Electrically driven transmission within integrated friction clutch and dog clutch on layshaft

Abstract

An electric drive is operable in both a high ratio mode and a low ratio mode. The electric drive axle includes a motor, a layshaft, and a differential assembly. The layshaft includes a clutch integrated gear assembly having a layshaft driven gear and a clutch hub with a friction clutch therebetween. The layshaft rotates with the layshaft driven gear, and rotationally drives a dog clutch assembly. In the low ratio mode, the dog clutch assembly engages a low ratio gear set that ultimately transfers torque to the differential housing. In the high ratio mode, the dog clutch moves into engagement with a high ratio drive gear that drives the differential housing. The friction clutch is engaged for synchronizing speeds to shift from low ratio to high ratio.

Description

ELECTRICALLY DRIVEN TRANSMISSION WITHIN INTEGRATED FRICTIONCLUTCH AND DOG CLUTCH ON LAYSHAFTFIELD

[0001] The present disclosure relates to an electric drive axle for motor vehicles. More particularly, the present disclosure relates to a two-speed electrically driven transmission.BACKGROUND

[0002] This section provides background information related to the present disclosure which is not necessarily prior art.

[0003] In view of the recent commitment of most motor vehicle OEM’s to develop electric vehicles (EV’s), in particular vehicles requiring increased performance, a great deal of engineering activity has been directed to providing driveline arrangements to provide high efficiency with two operating ratios in a compact arrangement. OEM’s and end users are also expecting transitions from low range to high range to occur without stopping the vehicle or significant torque interruption to the driven wheels. Therefore, such shifting systems must incorporate a clutch system that allows synchronization of various geartrain components when a shift occurs. Such a clutch system must smoothly engage these geartrain components without jerking or deacceleration felt in the vehicle. Examples of various two speed electrically driven transmissions are provided in DE102018216322B3, US9303745B2, and US11273701 to indicate the current state of the art. Although these arrangements do provide two operating ratios and often the abilityto transition from a low ratio to a high ratio, improvements may be made in packaging, efficiency, and functionality using the present disclosure.SUMMARY

[0004] This section provides a general summary of the many aspects associated with the inventive concepts embodied in the teachings of the present disclosure and is not intended to be considered a complete listing of its full scope of protection nor all of its features and advantages.

[0005] The present disclosure provides a power transmission with a single layshaft which includes a clutch integrated gear, where a first gear output is provided to a layshaft fixed to the inner portion of a gear body of the clutch integrated gear and a second selectable connection is provided, where a high ratio drive gear is engaged as the friction clutch is connected. The clutch integrated gear arrangement allows a power shift from the low to high ratio in a compact arrangement. The layshaft further includes a selectable dog clutch, which in a first position connects the layshaft to the low ratio drive gear, in a second position provides no torque transfer from the layshaft, and in a third position operates in conjunction with the friction clutch connecting a layshaft to a high ratio drive gear. In the present disclosure a planetary gearset positioned coaxially with the differential will provide the low ratio when engaged and driven. A method of operating the power transmission to allow a non-interrupted torque transfer during a shift from low to high ratio will also be provided.

[0006] It is an object of the present disclosure to provide a new single layshaft arrangement for a two-speed power shifting electrically driven axle which maximizes the available space, provides a power shift from low to high ratios, and utilizes a clutcharrangement which allows an engagement of a dog clutch during normal operation and a frictional clutch to assist in synchronizing component speeds.

[0007] It is an aspect of the present disclosure to provide an electrically driven axle with a coaxial arrangement between the electric motor and differential output, a single layshaft assembly including a clutch integrated gear assembly and a selectable dog clutch utilized to selectively engage a high ratio final drive gearset or a low ratio final drive gearset.

[0008] In one aspect, the electrically driven axle includes a planetary gearset between the low ratio final drive gearset and the differential.

[0009] It is another aspect of the present disclosure to provide a frictional clutch integrated within the gear body of the clutch integrated gear, where a first connection is provided for fixing the layshaft to the inner portion of the gear body, and a second selectable connection is provided where a high ratio drive gear is connected to the layshaft when the clutch is engaged.

