Electric drive unit layout

Abstract

A vehicle (100) includes a first electric drive unit (102) and a second electric drive unit (112) having a first elongated axis and a second elongated axis (110, 120). Each electric drive unit includes a gearbox (104, 114), an electric motor (106, 116) mounted to the gearbox (104, 114) and configured to provide drive to the gearbox (104, 114), and an inverter (108, 118) mounted to the gearbox (104, 114) and configured to provide drive current to the electric motor (106, 116). The first electric drive unit (102) is mounted so that the first axis (110) is at a first pitch angle relative to the vehicle, and the second electric drive unit (112) is mounted so that the second axis (120) is at a second pitch angle relative to the vehicle. The first pitch angle and the second pitch angle are different from each other. The first inverter (108) and the second inverter (118) are mounted in the same orientation relative to the vehicle (100).

Description

Technical Field

[0001] The invention relates to an electric vehicle having at least a first and a second electric drive unit (EDU), each of which has an inverter. Background Art

[0002] Electric and hybrid electric vehicles are becoming increasingly common. One such vehicle may include front and rear electric drive units (EDUs), each driving a respective pair of wheels.

[0003] The EDU may include a gearbox, an inverter, and an electric motor.

[0004] The use of at least two EDUs can complicate the manufacture and assembly of the vehicle relative to a vehicle employing only a single EDU. This can be exacerbated if the EDUs need to be mounted differently at the front and rear of the vehicle, for example due to packaging constraints.

[0005] It is desirable to reduce manufacturing and / or assembly complexity in an electric or hybrid electric vehicle having at least a first EDU and a second EDU. Summary of the Invention

[0006] The present invention provides a vehicle comprising:

[0007] A first electric drive unit having a first elongated axis and comprising:

[0008] a first gearbox, the first elongated axis being orthogonal to the input and output rotational axes of the first gearbox;

[0009] a first electric motor mounted to the first gearbox and configured to provide drive to the first gearbox; and

[0010] a first inverter mounted to the first gearbox and configured to provide a drive current to the first electric motor; and

[0011] A second electric drive unit having a second elongated axis and comprising:

[0012] a second gearbox, the second elongated axis being orthogonal to the input and output rotational axes of the second gearbox;

[0013] a second electric motor mounted to the second gearbox and configured to provide drive to the second gearbox; and

[0014] a second inverter mounted to the second gearbox and configured to provide a drive current to the second electric motor;

[0015] in:

[0016] The first electric drive unit is mounted with the first elongated axis at a first pitch angle relative to the vehicle;

[0017] the second electric drive unit is mounted with the second elongated axis at a second pitch angle relative to the vehicle, the first pitch angle and the second pitch angle being different from each other; and

[0018] The first inverter and the second inverter are mounted in the same orientation relative to the vehicle.

[0019] Using the same orientation for the first inverter and the second inverter may simplify the process of assembling the inverters to the gearbox and installing the electric drive units into the vehicle, even though the respective electric drive units have different pitch angles relative to the vehicle.

[0020] The pitch angle is measured relative to the body of the vehicle, for example relative to a lower surface of the body of the vehicle which is substantially parallel to the surface on which the vehicle rests in use.

[0021] The respective orientations of the inverters may be defined based on the locations of electrical connections on the respective first and second inverters and / or coolant connections on the respective first and second inverters.

[0022] The housings of the first and second inverters can be identical. This makes the process of mounting the inverters to their respective gearboxes more efficient, as the same tools, fasteners, and assembly methods can be used even if the gearboxes themselves are mounted at different spacings and optionally differ in structure. Using the same housing simplifies the supply chain, as only a single housing needs to be designed, manufactured, and stocked.

[0023] The first inverter and the second inverter may be identical to each other, which may further simplify the supply chain.

[0024] The first electric drive unit may be configured to drive a set of front wheels of the vehicle.

[0025] The second electric drive unit may be configured to drive a set of rear wheels of the vehicle.

[0026] Where a first electric drive unit is configured to drive a set of front wheels of a vehicle and a second electric drive unit is configured to drive a set of rear wheels of the vehicle, the orientation of the inverter may be selected to improve or optimize packaging efficiency.

