Nested twin clutch

Abstract

A drive unit for use in a vehicle includes a gear box cavity within a gear box housing, an output gear, a left output shaft spaced axially apart from a right output shaft, and a left control bearing axially spaced apart from a right control bearing. The output gear is rotationally fixed to the clutch drum assembly. The output gear and the clutch drum assembly are axially and radially supported within the gear box cavity by left and right control bearings, which in turn are supported by the gear box housing. The drive unit also includes a twin clutch comprising a clutch drum assembly housing a clutch pack. The clutch outer diameter is smaller than the outer diameter of the control bearings.

Description

NESTED TWIN CLUTCHCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application 63 / 715,307, filed on November 1, 2024, the disclosure of which is hereby incorporated by reference in its entirety.FIELD OF THE INVENTION

[0002] The present invention relates to a nested twin clutch for a drive unit of a transmission for an all-wheel drive vehicle. More specifically, the present invention relates to a nested twin clutch for a rear drive unit which is spaced radially inward of a set of drive gear control bearings.DESCRIPTION OF RELATED ART

[0003] All-wheel drive (AWD) vehicles may be primarily driven by a front axle powered by the vehicle engine through a gear box. Power may also be transferred to a rear axle by a power take off, drive axle and rear drive unit. The rear drive unit converts the rotational power from the drive axle to left and right side shafts to drive each of the left and right rear wheels of the vehicle. The rear drive unit may include a twin clutch for transferring the power from the drive axle to the left and right side shafts to provide all wheel drive to the vehicle.

[0004] A first known rear drive unit having a twin clutch is illustrated in U.S. Patent No. 11,994, 174. The first known rear drive unit includes a drive pinion meshed with a ring gear, which in turn is connected to an intermediate shaft in a rotationally fixed manner. In addition, the first known rear drive unit discloses that the intermediate shaft is supported within an outer housing by a first ring gear bearing spaced apart from a second ring gear bearing. The first known rear drive unit includes a first end of the intermediate shaft drivingly connected to a first friction clutch for driving a first side shaft. The first known rear drive unit also includes a second end of the intermediate shaft drivingly connected to a second friction clutch for driving a second side shaft. The first and second friction clutches of the first known rear drive unit are spaced axially outside of the ring gear bearings and have an outer clutch diameter larger than an outer diameter of the first and second ring gear bearings. However, spacing the friction clutches axially outside of thering gear bearings can result in a wide axle package and the inclusion of extra shafts and / or connections to accommodate the smaller diameter ring gear bearings.

[0005] A second known rear drive unit having a twin clutch is illustrated in U.S. Patent No. 11,187,281. The second known rear drive unit includes a drive pinion meshed with a ring gear, which in turn is connected to an intermediate shaft in a rotationally fixed manner. In addition, the second known rear drive unit discloses that the intermediate shaft is supported with the outer housing by spaced apart first and second ring gear bearings. The second known rear drive unit includes a first end of the intermediate shaft drivingly connected to an integrated disconnecting twin clutch system which includes a first friction clutch for driving a first side shaft and a second friction clutch for driving a second side shaft. A third known rear drive unit having a twin clutch is illustrated in U.S. Patent No. 1 1,890,927, which is similar in construction to the second known rear drive unit. Each of the second and third rear drive units also discloses that the first and second friction clutches have an outer clutch diameter larger than an outer diameter of the first and second ring gear bearings.

[0006] Further, an oil height within the rear drive unit is usually dictated by the outer diameter of the ring gear bearings to ensure the ring gear bearings are lubricated. The oil height is usually selected that submerges a lower portion of the ring gear bearings in the oil. However, the friction clutches have a clutch outer diameter larger than an outer diameter of the ring gear bearings, which causes a large portion of the friction clutches to be submerged in the oil during operation and creates considerable amounts of drag, which is undesirable for vehicle efficiency performance. The clutch oil height along the friction clutches directly affects the amount of disengaged parasitic drag created during operation.