[0010] It is an aspect of the present disclosure to provide a layshaft which includes a selectable dog clutch, which in a first position connects the layshaft to the low ratio drive gear, in a second position provides no torque transfer from the layshaft, and in a third position operates in conjunction with the friction clutch and connects the layshaft to a high ratio drive gear.

[0011] It is an aspect of the present disclosure to provide a layshaft including a layshaft shaft, a clutch integrated gear, and a dog clutch, where a first high ratio drive gear directly drives a differential and a low ratio drive gear drives a planetary assembly depending on friction clutch and dog clutch activation.

[0012] In another aspect, the dog clutch, when engaged to the high ratio drive gear, may allow the frictional clutch to be released, still transferring torque from the motor to the differential during high ratio operation.

[0013] In another aspect, the layshaft assembly includes a layshaft, a clutch integrated gear assembly rotationally fixed to the layshaft, and a high ratio drive gear and low ratio drive gear supported by the layshaft via bearings allowing rotation relative to the layshaft shaft.

[0014] It is a related aspect of the present disclosure to include a biasing device to allow the dog clutch to disengage, away from engagement to the low ratio drive gear, during a shift event to ensure disconnection when torque transfer is reduced to near zero.

[0015] It is a related aspect of the present disclosure to provide a high ratio final drive gearset positioned on a first side of the differential between the electric motor and the differential while a low ratio final drive gearset and planetary is positioned on a second side of the differential assembly, resulting in the differential being positioned near center of the electric drive axle.

[0016] In another aspect, a disconnect device may be positioned in the torque flow between the low ratio driven gear and the differential to prevent back driving of at least a portion of the planetary components and the low ratio driven gear to improve efficiency when in operating in high ratio.

[0017] It is another aspect of the present disclosure to provide a method of operating the electrically driven axle to provide a powershift between a low ratio operating mode and a high ratio operating mode

[0018] These and other features and advantages of the present disclosure will become more readily appreciated when considered in connection with the following detailed description and the drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are for illustrative purposes only of selected embodiments and are not intended to limit the scope of the present disclosure. The inventive concepts associated with the present disclosure will be more readily understood by reference to the following description in combination with the accompanying drawings wherein:

[0020] FIG. 1 is a cross sectional view of an electric drive axle of the present disclosure;

[0021] FIG. 2 is a cross sectional view of the layshaft assembly of the electric drive axle; and

[0022] FIG. 3 is a cross sectional view of the planetary and differential gear assembly of the electric drive axle.DETAILED DESCRIPTION

[0023] The present disclosure is directed to an electric drive axle with a power transmission that includes a single layshaft having a clutch integrated gear and a selectable dog clutch, a high ratio final drive gearset, a low ratio final drive gearset, and a differential. The electric drive axle is electrically-controlled for delivering motive power (i.e. , drive torque) to a pair of ground-engaging wheels. An example embodiment of thepower transmitting gear arrangement for use in an electrically drive axle will now be more fully described with reference to the accompanying drawings. Accordingly, various features and functional characteristics of the power transmitting gear arrangement will be set forth below in a manner permitting those skilled in relevant arts to fully comprehend and appreciate the significant advantages the present disclosure provides.

[0024] With initial attention directed to FIG. 1 , a cross section of the electrically driven axle of the present disclosure is provided. Electric drive axle 20 is shown without surrounding housings to focus on the features of the power transmission. An electric variable speed motor assembly 22 is provided and includes a stator 24 secured to said housing. A rotor 26 is fixed for rotation with a hollow rotor shaft 28 such that the rotor 26 and shaft 28 rotate together. Rotor shaft 28 is supported at a first end by rotor support bearing 30 for rotation relative to the surrounding housing. Rotor shaft 28 is supported at a second end by bearing 32 for rotation relative to the surrounding housing.

