Electric multi-speed axle with coaxial architecture

Abstract

Electric multi-gear axle arrangement, comprising: an electric machine that is rotaryally coupled to a sun gear in a first planetary gear set; a second planetary gear set which is rotaryally coupled to a carrier in the first planetary gear set; a third planetary gear set, which is rotaryally coupled to the second planetary gear set; and a differential that is rotaryally coupled to the third planetary gear set; wherein the electric machine, the first planetary gear set, the second planetary gear set, the third planetary gear set and the differential are arranged coaxially.

Description

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to U.S. Provisional Application No. 63 / 584,713, entitled "MULTI-SPEED ELECTRIC AXLE WITH COAXIAL ARCHITECTURE," filed September 22, 2023. The entire contents of the above-referenced application are hereby incorporated by reference for all purposes. TECHNICAL FIELD

[0002] The present disclosure relates to a multi-speed electric axle having a coaxial architecture for an electric machine, planetary gear sets, and a differential. BACKGROUND AND SUMMARY

[0003] Segments of the vehicle market are moving toward electrification. Certain vehicle platforms require both off-road and on-road capabilities. Some off-road vehicles require comparatively large gear ratios to achieve high torque while maintaining high system efficiency. Furthermore, in some electric vehicles (EVs), the available space for an electric axle is limited due to the layout of other systems such as the traction battery, vehicle frame, and suspension.

[0004] The inventors recognized the above challenges and developed an electric multi-speed axle assembly to at least partially overcome the challenges. In one example, the electric multi-speed axle assembly includes an electric machine rotationally coupled to the sun gear in a first planetary gear set. The electric multi-speed axle assembly further includes a second planetary gear set rotationally coupled to a carrier member of the first planetary gear set. The electric multi-speed axle assembly further includes a third planetary gear set rotationally coupled to the second planetary gear set. The electric multi-speed axle assembly additionally includes a differential rotationally coupled to the third planetary gear set. In the electric axle assembly, the electric machine, the first planetary gear set, the second planetary gear set, the third planetary gear set, and the differential are coaxially arranged.In this way, the electric axle is able to achieve a compact architecture with high efficiency, which can also be used in vehicle platforms with very limited space if required.

[0005] In one example, the multi-speed electric axle includes a clutch configured to selectively lock a sun gear and a carrier in the second planetary gear set in a position to rotate. When the clutch is arranged in this configuration, the electric axle operates in a higher speed mode. Conversely, when the clutch is moved to a different position where it locks a carrier in the second planetary gear set, the electric axle operates in a lower speed mode. In this way, the efficiency of the transmission is increased in the higher speed mode while the desired torque is achieved in the lower speed mode. By locking the sun gear and carrier in the second planetary gear set from rotation, the bearing and gear losses in the second planetary gear set are reduced.

[0006] Furthermore, in one example, a sun gear in the third planetary gear set may be rotationally coupled to a ring gear in the second planetary gear set. Furthermore, in such an example, a carrier of the third planetary gear set may be rotationally coupled to a differential. Furthermore, in such an example, a ring gear in the first planetary gear set and a ring gear in the third planetary gear set may be fixed. In this way, the electric multi-speed axle arrangement achieves targeted gear reduction in the smallest possible space.

[0007] It should be understood that the above summary is intended to introduce, in simplified form, a selection of concepts further explained in the detailed description. It is not intended to identify essential or critical features of the claimed subject matter, the scope of which is clearly defined by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that address the disadvantages noted above or elsewhere in this disclosure. SHORT DESCRIPTION OF THE CHARACTERS Fig. 1 shows a detailed representation of an electric multi-gear axle in a vehicle. Fig. 2 shows a cross-sectional view of the electric axis shown in Fig. 1 is shown. Fig. 3A-3B show mechanical power paths through the Fig. 1 shows the electrical axis in different operating modes. Fig. Figure 4 shows an example of a compound planetary gear set for an electric axle. DETAILED DESCRIPTION

[0008] An electric axle with a coaxial architecture is described that provides multi-speed functionality in a space-saving housing that can operate in at least a higher speed mode and a lower speed mode. To achieve the above characteristics, the electric axle includes three planetary gear sets, wherein a clutch is configured to switch the second planetary gear set between a higher range configuration and a lower range configuration. In the higher range configuration, in one example, a sun gear and a carrier in the second planetary gear set are rotationally coupled to each other and function as the input of the second planetary gear set. In the lower range configuration, in one example, the carrier of the second planetary gear set is fixed, and the sun gear functions as the input of the second planetary gear set.In both the higher speed and lower speed modes, a ring gear in the second planetary gear set can act as the output of the gear set.