[0027] The pitch angle of one of the first electric drive unit and the second electric drive unit may be less than 45°, and the pitch angle of the other of the first electric drive unit and the second electric drive unit may be greater than 45°. These pitch angle ranges can improve or optimize packaging efficiency.

[0028] A first electric drive unit may be positioned to drive a set of front wheels of the vehicle, and the pitch angle of the first electric drive unit may be substantially vertical. A second electric drive unit may be positioned to drive a set of rear wheels of the vehicle, and the pitch angle of the second electric drive unit may be substantially horizontal. This combination of pitch angles may improve or optimize packaging efficiency by enabling the vehicle to have a longitudinally compact front end and relatively high rear load volume.

[0029] The first and second electric motors can be mounted to their respective gearboxes in different orientations relative to the vehicle, wherein the respective orientations of the first and second electric motors can be defined based on the location of electrical connections on the respective first and second electric motors and / or coolant connections on the respective first and second electric motors. The different orientations of the electric motors can allow for improved or optimized positioning of the electrical connections and / or coolant connections relative to the respective mounting locations of the first and second electric drive units.

[0030] The first and second motors can be identical to each other. This makes the process of installing the motors into their respective gearboxes more efficient, as the same tools, fasteners, and assembly methods can be used even if the gearboxes themselves are mounted at different pitches. Using identical motors simplifies the supply chain, as only a single motor needs to be designed, manufactured, and stocked.

[0031] Each inverter can be mounted to its gearbox on a side opposite to the side where the corresponding electric motor is mounted. This arrangement can help place the gearbox relatively close to the centerline of the vehicle, which improves or optimizes packaging efficiency.

[0032] The first electric drive unit may include a pair of laterally positioned load-bearing mounts connected to the body of the vehicle at a respective pair of mounting points located at or adjacent respective front shock towers. This may provide a compact mounting arrangement.

[0033] The first electric drive unit may include at least one torque reaction mount that is connected to the vehicle's body at a lower position than the load-bearing mount. This allows for efficient torque transfer between the first electric drive unit and the vehicle, while optionally allowing for a relatively vertical positioning of the gearbox.

[0034] The second electric drive unit may include a plurality of combined load-bearing and torque-reacting mounts that connect the second electric drive unit to the vehicle's body at their respective mounting points. This allows for efficient mounting and torque transfer while optionally allowing for a relatively horizontal positioning of the gearbox.

[0035] The first gearbox may be different from the second gearbox, for example having a different housing or internal structure. This may allow each gearbox to be optimized for its intended installation orientation.

[0036] The first and second electric drive units can include mounting points to which respective mounting members can be attached. This can allow for compact electric drive units and mounting assemblies. In at least one embodiment, the first and second electric drive units have the same mounting points, but the first and second electric drive units have different mounting members attached to their respective mounting points. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order that the present invention may be more readily understood, embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which:

[0038] Figure 1 is a partial perspective side view of a vehicle including a first front electric drive unit (EDU) and a second rear EDU;

[0039] Figure 2 yes Figure 1 A partial perspective front view of a vehicle showing Figure 1 First EDU;

[0040] Figure 3 yes Figure 1 A partial perspective rear view of the vehicle showing Figure 1 The second EDU;

[0041] Figure 4 This is the floor plan of the First EDU;

[0042] Figure 5 is a perspective view of a first EDU with mounting members omitted for clarity;

[0043] Figure 6 is a side view of the second EDU;

[0044] Figure 7 is a perspective view of a second EDU with mounting members omitted for clarity;

[0045] Figure 8 This is the bottom view of the first EDU;

[0046] Figure 9 Is installed to Figure 1 Bottom view of the second EDU of the vehicle's subframe. DETAILED DESCRIPTION

[0047] Referring to the figures, a vehicle 100 includes a first electric drive unit (EDU) 102. The first EDU 102 includes a first gearbox 104. A first motor 106 is mounted to the first gearbox 104 and configured to provide drive to an input shaft (not shown) of the first gearbox 104. A first inverter in the form of a first inverter 108 is mounted to the first gearbox 104 and configured to provide drive current to the first motor 106.