[0025] An input gear 34 is provided at the second end of the rotor shaft 28. Input gear 34 provides torque to components downstream of the motor 22 in the direction of the torque flow. Input gear 34 may be integrally formed in rotor shaft 28 or a separate gear component fixed to the end of rotor shaft 28. In the coaxial arrangement of the present disclosure, differential assembly 36 and rotor shaft 28 are positioned on a common first axis. A left axle shaft 38A driven by differential assembly 36 provides a first output of differential assembly 36, and passes through the hollow portion of rotor shaft 28 to drive a left ground engaging vehicle wheel. A right axle shaft 38B provides a second output of differential assembly 36 to a right ground engaging vehicle wheel. A single layshaft assembly 40 is located on a second axis, offset from the first axis. Layshaftassembly 40 includes a clutch integrated gear assembly 42, a high ratio drive gear 44, a low ratio drive gear 46, a dog clutch assembly 48, and a layshaft 50. Layshaft assembly 40 is supported on a first end by bearing 52 closest to motor assembly 22 and on a second end by bearing 54. Bearings 52 and 54 allow layshaft assembly 40 to rotate relative to the surrounding housings. Clutch integrated gear assembly 42 includes a layshaft driven gear 56, which is in a fixed connection to layshaft 50 via a splined connection 58. Clutch integrated gear assembly 42 includes layshaft driven gear 56, a friction clutch 60, clutch hub 62, and high ratio drive gear 44. The integration of these components to form clutch integrated gear assembly 42 will be further described in FIG. 2. High ratio drive gear 44 is supported via bearings 64 and 66 on layshaft 50 to allow rotation of the high ratio drive gear 44 relative to layshaft 50. High ratio drive gear 44 may be selectably rotationally connected to the layshaft driven gear 56 via frictional clutch 60 when clutch 60 is engaged, or may be rotationally connected to layshaft 50 when dog clutch assembly 48 is engaged in a direction towards the high ratio drive gear 44. High ratio drive gear 44 is in constant meshed engagement with high ratio driven gear 68, which is rotationally fixed to differential assembly 36. These components will provide the power path from electric motor assembly 22 to axle shafts 38A and 38B when in high ratio.

[0026] When in a low ratio gear operating mode, dog clutch assembly 48 is moved towards and engaged to low ratio drive gear 46, with layshaft 50 being rotationally connected to low ratio drive gear 46 resulting in power to be transferred from layshaft 50. Low ratio drive gear 46 is in constant mesh arrangement with low ratio driven gear 70. Low ratio drive gear 46 is supported via bearing 72 on layshaft 50 to allow rotation of low ratio drive gear 46 relative to layshaft 50. Low ratio driven gear 70 provides an input forplanetary assembly 74. Further details of the arrangement and support of planetary assembly components and power path through planetary assembly 74 will be provided when describing FIG. 3. The output of planetary assembly 74 is connected to differential assembly 36. These components will provide the power path from electric motor assembly 22 to axle shafts 38A and 38B when in low ratio.

[0027] Turning attention to FIG. 2, the layshaft assembly 40 will be further described including the operation of friction clutch 60 and dog clutch assembly 48. Layshaft assembly 40 receives power from input gear 34 via the constant meshed connection of the input gear 34 to the layshaft driven gear 56 of the clutch integrated gear assembly 42. Power provided to clutch integrated gear assembly 42 is continually transferred to layshaft 50 due to the fixed spline connection 58. Friction clutch 60 is utilized during the transition from the low ratio to the high ratio operating conditions. Dog clutch assembly 48 is utilized to selectively transfer power from layshaft 50 to the high ratio drive gear 44 or the low ratio drive gear 46, depending on which ratio the electric drive axle 20 is operating in.