[0009] Fig. 1 shows an electric vehicle (EV) 100 including a powertrain 102 with an electric axle assembly 103 that includes an electric axle 104, which may be configured as an assembly. The electric vehicle 100 may be a hybrid electric vehicle (HEV) in one example or a pure electric vehicle (e.g., a battery electric vehicle (BEV)) in another example.

[0010] As described herein, an electric axle is an electric drivetrain incorporated into an axle. The electric axle may, in one example, be an electric live axle. A live axle is an axle with mechanical components that structurally support one another and that extend between drive wheels. For example, in one embodiment, the live axle may be a structurally continuous structure that extends between the drive wheels on a transverse axis. Thus, with the live axle, the wheels coupled to the live axle move substantially in unison during turn-in, such as when traveling on rough road surfaces. With the live axle, the camber angle of the wheels may remain substantially constant as the suspension moves through its travel. The live axle may, in one example, be coupled to a dependent suspension system 107. Therefore, the electric axle may represent an unsprung mass.

[0011] The electric axle 104 includes an electric machine 106 (e.g., a traction motor). The electric machine 106 may be, for example, an electric motor-generator. For example, the electric machine 106 may be configured as a multi-phase alternating current (AC) motor-generator. However, in other examples, the electric machine may be a motor without the capabilities of a generator.

[0012] As in Fig. 1, the electric machine 106 may be electrically coupled to an inverter 108. The inverter 108 is configured to convert direct current (DC) electrical power into alternating current (AC) electrical power and vice versa. Therefore, the electric machine 106 may be an AC electrical machine, as previously stated. However, in other examples, the electric machine may also be a DC machine, in which case the inverter may be omitted from the electric drive. The inverter 108 may receive electrical energy from one or more energy storage devices 110 (e.g., traction batteries, capacitors, combinations thereof, and the like). Arrows 112 indicate the transfer of electrical energy between the electric machine 106, the inverter 108, and the (at least one) energy storage device 110 during various operating modes of the electric axle (e.g.,during a drive mode and a regeneration mode). Thus, during a drive mode, electrical energy may flow from the (at least one) energy storage device 110 to the electric machine 106, and during a regeneration mode, electrical energy may flow in the opposite direction from the electric machine to the (at least one) energy storage device.

[0013] The electric axle 104 further includes a planetary gear set arrangement 114 having a plurality of planetary gear sets and at least one clutch configured to switch the gear train between at least one higher speed mode and a lower speed mode. In the example shown, the planetary gear set arrangement 114 includes a differential incorporated therein. The electric machine 106, the planetary gear sets, and the differential are arranged coaxially to enable a more compact design of the axle. Consequently, the electric axle can be installed in a wider range of vehicle platforms. The specifics of the planetary gear set arrangement are described herein with respect to the Fig. 2-3B is explained in more detail.

[0014] In the Fig. 1, the electric axle 104 further includes an axle shaft housing 116, which houses the axle shafts that rotationally couple the differential and the drive wheels 127 via wheel hubs 125, in the illustrated example. However, in other examples, other suitable component architectures may be used to couple the drive wheels and the differential. The drive wheels 127 are in Fig. 1 shown schematically.

[0015] The planetary gear set assembly 114 includes a housing 119 having a portion 120 removably coupled to a portion 122. The portion 120 may at least partially include a traction motor and / or one or more planetary gear sets, and the portion 122 may at least partially include a differential and one or more planetary gear sets, or vice versa. The axle shaft housing 116 includes various portions removably coupled to the housing portion 122 and the housing portion 120. However, in other examples, other suitable housing designs may be used. In the illustrated example, a heat exchanger 123 is coupled to the housing portion 120. However, other axle configurations are also possible.

[0016] The EV 100 may also include a control system 180 having a controller 182. The controller 182 includes a processor 184 and a memory 186. The memory 186 contains instructions stored therein that, when executed by the processor 184, cause the controller 182 to perform the various methods, control techniques, etc. described herein. The processor 184 may include a microprocessor unit and / or other types of circuitry. The memory 186 includes known data storage media, such as random access memory, read-only memory, keep-alive memory, combinations thereof, etc.

