Modular electric vehicle drive module

Abstract

A vehicle drive unit for a battery electric vehicle (BEV) includes: an electric motor having an output shaft for propelling the BEV; a planetary gearbox having an input end and an output end; a sprocket coupled to an output of the motor or an input of the planetary gearbox; and an endless ring rotatably coupled with the sprocket and the input end of the planetary gearbox so as to be configured to transmit rotational movement of the output shaft of the electric motor to the drive shaft of the BEV, where the rotational axis of the drive shaft of the BEV is offset from the rotational axis of the output shaft of the electric motor.

Description

Technical Field

[0001] This application relates to battery electric vehicles (BEVs), and more particularly to vehicle drive units for BEVs. Background Art

[0002] Modern vehicles increasingly use electric motors as the primary source of propulsion. These vehicles (commonly referred to as battery electric vehicles (BEVs)) include a traction motor, a gearbox, a battery, and power electronics for regulating the current supply to the traction motor. In passenger vehicles for personal use, the positions of these components may not vary greatly from one vehicle to another, so the components can be located in defined positions in each of the vehicles produced. However, commercial vehicles typically vary widely in their construction and design depending on their end use. Given this diversity, it would be helpful to have additional flexibility in choosing the location of the electric motor(s) and gearbox within the vehicle such that space can be utilized most effectively depending on the particular construction. It would be helpful to have a modular electric motor and gearbox assembly that can be coupled to the vehicle chassis to propel a BEV. Summary of the Invention

[0003] In one embodiment, a vehicle drive unit for a battery electric vehicle (BEV) includes: an electric motor for propelling the BEV having an output shaft; a planetary gearbox having an input end and an output end; a sprocket coupled to the output end of the electric motor or the input end of the planetary gearbox; and an endless loop rotatably coupled to the sprocket and the input end of the planetary gearbox so as to be configured to transmit rotational movement of the output shaft of the electric motor to the drive shaft of the BEV, wherein the rotational axis of the drive shaft of the BEV is offset from the rotational axis of the output shaft of the electric motor.

[0004] In another embodiment, a vehicle drive unit for a BEV includes: an electric motor for propelling the BEV having an output shaft; a planetary gearbox having an input end axially coupled to the output shaft of the electric motor and an output end; a second planetary gearbox having an input end and an output end configured to be coupled to the drive shaft of the BEV; and an endless loop rotatably coupled to the output end of the planetary gearbox and the input end of the second planetary gearbox such that the drive shaft of the BEV is offset from the output shaft of the electric motor.

[0005] In yet another embodiment, a vehicle drive unit for a BEV includes an electric motor for propelling the BEV having an output shaft; a planetary gearbox having an input end axially coupled to the output shaft of the electric motor and an output end; an endless loop rotatably coupled to the output end of the planetary gearbox and the differential of the BEV such that the differential of the BEV is offset from the shaft of the electric motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a perspective view depicting an embodiment of a battery electric vehicle (BEV) and a vehicle drive unit;

[0007] Figure 2 is another perspective view depicting an embodiment of a BEV and a vehicle drive unit;

[0008] Figure 3 is another perspective view depicting an embodiment of the vehicle drive unit;

[0009] Figure 4 is a cross-sectional view of an embodiment of the vehicle drive unit;

[0010] Figure 5 is a cross-sectional view of another embodiment of the vehicle drive unit; and

[0011] Figure 6 is a cross-sectional view of an embodiment of the vehicle drive unit. DETAILED DESCRIPTION

[0012] A vehicle drive unit for a battery electric vehicle (BEV) includes an electric motor for propelling the BEV having an output shaft. The vehicle drive unit further includes at least one planetary gearbox having an input end axially coupled to the output shaft of the electric motor and an output end. An endless ring is rotatably coupled to the output end of the planetary gearbox and the axle of the BEV such that the axis of rotation of the axle of the BEV is offset from the axis of rotation of the output shaft of the electric motor. The vehicle drive unit can be flexibly combined with a commercial vehicle such that the vehicle can be customized depending on the application. That is, the position of the vehicle drive unit can be selected depending on the desired configuration of the vehicle, and the position of the electric motor relative to the planetary gearbox and / or the axle of the BEV can be specified and changed.

