Electric Drivetrain

Abstract

An electric drivetrain having an axial-flux electric motor disposed along a drivetrain axis, the axial-flux electric motor arranged to rotate a hollow motor output shaft extending along the drivetrain axis, the hollow motor output shaft engaged with a first planetary gear set, the first planetary gear set capable of engaging and disengaging with a second planetary gear set coupled to a differential, the differential driving first and second main drive shafts, each of which also extend along the drivetrain axis, the first main drive shaft driving a first wheel hub assembly, and the second main drive shaft coaxially passing through the planetary gear set, the hollow motor output shaft, and the axial-flux electric motor to drive the second wheel hub assembly.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Patent Application No. 17 / 654,161, filed March 9, 2022, which claims priority to U.S. Patent Application No. 63 / 159,319, filed March 10, 2021, the entire disclosure of which is incorporated herein by reference.

[0002] This application relates generally to electric vehicles, and more particularly to electric vehicle drivetrains.

[0003] The present invention will be further described with reference to the accompanying drawings, in which like numerals refer to like parts throughout the several views. [Brief explanation of the drawings]

[0004] [Figure 1] FIG. 1 is a cross-sectional view of an electric drivetrain according to one or more embodiments. [Figure 2] FIG. 2 is a perspective view of the electric drivetrain of FIG. 1 according to one or more embodiments. [Figure 3] FIG. 2 is a cross-sectional view of the electric drivetrain of FIG. 1 according to one or more embodiments. [Figure 4] FIG. 10 is a cross-sectional view of another electric drivetrain according to one or more alternative embodiments. [Figure 5] FIG. 10 is a cross-sectional view of another electric drivetrain having two axial-flux electric motors according to one or more alternative embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0005] 1 and 2, an electric drivetrain 10 is shown. The electric drivetrain 10 includes at least one axial-flux electric motor 12, a planetary gear set 18, a differential 24, a first main drive shaft 34, and a second main drive shaft 36, each disposed along a drivetrain axis 16. The axial-flux electric motor 12 rotates a hollow motor output shaft 14 defined along the drivetrain axis 16. In some embodiments, the hollow output shaft 14 of the axial-flux electric motor 12 is or includes a spool through which the second main drive shaft 36 passes, as described in further detail below. In some embodiments, the axial-flux electric motor 12 includes at least one rotor attached to the hollow output shaft 14. For example, the axial-flux electric motor 12 may include at least one rotor attached to the hollow (and rotatable) output shaft 14, at least one stator fixed relative to the hollow output shaft 14, a plurality of magnets supported on the rotor, and a winding supported by the stator. Planetary gear set 18 is coaxial with drivetrain axis 16 and includes a sun gear 20, a planetary gear set carrier 22, one or more planet gears 23, and a ring gear 25. Sun gear 20 is coupled to or otherwise integrally formed on hollow output shaft 14 of axial-flux electric motor 12. In some embodiments, planetary gear set 18 is a compound planetary gear set having at least two sun gears and at least two sets of planet gears.

[0006] The differential 24 is coaxial with the drivetrain axis 16. While the differential 24 is not limited to a particular configuration, in one or more embodiments, the differential 24 may include an input mechanism 26, at least one intermediate gear 28, a first main driveshaft output gear 30, and a second main driveshaft output gear 32. In one or more embodiments, the input mechanism may be a pinion arm, such as a C-shaped pinion arm or yoke, to which the intermediate gear 28 is attached in the form of a pinion gear. In other embodiments, the input mechanism may be one or more input gears. The input mechanism 26 is coupled to the planetary gear set carrier 22 of the planetary gear set 18. In some embodiments, the input mechanism 26 of the differential 24 is a ring gear, and the at least one intermediate gear 28 is or includes at least one spider gear that meshes with the input mechanism 26. The first main driveshaft output gear 30 is attached to the first output carrier and meshes with at least one intermediate gear 28, and the second main driveshaft output gear 32 is attached to the second output carrier and meshes with at least one intermediate gear 28. The first output carrier is attached to the first main driveshaft 34, and the second output carrier is coupled to the second main driveshaft 36. In some embodiments, the input gears 26 of the differential 24 include first and second input gears, each attached to the differential input shaft. In such cases, the at least one intermediate gear 28 may include a ring gear having teeth disposed on its inner circumference. The first main driveshaft output gear 30 is attached to the first output carrier and engages the ring gear, and the second main driveshaft output gear 32 is attached to the second output carrier and also engages the ring gear. The first output carrier is attached to the first main driveshaft 34, and the second output carrier is coupled to the second main driveshaft 36. In other embodiments, the output carrier may be eliminated and the output gears 30, 32 may be attached to the first and second main drive shafts 34, 36, respectively.