[0007] It is desirable to optimize the weight, packaging space, complexity, disengaged parasitic drag, and engagement response time in the rear drive unit. It is also desirable to improve the packaging and efficiency of the rear drive unit. Further, it is desirable to lower the amount of churning and drag losses caused by the friction clutches in the rear drive unit.SUMMARY OF THE INVENTION

[0008] According to one embodiment, there is provided a drive unit for use in a vehicle. The drive unit includes a gear box housing having a gear box cavity, an output gear, and a left output shaft spaced axially apart from a right output shaft. The drive unit also includes a twin clutch comprising a clutch drum assembly and a clutch pack. The clutch pack has a clutch outer diameter and includes a first set of clutch plates and a second set of clutch plates. The clutch drum assembly houses the clutch pack. The first set of clutch plates are rotationally fixed to the clutch drum assembly. A first portion of the second set of clutch plates are fixed to the left output shaft. A second portion of the second set of clutch plates are fixed to the right output shaft. The drive unit also includes a left control bearing spaced axially apart from a right control bearing. Each one of the left and right control bearings has a bearing outer diameter. The output gear is rotationally fixed to the clutch drum assembly. The output gear and the clutch drum assembly are axially and radially supported within the gear box cavity by the left and right control bearings, which in turn are supported by the gear box housing. In addition, the clutch outer diameter is smaller than the bearing outer diameter.

[0009] According to a second embodiment, there is provided a drive unit for use in a vehicle. The drive unit includes a gear box housing enclosing a gear box cavity, an output gear, and a left output shaft spaced axially apart from a right output shaft. The rear drive unit also includes a twin clutch comprising a clutch drum assembly and a clutch pack. The clutch pack has a clutch outer diameter and includes a first set of clutch plates and a second set of clutch plates. The clutch drum assembly houses the clutch pack. The first set of clutch plates are rotationally fixed to the clutch drum assembly. A first portion of the second set of clutch plates are fixed to the left output shaft. A second portion of the second set of clutch plates are fixed to the right output shaft. The drive unit also includes a set of control bearings spaced axially apart, wherein each one of the set of control bearings has a bearing outer diameter and a respective outside end. The output gear is rotationally fixed to the clutch assembly. The output gear and the clutch drum assembly are axially and radially supported within the gear box cavity by the set of control bearings, which in turn are supported by the gear box housing. In addition, the bearing outer diameter is larger than the clutch outer diameter. Further, the clutch pack is spaced axially between the outside ends of the set of control bearings.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

[0011] Figure 1 is a diagram illustrating a vehicle drive train assembly including a rear drive unit, according to an embodiment of the present disclosure;

[0012] Figure 2 is a left perspective view of a rear drive unit, according to an embodiment of the present invention;

[0013] Figure 3 is a cross-sectional top view of the rear drive unit of Figure 2, taken along line-3-3 of Figure 2;

[0014] Figure 4 is a cross-sectional end view of the rear drive unit of Figure 3, taken along line 4-4 of Figure 3;

[0015] Figure 5 is a cross-sectional left side view of the rear drive unit of Figure 4, taken along line 5-5 of Figure 4;

[0016] Figure 6 is a cross-sectional end view of a known rear drive unit;

[0017] Figure 7 is a cross-sectional left side view of the known rear drive unit of Figure 6, taken along line 7-7 of Figure 6; and

[0018] Figure 8 is a diagram illustrating a vehicle drive train assembly including a drive unit, according to a second embodiment of the present disclosure.DETAILED DESCRIPTION OF THE INVENTION

[0019] Figures 1-5 and 8 illustrate a drive unit 10 for a vehicle, according to embodiments described herein. Directional references employed or shown in the description, figures or claims, such as top, bottom, upper, lower, upward, downward, lengthwise, widthwise, left, right, and the like, are relative terms employed for ease of description and are not intended to limit the scope of the invention in any respect. Referring to the Figures, like numerals indicate like or corresponding parts throughout the several views.

[0020] Figure 1 illustrates an exemplary vehicle drive train assembly 12 having all wheel drive functionality for transferring torque to a set of front wheels 14, 16 and a set of rear wheels 18, 20 of a vehicle 22. The drive train assembly 12 includes a main or front driveline 24 and a secondary or rear driveline 26. The front driveline 24 includes, among other components, an engine 28, a transmission 30, and a power train unit 32 (PTU). The PTU 32 includes an output 34 to transmit torque through a drive shaft 36 to a secondary drive unit and specifically to a rear drive unit or module 10 (RDU / RDM) for driving the rear wheels 18, 20, according to an embodiment of the present disclosure, as described herein. The PTU 32 also includes a disconnect system 38 for selectively engaging and disengaging the rear drive unit 10. A controller (not shown) may be in communication with the components in the front driveline 24 and rear driveline 26 and also in communication with one or more sensors (not shown) located throughout the vehicle 22. Further, the drive train assembly 12 includes a left side shaft 40 and a right side shaft 42 driveably coupled between the rear drive unit 10 and the left and right rear wheels 18, 20, respectively.