[0048] In the illustrated embodiment, the first motor 106 is mounted to a first lateral side of the first gearbox 104, and the first inverter 108 is mounted to a second lateral side of the first gearbox 104, opposite the first lateral side. The first EDU 102 is generally T-shaped, with the first gearbox 104 forming the vertical portion of the 'T', and the first inverter 108, the first motor 106, and the upper end of the first gearbox 104 forming the lateral portion of the 'T'.

[0049] The first EDU 102 has an elongated axis 110 that extends generally through the first gearbox 104. Figure 2 , Figure 4 and Figure 5 As best shown in FIG, the elongated axis 110 is defined in this embodiment as an axis orthogonal to the input and output rotational axes of the first gearbox 104. The elongated axis 110 generally extends through a centerline through the first gearbox 104.

[0050] Vehicle 100 includes a second EDU 112. Second EDU 112 includes a second gearbox 114. A second motor 116 is mounted to second gearbox 114 and configured to provide drive to an input shaft (not shown) of second gearbox 114. A second inverter in the form of a second inverter 118 is mounted to second gearbox 114 and configured to provide drive current to second motor 116.

[0051] In the illustrated embodiment, the second motor 116 is mounted to a first lateral side of the second gearbox 114, and the second inverter 118 is mounted to a second lateral side of the second gearbox 114, opposite the first lateral side. The second EDU 112 is generally T-shaped, with the second gearbox 114 forming the vertical portion of the 'T', and the second inverter 118, the second motor 116, and the upper end of the second gearbox 114 forming the lateral portion of the 'T'.

[0052] The second EDU 112 has an elongated axis 120 that extends generally through the second gearbox 114. Figure 6 and Figure 7 As best shown in FIG, the elongated axis 120 is defined in this embodiment as an axis that is orthogonal to the input and output rotational axes of the second gearbox 114. The elongated axis 120 generally extends through the centerline of the second gearbox 114.

[0053] The first EDU 102 is mounted with its axis 110 at a first pitch angle, and the second EDU 112 is mounted with its axis 120 at a second pitch angle. The first pitch angle and the second pitch angle are different from each other.

[0054] The first pitch angle can be greater than 45 °. In the embodiment shown, the first pitch angle is approximately vertical. In this context, "vertical" is used with its common meaning and is not necessarily limited to strict 90 °.

[0055] The second pitch angle may be less than 45°. In the embodiment shown, the second pitch angle is approximately horizontal. In this context, word "horizontal" is used with its ordinary meaning and is not necessarily limited to strict 0°.

[0056] By comparison Figure 4 and Figure 6 As best shown, the first inverter 108 and the second inverter 118 are mounted to their respective gearboxes such that the inverters 108, 118 have the same orientation relative to the vehicle 100. In this case, the first inverter 108 and the second inverter 118 are oriented such that the straight upper edges of the inverters are approximately horizontal.

[0057] The orientation of each of the first inverter 108 and the second inverter 118 may be defined based on the location of the coolant connections on the respective first and second inverters. Figure 4 and Figure 6 , the first coolant inlet 122 is positioned at the same location on the first inverter 108 as the second coolant inlet 124 on the second inverter 118. Similarly, the first coolant outlet 126 is positioned at the same location on the first inverter 108 as the second coolant outlet 128 on the second inverter 118. In at least some embodiments, it may be desirable for the coolant inlets and outlets to be horizontal because this helps avoid unnecessary turns in the cooling ducts.

[0058] Alternatively or additionally, the orientation of each of the first inverter 108 and the second inverter 118 may be defined based on the location of electrical connections on the respective first and second inverters.

[0059] In the illustrated embodiment, the first inverter 108 and the second inverter 118 are identical to each other. In this case, "identical" means that they share the same housing and internal electronic components. In practice, this may mean that the first inverter 108 and the second inverter 118 are actually the same component.