[0028] Clutch integrated gear assembly 42 includes layshaft driven gear 56, which is constructed of a radially extending disc portion 76 having a gear form 78 at the outer diameter and a cylindrical feature 80 with spline connection 58 at the internal diameter. An axially extending portion 82 of the layshaft driven gear 56 extends from disc portion 76 and extends to surround the friction clutch 60 around the outside of the friction clutch 60. A clutch hub 62 is positioned radially inward of the axially extending portion 82 to form a clutch cavity 84 in which the friction clutch 60 is positioned. Clutch cavity 84 axially overlaps at least a portion of the gear form 78 and is disposed within the axial length ofgear form 78 to provide an axially compact arrangement. Friction clutch 60 is made of a plurality of alternating sets of friction discs 60A and steel discs 60B, as is known. As an example, the frictional discs 60A engage with an outer clutch spline 86 formed into the axially extending portion 82. The steel discs 60B engage an inner clutch spline 88 formed into the outer diameter portion of clutch hub 62. The torque transferring characteristic of friction clutch 60 is dependent on the pressure applied by actuation force 90. Actuation force 90 can be provided by various sources including hydraulic pressure, electromechanical, or electromagnetic actuation systems. The source of actuation force 90 may be applied externally to clutch integrated gear assembly 42. Actuation force 90 will transfer through the radially extending disc portion 76 of layshaft driven gear 56 first via an axial thrust bearing 92, then via a plurality of pins 94 positioned in apertures 96 spaced roughly at the central diameter of friction clutch 60. Pins 94 will engage a clutch apply plate 98 which is located directly adjacent to friction clutch 60. As the discs of friction clutch 60 are captured between the clutch apply plate 98 and a radially extending shoulder from clutch hub 62, which has a fixed axial position relative to layshaft driven gear 56, actuation force 90 will result in discs 60A and 60B to become engaged on their faces, transmitting torque between the layshaft driven gear 56 and clutch hub 62 via respective splines 86 and 88. Axial thrust bearing 92 allows for clutch integrated gear assembly 42 to rotate while the actuation system providing actuation force 90 is stationary. High ratio drive gear 44 has a tubular form shape where at a first end a fixed connection 102 is provided to clutch hub 62. The gear form 104 of the high ratio drive gear 44, which is in constant mesh with high ratio driven gear 68, is located in a middle portion of high ratio drive gear 44. At the second end of high ratio drive gear 44, engagement teeth 106, whichallow engagement to dog clutch assembly 48, are provided. As previously described, high ratio drive gear 44 is supported and allowed to freely rotate about layshaft 50 via bearings 64 and 66 located at opposite ends on the inner diameter of high ratio drive gear 44 when not restricted or engaged by either friction clutch 60 or dog clutch assembly 48.

[0029] Continuing to refer to FIG. 2, dog clutch assembly 48 will be further described. Dog clutch assembly 48 will include a hub portion 108 which is connected to layshaft 50 via a fixed connection. Hub 108 will include an outer diameter 110 which mates to sleeve 112, allowing sleeve 112 to move axially relative to the hub 108 on a spline located at outer diameter 110. Engagement teeth 114 are provided on each side of sleeve 112. The sleeve engagement teeth 114 will mate to a similar engagement teeth 106 on high ratio drive gear 44 and the engagement teeth 116 of low ratio drive gear 46 on the surface closest to dog clutch assembly 48. An actuation system (not shown) will provide an axial actuating movement 118 to sleeve 112, where sleeve 112 has three main operating positions. Sleeve 112 moves to the right when low ratio is required, resulting in toothed engagement with low ratio drive gear 46, completing a torque transferring connection from layshaft 50 through dog clutch assembly 48 and then to low ratio drive gear 46. In a similar manner, when sleeve 112 is moved to the left, toothed engagement with high ratio drive gear 44 results in a torque transferring connection between layshaft 50 through dog clutch assembly 48 and then to high ratio drive gear 44. When sleeve 112 is aligned centrally with hub 108, no connection is made with the engagement teeth 106 or 116, resulting in no torque transfer from the layshaft 50 to either high ratio drive gear 44 or low ratio drive gear 46. As will be further described when discussing the operation of a low to high ratio shift, a biasing device such as a spring may be provided to forcesleeve 112 away from the engagement teeth 116 of low ratio drive gear 46 when the axial actuation movement 118 has not been made to position sleeve 112 into engagement with low ratio drive gear 46.