[0007] In another embodiment, planetary gear set 18 is coupled to output gear 32, which is coupled to output gear 30 by intermediate gear 28.

[0008] In one or more embodiments, the first main drive shaft output gear 30 and the second main drive shaft output gear 32 are each independently coupled to at least one intermediate gear 28. In some embodiments, the at least one intermediate gear 28 is or includes one or more spider gears. In some embodiments, the at least one intermediate gear 28 is or includes one or more planetary gears. In some embodiments, the at least one intermediate gear 28 includes opposing planetary gears mounted on the planetary gear set carrier 22. In some embodiments, the at least one intermediate gear 28 is or includes opposing first and second pinion gears, and a ring gear has teeth disposed along its outer periphery and a center opening through which the second main drive shaft output gear 32 extends.

[0009] In any event, as noted above, in some embodiments, the differential 24 need not be limited to any particular configuration or arrangement.

[0010] A first main drive shaft 34 is coupled to the first main drive shaft output gear 30 and extends along the drivetrain axis 16. A second main drive shaft 36 is coupled to the second main drive shaft output gear 32 and extends along the drivetrain axis 16, coaxially passing through the planetary gear set 18, the hollow output shaft 14, and the axial-flux electric motor 12. As a result, the second main drive shaft 36 extends from a first side 38 of the axial-flux electric motor 12, and the hollow output shaft 14 extends from a second side 40 of the axial-flux electric motor 12.

[0011] The electric drivetrain 10 may include a clutch assembly 42 for engaging and disengaging the planetary gear sets 18. In some embodiments, the clutch assembly 42 is an electric clutch assembly. In some embodiments, the clutch assembly 42 is a hydraulic clutch assembly. In some embodiments, the clutch assembly 42 may be utilized to engage and disengage the planetary gear sets 18 with the axial-flux electric motor 12, while in other embodiments, the clutch assembly 42 may be utilized to engage and disengage the planetary gear sets 18 with the differential 24. In still other embodiments, the clutch assembly 42 may be utilized to engage and disengage multiple planetary gear sets 18 with one another, as shown in FIGS. 4 and 5 .

[0012] In some embodiments, the clutch assembly 42 may include a spring assembly that urges the first output carrier away from the second output carrier. A first magnet is attached to one of the output carriers against which it is urged by the spring assembly, and a second magnet is adjacent to the first magnet. At least one of the first and second magnets is an electromagnet. For example, the first magnet may be a permanent magnet fixed to the first output carrier, and the first output carrier is urged away from the second output carrier by the spring assembly. The second magnet may be an energizable stationary electromagnet, and the polarities of the first and second magnets are adjusted such that energizing the second magnet repels the first magnet against the force of the spring and fixedly engages the first and second output carriers. In another example, the first magnet may be a permanent magnet affixed to the first output carrier, the first output carrier being urged away from the second output carrier by a spring assembly, and the second magnet may be an energizable stationary electromagnet coaxial with the drivetrain axis, the polarities of the first and second magnets being adjusted such that energizing the second magnet causes the first magnet to repel against the force of the spring and fixedly engage the first and second main driveshaft output gears.

[0013] A first wheel hub assembly 44 is coupled to the first main drive shaft 34, and a second wheel hub assembly 46 is coupled to the second main drive shaft 36. A drivetrain housing 48 encloses the axial-flux electric motor 12, the planetary gear set 18, and the differential 24. The drivetrain housing 48 may include a first chamber (or compartment) 50 in which the axial-flux electric motor 12 is disposed and a separate second chamber 52 in which the differential 24 and / or the planetary gear set 18 are disposed. For example, the first chamber 50 may contain a potting compound for thermal management, and the second chamber 52 may contain oil (or some other lubricating fluid). Additionally, a third chamber 60 may be formed in the drivetrain housing 48 between the first chamber 50 and the second chamber 52, respectively. In some embodiments, the third chamber 60 may be open to or in fluid communication with the second chamber 52, and the planetary gear set 18 is disposed in the third chamber 60.

[0014] As best seen in FIG. 3 and with continued reference to FIG. 1 , in one or more embodiments, a heat dissipation mechanism 56 may be positioned adjacent to the axial-flux electric motor 12 to remove heat during operation. The heat dissipation mechanism 56 is not limited to a particular configuration. In some embodiments, the heat dissipation mechanism 56 may be external fins disposed about the axial-flux electric motor 12. In some embodiments, the heat dissipation mechanism 56 may extend from the motor housing 37. In other embodiments shown, the heat dissipation mechanism 56 may be one or more heat pipes extending between the axial-flux electric motor 12 and the drivetrain housing 48. For example, multiple heat pipes may extend from the axial-flux electric motor 12 and be coupled to the drivetrain housing 48. Additionally or alternatively, the axial-flux electric motor 12 may be spaced apart from the inner circumferential wall 51 of the first chamber 50, thereby forming an air gap 58 therebetween.