[0017] The controller 182 may receive various signals from sensors 188 mounted at various locations within the vehicle 100, and in particular, the electric axle 104. The sensors may include an electric machine speed sensor, a clutch position sensor, one or more energy storage temperature sensors, one or more energy storage state of charge sensors, wheel speed sensors, and the like. The controller 182 may also send control signals to various actuators 190 mounted at various locations within the EV 100 and the electric axle 104. For example, the controller 182 may send signals to the inverter 108 to regulate the speed of the electric machine 106. The other controllable components in the vehicle and powertrain may function similarly with regard to command signals and actuator adjustment.For example, the controller 182 may send signals to a clutch in the planetary gear assembly 114 to engage and disengage the clutch and operate the axle in various range modes, which are explained in more detail herein.

[0018] The EV 100 may also include one or more input devices 192 (e.g., an accelerator pedal, a brake pedal, a gear selector, a drive mode selector, a differential lock actuator, a console instrument panel, a touch interface, a touch panel, a keypad, combinations thereof, and the like) in electronic communication with the controller 182. The input devices 192 may generate an acceleration adjustment request, a gear shift request, and the like in response to operator input.

[0019] An axis system is in Fig. 1 and in the Fig. 2-4 are shown for reference purposes where appropriate. In one example, the z-axis may be a vertical axis (e.g., parallel to a gravity axis), the x-axis may be a lateral axis (e.g., a horizontal axis), and / or the y-axis may be a longitudinal axis. However, in other examples, the axes may have different orientations.

[0020] Fig. Figure 2 shows a cross-sectional view of the electric axle 104 with the housing of the planetary gear assembly 114 removed to reveal the internal gear sets and other components. A first planetary gear set 200 is shown in Fig. 2. In the example shown, a sun gear 202 of the first planetary gear set 200 is rotationally coupled to a rotor shaft of the electric machine 106, which in Fig. 1. The first planetary gear set 200 also includes planet gears 204 that rotate on a carrier 206 and mesh with a ring gear 208. The planetary gear set assembly 114 further includes a second planetary gear set 210 that includes a ring gear 212, a first set of planet gears 214, a second set of planet gears 216, a sun gear 218, and a carrier 220 on which both sets of planet gears rotate.

[0021] Fig. 4 shows an example of a compound planetary gear set arrangement 400 that can be used in the electric axle 104 as a second planetary gear set. As in Fig. 4, the planetary gear set 400 includes a sun gear 402, a first set of planet gears 404, a second set of planet gears 406, a carrier 408 on which the sets of planet gears are mounted, and a ring gear 410. The first set of planet gears 404 meshes with the sun gear 402 and the second set of planet gears 406 meshes with the ring gear 410. The use of a compound planetary gear set in the electrical axis allows the input and output gears of the planetary gear set to have a similar direction of rotation.

[0022] Back to Fig. 2: The carrier member 206 in the first planetary gear set 200 is rotationally coupled to the sun gear member 218 in the second planetary gear set 210. A clutch 222 (e.g., a dog clutch) is also included in the planetary gear set assembly 114. The clutch 222 is configured to rotationally couple the carrier member 220 and the sun gear member 218 such that the carrier member 220 and the sun gear member 218 (which acts as the input of the compound planetary gear set) are locked together to rotate together in a first position (e.g., a higher speed position) to operate the electric axle in a higher speed mode. It should be understood that the ring gear member 212 acts as the output of the planetary gear set 210. Additionally, the clutch 222 is configured to lock the carrier 220 in a second position (e.g., a lower speed position) to operate the electric axle in a lower speed mode.However, in other embodiments, a first clutch may be configured to lock the sun gear 218 to the carrier 220, and a second clutch may be configured to lock the carrier 220.

[0023] As previously mentioned, locking the carrier 220 via clutch 222 enables the electric axle to operate in a lower speed mode, and locking the sun gear 218 with the carrier 220 enables the electric axle to operate in a higher speed mode. In the higher speed mode, the second planetary gear set 210 achieves a gear ratio of 1:1, in a specific example. When the electric axle operates in the higher speed mode, the bearing and winding losses in the second planetary gear set 210 are reduced (e.g., eliminated), thereby increasing the efficiency and service life of the electric axle.