[0021] Referring to Figures 1-5, the rear drive unit 10 includes a gear box housing 44, a drive gear 46, an output gear 48, a clutch drum assembly 50, a gear box cavity 52, and a set of control bearings 54, 56. The gear box housing 44 rotationally supports the drive gear 46, which is fixedly coupled to the drive shaft 36 for transferring power from the PTU 32 and the engine 28 of the vehicle 22. The drive gear 46 is in meshed engagement with the output gear 48. The output gear 48 is rotationally fixed to the clutch drum assembly 50. The output gear 48 and clutch drum assembly 50 are axially and radially supported within the gear box cavity 52 by the set of control bearings 54, 56, which in turn are supported by the gear box housing 44. It will be appreciated that the output gear 48 may be a ring gear or another suitable gear, as is commonly known in the art.

[0022] The rear drive unit 10 also includes a clutch pack 58, a first set of clutch plates 60, a second set of clutch plates 62, a left output shaft 64, a right output shaft 66, the left side shaft 40, and the right side shaft 42. The clutch drum assembly 50 houses the clutch pack 58, which includes the first set of clutch plates 60 rotationally fixed to the clutch drum 50 and the second set of clutch plates 62 fixed to the left and right output shafts 64, 66. A first portion 68 of the second set of clutch plates 62 are fixed to the left output shaft 64. A second portion 70 of the second set of clutch plates 62 are fixed to the right output shaft 64. The left and right output shafts 64, 66 are radially and axially supported by the gear box housing 44 and driveably coupled to the left and right sideshafts 40, 42, respectively. In alternate embodiments, the left and right output shafts 64, 66 are fixedly coupled to and / or integrally formed with the respective one of the left and right side shafts 40, 42. The clutch pack 58 controls torque to the left and right side shafts 40, 42 to transfer power to both rear wheels 18, 20. The left and right side shafts 40, 42 define a output axis 72 of the rear drive unit 10. The output gear 48, the control bearings 54, 56, the clutch drum 50, the clutch pack 58, and the left and right output shafts 64, 66 are radially aligned along a common axis and aligned with the output axis 72 of the rear drive unit 10.

[0023] The rear drive unit 10 also includes a left actuator 74 and a right actuator 76 for selectively actuating the clutch pack 58 to transfer power to the left and right rear wheels 18, 20, respectively. Exemplary known actuators for selectively actuating a clutch pack are described in U.S. Patent 11,187,281 , the disclosure of which is incorporated by reference herein in its entirety. Further, the clutch drum 50, the clutch pack 58, and related components are generically described as a nested twin clutch 78 for simplicity.

[0024] Depicted in Figure 3, the set of control bearings 54, 56 includes a left control bearing 54 and a right control bearing 56, which are axially spaced apart along the output axis 72. In one exemplary embodiment, each one of the control bearings 54, 56 is a tapered roller bearing 54, 56 and which includes a tapered raceway 80, a plurality of tapered rollers (not shown), an inner ring 82, an outer ring 84, and a front face 86 opposing a rear face 88. The tapered raceway 80 contains and supports the tapered rollers (not shown), as is commonly known in the art. The tapered raceway 80 includes an outer surface 90, a front end 92, and a rear end 94. The outer surface 90 extends in a circumferential direction with a slope in an axial direction between the front end 92 and the rear end 94. The tapered raceway 80 has an outer diameter adjacent the rear end 94 that is larger than the outer diameter adjacent the front end 92. In addition, the tapered raceway 80 is spaced radially between the inner ring 82 and the outer ring 84 and spaced axially between the front face 86 and the rear face 88. In alternate embodiments, each one of the control bearings 54, 56 optionally comprise one or more of an angular contact ball bearing, a thrust bearing, a radial bearing, a deep groove bearing, and the like, without altering the scope of the present invention.