[0015] 1 and 2 , the first brake 62 is positioned adjacent to the first main drive shaft 34, and the second brake 64 is positioned adjacent to the second main drive shaft 36. In one or more embodiments, each brake 62, 64 may be coaxially mounted along the corresponding main drive shaft 34, 36. In some embodiments, the first brake 62 may be located adjacent to the differential 24, and the second brake 64 may be located adjacent to the axial-flux electric motor 12. In one or more embodiments, the brakes 62, 64 may be electrically actuated. The brakes 62, 64 may be enclosed within additional chambers or cavities formed in the drivetrain housing 48, or may be enclosed by wheel support housings 76, 78, respectively.

[0016] A first outboard drive shaft 63 interconnects the first wheel hub assembly 44 to the first main drive shaft 34, and a second outboard drive shaft 65 interconnects the second wheel hub assembly 44 to the second main drive shaft 36. A universal joint 66a is disposed between the first outboard drive shaft 63 and the first main drive shaft 34, and a universal joint 66b is disposed between the second outboard drive shaft 65 and the second main drive shaft 36. A hub gear assembly 68 is mounted within a wheel housing 70 of each wheel hub assembly 44 and 46. The first and second main drive shafts 34 and 36 have distal ends 34' and 36', respectively, and the wheel hub assemblies 44 and 46 are pivotally mounted adjacent the distal ends 34' and 36' of the respective first and second main drive shafts 34 and 36. As a result, the first wheel hub assembly 44 is pivotable about a pivot axis 72 adjacent the distal end 34' of the first main drive shaft 34, the pivot axis 72 being perpendicular to the drivetrain axis 16. Additionally, the second wheel hub assembly 46 is pivotable about a pivot axis 73 adjacent the distal end 36' of the second main drive shaft 36, the pivot axis 73 being perpendicular to the drivetrain axis 16 (and substantially parallel to the pivot axis 72). Each wheel hub assembly 44 and 46 also includes a rotatable wheel hub 74.

[0017] The first wheel support housing 76 extends from the drivetrain housing 48 and is disposed around the first main drive shaft 34. The second wheel support housing 78 extends from the drivetrain housing 48 and is disposed around the second main drive shaft 36. The wheel support housings 76 and 78 each have a first closed end 80a attached to the drivetrain housing 48 and a second open end 80b from which the respective first and second main drive shafts 34 and 36 extend. For example, the second open end 80b of each wheel support housing 76 and 78 may be shaped with an inner contour 82 on opposite sides thereof. In some embodiments, the inner contour 82 is parabolic.

[0018] The first yoke 86a is pivotally mounted to the first wheel support housing 76 adjacent its second open end 80b. The first wheel hub assembly 44 is mounted to the first yoke 86a. The first yoke 86a has a base 88 with a first yoke arm 90a extending from the base 88, an opposing second yoke arm 90b extending from the base 88 adjacent to (but spaced from) the first yoke arm 90a, and a third yoke arm 92 (see FIG. 2) extending from the base 88 away from the first and second yoke arms 90a, 90b. The first yoke arm 90a and the second yoke arm 90b each have end portions 94 pivotally mounted on opposite sides thereof to the first wheel support housing 76. The first yoke 86a further includes a mounting plate 96 adjacent to the first yoke arm 90a and the second yoke arm 90b. The first wheel hub assembly 44 is mounted to a mounting plate 96 of the first yoke 86a. A control shaft 98 (see FIG. 2) is pivotally coupled to the third yoke arm 92 and extends toward the drivetrain housing 48. In some embodiments, the control shaft 98 is substantially parallel to the drivetrain axis 16. As shown in FIG. 2, the control shaft 98 is engaged by a control mechanism 100 arranged to actuate the control shaft 98. In some embodiments, the control mechanism 100 is electric. In some embodiments, the control mechanism 100 is hydraulic. A second yoke 86b (substantially identical to the first yoke 86a) may be pivotally mounted to the second wheel support housing 78 adjacent the second open end 80b of the second wheel support housing 78. As shown, the second wheel hub assembly 46 is mounted to the mounting plate 96 of the second yoke 86b.

[0019] With reference to FIG. 4 , and continuing reference to FIGS. 1 through 3 , in one or more other embodiments, electric drivetrain 10 includes an axial-flux electric motor 12 coaxial with a drivetrain axis 16. Axial-flux electric motor 12 is arranged to drive a hollow output shaft 14 that extends from axial-flux electric motor 12 along drivetrain axis 16. In the embodiment of FIG. 4 , electric drivetrain 10 includes a first planetary gear set 18 a and a second planetary gear set 18 b, each of which is coaxial with drivetrain axis 16. First planetary gear set 18 a may be engaged by being coupled to hollow output shaft 14. In one or more embodiments, second planetary gear set 18 b may be engaged and disengaged with either first planetary gear set 18 a or hollow output shaft 14.

