ELECTRIC DRIVE SYSTEM

Abstract

The product comprises a differential unit (16) engaging with first and second axle shafts driven by a common gear (21), an electric machine (30) positioned on one side of the differential unit (16), and a first shaft (34, 38) extending away from the electric machine (30) and into the differential unit (16), as well as a power transmission unit (32) positioned on a second side of the differential unit (16) opposite the first side, with a second shaft (64) extending into the differential unit (16) and the power transmission unit (32), respectively, wherein the first and second shafts (34, 38;64) are rotationally engageable by the power transmission unit (32), characterized in that the power transmission unit (32) comprises a first gear set (49) with a first gear (44) extending around the second shaft (64) and rotatable relative to the second shaft (64), and a second gear (42) which is rotationally engaged with the first gear (44) and is fixed to the first shaft (34, 38), further comprising a second gear set with a third gear (48) which is rotationally fixed to the first gear (44), a fourth gear (55) which is rotationally fixed, and at least a fifth gear (50, 51) which is rotationally engaged between the third and the fourth gear (48, 55).

Description

TECHNICAL AREA

[0001] The area to which the disclosure generally relates includes vehicle propulsion systems, and in particular vehicle propulsion systems with an electric motor input. BACKGROUND

[0002] Vehicle propulsion systems can include an internal combustion engine, an electric motor, or another type of engine for propulsion. Hybrid vehicles can include a combination of different types of engines.

[0003] US Patent 2005 / 0272547A1 describes a drive axle assembly for a hybrid vehicle, wherein the assembly comprises a differential unit, a power transmission unit, and an electric machine. The power transmission unit and the electric machine are arranged on opposite sides of the differential unit. The shafts connecting the power transmission unit or electric machine on the one hand and the differential unit on the other are connected to each other via a planetary gear set.

[0004] US Patent 3,645,153 A describes a differential for vehicles with a first and a second shaft that can be engaged via gears to transmit a predetermined torque to the differential. One gear is driven by an internal combustion engine.

[0005] DE 10 2011 007 268 A1 describes a drive device in which a differential unit is driven by an electric machine via an engagement clutch and a planetary gear. Summary of embodiments

[0006] The present invention relates to a product comprising a differential unit that engages with first and second axle shafts driven by a common gear. An electric motor is positioned on a first side of the differential unit. A first shaft extends from the electric motor into the differential unit. A power transmission unit is positioned on a second side of the differential unit opposite the first side. A second shaft extends into both the differential unit and the power transmission unit. The first and second shafts can be rotated into engagement by the power transmission unit. The power transmission unit comprises a first gear set, which includes a first gear arranged around the second shaft and rotatable relative to the second shaft.A second gear meshes rotationally with the first gear and is fixed to the first shaft. The product comprises a second gear set, which includes a third gear that is fixed to the first gear. A fourth gear is fixed to prevent rotation. At least a fifth gear meshes rotationally between the third and fourth gears.

[0007] The present invention further relates to a product comprising a differential unit that engages with at least one axle shaft. A road wheel is connected to the at least one axle shaft. A first gear engages with the at least one axle shaft in a drive-oriented manner. A second shaft defines an axis about which the second shaft is rotatable. The second shaft is connected to the first gear. A second gear is provided through which the second shaft extends. The second gear is rotatable relative to the second shaft. An electric motor engages with the second gear in a drive-oriented manner. The first and second gears both rotate about the axis. A third gear extends around the second shaft. The third gear is rotatable relative to the second shaft. A fourth gear is fixed against rotation and extends around the third gear.At least one fifth gear is rotationally engaged between the third and fourth gears.

[0008] The present invention further relates to a product comprising a differential that engages with first and second axle shafts, both of which are driven by a first gear. A first shaft is fixed to the first gear in a rotationally fixed manner. An electric machine has a rotor. A second gear is fixed to the rotor in a rotationally fixed manner. A third gear engages with the second gear. The third gear is fixed to a fourth gear in a rotationally fixed manner. The fourth gear can be selectively engaged with the shaft by means of an engagement clutch. A fifth gear engages with the fourth gear in a toothed manner and is supported on a carrier. The carrier is rotatable and engages selectively with the shaft by means of the engagement clutch.