[0030] FIG. 3 provides a focused view of low ratio driven gear 70, planetary assembly 74, and differential assembly 36. Low ratio driven gear 70 receives power from low ratio drive gear 46 when electric drive axle 20 is operating in a low ratio mode. Low ratio driven gear 70 includes an axial extension 118 at its inner portion. This axial extension 118 may be integral or a secondary component fixed to the main body 120 of low ratio driven gear 70. The axial extension 118 is hollow and receives a bearing 124 on an inner diameter 122. Bearing 124 provides support to position low ratio driven gear 70 relative to the transfer shaft 126 and surrounds transfer shaft 126, and allows rotation of low ratio driven gear 70 about the transfer shaft 126. Transfer shaft 126 is supported on a first end by bearing 128 fitted into a housing not shown. The second end of transfer shaft 126 extends towards differential assembly 36. The connection between differential assembly 36 and transfer shaft 126 will be described later. On the outer diameter of axial extension 118, a gear form 130 is provided which functions as the sun gear 132 for planetary assembly 74. Planetary assembly also includes an annulus gear 134, and a plurality of pinion gears 136 positioned in constant meshed engagement with sun gear 132 and annulus gear 134. A planet carrier 138 includes pinion shafts 140 rotatably supporting pinion gears 136. Annulus gear 134 is fixed by a surrounding housing not shown. Carrier 138 is in a fixed connection to the transfer shaft 126 near the first end of transfer shaft 126 via spline 139. Low ratio driven gear 70 and sun gear 132 rotate in afixed relationship as driven by low ratio drive gear 46, resulting in pinion gears 136 driving carrier 138, transfer shaft 126, and differential assembly 36 at a reduced speed.

[0031] Differential gear assembly 36 may be a standard bevel differential known by those in the art. Differential gear assembly 36 is supported by bearings 142 to a surrounding housing. Differential gear assembly 36 receives power either from high ratio driven gear 68 when in high ratio operating mode, or transfer shaft 126 when in low ratio operating mode. Differential housing 144 may be a two piece design, with a first cup shaped portion 144A and a second cover portion 144B. Both portions 144A and 144B are fixed together via welding or other attachment methods to form differential housing 144. Optionally, differential housing 144 may also be a single piece design. When in high ratio operating mode, differential housing 144 receives power from high ratio driven gear 68 via a fixed connection to portion 144A. When in low ratio operating mode, differential housing 144 receives power from transfer shaft 126 via cover portion 144B. A spline 146 or other connection feature may join cover portion 144B with the second end of transfer shaft 126. This results in power being transmitted from either power source (high ratio driven gear 68 or transfer shaft 126), through differential housing 144, and into bevel gear arrangement 148, depending on whether the drive axle 20 is operating in a high or low ratio operating mode. Bevel gear arrangement 148 includes a first side gear 150 fixed via a spline connection 152 to a left axle shaft 38A, a second side gear 154 fixed via a spline connection 156 to a right axle shaft 38B, and at least one set of pinions 158 meshed with side gears 150 and 154. Pinions 158 are rotatably supported on a pinion shaft 160 having its ends located in opposing bores 162 formed in differential housing 144. Power therefore is provided to differential gear assembly 36, through the differential housing 144, into thebevel differential gearset 148, and distributing power between the left and right axle shafts38A and 38B, which drive a pair of ground engaging wheels.

[0032] When electric drive axle 20 is operating in high ratio mode, a portion of the gearsets previously described transmit power from electric motor assembly 22, while another potion of the gearsets are back-driven by the ground engaging wheels. Specifically, when in high mode, the power path is from input gear 34, layshaft driven gear 56, layshaft 50, high ratio drive gear 44 via dog clutch assembly 48, high ratio driven gear 68 and finally into differential assembly 36 to drive the ground engaging wheels via axle shafts 38. While sleeve 112 of dog clutch assembly 48 is connected only to high ratio drive gear 44, the low ratio gearsets including low ratio drive gear 46, low ratio driven gear 70, and planetary assembly 74 will continue to spin, due to being back-driven by the connection of transfer shaft 126 between differential assembly 36 and planetary assembly 74. Because the primary mode for electric drive axle 20 is operating in high ratio, the continual rotation of the low ratio gearset components can result in reduced operating efficiency. Therefore, as an option, a disconnect device 162 may be included into transfer shaft 126 to disconnect the fixed connection between the differential assembly 36 and the planetary assembly 74. Such a disconnect device described in US9845834B2 or similar could be utilized, providing a selectable interruption or engagement. This can accordingly result in an elimination of back driving the low range gearset components, because no connection between layshaft 50 and low ratio drive gear 46 or planetary assembly 74 and differential assembly 36 would be provided, resulting in the low range gearset components being in standstill and eliminating rotational losses when electric drive axle 20 is operating in high ratio mode.