[0024] The use of a compound planetary gear set with a first set of planetary gears and a second set of planetary gears allows the second planetary gear set 210 to maintain a similar direction of rotation with respect to the input and output of the planetary gear set. However, the second planetary gear set may have another suitable arrangement in other embodiments.

[0025] A parking gear 225 may be coupled to the ring gear 212. A parking lock device 227, which in Fig. 2 is shown schematically, can be configured to engage the parking wheel 225.

[0026] In the illustrated example, the carrier 206 is rotationally coupled to the sun gear 218. Furthermore, the ring gear 212 is rotationally coupled to a sun gear 223 of a third planetary gear set 226. The third planetary gear set 226 further includes a carrier 228, planetary gears 230 rotating on the carrier, and a ring gear 232.

[0027] In the illustrated example, the carrier 228 is rotationally coupled to a planetary differential 234 (e.g., a ring gear 236 of the planetary differential 234). The planetary differential 234 is rotationally coupled to the axle shafts 238. The planetary differential 234 may also include a locking device 240 configured to prevent speed differentiation between the axle shafts. A carrier 242 of the planetary differential may be rotationally coupled to one of the axle shafts, and a sun gear 244 may be rotationally coupled to the other axle shaft. The planetary differential 234 also includes planet gears 246 that rotate on the carrier 242. In other embodiments, the differential may also be another suitable type of differential, such as an open differential, a limited-slip differential, and the like.

[0028] The first and third planetary gear sets 200 and 226 are simple planetary gear sets in the example shown. Furthermore, the second planetary gear set 210 is a compound planetary gear set in the example shown. This increases the compactness of the axle while simultaneously achieving the same direction of rotation of the input and output gear sets of the second planetary gear set.

[0029] Fig. 3A shows a mechanical power path 300 in the electric axle 104 in the higher speed mode. In both the higher speed and lower speed modes, the ring gear 212 and the ring gear 232 are locked. Further, in the higher speed mode, the clutch 222 locks the sun gear 218 to the carrier 220. As shown, power flows from the electric motor to the sun gear 202, from the sun gear 202 to the carrier 206 via the planet gears 204, from the carrier 206 to the sun gear 218 and to the carrier 220 via the clutch 222, from the carrier 220 to the ring gear 212 via the first set of planet gears 214 and the second set of planet gears 216 (shown in Fig. 2), from the ring gear 212 to the sun gear 223, from the sun gear 223 to the carrier 228 via the planetary gears 230, and from the carrier 228 to the planetary differential 234 via the ring gear 236. In the planetary differential 234, the torque is split between the carrier 242 and the sun gear 244 when the differential is unlocked.

[0030] Fig. 3B shows a mechanical power path 302 in the electric axle 104 in the lower speed mode. In the lower speed mode, the clutch 222 locks the carrier 220. As shown, power flows from the electric motor to the sun gear 202, from the sun gear 202 through the planet gears 204 to the carrier 206, from the carrier 206 through the clutch 222 to the sun gear 218, from the sun gear 218 through the first set of planet gears 214 and the second set of planet gears 216 (shown in Fig. 2) to the ring gear 212, from the ring gear 212 to the sun gear 223, from the sun gear 223 via the planetary gears 230 to the carrier 228 and from the carrier 228 via the ring gear 236 to the planetary differential 234. In the planetary differential 234, the torque is divided between the carrier 242 and the sun gear 244 when the differential is unlocked.

[0031] The electric axles described here achieve two-speed functionality in a compact package. In lower-speed mode (e.g., in first gear), the electric axle can be used for high-torque off-road maneuvers, for example. Conversely, in higher-speed mode (e.g., in second gear mode), the vehicle can be operated at higher speeds, such as in road traffic. The planetary gearset arrangement achieves high efficiency in higher-speed mode because bearing and meshing losses in the second planetary gearset are reduced, thereby increasing the vehicle's range.

[0032] The multi-speed electric axles described here feature a coaxial arrangement with respect to the electric machine, planetary gear sets, and differential. This coaxial electric axle layout allows the axle to be installed into highly constrained vehicle platforms if desired. The coaxial electric axle architecture also makes it possible to reduce or eliminate excessive flyweight. Furthermore, the coaxial electric axles described here achieve high efficiency in a higher-speed mode suitable for on-road use. Furthermore, the electric axles described here achieve the efficiency of a two-speed reduction in the higher-speed mode while maintaining the torque capacity of a three-speed reduction in a lower-speed mode.