[0009] Further embodiments for illustrative purposes, which fall within the scope of the invention, will become clear from the detailed description given herein. It should be clear that the detailed description and the specific examples, even if they disclose variations within the scope of the invention, serve purely for illustrative purposes and are not intended to limit the scope of the invention in any way. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Selected examples of modifications within the scope of the invention will become clear from the detailed description and the accompanying drawings, in which: Fig. 1 is a schematic illustration of a product and shows part of a vehicle powertrain according to a series of variations. Fig. Figure 2 is a fragmentary cross-sectional view of a product and shows part of a vehicle powertrain according to a number of variations. Fig. Figure 3 is a schematic illustration of part of a product and shows part of an engagement coupling after a series of variations. Fig. Figure 4 is a schematic illustration of part of a product and shows part of an engagement coupling after a series of variations. DETAILED DESCRIPTION OF EXAMPLES OF EXECUTION

[0011] The following description of exemplary embodiments is purely for illustrative purposes and is in no way intended to limit the scope of the invention, its application or its possible uses.

[0012] In a number of variations, a product can be 7, as in Fig. Figure 1 illustrates road wheels 3 and 4, which can be connected to an axle assembly 5. The axle assembly 5 can include inner joints 6 and 8, which can be constant velocity joints that transmit rotation and allow angular variation between the connected components, as is known in the art. Joint 6 can connect an axle shaft 9 to an axle shaft 10. Joint 8 can connect an axle shaft 11 to an axle shaft 12. Axle shafts 10 and 12 can each be connected to outer joints 14 and 15, which can be constant velocity joints and each be connected to road wheels 3 and 4, either directly or by means of another axle shaft element.

[0013] In a number of variations, the axle assembly 5 can include a differential unit 16. The differential unit 16 can comprise a cage 17 and can have a pinion shaft 18 that can engage with the cage 17 at either of its ends. The cage 17 can be rotatable and supported by bearings 19 and 20. A gear 21 can engage with the cage 17 to rotate with it. The gear 21 can be a ring gear, a bevel gear, or a spiral bevel gear. The pinion shaft 18 can carry a drive gear 22 and a drive gear 23, each of which can be rotatable on the pinion shaft 18. A lateral gear 24 can mesh with each of the drive gears 22 and 23, and another lateral gear 25 can mesh with each of the drive gears 22 and 23.The rotation of the cage 17 can cause the gears 22, 23 to rotate, which can cause the side gears 24, 25 to rotate.

[0014] In several variations, the axle shaft 9 can have one end that engages with the side gear 24 for rotation, and its opposite end can engage with the inner joint 6. The axle shaft 11 can have one end that engages with the side gear 25 for rotation, and its opposite end can engage with the inner joint 8. The rotation of the gear 21 can cause the cage 17 to rotate, and through the bevel gears 122, 123 and the side gears 124, 126, can cause the axle shafts 109 and 111 to rotate, thereby driving the road wheels 3, 4.

[0015] In a number of variations, an electric machine 30 can be connected to the shaft assembly 5 by a power transmission unit 32. The electric machine 30 can be a motor, a motor / generator, or another type of electric machine to supply power to the power transmission unit 32. A shaft 34, which can be a rotor shaft and can be part of the rotor, can extend from the electric machine 30 and can be supported by bearings 36. The shaft 34 can engage with the proximal end of a shaft 38, or it can extend beyond the shaft assembly 5 (without being directly connected to it) and can have a distal end that is supported for rotation by bearings 40. A gear 42, which can be a helical gear, can be fixed to the shaft 34 or 38 for rotation and can be arranged in the power transmission unit 32.