[0020] The differential 24 may be provided coaxially along the drivetrain axis 16. While the differential 24 is not limited to a particular configuration, in one or more embodiments, the differential 24 may include a first main driveshaft output gear 30 and a second main driveshaft output gear 32, with the first main driveshaft output gear attached to a first main driveshaft 34 extending along the drivetrain axis 16. Similarly, the second main driveshaft output gear 32 may be attached to a second main driveshaft 36 and extending along the drivetrain axis 16. The second main driveshaft 36 coaxially passes through the first planetary gear set 18a, the second planetary gear set 18b, the hollow output shaft 14, and the axial-flux electric motor 12.

[0021] The clutch assembly 42 may be positioned to engage and disengage at least one of the planetary gear sets 18 a, 18 b. Thus, in some embodiments, the clutch assembly 42 may be positioned between the first planetary gear set 18 a and the second planetary gear set 18 b to engage and disengage the two planetary gear sets 18 a, 18 b. In other embodiments, the clutch assembly 42 may engage and disengage the planetary gear set 18 and the differential 24. Furthermore, in other embodiments, the clutch assembly 42 may be positioned to engage and disengage the planetary gear set 18 with the hollow output shaft 14, and more specifically, with the sun gear 20 mounted along the hollow output shaft 14.

[0022] 5 shows another embodiment of an electric drivetrain 10 in which two axial-flux electric motors 12 are provided, namely, a first axial-flux electric motor 12 a and a second axial-flux electric motor 12 b. Cooperating with the two axial-flux electric motors 12 a, 12 b are two planetary gear sets 18, namely, a first planetary gear set 18 a and a second planetary gear set 18 b, with the first axial-flux electric motor 12 a engaged with the first planetary gear set 18 a via a first hollow output shaft 14 a and the second axial-flux electric motor 12 b engaged with the second planetary gear set 18 b via a second hollow output shaft 14 b extending through the first hollow output shaft 14 a.

[0023] The first planetary gear set 18a includes a first sun gear 20a mounted on the first hollow output shaft 14a. The first sun gear 20a engages one or more planet gears 23a mounted on a first carrier 22a, which in turn engage a first ring gear 25a.

[0024] Similarly, the second planetary gear set 18b includes a second sun gear 20b mounted on the second hollow output shaft 14b. The second sun gear 20b engages one or more planet gears 23b mounted on the second carrier 22b, and the second planet gears 23b engage a second ring gear 25b. In one or more embodiments, the ring gears 25a, 25b can be a single ring gear.

[0025] Although the first axial-flux electric motor 12 a and the second axial-flux electric motor 12 b are shown as separate modules with separate motor housings 37, those skilled in the art will understand that in other embodiments, the first axial-flux electric motor 12 a may be a first rotor mounted on a first hollow output shaft 14 a and the second axial-flux electric motor 12 b may be a second rotor mounted on a second hollow output shaft 14 b, with the first rotor and second rotor all within the same motor housing 37 so long as each rotor can be separately energized to rotate the corresponding hollow output shaft 14.

[0026] In either case, a clutch assembly 42 is provided and can be selectively actuated to engage and disengage the first and second planetary gear sets 18 a, 18 b. In one or more embodiments, the clutch assembly 42 may engage the sun gears 20 a, 20 b of the first and second planetary gear sets 18 a, 18 b. In one or more other embodiments, the clutch assembly 42 may engage the carriers 22 a, 22 b of the first and second planetary gear sets 18 a, 18 b.

[0027] 5 may include a drivetrain housing 48 in which a first chamber (or compartment) 50 is defined and separated from a second chamber 52 in which the differential 24 and planetary gear sets 18a, 18b are disposed. The second planetary gear set 18b is coupled to the differential 24. It will be appreciated that the first planetary gear set 18a may also be coupled to the differential 24 when the clutch assembly 42 is engaged and disengaged.

[0028] First and second main drive shafts 34, 36 extend from the differential 24, with the second main drive shaft 36 passing coaxially through the first and second hollow output shafts 14a, 14b, as well as the first and second planetary gear sets 18a, 18b and the first and second axial-flux electric motors 12a, 12b.