[0013] Figures 1 to 3Depicts a battery electric vehicle (BEV) 10 having a vehicle drive unit 12. The vehicle drive unit 12 can be positioned between two wheels 14 of the BEV 10 and coupled to its frame 16. The vehicle drive unit 12 can include a housing 18, a first output 20 coupled to a first drive shaft 22, and a second output 24 coupled to a second drive shaft 26. The first drive shaft 22 can be coupled to one wheel 14 of the vehicle 10, and the second drive shaft 26 can be coupled to the other wheel of the vehicle. Typically, a BEV includes a vehicle battery, at least one electric motor, and a power control module that regulates the current supplied from the vehicle battery to the electric motor(s). The electric motor(s) is / are mechanically coupled to the wheels 14 of the BEV 10 such that the electric motor(s) propels the BEV 10 either individually or at least in part. It should be understood that the term "electric motor" can refer to a rotating electrical machine having a rotor assembly and a stator assembly that receives stator windings. The stator windings can receive a current that causes an angular displacement of the rotor assembly relative to the stator assembly. The electric motor can also be used as a generator, where a torque applied to the rotor assembly can cause a current to flow in the stator windings.

[0014] In this embodiment, the BEV 10 can be a commercial vehicle manufactured by an original equipment manufacturer (OEM), but can later be customized or configured for a specific commercial purpose. In one example, the BEV 10 can have a frame 16, an enclosure 30 in which an operator or passenger sits, and a cargo area 32 to which an aftermarket manufacturer can attach a box for carrying cargo. An example of a commercial vehicle is an F-450 manufactured by Ford Motor Company. A commercial vehicle can also be described as a vehicle having a gross vehicle weight of more than 10,000 pounds, designed or used to transport more than nine persons for compensation, or designed or used to transport more than fifteen persons. However, it is possible to use the vehicle drive unit described herein in a non-commercial BEV.

[0015] Turning to Figure 4, which more particularly shows an embodiment of the vehicle drive unit 12. The vehicle drive unit 12 includes a first electric motor 34 having an output shaft 36 coupled to an input end 38 of a first planetary gearbox 40. The input end 38 may be a sun gear having gear teeth facing radially outward. The first planetary gearbox 40 may have a first planetary gear set 45 having an output end 42 coupled to an input sprocket 44 and a mechanical linkage connected to the input end 38. The output end 42 may include a plurality of planetary gears engaging the sun gear. A second planetary gear set 46 may include an input end 48 coupled to an output sprocket 50. The input end 48 may be a sun gear similar to the input end 38. The input sprocket 44 and the output sprocket 50 may be rotatably coupled by an endless loop 52 (such as a belt or a chain). An output end 54 of the second planetary gear set 46 may be coupled to a first drive shaft 22 driving a wheel 14 of the BEV 10. The output end 54 may include a plurality of planetary gears engaging the sun gear.

[0016] The vehicle drive unit 12 may further include a second electric motor 56 having an output shaft 58 coupled to an input end 60 of a second planetary gearbox 62. The input end 60 may be a sun gear having gear teeth facing radially outward. The second planetary gearbox 62 may include a first planetary gear set 63 and a second planetary gear set 68. The first planetary gear set 63 may have an output end 64 coupled to an input sprocket 66. The output end 64 may include a plurality of planetary gears engaging the sun gear. The second planetary gear set 68 may include an input end 70 coupled to an output sprocket 72. The input sprocket 66 and the output sprocket 72 may be rotatably coupled by a second endless loop 74 (such as a belt or a chain). An output end 76 of the second planetary gearbox 68 may be coupled to a second drive shaft 26 driving another wheel 14 of the BEV 10.

