheel hub to achieve a dual wheel arrangement.

[0009] Since both the motor and the rim assembly are coupled to the wheel hub, the wheel hub carries the load of the vehicle, while the rotor housing does not carry (any) load, which makes the non-structural rotor housing significantly lighter. In fact, it allows the use of a standard motor. Therefore, this not only allows the use of a lighter motor, but also the drive assembly can include a standard wheel hub with little or no modification.

[0010] As used herein, the terms "inboard" and "outboard" refer to a vehicle to which a drive assembly may be coupled in use, relative to the orientation of the vehicle. In particular, inboard may refer to a location closer to such a vehicle, while outboard may refer to a location farther from the vehicle. The term "vehicle side" may be used instead of "inboard", and the term "roadside" may be used instead of "outboard".

[0011] The term "circumferential portion of the rim assembly" may refer to a rim configured to carry a tire.

[0012] Optionally, the rim assembly is directly coupled to the center hub. In other words, the rim assembly is not coupled to the center hub through or with the motor or through any other element, but is directly coupled to the hub. This can ensure that the load on the drive assembly can be directly transferred to the hub.

[0013] Optionally, the rim assembly is coupled directly to a central hub inside the motor. Advantageously, this may allow the rim assembly to be coupled to a central (standard) hub inside the motor, i.e., on the same side that the motor is coupled to the central hub. In this way, a standard hub may be used without requiring any significant modifications to the hub.

[0014] Optionally, the rim assembly comprises a substantially planar attachment portion for mounting the rim assembly to the center hub. Advantageously, the substantially planar attachment portion may provide a particularly suitable structure for attachment of the rim assembly.

[0015] Optionally, the rim assembly further comprises: an inner bridge portion extending between the attachment portion and the rim portion of the inner circumferential portion, the inner bridge portion extending at least partially in a first direction of the rotation axis of the hub; and an outer bridge portion extending between the attachment portion and the rim portion of the outer circumferential portion, the outer bridge portion extending at least partially in a second direction of the rotation axis of the hub. Such a bridge portion can advantageously connect the attachment portion to the inner circumferential portion and the outer circumferential portion.

[0016] Optionally, the inner bridge portion is integral with the attachment portion. Advantageously, an inner bridge portion integral with the attachment portion can produce a more robust rim assembly. In fact, it can allow the rim assembly to be coupled to the center hub with fewer steps.

[0017] Optionally, the inner bridge portion is fixedly connected to the rim portion of the inner circumferential portion. Advantageously, this can produce a more robust rim assembly and can allow the rim assembly to be coupled to the central hub in fewer steps or a single step.

[0018] Optionally, the outer bridging portion is integral with the attachment portion. Advantageously, an outer bridging portion integral with the attachment portion can produce a more robust rim assembly. In fact, it can allow the rim assembly to be coupled to the center hub with fewer steps.

[0019] Optionally, the outer bridge portion is fixedly connected to the rim portion of the outer circumferential portion. Advantageously, this can produce a more robust rim assembly and can allow the rim assembly to be coupled to the central hub in fewer steps or a single step.

[0020] The specific shape of the outer bridge portion and the inner bridge portion may vary depending on the application. However, at least one of the outer bridge portion and the inner bridge portion may include a curved portion. This may increase the strength of the bridge portion and may allow a thinner bridge portion to be used, thereby saving weight and material.

[0021] Optionally, the inner bridge portion is integral with the first inner portion of the attachment portion, and the outer bridge portion is integral with the second outer portion of the attachment portion. By providing an attachment portion having a first inner portion and a second outer portion integral with the respective bridge portion, the bridge portions can be more securely coupled to the central hub and can be coupled to the central hub independently of each other.

[0022] Optionally, the rim assembly is coupled to the wheel hub by a plurality of fasteners having a pitch circle diameter, the pitch circle diameter being larger than the diameter of the in-wheel motor. Advantageously, such a diameter arrangement of the pitch circle and the in-wheel motor, i.e., the relative size of the motor with respect to the rim allows the pitch circle diameter to be larger than the motor, can facilitate easier attachment of the rim assembly to the center hub.