[0029] An electric drivetrain is disclosed. In one or more embodiments, the electric drivetrain may include an electric motor, first and second main drive shafts, and a differential driven by the electric motor, the differential driving the first and second main drive shafts, the second main drive shaft coaxially passing through the electric motor. In other embodiments, the electric drivetrain may include a hollow motor output shaft, first and second main drive shafts, and a differential driven by the hollow motor output shaft, the differential driving the first and second main drive shafts, the second main drive shaft coaxially passing through the hollow motor output shaft. In other embodiments, the electric drivetrain may include a planetary gear set, first and second main drive shafts, and a differential driven by the planetary gear set, the differential driving the first and second main drive shafts, the second main drive shaft coaxially passing through the planetary gear set. In other embodiments, the electric drivetrain may include a first axial-flux electric motor disposed along the drivetrain axis, first and second main drive shafts extending along the drivetrain axis, and a differential driven by the electric motor, the differential driving the first and second main drive shafts, the second main drive shaft coaxially passing through the electric motor.In other embodiments, the electric drivetrain may include a first axial-flux electric motor disposed along the drivetrain axis, a first planetary gear set disposed along the drivetrain axis, a second planetary gear set disposed along the drivetrain axis, a first hollow motor output shaft disposed along the drivetrain axis arranged to couple the first axial-flux electric motor to one of the planetary gear sets, a differential disposed along the drivetrain axis and coupled to one of the planetary gear sets, a first main drive shaft coupled to the differential and extending along the drivetrain axis, and a second main drive shaft coupled to the differential and extending along the drivetrain axis, the second main drive shaft coaxially passing through the first planetary gear set, the second planetary gear set, and the axial-flux electric motor. In other embodiments, the electric drivetrain may include a first axial-flux electric motor disposed along the drivetrain axis, a first planetary gear set disposed along the drivetrain axis, a second planetary gear set disposed along the drivetrain axis, a first hollow motor output shaft disposed along the drivetrain axis and positioned to couple the first axial-flux electric motor to one of the planetary gear sets, a clutch assembly disposed between the first and second planetary gear sets and operable to selectively engage and disengage the first and second planetary gear sets from one another, a differential disposed along the drivetrain axis and coupled to one of the planetary gear sets, a first main drive shaft coupled to the differential and extending along the drivetrain axis, and a second main drive shaft coupled to the differential and extending along the drivetrain axis, the second main drive shaft coaxially passing through the first planetary gear set, the second planetary gear set, and the axial-flux electric motor.In other embodiments, an electric drivetrain may include an axial-flux electric motor having a hollow motor output shaft defined along a drivetrain axis; a planetary gear set coaxial with the drivetrain axis and having a sun gear coupled to the hollow output shaft of the axial-flux electric motor, the planetary gear set including a planetary gear set carrier; a differential coaxial with the drivetrain axis, the differential having an input gear coupled to the planetary gear set carrier of the planetary gear set, at least one intermediate gear, a first main driveshaft output gear, and a second main driveshaft output gear, each independently coupled to an intermediate gear; a first main driveshaft coupled to the first main driveshaft and extending along the drivetrain axis; and a second main driveshaft coupled to the second main driveshaft output gear and extending along the drivetrain axis, the second main driveshaft coaxially passing through the planetary gear set, the hollow output shaft, and the axial-flux electric motor. In other embodiments, an electric drivetrain may include an axial-flux electric motor having a hollow output shaft defined along a drivetrain axis; a first planetary gear set coaxial with the drivetrain axis and coupled to the hollow output shaft; a differential coaxial with the drivetrain axis, the differential having a first main driveshaft output gear and a second main driveshaft output gear; a first main driveshaft coupled to the first main driveshaft output gear and extending along the drivetrain axis; and a second main driveshaft coupled to the second main driveshaft output gear and extending along the drivetrain axis, the second main driveshaft coaxially passing through the planetary gear set, the hollow output shaft, and the axial-flux electric motor.