[0025] Depicted in Figure 4, the outer ring 84 of the control bearings 54, 56 has a bearing outer diameter 96 (bearing OD). The clutch pack 58 is spaced axially between the outside ends 86, 88of the control bearings 54, 56 and includes a clutch outer diameter 98 (clutch OD) that is smaller than the bearing OD 96. Additionally, one of the control bearings 54, 56 is flipped from a traditional arrangement for optimized weight, packaging, and efficiency. In a traditional arrangement, the left and right control bearings are tapered roller bearings which are spaced axially apart with the front faces of the control bearings facing each other, as commonly known in the art. However, the left and right control bearings 54, 56 of the present invention are spaced axially apart with the front face 86 of the left control bearing 54 oriented towards the rear face 88 of the right control bearing 56. Reversing the orientation of one of the control bearings 54, 56 improves the packaging within the rear drive unit 10, optimizes the weight, and improves the efficiency of the rear drive unit 10. The reversed orientation of one of the control bearings 54, 56 allows for compact axle package with a decreased overall width since fewer shafts and / or fewer connections are required within the rear drive unit 10 in comparison to a traditional rear drive unit having a traditional twin clutch.

[0026] Depicted in Figures 4 and 5, the rear drive unit 10 also includes an oil reservoir 100, oil 102, a base oil surface 104, and a base oil height 106. The oil reservoir 100 is defined within a lower portion of the gear box cavity 52 and contains oil 102 for lubricating internal components of the rear drive unit 10. Under static conditions, the oil 102 has an oil surface 104 spaced radially apart from the output axis 72 by the base oil height 106.

[0027] The base oil height 106 shown in Figure 5 represents an exemplary oil height of about 35 mm within the gear box housing 44, which corresponds to a base oil height 306 within a traditional rear drive unit 210 described below. The base oil height 106 is usually dictated by bearing OD 96 of the control bearings 54, 56 to ensure that the control bearings 54, 56 are lubricated.

[0028] In the present invention, the control bearings 54, 56 require a first minimum oil level 110, which corresponds to a bearing oil height 108, to ensure that a portion of the control bearings 54, 56 is submerged in the oil 102. In contrast, the clutch plates 60, 62 require a second minimum oil level 112, which corresponds to a clutch oil height 114, to ensure that a portion of the clutch plates 60, 62 is submerged in the oil 102. The clutch oil height 114 is selected based on the clutch pack 58 instead of based on the control bearings 54, 56, since the control bearings 54, 56 have a larger diameter 98, 96 than the clutch plates 60, 62.

[0029] Referring to Figures 4-7, a comparison is shown between a traditional rear drive unit 210 having a traditional twin clutch 278 (Figures 6, 7) and the rear drive unit 10 having the nested twin clutch 78 design of the present invention (Figures 4, 5). Depicted in Figures 6 and 7, the traditional rear drive unit 210 includes a gear box housing 244, a drive gear (not shown), a ring gear 248, a clutch drum assembly 250, a gear box cavity 252, a left control bearing 254, a right control bearing 256, a clutch pack 258, a first set of clutch plates 260, a second set of clutch plates 262, a left output shaft 264, a right output shaft 266, a left side shaft 240, and a right side shaft 242. The drive gear (not shown) is in meshed engagement with the ring gear 248. The drive gear (not shown) and ring gear 248 may be rotationally fixed to the clutch drum assembly 250. The drive gear (not shown), the ring gear 248, and clutch drum assembly 250 are axially and radially supported within the gear box cavity 252 by the left and right control bearings 254, 256, which in turn are supported by the gear box housing 244. The clutch drum assembly 250 houses the clutch pack 258, which includes the first set of clutch plates 260 rotationally fixed to the clutch drum 250 and the second set of clutch plates 262 fixed to the left and right output shafts 264, 266. The clutch pack 258 controls torque to the left and right side shafts 240, 242 via the left and right output shafts 264, 266, respectively. Further, the clutch drum 250, the clutch pack 258, and related components are generically described as the twin clutch 278 for simplicity. The left and right side shafts 240, 242, the ring gear 248, the control bearings 254, 256, the clutch drum 250, the clutch pack 258, and the left and right output shafts 264, 266 are radially aligned along the output axis 272.