[0016] In a number of variations, the gear 42 can mesh with a gear 44, which may also be contained in the power transmission unit 32, and engage with it in a positive-locking manner. The gear 44 can be a helical gear and can have a larger diameter than the gear 42 to provide a reduction ratio between them of the shaft 34 or 38. The gear 44 can be connected to a torque-transmitting element 46, which may have a tubular shape and may be connected to or mesh with a gear 48, and engage with it in a positive-locking manner to rotate with it. The gear 48 can be a sun gear in a gear set 49, which may be a planetary gear set. The gear 48 can mesh with gears 50 and 51 and may engage with them in a positive-locking manner to rotate with them.The gears 50 and 51 can be planet gears; a different number of them can also be provided. The gears 50 and 51 can each rotate on journals 52 and 53, which can be fixed to a carrier 54. The gears 50 and 51 can mesh with a gear 55, which can be a ring gear or a ring gear and can include internal teeth, and can engage with it in a positive-locking manner to rotate. The gear 55 can be held or locked so that it is secured against rotation. The rotation of the gear 48 can cause the gears 50 and 51 to rotate and move around the inside of the gear 55, which can cause the carrier 54 to rotate. The torque-transmitting element 46, or the gear 48, can be connected to or formed together with a torque-transmitting element 57.The torque-transmitting element 46, the gear 48, and the torque-transmitting element 57 can rotate with the gear 44. The support 54 can be connected to or formed together with a torque-transmitting element 58 and can rotate with it. An additional torque-transmitting element 59 can be connected to the torque-transmitting element 58 and can be mounted by bearings for rotation about a shaft 64.

[0017] In a number of variations, an engagement coupling 60 can include an engagement element 62, which may be fixed to rotate with the shaft 64 and may be axially displaceable on the shaft 64. The shaft 64 may be supported for rotation by bearings 65, 67 and may extend through the torque-transmitting element 46. A gear 68 may be fixed to the shaft 64 to rotate with it and may be toothed with the gear 21 and may engage positively with it to rotate in order to drive or be driven by the axle assembly 5. The gear 68 may be a bevel gear and may be a right-hand spiral bevel gear. The gear 68 may be a common gear that drives both axle shafts 9 and 11. The engagement element 62 can selectively disengage the driven gear set 49 from the shaft 64, as in Fig. 1 shown, and can be moved into a centered neutral position. The engagement element 62 can, as shown in Fig. As can be seen in Figure 1, a shift fork 63 can be selectively switched to the right to selectively connect the gear set 49 to the shaft 64 with output from the gear 48 and the torque-transmitting element 57 connected to it, in order to provide a high-range operating mode. The engagement element 62 can, as shown in Figure 1, be selectively switched to the right by a shift fork 63 to selectively connect the gear set 49 to the shaft 64 with output from the gear 48 and the torque-transmitting element 57 connected to it, in order to provide a high-range operating mode. The engagement element 62 can be, as shown in Figure 1, selectively switched to the right by a shift fork 63 to selectively connect the gear set 49 to the shaft 64 with output from the gear 48 and the torque-transmitting element 57 connected to it, in a high-range operating mode. Fig. As can be seen in Figure 1, the shift fork 63 can be selectively shifted to the left to selectively connect the gear set 49 to the shaft 64 with output from the carrier 54 and the torque-transmitting elements 58, 59 connected to it, in order to provide a low-range operating mode. If an input from the gear 48 can be supplied to the shaft 64, the rotational speed of the torque-transmitting element 46 can be maintained. If an input from the carrier 54 can be supplied to the shaft 64, the rotational speed of the torque-transmitting element 46 can be reduced and the torque increased.