[0060] In alternative embodiments, the respective housings of first inverter 108 and second inverter 118 may be identical to one another, despite having different internal components. This may occur, for example, when first EDU 102 and second EDU 112 have different torque requirements, and therefore fewer and / or lower-rated electrical switching components may be used in the inverter of the lower-torque EDU.

[0061] In other embodiments, the overall structure and / or layout of the inverters may be substantially similar, but the details of the inverter housings are different to account for differences in the requirements for mounting to the first and second EDUs.

[0062] The illustrated example shows the first EDU 102 driving a set of front wheels 130 of the vehicle 100, and the second EDU 112 driving a set of rear wheels 132 of the vehicle 100. In this embodiment, the respective orientations of the inverters improve packaging efficiency.

[0063] In the illustrated embodiment, the first motor 106 is mounted to the first gearbox 104 in a different orientation than the orientation in which the second motor 116 is mounted to the second gearbox 114. The orientations of the first and second motors can be defined based on the location of electrical connections on the respective first and second motors and / or the location of coolant connections on the respective first and second motors. As can be seen, in this embodiment, the first motor 106 rotates relative to the second motor 116, with the rotation occurring about the axis of the output shaft of the respective motors 106, 116.

[0064] In the illustrated embodiment, the first motor 106 is identical to the second motor 106. This makes the process of mounting the motors to their respective gearboxes more efficient because the same tools, fasteners, and assembly methods can be used even if the gearboxes themselves are mounted at different spacings.

[0065] In the illustrated embodiment, the first EDU 102 includes a pair of laterally positioned load-bearing mounts 134 that are connected to the vehicle 100 at mounting points 136 on a cross member 137 extending between front shock towers 138. The first EDU 102 also includes a torque reaction mount 140 that is connected to a subframe 141 of the vehicle 100 at a location lower than the load-bearing mounts 134 (see FIG. Figure 1 ). It will be appreciated that other combinations of load bearing and / or torque reaction mounts may be employed, for example, depending on packaging requirements.

[0066] By tightening the bolt 142 (see Figure 4 ) is screwed into the corresponding threaded boss 144 on the first inverter 108 (see Figure 5 ), the load-bearing mount 134 on the inverter side of the first EDU 102 is bolted directly to the first inverter 108. The load-bearing mount 134 on the motor side of the first EDU 102 is bolted directly to the motor in a similar manner.

[0067] By tightening the bolt 143 (see Figure 4 ) are screwed into the corresponding threaded bosses 145 on both lateral sides of the gear box 104 (see Figure 5 ) in which the torque reaction mount 140 is bolted directly to the gearbox 104.

[0068] like Figure 6 and 8 As best shown, in the illustrated embodiment, the second EDU 112 includes a plurality of combined load-bearing and torque-reacting mounts 146 that connect the second EDU 112 to the vehicle 100 at corresponding mounting points 148 on a rear subframe 150 of the vehicle 100. The details of the mounting points 148 and the rear subframe 150 are not relevant to the present invention and, therefore, will not be described herein for the sake of brevity.

[0069] By tightening the bolt 152 (see Figure 6 ) is screwed into the corresponding threaded boss 154 on the second inverter 118 (see Figure 7 ), the load-bearing mount 146 on the inverter side of the second EDU 112 is bolted directly to the second inverter 118. The mount 146 on the motor side of the second EDU 112 is bolted directly to the motor in a similar manner. The remaining mounts 146 are bolted directly to the second gearbox 114 at the front end of the second EDU 112.

[0070] In the illustrated embodiment, the mounts are separate elements that are attached to the inverter, motor, and gearbox. In other embodiments, one or more mounts may form part of the corresponding motor, inverter, or gearbox, in which case no separate mounting elements are required. Alternatively, one or more mounts may be attached to or form part of an EDU other than the inverter and / or motor. For example, all mounts on one or more EDUs may be attached to or form part of the gearbox.

[0071] In the illustrated embodiment, the first gearbox 104 is distinct from the second gearbox 114. Internal features may differ between the gearboxes to account for the different orientations. For example, internal splash lubrication features are positioned to account for the specific orientation of each gearbox. However, the gearboxes may have identical gear sets, particularly in embodiments where the first and second motors are identical. If one motor has a higher peak torque than the other, the gear set of its gearbox may include stronger, more resilient components.