[0030] The left and right control bearings 254, 256 are tapered roller bearings 254, 256 which have a front face 286 and a rear face 288, and are constructed as generally known in the art. Further, the control bearings 254, 256 are spaced axially apart with the front face 286 of the left control bearing 254 facing the front face 286 of the right control bearing 256, which is the traditional arrangement for a set of tapered roller bearings 254, 256. In the traditional twin clutch design 278 shown in Figure 6, the clutch pack 258 sits outside of the control bearings 254, 256. In addition, the clutch pack 258 usually as a clutch outer diameter 298 (clutch OD) larger than a bearing outer diameter 296 (bearing OD) of the control bearings 254, 256. The control bearings 254, 256 having a bearing OD 296 smaller than the clutch diameter298 drives a wide axle package, extra shafts, and / or extra connections to accommodate the smaller control bearings 254, 256.

[0031] Depicted in Figures 6 and 7, the traditional rear drive unit 210 also includes an oil reservoir 300, oil 302, an oil surface 304, and a base oil height 306. The oil reservoir 300 is defined within a lower portion of the gear box cavity 252 and contains oil 302 for lubricating internal components of the traditional rear drive unit 210. Under static conditions, the oil 302 has an oil surface 304 spaced radially apart from the output axis 272 by the base oil height 306.

[0032] Referring to Figure 7, the base oil height 306 is usually dictated by bearing OD 296 of the control bearings 254, 256 since the bearing OD 296 is smaller than the clutch OD 298. The base oil height 306 is selected to ensure that there is sufficient lubrication for the control bearings 254, 256 and that a portion of the control bearings 254, 256 are submerged in the oil 302. In the exemplary traditional rear drive unit 210, the base oil height 306 is set to about 35 mm from the axial center 272.

[0033] In the traditional design, the outer diameter 298 of the clutch plates 260, 262 is much larger than the outer diameter 296 of the tapered roller bearings 254, 256 so that a large portion of the clutch plates 260, 262 are submerged in the oil 302 stored in the gear box housing 244. Additionally, the surface speed of the clutch plates 260, 262 churning through the oil 302 is high since the outer diameter 298 of the clutch plates 260, 262 is large, which creates a large amount of fluid sheer, creates considerable amounts of drag, and causes parasitic losses. The end result of the clutch plates 260, 262 having larger diameter 298, 296 than the tapered roller bearings 254, 256 is the large clutch plates 260, 262 are submerged in a large amount of oil 302 creating a considerable amount of drag, which is undesirable for vehicle efficiency performance.

[0034] In contrast, the smaller diameter 98 of the clutch pack 58 of the present invention relative to the bearing outer diameter 96 of the control bearings 54, 56 allows for selection of a base oil height 106, 114 that is relative to the clutch plates 60, 62 and not relative to the larger control bearings 54, 56. Referring to Figure 5, the base oil height 106 is shown as about 35 mm and corresponds to the base oil height 306 within the traditional rear drive unit 210 of Figure 7. In the present invention in Figure 5, the level of oil 102 in the gear box housing 44 can be reduced from the base oil level 104 to the minimum clutch oil level 112, which continues to provide sufficient lubrication for the clutch plates 60, 62 and the control bearings 54, 56. Reducing the oil level in the gear box housing 44 to the minimum clutch oil level 112 changes the base oil height 106 to theclutch oil height 114, and reduces oil coverage of the clutch plates 60, 62 by a height difference 116, which in turn reduces the amount of the clutch plates 60, 62 submerged in the oil 102. It will be appreciated that the clutch oil height 114 can be selected based on the desired amount of the clutch plates 60, 62 to be submerged in the oil 102. In the present invention shown in Figure 5, the outer diameter 98 of the clutch plates 60, 62 is much smaller than the outer diameter 98 of the tapered roller bearings 54, 56, so that the oil height 114 can vary to adjust the amount the clutch plates 60, 62 submerged in the oil 102 while keeping adequate oil flow for the control bearings 54, 56. Also, since the outer diameter 98 of the clutch plates 60, 62 is small in comparison to the outer diameter 96 of the left and right control bearings 54, 56, the surface speed of the clutch plates 60, 62 is reduced, which in turn reduces the churning through the oil 102, resulting in less drag and parasitic losses during operation.