[0023] In fact, such a drive assembly can allow for the largest possible motor diameter while still providing a standardized way of mounting the rim to a standard hub. Since motor volume is directly related to the peak torque of the motor, allowing for the largest possible motor diameter can enable the drive assembly to provide the maximum possible torque.

[0024] Optionally, each fastener is accessible from the inside of the center hub. Alternatively, each fastener is accessible from the outside of the center hub. Advantageously, if the fasteners are accessible from the outside of the center hub, the rim assembly can be easily coupled to the center hub from the road side of the drive assembly. Making the fasteners accessible from the inside of the center hub can make the connection between the center hub and the rim assembly more secure.

[0025] Optionally, the in-wheel motor is coupled to the wheel hub independently of the rim assembly. Advantageously, this can allow the rim assembly to be detachable from the center hub without removing the in-wheel motor, thereby facilitating maintenance and repair of the drive assembly, and possibly other components of the vehicle employing the drive assembly.

[0026] Optionally, according to any one of the preceding claims, the in-wheel motor is a direct drive in-wheel motor. Advantageously, a direct drive in-wheel motor can facilitate maintenance, reduce noise during operation and provide higher efficiency compared to an indirect motor.

[0027] Optionally, the drive assembly can be configured to provide a torque of at least 3000 Nm, optionally at least 4000 Nm, optionally at least 5000 Nm, optionally up to 5500 Nm. Such torque can be sufficient to drive a vehicle, such as a US Class 6 / 7 truck in a 6x4 configuration. As will be appreciated, the drive assembly of the present disclosure is not limited to such torque provision, and can be adapted to provide any desired torque.

[0028] Optionally, the drive assembly further comprises a gearbox. Advantageously, the gearbox allows the torque-to-weight ratio of the electric machine to be adjusted according to the desired application, for example, to increase the torque-to-weight ratio of an electric motor or a generator.

[0029] Optionally, the gearbox is a planetary gearbox. Advantageously, the planetary gearbox can be combined with the in-wheel motor without significantly increasing the size of the in-wheel motor by attaching the planetary gearbox to the end face of the motor.

[0030] Optionally, the planetary gearbox is arranged outside the in-wheel motor. Advantageously, in this way, a planetary gearbox can be provided without changing the in-wheel motor or the coupling of the rim assembly to the central hub.

[0031] Optionally, the in-wheel motor is an in-wheel electric motor and the planetary gearbox is configured to increase the motor speed relative to the wheel speed to increase the maximum torque output of the drive assembly. Advantageously, this allows a given electric motor to achieve a higher torque-to-weight ratio.

[0032] Optionally, the drive assembly is configured to provide a torque of at least 5000 Nm, optionally at least 8000 Nm, optionally at least 10000 Nm, optionally about 10500 Nm. Such torque may be sufficient to drive a vehicle, such as a US Class 8 truck in a 6x4 drive configuration. As will be appreciated, the drive assembly of the present disclosure is not limited to such torque provision, and may be adapted to provide any desired torque.

[0033] Optionally, the stator is cooled by a liquid coolant. The liquid coolant optionally comprises water. The liquid coolant optionally comprises ethylene glycol. Preferably, the coolant comprises a water / ethylene glycol mixture. Advantageously, liquid cooling can improve heat dissipation of the motor, thereby achieving higher current density and, therefore, higher torque density.

[0034] Optionally, the drive assembly includes a tube for providing liquid coolant to the stator through a main shaft of the drive assembly attached to the center hub and a central hole of the center hub. Advantageously, this arrangement allows coolant to be easily supplied to the motor without modifying a standard center hub.

[0035] Optionally, the drive assembly includes or is configured to be connected to electrical wires that pass through a spindle of the drive assembly attached to the central hub and a central hole of the central hub.

[0036] Advantageously, this arrangement allows the required connection to the motor of the drive assembly to be made without modifying the standard central hub.