[0033] Referring back to FIG.1 of the overall arrangement of electric drive axle 20, a method of operation to perform a shift from low ratio to high ratio with minimal or no torque interruption felt by the vehicle’s occupants will now be described. In the initial state where electric drive axle 20 is in low ratio, electric motor 20 provides power to input gear 34, driving layshaft driven gear 56, and dog clutch assembly 48 is engaged towards low ratio drive gear 46, thereby resulting in layshaft 50 driving the low ratio drive gear 46. The low ratio drive gear 46, being driven by the layshaft 50 in this state, drives low ratio driven gear 70, planetary assembly 74, and differential assembly 36. If a disconnect 162 is provided, it is in the connected state to transfer the torque from the transfer shaft 126 to the differential housing 144. Therefore, in this state, axle shafts 38A and 38B are driven at a significantly reduced rotational speed than motor assembly 22, with an approximate gear ratio of 30:1.

[0034] A controller 170 using a control algorithm based on vehicle conditions and operator inputs may conduct several operations when a shift from low range to high range is requested. Because high ratio drive gear 44 is always engaged to high ratio driven gear 68 and differential assembly 36, high ratio drive gear 44 and clutch hub 62 will be back driven in the low ratio mode at a speed different than when operating in high ratio. Thus, a synchronization of these and other connected components is required prior to finalizing the shift from low range to high range.

[0035] Friction clutch 60 may be utilized to perform the synchronization of the components as further described. In order to utilize friction clutch 60 most effectively, torque provided by motor assembly 22 in the low ratio mode may be reduced if the torque is above a particular threshold, without resulting in a noticeable reduction in vehiclespeed. To synchronize, controller 170 may request friction clutch 60 to be partially engaged, resulting in deaccelerating the speed and associated inertias of layshaft driven gear 56, input gear 34, rotor shaft 28, and rotor 26 to approximately approach or match the rotational speed of high ratio drive gear 44, which is being rotated along with the rotation of the differential housing 144.

[0036] As the previous components synchronize, controller 170 requests an actuation movement 118 to move sleeve 112 of dog clutch assembly 48, thereby releasing engagement with the low ratio drive gear 46. The disengagement is further assisted when torque through engagement teeth 114 and 116 is reduced, resulting in sleeve 112 being disengaged from low ratio drive gear 46 due to the force provided by the biasing device. At this moment of disengagement, friction clutch 60 provides the sole torque connection between layshaft driven gear 56 and high ratio drive gear 44, transmitting power from electric motor assembly 22 finally to differential assembly 26. Layshaft 50 and high ratio drive gear 44 will be matched in speeds.

[0037] Controller 170 may then request further actuation movement 118 to move sleeve 112 of dog clutch assembly 48 towards high ratio drive gear 44, resulting in engagement between teeth 106 and 114. At this point during the shift, both the friction clutch 60 and dog clutch assembly 48 will share the transferring of torque in high ratio, with torque passing through clutch hub 62 to the high ratio drive gear 44, and torque also passing through sleeve 112 to the high ratio drive gear 44. Shortly after, controller 170 may then request the friction clutch 60 to be fully released, thereby resulting in dog clutch assembly 48 transmitting all torque from electric motor assembly 22 to differential assembly 36 in high ratio via the sleeve 112. Additionally, optional disconnect 162 mayalso be actuated by controller 170 at this time, interrupting the connection of transfer shaft 126 and differential housing 144B resulting in planetary assembly 74, low ratio driven gear 70, and low ratio drive gear 46 being in standstill for further efficiency improvements.