[0035] A second embodiment of the drive unit 10' is illustrated in Figures 4 and 8, where like primed reference numerals represent similar elements as those described above. Only significant differences between the two embodiments are reflected in the Figures and the description below. The second embodiment of the drive unit 10' is driveably coupled to an electric motor 308 in an electric vehicle 22'. In contrast, the drive unit 10 of the first embodiment includes the output gear 48 driveably connected to a drive shaft 36 for transferring torque from the drive shaft 36 to the set of rear wheels 18, 20 of the vehicle 22.

[0036] Figure 8 illustrates an exemplary vehicle drive train assembly 12' having front wheel drive functionality for transferring torque to a set of front wheels 14', 16'. The drive train assembly 12' includes a main or front driveline 24'. The front driveline 24' includes, among other components, an electric motor 308 having a motor shaft 309 driveably coupled to the drive unit 10'. The drive train assembly 12' includes a left side shaft 40' and a right side shaft 42' driveably coupled between the drive unit 10' and the left and right front wheels 14', 16', respectively. The drive unit 10' is commonly described as a front drive unit 10' when the drive unit 10' is configured to transfer torque to the set of front wheels 14', 16' of the vehicle 22'. It will be appreciated that the drive unit 10' may be driveably coupled to the set of rear wheels 18', 20' and described as a rear drive unit 10'. The exemplary vehicle drive train assembly 12' may include a secondary or rear driveline 26' for transferring torque to a set of rear wheels 18', 20', as commonly known in the art.

[0037] The drive unit 10' includes a first drive gear 310, a first driven gear 312, a second drive gear 314, and an output gear 48'. The first drive gear 310 is driveably coupled to the motor shaft 309 and meshingly engaged with the first driven gear 312, forming a first gear mesh 316. The second drive gear 314 rotationally fixed to the first driven gear 312, such that the second drive gear 314 and the first driven gear 312 have a common axis of rotation. The output gear 48' is meshingly engaged with the second drive gear 314, forming a second gear mesh 318. It will be appreciated that the drive unit 10' might include alternate gear arrangements in place of the first and second gear meshes 316, 318, as is commonly known in the art.

[0038] Depicted in Figure 4, the drive unit 10' of the second embodiment is constructed similarly to the drive unit 10 of the first embodiment. In more detail, the output gear 48' is rotationally fixed to the clutch drum assembly 50'. The output gear 48' and the clutch drum assembly 50' are axially and radially supported within the gear box cavity 52' by the left and right control bearings 54', 56', which in turn are supported by the gear box housing 44'. The clutch drum assembly 50' includes a clutch pack 58', which is spaced axially between the outside ends 86, 88 of the left and right control bearings 54', 56'. In addition, the left and right control bearings 54', 56' have a bearing outer diameter 96' larger than an outer diameter 98' of the clutch pack 58'.

[0039] As discussed above, the drive unit 10, 10' of the present invention includes a gear box housing 44, 44’ containing a gear box cavity 52, 52' with an output gear 48, 48' rotationally fixed to a clutch drum assembly 50, 50'. Further, the output gear 48, 48', and the clutch drum assembly 50, 50' are axially and radially supported within the gear box cavity 52, 52’ by a set of left and right control bearings 54, 54', 56, 56', which in turn are supported by the gear box housing 44, 44'. The drive unit 10, 10' also includes a left output shaft 64 spaced axially apart from a right output shaft 66, wherein the left and right output shafts 64, 66 are radially and axially supported by the gear box housing 44, 44'. In addition, the drive unit 10, 10' includes a twin clutch 78 comprising a clutch drum assembly 50, 50' and a clutch pack 58, 58', wherein the clutch drum assembly 50, 50' houses the clutch pack 58, 58'. The clutch pack 58, 58' has a clutch outer diameter 98, 98' which is smaller than an outer diameter 96, 96' of the control bearings 54, 54', 56, 56', which in turn allows for a unique package of the drive unit 10, 10' that is reduced in weight, size, and complexity in comparison to traditional variants.

[0040] The invention has been described in an illustrative manner, and it is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced other than as specifically described.