[0030] For any one of the electric drivetrain embodiments described above, the following elements may be included alone or in combination with any other elements. A second planetary gear set located along the drivetrain axis. A differential located along the drivetrain axis and coupled to one of the planetary gear sets. The second main drive shaft passes coaxially through the first and second planetary gear sets and the axial flux electric motor. A clutch assembly disposed between the first and second planetary gear sets and operable to selectively engage and disengage the first and second planetary gear sets from one another. and a clutch assembly disposed between the first planetary gear set and the second planetary gear set and operable to selectively engage and disengage the first hollow output shaft with one of the first planetary gear set and the second planetary gear set. The first hollow motor output shaft engages the first planetary gear set and the second planetary gear set is coupled to the differential. a second axial-flux electric motor disposed along the drivetrain axis; and a second hollow motor output shaft, the first hollow motor output shaft coupling the first axial-flux electric motor to one planetary gear set and the second hollow motor output shaft coupling the second axial-flux electric motor to the other planetary gear set. The first axial-flux electric motor includes a first rotor mounted on a first hollow motor output shaft, and the second axial-flux electric motor includes a second rotor mounted on a second axial-flux electric motor output shaft, the first and second rotors being disposed within the same motor housing. A first wheel hub assembly disposed along the driveline axis and coupled to the first main drive shaft, and a second wheel hub assembly disposed along the driveline axis and coupled to the second main drive shaft. A first brake disposed along the first main drive shaft, and a second brake disposed along the second main drive shaft. 1. A drivetrain housing enclosing an electric motor, a differential, and a planetary gear set, the drivetrain housing defining a first chamber in which the axial-flux electric motor is disposed, a second chamber in which the differential is disposed, and a third chamber in which the planetary gear set is disposed, the second and third chambers being sealed and isolated from the first chamber. a first wheel hub assembly disposed along the driveline axis and coupled to the first main drive shaft; a second wheel hub assembly disposed along the driveline axis and coupled to the second main drive shaft; a first brake disposed along the first main drive shaft; and a second brake disposed along the second main drive shaft. A second axial-flux electric motor located along the drivetrain axis. A second hollow motor output shaft, the first hollow motor output shaft coupling the first axial-flux electric motor to one planetary gear set and the second hollow motor output shaft coupling the second axial-flux electric motor to the other planetary gear set. The first axial-flux electric motor includes a first rotor mounted on a first hollow motor output shaft, and the second axial-flux electric motor includes a second rotor mounted on a second axial-flux electric motor output shaft, the first and second rotors being disposed within the same motor housing. The differential includes first and second main drive shaft output gears, the first main drive shaft coupled to the first main drive shaft output gear and the second main drive shaft coupled to the second main drive shaft output gear. A planetary gear set coupled to a hollow motor output shaft, with a second main drive shaft also coaxially passing through the planetary gear set. The planetary gear set includes a sun gear coupled to a hollow motor output shaft and a planetary gear set carrier. The differential further includes an input gear coupled to the planetary gear set and at least one intermediate gear, and the first and second main drive shaft output gears are each independently coupled to the at least one intermediate gear. The first chamber contains a potting compound and the second chamber contains an oil. The input gear of the differential is a ring gear, the intermediate gear is at least one spider gear that meshes with the input gear, a first main drive shaft output gear is attached to the first output carrier and meshes with the intermediate gear, a second axial output gear is attached to the second output carrier and meshes with the intermediate gear, the first output carrier is attached to the first main drive shaft, and the second output carrier is coupled to the second main drive shaft. The intermediate gears are opposing planetary gears mounted on a carrier. The intermediate gears are one or more spider gears. The intermediate gears are one or more planetary gears. The intermediate gears are first and second opposing pinion gears, and the ring gear has teeth arranged along its outer periphery and an opening in the center of the ring gear through which the second main drive shaft output gear extends. The hollow output shaft of an axial-flux electric motor is a spool through which the second main drive shaft passes. A clutch assembly disposed coaxially along a drivetrain axis and mounted adjacent to the planetary gear set, the clutch assembly including a spring assembly urging one carrier away from the other carrier, a first magnet mounted on the carrier urged by the spring, and a second magnet adjacent to the first magnet, one of the magnets being an electromagnet. The first magnet is a permanent magnet fixed to the first output carrier, a spring assembly urging the first output carrier away from the second output carrier, and the second magnet is an energizable stationary electromagnet coaxial with the drivetrain axis, the polarities of the first and second magnets being adjusted such that energizing the second magnet causes the first magnet to repel against the force of the spring, fixedly engaging the first and second output carriers. The first magnet is a permanent magnet fixed to the first output carrier, a spring assembly urging the first output carrier away from the second output carrier, and the second magnet is an energizable stationary electromagnet coaxial with the drivetrain axis, the polarities of the first and second magnets being adjusted such that energizing the second magnet causes the first magnet to repel against the force of the spring and fixedly engage the first and second main driveshaft output gears. A first wheel hub assembly coupled to the first main drive shaft and a second wheel hub assembly coupled to the second main drive shaft. 10. The electric drivetrain of any one of claims 1 to 9, further comprising a drivetrain housing enclosing the axial-flux electric motor, the planetary gear set, and the differential. The drivetrain housing includes a first section in which the axial-flux electric motor is located and a separate second section in which the differential and planetary gear set are located. The planetary gear set is a compound planetary gear set having at least two sun gears and at least two sets of planet gears. A second planetary gear set coupled to the first planetary gear set. An axial-flux electric motor includes at least one rotor mounted on a hollow output shaft. The axial flux electric motor comprises at least one rotor mounted on a hollow rotatable output shaft, at least one stator fixed relative to the hollow rotatable output shaft, a plurality of magnets supported on the rotor, and windings supported by the stator. The axial flux electric motor is spaced from the inner peripheral wall of the first chamber to define an air gap therebetween. a third chamber formed in the drivetrain housing between the first chamber and the second chamber, the third chamber open to the second chamber, and the planetary gear set disposed in the third chamber; A lubricating fluid disposed in the second chamber. A clutch assembly disposed between the first planetary gear set and the differential. A clutch assembly disposed between the first planetary gear set and the second planetary gear set. The clutch assembly is an electric clutch assembly. The clutch assembly is a hydraulic clutch assembly. a first outer drive shaft interconnecting the first wheel hub assembly to the first main drive shaft, and a second outer drive shaft interconnecting the second wheel hub assembly to the second main drive shaft. A universal joint is disposed between the first outer drive shaft and the first main drive shaft, and a universal joint is disposed between the second outer drive shaft and the second main drive shaft. The wheel hub assembly further includes a gear assembly mounted within the housing of the wheel hub assembly. Each of the first and second main drive shafts has a distal end, and each wheel hub assembly is pivotally mounted adjacent the distal end of the respective first and second main drive shaft. Each wheel hub assembly pivots about a pivot axis adjacent the distal end of the main drive shaft that is perpendicular to the drivetrain axis. a first wheel support housing extending from the drivetrain housing and disposed around the first main driveshaft, and a second wheel support housing extending from the drivetrain housing and disposed around the second main driveshaft. a yoke pivotally mounted on the wheel support housing adjacent the second end of the wheel support housing, the hub assembly being mounted on the yoke; The yoke has a yoke base with a first yoke arm extending from the base, an opposing second yoke arm extending from the base adjacent to the first yoke arm but spaced apart from the first yoke arm, and a third yoke arm extending from the base away from the first yoke arm and the second yoke arm, each of the first yoke arm and the second yoke arm having an end pivotally attached to the wheel support housing on an opposite side of the wheel support housing. The yoke further includes a mounting plate adjacent the first and second yoke arms, and the hub assembly is mounted to the mounting plate. A control shaft pivotally coupled to the third yoke arm and extending toward the motor housing. The control shaft is substantially parallel to the drivetrain axis. The control shaft is engaged by a control mechanism arranged to actuate the control shaft. The control mechanism is electrically operated. The control mechanism is hydraulic. a first yoke pivotally mounted to the first wheel support housing adjacent a second end of the first wheel support housing, the first hub assembly being mounted to the first yoke, and a second yoke pivotally mounted to the second wheel support housing adjacent a second end of the second wheel support housing, the second hub assembly being mounted to the second yoke.