[0033] Fig. Figures 2-4 are drawn approximately to scale, except for the schematically illustrated components. However, in other embodiments, the components may have different relative dimensions.

[0034] Fig.1-4 show example configurations with the relative arrangement of the various components. Note, however, that when these elements are shown in direct contact with one another or directly coupled, they may be referred to as being in direct contact or directly coupled, respectively, in at least one example. Similarly, elements shown side by side or adjacent to one another may be referred to as being side by side or adjacent to one another, in at least one example. For example, components that are in surface contact with one another may be referred to as being in surface contact. As another example, elements that are separated from one another with only a space between them and that do not have any other components may be referred to as such, in at least one instance.In yet another example, elements depicted above / below, on opposite sides, or to the left / right of each other may be referred to as such, relative to each other. Further, in at least one example, as depicted in the figures, a topmost element or point of an element may be referred to as a "top" of the component, and a bottommost element or point of the element may be referred to as a "bottom" of the component. As used herein, the terms top / bottom, upper / lower, above / below may refer to a vertical axis of the figures and may be used to describe the positioning of elements of the figures relative to each other. Thus, in one example, elements displayed above other elements are arranged vertically above the other elements.As another example, the shapes of the elements depicted in the figures may be referred to as such (e.g., circular, straight, flat, curved, rounded, beveled, angled, or the like). Furthermore, in one example, elements that are coaxial with one another may be referred to as such. Further, in at least one example, the depicted elements that intersect one another may be referred to as intersecting elements or as intersecting elements. Furthermore, an element depicted inside another element or outside another element may be referred to as such. In other examples, elements that are offset from one another may also be referred to as such. In yet other examples, elements that are coaxial or parallel to one another may be referred to as such.

[0035] The invention is described in more detail in the following paragraphs. In one aspect, a multi-speed electric axle assembly is provided that includes an electric machine rotationally coupled to a sun gear in a first planetary gear set; a second planetary gear set rotationally coupled to a carrier in the first planetary gear set; a third planetary gear set rotationally coupled to the second planetary gear set; and a differential rotationally coupled to the third planetary gear set; wherein the electric machine, the first planetary gear set, the second planetary gear set, the third planetary gear set, and the differential are coaxially arranged. In one example, the multi-speed electric axle assembly may further include a clutch configured to selectively lock a sun gear and a carrier in the second planetary gear set from rotating in a higher speed position.In one example, the electric multi-speed axle assembly may further include a clutch configured to lock a carrier gear in the second planetary gear set in a lower speed position. In another example, a sun gear in the third planetary gear set may be rotationally coupled to a ring gear in the second planetary gear set. In another example, a carrier gear in the third planetary gear set may be rotationally coupled to a differential. In another example, a ring gear of the first planetary gear set and a ring gear of the third planetary gear set may be locked. In another example, the clutch may be a dog clutch. In another example, the first planetary gear set and the third planetary gear set may be simple planetary gear sets. In another example, the second planetary gear set may be a compound planetary gear set. In another example, the electric multi-speed axle assembly may be an electric solid axle.In another example, the differential may be a planetary differential having a first axle shaft coupled to a sun gear in the planetary differential and a second axle shaft rotationally coupled to a carrier in the planetary differential.

[0036] In another aspect, a multi-speed electric solid axle is provided, comprising a traction motor rotationally coupled to a sun gear in a first planetary gear set; a second planetary gear set rotationally coupled to a carrier in the first planetary gear set; a third planetary gear set rotationally coupled to the second planetary gear set; a differential rotationally coupled to the third planetary gear set; and a clutch configured to shift the second planetary gear set between a lower speed mode and a higher speed mode; wherein the traction motor, the first planetary gear set, the second planetary gear set, the third planetary gear set, and the differential are coaxially arranged.In one example, the clutch may be configured to lock a sun gear member and a carrier member in the second planetary gear set in a higher speed position for rotation in the higher speed mode; and to lock the carrier member in the second planetary gear set in a lower speed position in the lower speed mode. In another example, the second planetary gear set may be a compound planetary gear set. In another example, the first planetary gear set and the third planetary gear set may be simple planetary gear sets. In another example, a ring gear member of the first planetary gear set and a ring gear member of the third planetary gear set may be locked. In another example, a carrier member in the third planetary gear set may be rotationally coupled to a differential. In another example, a sun gear member in the third planetary gear set may be rotationally coupled to a ring gear member in the second planetary gear set.In another example, the differential may be a planetary differential with a first axle shaft coupled to a sun gear in the planetary differential and a second axle shaft rotationally coupled to a carrier in the planetary differential. In another example, the electric multi-speed solid axle may be installed in a fully electric vehicle.