Claims

What is claimed is:

1. A drive unit for use in a vehicle, the drive unit comprising: a gear box housing including a gear box cavity; an output gear; a left output shaft spaced axially apart from a right output shaft; a twin clutch comprising a clutch drum assembly and a clutch pack, the clutch pack having a clutch outer diameter and including a first set of clutch plates and a second set of clutch plates, wherein the clutch drum assembly houses the clutch pack, the first set of clutch plates are rotationally fixed to the clutch drum assembly, a first portion of the second set of clutch plates are fixed to the left output shaft, and a second portion of the second set of clutch plates are fixed to the right output shaft; and a left control bearing spaced axially apart from a right control bearing, each one of the left and right control bearings having a bearing outer diameter; wherein the output gear is rotationally fixed to the clutch drum assembly; wherein the output gear and the clutch drum assembly are axially and radially supported within the gear box cavity by the left and right control bearings, which in turn are supported by the gear box housing; and wherein the clutch outer diameter is smaller than the bearing outer diameter.

2. The drive unit as set forth in claim 1, wherein: each one of the left and right control bearings includes a respective outside end; and the clutch pack is spaced axially between the outside ends of the left and right control bearings.

3. The drive unit as set forth in claim 1 or claim 2, further comprising: a left actuator and a right actuator for selectively actuating the clutch pack to transfer power to the left and right output shafts, respectively.

4. The drive unit as set forth in any one of claims 1 to 3, wherein: the output gear, the left control bearing, the right control bearing, the clutch drum assembly, the clutch pack, the left output shaft, and the right output shaft are radially aligned along a common axis.

5. The drive unit as set forth in any one of claims 1 to 4, wherein: each of the left and right control bearings includes a front face opposing a rear face; and the left and right control bearings are spaced axially apart with the front face of one of the left and right control bearings oriented towards the rear face of the other one of the left and right control bearings.

6. The drive unit as set forth in any one of claims 1 to 5, further comprising: a drive gear in meshed engagement with the output gear.

7. The drive unit as set forth in any one of claims 1 to 5, further comprising: an electric motor including a motor shaft; a first drive gear driveably coupled to the motor shaft; a first driven gear meshingly engaged with the first drive gear; a second drive gear rotationally fixed to the first driven gear; and the output gear meshingly engaged with the second drive gear.

8. The drive unit as set forth in any one of claims 1 to 7, wherein: the drive unit is a rear drive unit for transferring torque to a set of rear wheels of the vehicle; or the drive unit is a front drive unit for transferring torque to a set of front wheels of the vehicle.

9. A drive unit for use in a vehicle, the drive unit comprising: a gear box housing including a gear box cavity; an output gear; a left output shaft spaced axially apart from a right output shaft; a twin clutch comprising a clutch drum assembly and a clutch pack, the clutch pack having a clutch outer diameter and including a first set of clutch plates and a second set of clutch plates, wherein the clutch drum assembly houses the clutch pack, the first set of clutch plates are rotationally fixed to the clutch drum assembly, a first portion of the second set of clutch plates are fixed to the left output shaft, and a second portion of the second set of clutch plates are fixed to the right output shaft; anda set of control bearings spaced axially apart, each one of the set of control bearings having a bearing outer diameter and a respective outside end; wherein the output gear is rotationally fixed to the clutch drum assembly; wherein the output gear and the clutch drum assembly are axially and radially supported within the gear box cavity by the set of control bearings, which in turn are supported by the gear box housing; wherein the bearing outer diameter is larger than the clutch outer diameter; and wherein the clutch pack is spaced axially between the outside ends of the set of control bearings.

10. The drive unit as set forth in claim 9, further comprising: a left actuator and a right actuator for selectively actuating the clutch pack to transfer power to the left and right output shafts, respectively.

11. The drive unit as set forth in claim 9 or claim 10, wherein: the first set of clutch plates and the second set of clutch plates have an outer diameter smaller than the outer diameter of the set of control bearings.

12. The drive unit as set forth in any one of claims 9 to 11, further comprising: an electric motor including a motor shaft; a first drive gear driveably coupled to the motor shaft; a first driven gear meshingly engaged with the first drive gear; a second drive gear rotationally fixed to the first driven gear; and the output gear meshingly engaged with the second drive gear.

13. The drive unit as set forth in any one of claims 9 to 11, further comprising: a drive gear in meshed engagement with the output gear.

14. The drive unit as set forth in any one of claims 9 to 13, wherein: the drive unit is a rear drive unit for transferring torque to a set of rear wheels of the vehicle.

15. The drive unit as set forth in any one of claims 9 to 12, wherein: the drive unit is a front drive unit for transferring torque to a set of front wheels of the vehicle.

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