[0017] The electric motors 34, 56 of the vehicle drive unit 12 generally include a rotor 78 and a stator 80 having electrical windings capable of receiving current regulated by a power control module. In one embodiment, the electric motors 34, 56 may be permanent magnet traction motors such that the rotor 78 includes permanent magnets, and the current flowing through the electrical windings of the stator 80 is regulated by the power control module in a manner such that it causes an angular displacement of the stator relative to the rotor 78. The output shafts 36, 58 may be coupled to the rotor 78 in a manner such that angular displacement of the output shafts 36, 58 relative to the rotor 78 is prevented. Then, the rotor 78 undergoes an angular displacement relative to the stator 80. The power control module may include an inverter that regulates the current supply through the windings.

[0018] The planetary gearbox and / or sprockets may have appropriate sizes and gears to establish a desired gear ratio. For example, the planetary gear sets 45, 46, 63, 68 may each include a sun gear 82 having gear teeth extending radially outwardly, which engages one or more planet gears 84 also having gear teeth extending radially outwardly. The diameters of the sun gear / planet gears and the size and number of the gear teeth facing radially outwardly may be selected to produce a specific gear ratio. The input sprockets 44, 66 and the output sprockets 50, 72 may include gear teeth facing radially outwardly that engage endless rings 52, 74. The output shafts 36, 58 of the electric motors 34, 56 may rotate the input ends of the planetary gear sets 45, 63, thereby transmitting the rotation to the output ends of the gearboxes 42, 64. The output ends 42, 64 coupled to the input sprockets 44, 66 may transfer motion through the endless rings 52, 74 to the input sprockets 50, 72 and the input ends 48, 70 of the second planetary gearboxes 46, 68. Then, the output ends 54, 76 of the second planetary gearboxes 46, 68 may transfer rotation to the drive shafts 22, 26. The diameters of the input sprockets and the input sprockets and the design of the sun gear / planet gears may be selected to produce a specific gear ratio. The endless ring may be implemented in any of a variety of ways. For example, the endless ring may be a chain including a plurality of links, or the endless ring may be a belt that engages the output sprockets and the input sprockets.

[0019] Go to Figure 5 , another embodiment of the vehicle drive unit 12' is shown. The vehicle drive unit 12' includes an electric motor 34, a first planetary gearbox 40 having a first planetary gear set 45 and a second planetary gear set 46, an endless ring 52, and a differential 86. The differential 86 may be coupled to two or more wheels 14 of the BEV 10 and transfer rotational torque from the electric motor 34 to the wheels 14. The output shaft 36 of the electric motor 34 may be coupled to the input end 38 of the first planetary gear set 45. The first planetary gear set 45 may have an output end 42 coupled to the input sprocket 44. The second planetary gearbox 46 may include an input end 48 coupled to the output sprocket 50. The input sprocket 44 and the output sprocket 50 may be rotatably coupled by an endless ring 52 such as a belt or a chain. The output end 54 of the second planetary gearbox 46 may be coupled to the differential 86. The differential 86 may include an input end 88 coupled to the output end 54 of the second planetary gearbox 46 and an output end 90 ultimately connected to the wheels 14 of the BEV 10. The differential may be implemented in a variety of ways but typically includes a plurality of gears to allow one wheel of the BEV to rotate at a different angular velocity than the other wheel.

[0020] Figure 6Depicts another embodiment of the vehicle drive unit 12". The vehicle drive unit 12" may include an electric motor 34, an input sprocket 44, an endless loop 52, an output sprocket 50, a planetary gear set 45', and a differential 86. The output shaft 36 of the electric motor 34 may be coupled to the sprocket 44. The first planetary gear set 45' may have an input end 38 coupled to the output sprocket 50. The input sprocket 44 and the output sprocket 50 may be rotatably coupled by an endless loop 52 such as a belt or a chain. The output end 42 of the first planetary gear set 45' may be coupled to the differential 86. The differential 86 may include an input end 88 coupled to the output end 42 of the first planetary gear set 45 and an output end 90 ultimately connected to the wheel 14 of the BEV 10. The differential 86 may be coupled to two or more wheels 14 of the BEV 10 and transmit rotational torque from the electric motor 34 to the wheels 14. In this embodiment, a single planetary gear set may be used.