[0037] It should be noted that the example control and estimation routines contained herein can be used with various powertrain, transmission, and / or vehicle system configurations. The control methods and routines disclosed herein can be stored as executable instructions in non-transitory memory and can be performed by the control system including the controller in combination with the various sensors, actuators, and other vehicle hardware. Further, the described actions, operations, and / or functions can graphically represent code to be programmed into the non-transitory memory of the computer-readable storage medium in the vehicle controller, wherein the described actions are performed by executing the instructions in a system including the various hardware components in combination with the electronic controller.One or more of the process steps described here can be omitted if desired.

[0038] Although various embodiments have been described above, they are to be considered as examples and not as limitations. Those skilled in the art will appreciate that the disclosed subject matter may be embodied in other specific forms without departing from the spirit of the subject matter. The embodiments described above are, therefore, to be considered in all respects as illustrative and not restrictive. Thus, these specific examples are not to be understood as limiting, as numerous variations are possible. For example, the technology described above may be applied to powertrains that incorporate various types of power sources, including various types of electric machines and motors (e.g., internal combustion engines).The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations, as well as other features, functions and / or properties disclosed herein.

[0039] The following claims particularly point out certain combinations and subcombinations that are considered novel and non-obvious. These claims may refer to "a" element or "a first" element, or the equivalent thereof. Such claims are to be construed as including the inclusion of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements, and / or properties may be claimed by amending the present claims or by filing new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope than the original claims, are also to be considered included within the subject matter of the present disclosure. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 584,713

[0001]

Claims

[1] Electric multi-speed axle arrangement, comprising: an electric machine rotationally coupled to a sun gear in a first planetary gear set; a second planetary gear set rotationally coupled to a carrier in the first planetary gear set; a third planetary gear set which is rotationally coupled to the second planetary gear set; and a differential that is rotationally coupled to the third planetary gear set; wherein the electric machine, the first planetary gear set, the second planetary gear set, the third planetary gear set and the differential are arranged coaxially. [2] The multi-speed electric axle assembly of claim 1, further comprising a clutch configured to selectively lock a sun gear and a carrier in the second planetary gear set from rotating in a higher speed position. [3] Electric multi-speed axle assembly according to claim 2, wherein a ring gear is fixed in the first planetary gear set and a ring gear is fixed in the third planetary gear set. [4] An electric multi-speed axle assembly according to claim 2 or 3, wherein the clutch is a dog clutch. [5] Electric multi-speed axle arrangement according to one of claims 2 to 4, wherein a sun gear in the third planetary gear set is rotationally coupled to a ring gear in the second planetary gear set. [6] An electric multi-speed axle assembly according to claim 5, wherein a carrier in the third planetary gear set is rotationally coupled to a differential. [7] The multi-speed electric axle assembly of any preceding claim, further comprising a clutch configured to lock the carrier in the second planetary gear set in a lower speed position. [8] Electric multi-speed axle arrangement according to one of the preceding claims, wherein the first planetary gear set and the third planetary gear set are simple planetary gear sets. [9] The multi-speed electric axle assembly of claim 8, wherein the second planetary gear set is a compound planetary gear set. [10] Electric multi-speed axle arrangement according to one of the preceding claims, wherein the electric multi-speed axle arrangement is an electric rigid axle. [11] An electric multi-speed axle assembly according to any one of the preceding claims, wherein the differential is a planetary differential in which a first axle shaft is coupled to a sun gear in the planetary differential and a second axle shaft is rotationally coupled to a carrier in the planetary differential. [12] An electric multi-speed axle assembly according to any one of the preceding claims, wherein the clutch is arranged to: in the higher speed mode, rotationally locking a sun gear and a carrier in the second planetary gear set in a higher speed position; and in lower speed mode, locking the carrier in the second planetary gear set to a lower speed position. [13] Electric multi-speed axle arrangement according to one of the preceding claims, wherein the electric multi-speed rigid axle is included in a fully electric vehicle.

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