[0072] Although the illustrated vehicle 100 is a sedan, the present invention is applicable to other types of vehicles, such as trucks and vans.

[0073] Although the invention has been described with reference to specific embodiments, it will be appreciated that the invention can be embodied in many other forms within the scope of the appended claims.

Claims

1. A vehicle comprising: A first electric drive unit having a first elongated axis and comprising: a first gearbox, the first elongated axis being orthogonal to the input and output rotational axes of the first gearbox; a first electric motor mounted to the first gearbox and configured to provide drive to the first gearbox; and a first inverter mounted to the first gearbox and configured to provide a drive current to the first electric motor; and A second electric drive unit having a second elongated axis and comprising: a second gearbox, the second elongated axis being orthogonal to the input and output rotational axes of the second gearbox; a second electric motor mounted to the second gearbox and configured to provide drive to the second gearbox; and a second inverter mounted to the second gearbox and configured to provide a drive current to the second electric motor; in: the first electric drive unit being mounted with the first elongate axis at a first pitch angle relative to the vehicle, wherein the first pitch angle is oriented relative to a surface of a body of the vehicle that is substantially parallel to a planar surface on which the vehicle rests in use; the second electric drive unit is mounted with the second elongated axis at a second pitch angle relative to the vehicle, the first pitch angle and the second pitch angle being different from each other; and The first inverter and the second inverter are mounted in the same orientation relative to the vehicle.

2. The vehicle according to claim 1, wherein The orientation of each inverter is defined based on the following positions: the locations of the electrical connections on the respective first and second inverters; and / or The locations of the coolant connections on the respective first and second inverters.

3. The vehicle according to claim 1, wherein: The housings of the first inverter and the second inverter are identical to each other.

4. The vehicle according to claim 3, wherein: The first inverter and the second inverter are identical to each other.

5. A vehicle according to any one of the preceding claims, wherein The first electric drive unit is configured to drive a set of front wheels of the vehicle.

6. The vehicle according to any one of claims 1 to 4, wherein: The second electric drive unit is configured to drive a set of rear wheels of the vehicle.

7. The vehicle according to any one of claims 1 to 4, wherein: A pitch angle of one of the first electric drive unit and the second electric drive unit is smaller than 45°, and a pitch angle of the other of the first electric drive unit and the second electric drive unit is larger than 45°.

8. The vehicle according to any one of claims 1 to 4, wherein: The first electric drive unit is positioned to drive a set of front wheels of the vehicle, and a first pitch angle of the first electric drive unit is 90°; and The second electric drive unit is positioned to drive a set of rear wheels of the vehicle, and the second pitch angle of the second electric drive unit is 0°.

9. The vehicle according to any one of claims 1 to 4, wherein: The first and second electric motors are mounted to their respective gearboxes in different orientations relative to the vehicle, wherein the respective orientations of the first and second electric motors are defined based on the following positions: the locations of the electrical connections on the respective first and second electric motors; and / or Locations of coolant connections on the respective first and second electric motors.

10. The vehicle according to any one of claims 1 to 4, wherein: The first motor and the second motor are identical to each other.

11. The vehicle according to any one of claims 1 to 4, wherein: Each of the inverters is mounted to its gearbox on a side opposite to a side on which the corresponding electric motor is mounted.

12. The vehicle according to any one of claims 1 to 4, wherein: The first electric drive unit includes a pair of laterally positioned load-bearing mounts connected to the body of the vehicle at a respective pair of mounting points located at or adjacent respective front shock towers.

13. The vehicle according to any one of claims 1 to 4, wherein: The first electric drive unit includes at least one torque reaction mount connected to the body of the vehicle at a location below the load bearing mount.

14. The vehicle according to any one of claims 1 to 4, wherein: The second electric drive unit includes a plurality of combined load bearing and torque reaction mounts connecting the second electric drive unit to the body of the vehicle at respective mounting points thereof.

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