[0018] With reference to Fig. 2. Elements will be added there, which are elements in Fig. 1. Similar to the above, the product 69 is designated with the same reference numerals. In a number of variations, a product 69 can comprise the electric machine 30, which can supply torque to the axle shafts 9 and 11, or receive torque from the axle shafts 9 and 11, for example, for regenerative braking. The electric machine 30 can comprise a shaft 34, which can extend through the housing assembly 61 to the gear 42, which can mesh with the gear 44. The gear 44 can be connected to the torque-transmitting element 46, which can have an end 75 that can be positioned inside the gear 48 and fixed to it in a rotationally fixed manner by means of a keyed connection. The gear 48 can be connected to the torque-transmitting element 57, which can extend to a position adjacent to the engagement clutch 60.On one side of the engagement coupling 60, opposite the torque-transmitting element 57, the torque-transmitting element 59 can be connected to the support 54 and fixed to it in a rotationally fixed manner, which can be achieved by an intermediate torque-transmitting element 58. The torque-transmitting element 58 can be connected to the torque-transmitting element 59 and can include an end 76 that can extend over the support 54 and engage with it. The support 54 can carry the gears 50 and 51. The gears 50 and 51 can be rotationally engaged between the gear 55 and the gear 48. The engagement element 62 can be connected to the shaft 64, for example, by an axially movable keyed connection, so that the engagement element 62 and the shaft 64 can rotate together. The shaft 64 can be connected to the gear 68, which can engage with the gear 21 to rotate with it.The gear 21 can be fixed to the cage 17, the rotation of which can transmit a rotation to the drive gears 22 and 23. The drive gear 23, which is shown in the sectional view in . Fig. The gear 21, cage 17, drive gears 22, 23, and side gears 24, 25, which can be fixed to axle shafts 9, 11, can rotate on the pinion shaft 18. In several variations, gear 21, cage 17, drive gears 22, 23, and side gears 24, 26 can be assembled in a differential unit 78. Gears 42, 44, gear set 49, and engagement clutch 60 can be assembled in the power transmission unit 32, which can be positioned on one side 77 of the differential unit 78. The reduction gear assembly of gear set 42, 44 within the power transmission unit 32 can be easily lubricated by oil in the power transmission unit 32 if the gear interface is created at one position. The electric machine 30 can be positioned on one side 79 of the differential unit 78 opposite side 77.The motor shaft 34 and the shaft 64 can be parallel to each other, and each can extend into the differential unit 78. The gear 21 can generate spray oil for lubrication and cooling of the electric machine 30 using oil from inside the differential unit 78. The gear 44 and the gear 68 can rotate about a common axis 80, which can simplify the arrangement. Separating the electric machine 30 and the power transmission unit 32 on opposite sides of the differential unit 78 can provide advantageous packing options.

[0019] In a number of variations, the engagement clutch 60 can include the engagement element 62, which may be the hub of a synchronous clutch or synchronizer of the double-cone type. An annular groove 70 can be provided around the outer circumference of the engagement element 62, in which the shift fork 63 can be received. Range selection can be effected by an actuator (not shown) that can move the shift fork 62 to move the engagement element 62 axially on the shaft 64. The engagement clutch can include reaction rings 71 and 72, which can be fixed to the respective torque-transmitting elements 57 and 59. A locking ring 73 can be positioned between the reaction ring 71 and the engagement element 62, and a locking ring 74 can be positioned between the reaction ring 72 and the engagement element 62. Friction material can be carried between the corresponding mating surfaces of the locking rings and reaction rings.The shift fork 63 can, as in . Fig. 3, can be moved to the left to transmit the torque between the engagement element 62 and the torque-transmitting element 59 through the locking ring 71 and the reaction ring 73. The shift fork can center the engagement element 62 for neutral mode, as shown in Fig. 1 shown. The shift fork 63 can, as in Fig. 4, can be seen, moved to the right to transmit the torque between the engagement element 62 and the torque-transmitting element 57 through the locking ring 72 and the reaction ring 74. With reference to Fig. 1, Fig. 2 to Fig. 3. The rotational engagement of the locking ring 71 with the reaction ring 73 can transmit torque between the carrier 54 (via the torque-transmitting elements 58, 59) and the engagement element 62 by moving the shift fork 63, which displaces the engagement element 62 towards the reaction ring 73. This can provide a mode in which the shaft 64 can be driven by the carrier 54. Providing an output from the gear set 49 on the carrier 54 with the gear 55 fixed can provide a low-range mode in a first gear ratio. The rotational engagement of the locking ring 72 with the reaction ring 74 by moving the shift fork 63, which displaces the engagement element 62 towards the reaction ring 74, can transmit torque between the gear 48 (via the torque-transmitting element 57) and the engagement element 62.This can provide a mode in which shaft 64 can be driven by gear 48, which can be a sun gear. Providing an output from gear set 49 to gear 48 can provide a high-range mode with a second gear ratio, which delivers a higher speed transmission than the low-range mode. As shown in... Fig. As shown in Figure 1, the shift fork 63 can center the engagement element 62 between the reaction rings 73, 74, so that no torque can be transmitted through the engagement clutch 60.