[0038] To return to a low ratio operating mode, assuming disconnect 162 has reengaged, and because no significant synchronization capability exists within dog clutch assembly 48, the rotational speed of motor assembly 22 may be reduced while friction clutch 60 is partially released by controller 170, allowing high ratio drive gear 44, sleeve 112, and layshaft 50 to reduce speed. This reduced speed will allow sleeve 112 to move into engagement with low ratio drive gear 46 when speeds are matched. The low ratio drive gear 46, which will become engaged with the sleeve 112, will be rotating via the rotational of the planetary gear assembly 74 when the disconnect 162 is in the connected state. Because a high to low ratio shift is not the primary operating condition, such a perceived interrupt in torque to the drive is acceptable.

[0039] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varies in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of disclosure.

Claims

CLAIMSWhat is claimed is:1 . An electric drive module for transferring torque to wheels of a motor vehicle, comprising: an electric motor including a rotatable rotor; an input gear rotationally fixed with the rotor and driven by the rotor; a clutch integrated gear assembly in constant meshed engagement with said input gear driving a layshaft; a layshaft driven by the clutch integrated gear assembly; a high ratio gearset; a low ratio gearset including a planetary gear assembly; a friction clutch of the clutch integrated gear assembly; wherein the friction clutch provides synchronization between the high ratio gearset and the low ratio gearset for shifting from a low ratio operating mode to a high ratio operating mode; a selectable clutch that moves between engagement with the low ratio gearset and the high ratio gearset, wherein the selectable clutch is rotationally fixed with the layshaft and rotates with the layshaft such that the layshaft selectively transfer torque to the low ratio gearset or the high ratio gearset; a differential assembly having an input driven by either the high ratio gearset or low ratio gearset depending on the position of the selectable clutch where a first differential output drives a first axle shaft, and a second differential output drives a second axle shaft.

2. The electric drive module of claim 1 , wherein the selectable clutch is a dog clutch assembly.

3. The electric drive module of claim 2, wherein the dog clutch assembly includes a hub and a sleeve, wherein the hub is rotationally fixed to the layshaft, and the sleeve is rotationally fixed to the hub, wherein the sleeve selectively engages with the high ratio gearset and the low ratio gearset.

4. The electric drive module of claim 3, wherein the sleeve is biased away from engagement with the low ratio gearset and toward engagement with the high ratio gearset.

5. The electric drive module of claim 1 , wherein the clutch integrated gear assembly includes a layshaft driven gear, a clutch hub, and the friction clutch having plurality of clutch plates fixed to the layshaft driven gear or the clutch hub, wherein the layshaft driven gear is constant meshed engagement with the input gear that is driven by the rotor, wherein the clutch hub is fixed for rotation with the high ratio gearset.

6. The electric drive module of claim 5, wherein the friction clutch is controllable to transfer torque via the friction clutch, from the layshaft driven gear to the friction clutch to the clutch hub, wherein the clutch hub transfers torque directly to the high ratio gearset.

7. The electric drive module of claim 6, wherein the high ratio gearset includes a high ratio driven gear fixed for rotation with a differential housing of the differential assembly and a high ratio drive gear fixed for rotation with the clutch hub.

8. The electric drive module of claim 8, wherein the low ratio gearset includes a low ratio driven gear in constant meshed engagement with the planetary gear assembly, wherein the planetary gear assembly is rotationally fixed to a transfer shaft, wherein the transfer shaft transfers torque to the differential housing.

9. The electric drive module of claim 8, wherein the selectable clutch is moveable between engagement with the low ratio drive gear and the high ratio drive gear.

10. The electric drive axle of claim 9, wherein when the selectable clutch is engaged with the low ratio drive gear, torque transfers from the layshaft to the low ratio drive gear via the selectable clutch, wherein the torque is transmitted to the transfer shaft via the planetary gearset.