[0031] Although various embodiments are shown in detail, the present disclosure is not limited to the shown embodiments. Modifications and adaptations of the above-described embodiments may occur to those skilled in the art. Such modifications and adaptations are within the spirit and scope of the present disclosure.

Claims

1. 1. An electric drivetrain comprising: a first axial-flux electric motor disposed along the drivetrain axis; first and second main drive shafts extending along the drivetrain axis; a single differential driven by the first axial-flux electric motor, the differential driving the first and second main drive shafts; an integrally formed drivetrain housing enclosing the electric motor and the differential, the drivetrain housing defining at least a first chamber at one end of the housing, the axial-flux electric motor disposed within the first chamber, and at least a second chamber at an opposite end of the housing, the differential disposed within the second chamber, the second chamber being sealed and isolated from the first chamber; Equipped with an electric drivetrain, wherein the second main drive shaft passes coaxially through the first axial-flux electric motor;

2. 2. The electric drivetrain of claim 1, further comprising: a first hollow motor output shaft disposed along the drivetrain axis and coupled to the first axial-flux electric motor; and a first planetary gear set disposed along the drivetrain axis and coupled to the first hollow motor output shaft, wherein the second main drive shaft passes coaxially through the planetary gear set and the first hollow motor output shaft.

3. 2. The electric drivetrain of claim 1, wherein the drivetrain housing further comprises a third chamber having a planetary gear set disposed therein, the second chamber being in fluid communication with the third chamber, and the third chamber being isolated from the first chamber.

4. 3. The electric drivetrain of claim 2, further comprising: a second axial-flux electric motor disposed within the first chamber along the drivetrain axis; a second planetary gear set disposed along the drivetrain axis; and a second hollow motor output shaft coupling the second axial-flux electric motor to the second planetary gear set.

5. 5. The electric drivetrain of claim 4, further comprising a clutch assembly disposed between the first planetary gear set and the second planetary gear set and operable to selectively engage and disengage the first planetary gear set and the second planetary gear set from one another.

6. The electric drivetrain of claim 1 , wherein the differential is disposed along the drivetrain axis.

7. The electric drivetrain of claim 4 , wherein the second hollow motor output shaft extends coaxially within the first hollow motor output shaft.

8. 8. The electric drivetrain of claim 7, wherein the first planetary gear set comprises a first sun gear mounted to the first hollow motor output shaft, and the second planetary gear set comprises a second sun gear mounted to the second hollow motor output shaft.