[0020] The axle assembly 5 can be the rear axle of a vehicle that has a front axle driven by an internal combustion engine or a transaxle module, and can provide a hybrid powertrain. For efficient power input or output, the electric machine 30 can be driven by the axle assembly 5, or it can drive the axle assembly 5 without passing through the engine. To recover braking energy from the road wheels 3, 4, the engagement clutch 60 can be engaged so that the electric machine 30 can be driven by the axle assembly 5. In a number of variations, the axle 5 can be driven by the electric machine 30 in an electric all-wheel drive mode.Energy recovery can be maximized by using the electric machine 30 on the rear axle, while simultaneously providing control with improved stability by controlling the torque at each axle assembly of an associated vehicle. A method for controlling vehicle dynamics can be provided by allocating regenerative torque to the axle assembly 5 via the electric machine 30. A method for controlling vehicle dynamics can be provided by allocating propulsive torque to the axle assembly 5 via the electric machine 30. By using the electric machine 30 on the rear axle 5, electric drive assistance can increase gradient performance and can provide electric starting assistance or a creep mode for low-speed maneuvers.

[0021] The following description of exemplary embodiments serves solely to illustrate components, elements, actions, products, and processes that are considered to fall within the scope of the invention and is in no way intended to limit the scope by what is disclosed in detail or not expressly stated. The components, elements, actions, products, and processes described herein may be combined and rearranged in ways other than expressly described herein and will nevertheless be considered to fall within the scope of the invention.

[0022] In one embodiment of the product, an axis can extend through the second shaft, around which the second shaft can rotate. The common gear and the first gear can both rotate around the axis.

[0023] In another embodiment of the product, the first and second gears can be helical gears. The first gear can be larger than the second gear and can provide a reduced rotational speed from the first shaft to the second shaft.

[0024] In another embodiment of the product, the second shaft can be driven by the third gear.

[0025] In another embodiment of the product, the third gear can be selectively engaged with the second shaft by means of an engagement clutch.

[0026] In another embodiment of the product, at least one fifth gear can be supported by a carrier.

[0027] In another embodiment of the product, the second shaft can be driven by the carrier.

[0028] In another embodiment of the product, the carrier can be selectively engaged with the second shaft by means of an engagement coupling.

[0029] In another embodiment of the product, the second shaft can be selectively driven by the third gear. The third gear can be selectively engaged with the second shaft by means of an engagement clutch.

[0030] In a further embodiment of the product, at least one fifth gear can be supported by a carrier. The second shaft can be selectively driven by the carrier. The carrier can be selectively engaged with the second shaft by means of the engagement clutch.

[0031] In another embodiment of the product, the product can include a hybrid all-wheel drive mode in which the axle shaft can be part of a rear axle, and the electric machine can drive the rear axle.

[0032] In another embodiment of the product, the electric machine can operate as a motor that provides traction torque to the axle shaft, and as a generator that provides braking torque to the axle shaft.

[0033] In another embodiment of the product, the traction or braking torque can be assigned to the axle shaft.

[0034] In another embodiment of the product, the engagement clutch can be selectively engaged to allocate the traction or braking torque.

[0035] In another embodiment of the product, the product can include a hybrid all-wheel drive mode in which the axle shaft can be part of a rear axle, and the electric machine can drive the rear axle.