[0037] The electrical wires may include: cables for conducting power to and / or from the motor, such as motor phase cables; and / or temperature sensors and / or wiring for temperature sensors; and / or wires for motor rotational position sensors (such as motor rotational position sensors); and / or wires for a high voltage interlock loop (HVIL); and / or a ground wire.

[0038] The drive assembly may include at least one temperature sensor for measuring the temperature of a temperature-sensitive component of the drive assembly (e.g., a motor). In this way, the motor can be protected from overheating.

[0039] The drive assembly may include at least one motor rotation position sensor, such as an electric motor rotation position sensor. Such a position sensor may improve the control of the motor.

[0040] In a second aspect, the present disclosure provides a vehicle comprising at least one drive assembly according to the first aspect.

[0041] Optionally, the vehicle is a truck. Further optionally, the vehicle is a tractor. Optionally, the vehicle is a flatbed truck, a box truck, etc. Specifically, the vehicle can be a US Class 6 / 7 truck with a 6x4 configuration, or a US Class 8 truck with a 6x4 configuration. Alternatively, the vehicle can be an active trailer.

[0042] It should be understood that the features described in relation to one aspect of the present disclosure may also be applied to all other aspects of the present disclosure. The features described in relation to the first aspect of the present disclosure may also be applied to the second aspect of the present disclosure, and vice versa. For example, the features of the drive assembly described in relation to the first aspect may be applied to the vehicle of the second aspect after appropriate modification.

[0043] It will also be appreciated that specific combinations of the various features described and defined in any aspect of the invention may be implemented and / or provided and / or used independently. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Specific embodiments of the present invention will now be described with reference to the accompanying drawings, in which:

[0045] Figure 1 shows a perspective view of a drive assembly according to the present disclosure;

[0046] Figure 2 Shows Figure 1 A perspective cross-sectional view of the drive assembly;

[0047] Figure 3 Shows Figure 1 and Figure 2 Another perspective cross-sectional view of the drive assembly;

[0048] Figure 4 shows a cross-sectional view of a portion of another drive assembly according to the present disclosure; and

[0049] Figure 5 Shown according to Figure 4 Another cross-sectional view of another drive assembly. DETAILED DESCRIPTION

[0050] Figure 1 An example system 100 is shown including a drive assembly 102 for a truck, particularly a flatbed truck, having two tires 104a, 104b attached thereto.

[0051] A spindle 108 is attached to the drive assembly 102 , through which tubes 112 for liquid coolant and electrical wires 110 extend.

[0052] like Figure 2 and Figure 3As shown, the roadside or outer tire 104a is carried by the outer circumferential rim 204a, while the vehicle side or inner tire 104b is carried by the inner circumferential rim portion 204b. Respective bridge portions 205a, 205b attach the circumferential rim portions 204a, 204b to the central hub 206 of the drive assembly 102.

[0053] The center hub 206 has a center cavity 208. The center hub 206 is a standardized hub for flatbed trucks that forms part of the drive assembly 102. The spindle 108 extends through the center cavity 208 so that the tubes 112 and wires 110 extend from the vehicle side to the road side or outside of the center hub 206.

[0054] Formed as a single part with each of the respective bridging portions 205a, 205b is a respective, substantially planar attachment portion 210a, 210b. The attachment portions 210a, 210b are attached to the central hub 206 by fasteners 212 disposed about the rim pitch diameter.

[0055] An electric machine is also attached to the center hub 206, in this case the motor 214. The motor 214 is disposed on the wayside of the center hub 206, i.e., outside the center hub 206. When the tubes 112 and wires 110 extend to the wayside of the center hub 206, they provide not only liquid coolant (water / glycol mixture) and power to the motor 214, but also provide a temperature sensor (and / or power for the temperature sensor) and wires for a motor rotational position sensor, wires for a high voltage interlock loop (HVIL), and a ground wire for grounding the metal parts of the motor.

[0056] The relative diameters of the motor 214, the pitch diameter of the fastener 212, and the circumferential rim portions 204a, 204b are selected so that the fastener 212 can be tightened to attach the rim to the central hub 206 from the roadside.