9. 1. An electric drivetrain comprising: a first axial-flux electric motor disposed along the drivetrain axis; a first planetary gear set disposed along the drivetrain axis; and a second planetary gear set disposed along the drivetrain axis; and a first hollow motor output shaft disposed along the drivetrain axis arranged to couple the first axial-flux electric motor to one of the planetary gear sets; a differential disposed along the drivetrain axis and coupled to one of the planetary gear sets; a first main drive shaft coupled to the differential and extending along the drivetrain axis; a second main drive shaft coupled to the differential and extending along the drivetrain axis, the second main drive shaft coaxially passing through the first and second planetary gear sets and the axial-flux electric motor; an integrally formed drivetrain housing enclosing the electric motor and the differential, the drivetrain housing defining at least a first chamber at one end of the housing, the first axial-flux electric motor disposed within the first chamber, and at least a second chamber at an opposite end of the housing, the differential and the planetary gear set disposed within the second chamber, the second chamber being sealed and separated from the first chamber; An electric drivetrain.

10. 10. The electric drivetrain of claim 9, further comprising a clutch assembly disposed between the first planetary gear set and the second planetary gear set and operable to selectively engage and disengage the first planetary gear set and the second planetary gear set from one another.

11. 10. The electric drivetrain of claim 9, further comprising a clutch assembly disposed between the first planetary gear set and the second planetary gear set, the clutch assembly operable to selectively engage and disengage the first hollow motor output shaft with one of the first planetary gear set and the second planetary gear set.

12. The electric drivetrain of claim 10 , wherein the first hollow motor output shaft engages the first planetary gear set and the second planetary gear set is coupled to the differential.

13. 10. The electric drivetrain of claim 9, further comprising: a second axial-flux electric motor disposed within the first chamber along the drivetrain axis; and a second hollow motor output shaft, the first hollow motor output shaft coupling the first axial-flux electric motor to one planetary gear set and the second hollow motor output shaft coupling the second axial-flux electric motor to another planetary gear set.

14. 14. The electric drivetrain of claim 13, wherein the first axial-flux electric motor comprises a first rotor mounted on the first hollow motor output shaft and the second axial-flux electric motor comprises a second rotor mounted on a second axial-flux electric motor output shaft, the first and second rotors being disposed within a same motor housing.

15. An electric drivetrain as described in claim 9, further comprising: a first wheel hub assembly arranged along the drivetrain axis and coupled to the first main drive shaft; and a second wheel hub assembly arranged along the drivetrain axis and coupled to the second main drive shaft.

16. 10. The electric drivetrain of claim 9, further comprising: a first brake disposed along the first main drive shaft; and a second brake disposed along the second main drive shaft.

17. 1. An electric drivetrain comprising: a first axial-flux electric motor disposed along the drivetrain axis; a first planetary gear set disposed along the drivetrain axis; and a second planetary gear set disposed along the drivetrain axis; and a first hollow motor output shaft disposed along the drivetrain axis arranged to couple the first axial-flux electric motor to one of the planetary gear sets; a clutch assembly disposed between the first planetary gear set and the second planetary gear set and operable to selectively engage and disengage the first planetary gear set and the second planetary gear set from one another; a differential disposed along the drivetrain axis and coupled to one of the planetary gear sets; a first main drive shaft coupled to the differential and extending along the drivetrain axis; a second main drive shaft coupled to the differential and extending along the drivetrain axis, the second main drive shaft coaxially passing through the first and second planetary gear sets and the axial-flux electric motor; an integrally formed drivetrain housing enclosing the electric motor and the differential, the drivetrain housing defining at least a first chamber at one end of the housing, the axial-flux electric motor disposed within the first chamber, and at least a second chamber at an opposite end of the housing, the differential and the planetary gear set disposed within the second chamber, the second chamber being sealed and separated from the first chamber; An electric drivetrain.

18. 18. The electric drivetrain of claim 17, further comprising: a first wheel hub assembly disposed along the drivetrain axis and coupled to the first main drive shaft; a second wheel hub assembly disposed along the drivetrain axis and coupled to the second main drive shaft; a first brake disposed along the first main drive shaft; and a second brake disposed along the second main drive shaft.

19. The electric drivetrain of claim 17 further comprising a second axial-flux electric motor disposed along the drivetrain axis.

20. 20. The electric drivetrain of claim 19, further comprising a second hollow motor output shaft, the first hollow motor output shaft coupling the first axial-flux electric motor to one planetary gear set and the second hollow motor output shaft coupling the second axial-flux electric motor to another planetary gear set.

21. 21. The electric drivetrain of claim 20, wherein the first axial-flux electric motor comprises a first rotor mounted on the first hollow motor output shaft, and the second axial-flux electric motor comprises a second rotor mounted on the second hollow motor output shaft, the first and second rotors being disposed within a same motor housing.

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