[0021] It should be understood that the foregoing is a description of one or more embodiments of the present invention. The present invention is not limited to the specific embodiment(s) described herein, but is defined only by the following claims. Furthermore, the statements contained in the foregoing description relate to specific embodiments and should not be construed as limiting the scope of the present invention or the definition of terms used in the claims, unless the terms or phrases are expressly defined above. For those skilled in the art, various other embodiments and various changes and modifications to the disclosed embodiment(s) will be apparent. All such other embodiments, variations, and modifications are intended to fall within the scope of the appended claims.

[0022] As used in this specification and the claims, the terms "e.g.", "for example", "such as", "including", "having", "containing", and other verb forms, when used in conjunction with a list of one or more components or other items, shall be construed as open-ended, meaning that the list should not be regarded as excluding other additional components or items. Other terms should be construed in their broadest reasonable sense unless they are used in a context that requires a different interpretation.

Claims

1. A vehicle drive unit for a battery electric vehicle (BEV), comprising: An electric motor for propelling the BEV having an output shaft; A planetary gearbox having an input end and an output end; A sprocket coupled to the output end of the electric motor or the input end of the planetary gearbox; And An endless ring rotatably coupled to the sprocket and the input end of the planetary gearbox, thereby configured to transmit the rotational movement of the output shaft of the electric motor to the drive shaft of the BEV, wherein the rotational axis of the drive shaft of the BEV is offset from the rotational axis of the output shaft of the electric motor.

2. The electric vehicle drive unit according to claim 1, further comprising a second planetary gearbox having an input end coupled to the output end of the planetary gearbox and an output end coupled to the drive shaft of the BEV.

3. The electric vehicle drive unit according to claim 2, further comprising a sprocket coupled to the output end of the planetary gearbox and a sprocket coupled to the input end of the second planetary gearbox, wherein the sprockets engage the endless ring.

4. The electric vehicle drive unit according to claim 1, further comprising a differential coupled to the output end of the planetary gearbox.

5. A vehicle drive unit for a battery electric vehicle (BEV), comprising: An electric motor for propelling the BEV having an output shaft; A first planetary gearbox having an input end axially coupled to the output shaft of the electric motor and an output end; A second planetary gearbox having an input end and an output end configured to be coupled to the drive shaft of the BEV; And An endless ring rotatably coupled to the output end of the planetary gearbox and the input end of the second planetary gearbox, wherein the rotational axis of the drive shaft of the BEV is offset from the rotational axis of the output shaft of the electric motor.

6. The electric vehicle drive unit according to claim 5, further comprising a sprocket coupled to the output end of the planetary gearbox and a sprocket coupled to the input end of the second planetary gearbox, wherein the sprockets engage the endless ring.

7. The electric vehicle drive unit according to claim 6, further comprising a second planetary gear set, the second planetary gear set including a plurality of planetary gearboxes.

8. A vehicle drive unit for a battery electric vehicle (BEV), comprising: An electric motor for propelling the BEV having an output shaft; A planetary gearbox having an input end axially coupled to the output shaft of the electric motor and an output end; An endless ring rotatably coupled to the output end of the planetary gearbox and the differential of the BEV, wherein the differential of the BEV is offset from the axis of the electric motor.

9. The electric vehicle drive unit according to claim 8, further comprising a second planetary gearbox having an input end coupled to the output end of the planetary gearbox and an output end coupled to the differential of the BEV.

10. The electric vehicle drive unit according to claim 9, further comprising a sprocket coupled to the output end of the planetary gearbox and a sprocket coupled to the input end of the second planetary gearbox, wherein the sprockets engage the endless ring.

Images