11. The electric drive axle of claim 10 further comprising a disconnect disposed on the transfer shaft, wherein the disconnect selectively disconnects the transfer shaft from the differential housing such that torque is not transferred therebetween.

12. The electric drive axle of claim 10, wherein when the selectable clutch is engaged with the high ratio drive gear, torque transfers from the layshaft to the high ratio drive gear via the selectable clutch, wherein the torque is transmitted to the differential housing via the high ratio driven gear.

13. The electric drive axle of claim 12, wherein when the selectable clutch is engaged with the high ratio drive gear and the friction clutch is connected, both the layshaft driven gear and the selectable clutch provide torque to the high ratio drive gear.

14. The electric drive axle of claim 12, wherein when the selectable clutch is disengaged with the high ratio drive gear and the friction clutch is connected, torque transfers between layshaft driven gear and the high ratio drive gear for synchronizing the high ratio drive gear with the low ratio drive gear.

15. The electric drive axle of claim 10 further comprising a controller, wherein the controller controls the motor, the friction clutch, and the selectable clutch.

16. The electric drive axle of claim 15, wherein the controller causes an actuation movement of the selectable clutch away from engagement with the low ratio drive gear, wherein the controller causes a connection of the friction clutch and a reduction in speed of the layshaft, the controller causes a further actuation movement of the selectable clutch into engagement with the high ratio drive gear, and the controller causes a disconnection of the friction clutch.

17. A method of operating an electric drive axle, the method comprising: providing power from an electric motor to an input gear fixed to a rotor of the electric motor; driving an layshaft driven gear that is constant meshed engagement with the input gear, and driving a layshaft fixed to the layshaft driven gear; driving a dog clutch assembly, wherein the dog clutch assembly is rotationally fixed with the layshaft and axially translatable between an engaged position with a low ratio gear seat and an engaged position with a high ratio gear set to controllably switch from a low ratio mode to a high ratio mode of the electric drive axle; in a low ratio mode: engaging the dog clutch assembly with a low ratio drive gear of the low ratio gear set and driving a low ratio driven gear and planetary gear assembly via rotation of the layshaft, dog clutch assembly, and low ratio drive gear; transferring torque from the planetary gear assembly to a transfer shaft and from the transfer shaft to a differential housing of a differential assembly, and driving a pair of axle shafts connected to the differential assembly;in a high ratio mode: engaging the dog clutch assembly with a high ratio drive gear of the high ratio gear set, and driving a high ratio driven gear via rotation of the layshaft, the dog clutch assembly, and high ratio drive gear assembly; transferring torque from the high ratio driven gear to the differential housing, wherein the differential housing is fixed for rotation with the high ratio driven gear.

18. The method claim 17, further comprising, shifting from the low ratio mode to the high ratio mode, synchronizing a rotational speed of the high ratio drive gear with the low ratio drive gear and the dog clutch assembly; partially engaging a friction clutch of a clutch integrated gear assembly, wherein the clutch integrated gear assembly includes the layshaft driven gear and a clutch hub, wherein the friction clutch is disposed between the layshaft driven gear and the clutch hub, and the clutch hub is fixed for rotation with the high ratio drive gear; reducing a rotational speed of layshaft driven gear to match a rotational speed of the high ratio drive gear, wherein the high ratio drive is always fixed for rotation with the differential housing and rotates therewith; in response to synchronizing, controlling the dog clutch and moving the dog clutch out of engagement with the low ratio drive gear; further controlling and moving the dog clutch into engagement with the high ratio drive gear.

19. The method of claim 18, further comprising transferring torque to the high ratio drive gear via the friction clutch and the dog clutch at the same time when the dog clutch engages with the high ratio drive gear and the friction clutch is engaged.

20. The method of claim 19, releasing the friction clutch and transferring torque to the high ratio drive gear via the dog clutch and without the friction clutch, and controlling a disconnect mechanism disposed on the transfer shaft between the transfer shaft and the differential housing, and disconnecting the transfer shaft from the differential housing such that torque does not transfer from the differential housing to the planetary gear assembly while operating in the high ratio mode.

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