[0057] The electric motor 214 includes a housing 216 or rotor casing. Figures 1 to 3 As can be clearly seen, the housing 216 is relatively thin. This is because the load of the vehicle is carried by the central hub 206, rather than by the rotor housing 216 of the electric motor 214 as is common in the prior art.

[0058] like Figure 3 As best shown, the drive assembly 102 also includes a standard brake disc 218 that requires no or minimal modification to function in a drive assembly 102 that includes the motor 214 .

[0059] Figure 4 Another example of a drive assembly 602 is shown. The drive assembly includes a motor 214. Figures 1 to 3Compared to drive assembly 102 of FIG. 6 , motor 214 of drive assembly 602 includes planetary gearbox 604 . Planetary gearbox 604 is configured to increase the torque generated by motor 214 , which may allow a smaller motor to be used in drive assembly 602 .

[0060] The drive assembly 602 also includes a main shaft 108 through which tubes 112 for liquid coolant and wires 110 extend. The center hub 206 also has a center cavity 208 and is a standardized hub for flatbed trucks that form part of the drive assembly 602. The main shaft 108 extends through the center cavity 208 so that the tubes 112 and wires 110 extend from the vehicle side to the road side or outside of the center hub 206.

[0061] In the drive assembly 602, the main shaft 108, tube 112 and wire 110 extend centrally through the motor 214 to provide power and cooling to the motor 214, while also providing a mechanical connection to the planetary gearbox 604, which is disposed on the outside, i.e., road side, of the motor 214.

[0062] The rim assembly of drive assembly 602 is very similar or identical to the rim assembly of drive assembly 102 .

[0063] In particular, the roadside or outer circumferential rim 204a carries the outer tire 104a, while the vehicle side or inner circumferential rim portion 204b (only partially shown) carries the inner tire 104b. Respective bridge portions 205a, 205b attach the circumferential rim portions 204a, 204b to the central hub 206 of the drive assembly 102.

[0064] like Figure 4 As best shown, the bridge portions 205a, 205b are fixedly attached to the respective circumferential rim portions 204a, 204b along respective interfaces 606a, 606b. The fixed attachment may be achieved by welding or any other suitable means.

[0065] Formed as a single part with each of the respective bridging portions 205a, 205b is a respective, substantially planar attachment portion 210a, 210b. The attachment portions 210a, 210b are secured to the rim by fasteners ( Figure 4 or Figure 5 ) is attached to the central hub 206.

[0066] The relative diameters of the motor 214, the pitch diameter of the fastener, and the circumferential rim portions 204a, 204b are selected so that the fastener can be tightened to attach the rim to the central hub 206 from the roadside.

[0067] like Figure 4 and Figure 5 As shown, the motor 214 is attached to the center hub 206 by different fasteners 608 (relative to those fasteners that attach the rim assembly to the center hub 206). These fasteners 608 are accessible from the vehicle side of the drive assembly 602. The housing or casing of the motor may include threaded holes for receiving the fasteners. Alternatively, the fasteners 608 may include nuts (not shown) within the motor 214.

[0068] As discussed above with respect to drive assembly 102, electric motor 214 of drive assembly 602 includes housing 216 or rotor housing. Housing 216 of the drive assembly is relatively thin because center hub 206, rather than rotor housing 216, carries the load of the vehicle.

[0069] The drive assembly 602 also includes a standard brake disc 218 that can function in a drive assembly 102 including the gear motor 214 with no or minimal modification.

Claims

1. A drive assembly for a vehicle, comprising: a central hub having an axis of rotation; an in-wheel motor including a stator and a rotor; and a rim assembly comprising an inner circumferential portion and an outer circumferential portion, the inner circumferential portion and the outer circumferential portion being disposed adjacent to each other along the rotation axis, each portion comprising a rim portion for carrying a corresponding tire, wherein the rim assembly is coupled to a wheel hub, and Wherein, the in-wheel motor is arranged on the outer side of the wheel hub and connected to the wheel hub.