Claims

[1] Product comprising a differential unit (16) engaging with first and second axle shafts driven by a common gear (21), an electric machine (30) positioned on one side of the differential unit (16), and a first shaft (34, 38) extending away from the electric machine (30) and into the differential unit (16), as well as a power transmission unit (32) positioned on a second side of the differential unit (16) opposite the first side, with a second shaft (64) extending into the differential unit (16) and the power transmission unit (32), respectively, wherein the first and second shafts (34, 38; 64) can be rotationally engaged by the power transmission unit (32), characterized by, that the power transmission unit (32) comprises a first gear set (49) with a first gear (44) extending around the second shaft (64) and rotatable relative to the second shaft (64), and a second gear (42) rotatingly meshed with the first gear (44) and fixed to the first shaft (34, 38), further comprising a second gear set with a third gear (48) fixed non-rotatably to the first gear (44), a fourth gear (55) fixed non-rotatably, and at least a fifth gear (50, 51) rotatingly meshed between the third and fourth gears (48, 55). [2] Product according to claim 1, further comprising an axis (80) extending through the second shaft (64) and about which the second shaft (64) rotates, wherein the common gear (21) and the first gear (44) both rotate about the axis (80). [3] The product according to claim 1, wherein the first and second gear (44, 42) are helical gears and the first gear (44) is larger than the second gear (42), thereby providing a reduced rotational speed from the first shaft (34, 38) to the second shaft (64). [4] Product according to claim 1, wherein the second shaft (64) can be driven by the third gear (48). [5] Product according to claim 4, wherein the third gear (48) can be selectively engaged with the second shaft (64) by means of an engagement clutch (60). [6] Product according to claim 1, wherein the at least one fifth gear (50, 51) is supported by a carrier (54). [7] Product according to claim 6, wherein the second shaft (64) can be driven by the carrier (54). [8] Product according to claim 7, wherein the carrier (54) can be selectively engaged with the second shaft (64) by means of an engagement coupling (60). [9] Product comprising a differential unit (16) engaging with at least one axle shaft, a road wheel (3, 4) connected to the at least one axle shaft, a first gear (68) engaging with the at least one axle shaft in a drive-related manner, a second shaft (64) defining an axis (80) about which the second shaft (64) is rotatable, the second shaft (64) being fixedly connected to the first gear (68), a second gear (44) through which the second shaft (64) extends, the second gear (44) being rotatable relative to the second shaft (64), and a machine (30) engaging with the second gear (44) in a drive-related manner, the first and second gears (68, 44) both rotating about the axis (80), characterized by, that the machine (30) is an electric machine (30), further comprising a third gear (48) extending around the second shaft (64), wherein the third gear (48) is rotatable relative to the second shaft (64), a fourth gear (55) fixed in a rotationally fixed position and extending around the third gear (48), and at least a fifth gear (50, 51) which is rotationally engaged between the third and the fourth gear (48, 55). [10] Product according to claim 9, wherein the second shaft (64) is selectively driven by the third gear (48), wherein the third gear (48) can be selectively engaged with the second shaft (64) by means of an engagement clutch (60). [11] Product according to claim 10, wherein the at least one fifth gear (50, 51) is supported by a carrier (54), wherein the second shaft (64) is selectively driven by the carrier (54), and wherein the carrier (54) can be selectively engaged with the second shaft (64) by the engagement clutch (60). [12] Product according to claim 9, further comprising a hybrid all-wheel drive mode, wherein the axle shaft is part of a rear axle and the electric machine (30) drives the rear axle. [13] Product according to claim 9, wherein the electric machine (30) operates as a motor that delivers a traction torque to the axle shaft and as a generator that delivers a braking torque to the axle shaft. [14] Product according to claim 13, wherein the traction or braking torque is allocated to the axle shaft. [15] Product according to claim 14, wherein the engagement clutch (60) is selectively engaged to allocate the traction or braking torque. [16] Product according to claim 13, further comprising a hybrid all-wheel drive mode, wherein the axle shaft is part of a rear axle and the electric machine (30) drives the rear axle. [17] Product comprising a differential (16) engaging with first and second axle shafts, both driven by a first gear (68), a first shaft (64) fixed non-rotatably to the first gear (68), an electric machine (30) with a rotor, a second gear (42) fixed non-rotatably to the rotor, a third gear (44) in meshing engagement with the second gear (42), and a fourth gear (48) fixed non-rotatably to the third gear (44), wherein the fourth gear (48) is selectively engaged with the first shaft (64) by means of an engagement clutch (60), a fifth gear (50, 51) in meshing engagement with the fourth gear (48) and supported on a carrier (54), wherein the carrier (54) is rotatable and selectively engaged with the first shaft (64) by means of the engagement clutch (60) becomes.

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