2. The drive assembly according to claim 1, wherein: The rim assembly is directly coupled to the center hub.

3. The drive assembly according to claim 2, wherein: The rim assembly is coupled directly to the central hub inside the motor.

4. A drive assembly according to claim 2 or 3, wherein: The rim assembly includes a substantially planar attachment portion for mounting the rim assembly to the center hub.

5. The drive assembly according to claim 4, wherein: The rim assembly further comprises: an inner bridge portion extending between the attachment portion and a rim portion of the inner circumferential portion, the inner bridge portion extending at least partially in a first direction along a rotational axis of the hub; and An outboard bridging portion extends between the attachment portion and a rim portion of the outboard circumferential portion, the outboard bridging portion extending at least partially along a second direction of the rotational axis of the hub.

6. The drive assembly according to claim 5, wherein: The inner bridge portion is integral with the attachment portion.

7. The drive assembly according to claim 6, wherein: The inner bridge portion is fixedly connected to a rim portion of the inner circumferential portion.

8. A drive assembly according to claim 5, 6 or 7, wherein: The outer bridging portion is integral with the attachment portion.

9. The drive assembly according to claim 8, wherein: The outer bridge portion is fixedly connected to a rim portion of the outer circumferential portion.

10. A drive assembly according to any one of claims 5 to 9, wherein: The medial bridge portion is integral with a first medial portion of the attachment portion, and the lateral bridge portion is integral with a second lateral portion of the attachment portion.

11. A drive assembly according to any one of the preceding claims, wherein: The rim assembly is coupled to the wheel hub via a plurality of fasteners having a pitch diameter that is greater than a diameter of the in-wheel motor.

12. The drive assembly according to claim 11, wherein: Each fastener may be accessible from an inner side of the central hub, or each fastener may be accessible from an outer side of the central hub.

13. A drive assembly according to any one of the preceding claims, wherein: The in-wheel motor is coupled to the wheel hub independently of the rim assembly.

14. A drive assembly according to any one of the preceding claims, wherein: The in-wheel motor is a direct drive in-wheel electric motor.

15. A drive assembly according to claim 14, configured to provide a torque of at least 3000 Nm, optionally at least 4000 Nm, optionally at least 5000 Nm, optionally up to 5500 Nm.

16. A drive assembly as claimed in any one of claims 1 to 13 comprising a gearbox.

17. The drive assembly of claim 16, wherein: The gearbox is a planetary gearbox.

18. The drive assembly of claim 17, wherein: The planetary gearbox is arranged on the outer side of the in-wheel motor.

19. A drive assembly according to claim 17 or 18, wherein: The in-wheel motor is an in-wheel electric motor, and wherein the planetary gearbox is configured to increase a motor speed of the electric motor relative to a wheel speed to increase a maximum torque output of the drive assembly.

20. A drive assembly according to claim 17, 18 or 19, wherein: The drive assembly is configured to provide a torque of at least 5000 Nm, optionally at least 8000 Nm, optionally at least 10000 Nm, optionally about 10500 Nm.

21. A drive assembly according to any one of the preceding claims, wherein: The stator is cooled by a liquid coolant, optionally the liquid coolant comprises at least one of water and ethylene glycol, optionally the liquid coolant comprises a water / ethylene glycol mixture.

22. A drive assembly according to claim 21, comprising or configured to be connected to a tube for providing liquid coolant to the stator through a main shaft of the drive assembly attached to the central hub and a central aperture of the central hub.

23. A drive assembly according to any one of the preceding claims, further comprising or being configured to be connected to electrical wires which pass through a spindle of the drive assembly attached to a central hub and a central aperture of the central hub.

24. A drive assembly according to claim 23, wherein: The electrical wire comprises at least one of the following: at least one cable for conducting power to and / or from the electric machine, such as a motor phase cable; and at least one temperature sensor and / or wiring for at least one temperature sensor; and Wires for motor rotational position sensors, such as electric motor rotational position sensors; and Wires for the High Voltage Interlock Loop (HVIL); and Ground wire.

25. A vehicle comprising at least one drive assembly according to any one of the preceding claims.

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