Dual speed disconnect all wheel drive system (AWD) system with pinion coupling

Abstract

A power take-off unit (PTU) for an all-wheel drive vehicle includes an input shaft configured to receive power, a main shaft, and an output conversion collar axially slidable between an engaged position connecting the input shaft to the main shaft and a disengaged position disconnecting the main shaft from the input shaft. When the output conversion collar is in the engaged position, power received by the input shaft is transmitted through the output conversion collar to the main shaft, through the main ring gear, the hypoid pinion, and through the pinion shaft, where the main shaft is disengaged from the input shaft when the output conversion collar is in the disengaged position.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 63 / 359,217, filed on July 8, 2022, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] The present invention relates to a disconnect assembly for an all-wheel drive (AWD) vehicle. More particularly, the present invention relates to a power take-off unit (PTU) and a rear drive module (RDM) for an all-wheel drive (AWD) vehicle. Background Art

[0004] An automatic all-wheel drive (AWD) vehicle may be driven primarily by the front axle, with the vehicle engine providing power to the front axle through a gearbox. An AWD vehicle may include an all-wheel drive system (AWD system) that includes a power take-off unit (PTU) and a rear drive module (RDM). Power may be transferred to the rear axle via the power take-off unit (PTU), the drive axle, and the rear drive module (RDM). As is known, the PTU selectively transfers power to the RDM via a gear set within the PTU. In addition, as is known, the PTU includes an optional low range mode, in which the PTU is able to switch to a low gear range.

[0005] The RDM converts rotational force from the drive axle to the left and right output shafts to drive each of the left and right rear wheels of the vehicle. The RDM transmits the power received from the drive axle through the clutch drum, pinion gear, ring gear and rear differential. The output shaft is driven by the side gears in the rear differential, which is driven by the rotation of the ring gear. As is well known, the vehicle includes a disconnect assembly that engages between the ring gear and the differential pinion to connect and disconnect the ring gear with the differential pinion. As is well known, the disconnect assembly is actuatable by an actuator assembly, such as a hydraulically or electrically actuated clutch, solenoid, etc.

[0006] It is known that vehicles include a locking differential to prevent relative rotation of one driven wheel with respect to the other driven wheel. This is typically accomplished by locking one of the differential side gears to the differential housing, thereby preventing rotation of the side gear relative to the differential housing. It is also known to provide a hydraulically or electrically actuated clutch for locking and unlocking one of the side gears or output shafts of the rear differential relative to the differential housing. In addition, it is known that the RDM includes an optional low range mode in which the RDM is able to shift into a low gear range.

[0007] It is desirable to provide an AWD system that is capable of decoupling the PTU and RDM and stopping the rotation of certain components within the AWD system. It is also desirable to disconnect the input shaft of the PTU from the gear set to prevent power from being transferred from the input shaft to the RDM. In addition, it is desirable that the PTU include a single actuator to selectively transfer power to the RDM and selectively shift to a selectable low range gear.

[0008] In addition, it is also desirable to disconnect the RDM at the clutch drum to prevent power from being transferred between the clutch drum and the drive axle. In addition, it is desirable to provide a disconnect assembly operated by a single actuator that is configured to lock / unlock the locking differential and selectively shift into a selectable low range gear. Summary of the invention

[0009] According to one embodiment, a power output unit for a vehicle is provided. The power output unit includes an input shaft configured to receive power provided to the power output unit; a main shaft; and a main ring gear, the main ring gear being non-rotatably coupled to the main shaft and rotating in response to the rotation of the main shaft. The power output unit also includes a hypoid pinion meshingly engaged with the main ring gear and a pinion shaft non-rotatably coupled to the hypoid pinion, so that the rotation of the main ring gear causes the hypoid pinion and the pinion shaft to rotate. In addition, the power output unit includes an output conversion collar, the output conversion collar being axially slidable between an engagement position connecting the input shaft to the main shaft and a disengagement position disconnecting the input shaft from the main shaft. When the output conversion collar is in the engagement position, the power received by the input shaft is transmitted to the main shaft through the output conversion collar, and transmitted to the pinion shaft through the main ring gear and the hypoid pinion, wherein when the output conversion collar is in the disengagement position, the main shaft is separated from the input shaft.

[0010] According to another embodiment, a rear drive module for a vehicle is provided. The rear drive module includes an input hub configured to receive power, a clutch drum, a torque transfer coupling, the torque transfer coupling being configured to selectively transfer power between the input hub and the clutch drum when the torque transfer coupling is in an engaged state, wherein the input hub is separated from the clutch drum when the torque transfer coupling is in a disengaged state. The rear drive module also includes a hypoid pinion shaft non-rotatably coupled to the clutch drum, a hypoid pinion non-rotatably coupled to the hypoid pinion shaft, and a main ring gear meshingly engaged with the hypoid pinion, wherein the hypoid pinion and the clutch drum rotate together. The rear drive module also includes a differential, the differential including: a differential housing, a differential shaft non-rotatably connected to the differential housing, opposite pinions rotatably connected together by a pinion shaft mechanically connected to the differential housing, and opposite first side gears and second side gears meshingly engaged with the pinions, so that power can be transmitted from the differential housing to the pinions and then to the first side gears and the second side gears. In addition, the rear drive module also includes a first output shaft non-rotatably connected to the first side gear and a second output shaft non-rotatably connected to the second side gear. The rear drive module also includes a planetary gear set, the planetary gear set including a sun gear non-rotatably connected to a sun shaft, the sun shaft non-rotatably connected to a main ring gear, a planetary ring gear arranged radially outside the sun gear, and a planetary carrier assembly, the planetary carrier assembly including a planetary carrier rotatably supporting one or more planetary gears thereon, wherein the planetary carrier is engaged with the planetary gears so as to rotate together, and during the rotation of the planetary carrier, the planetary gears rotate between the sun gear and the planetary ring gear. The rear drive module also includes a conversion collar splined to the differential shaft so that the conversion collar rotates with the differential shaft while being axially slidable relative to the differential shaft, the conversion collar being axially slidable between a 4HI position and a 4LO position, the 4HI position connecting the sun shaft to the differential shaft for transmitting power received from the hypoid pinion to the differential housing, the 4LO position connecting the planet carrier to the differential shaft for transmitting power received from the planet carrier to the differential housing, wherein the 4HI position is axially spaced from the 4LO position.

[0011] According to another embodiment, a rear drive module for a vehicle is provided. The rear drive module includes an input hub configured to receive power, a clutch drum, and a torque transfer coupling configured to selectively transfer power between the input hub and the clutch drum when the torque transfer coupling is in an engaged state, wherein the input hub is separated from the clutch drum when the torque transfer coupling is in a disengaged state. The rear drive module also includes a hypoid pinion shaft non-rotatably coupled to the clutch drum, a hypoid pinion non-rotatably coupled to the hypoid pinion shaft, and a main ring gear meshingly engaged with the hypoid pinion, wherein the hypoid pinion and the clutch drum rotate together. The rear drive module also includes a differential, the differential including: a differential housing, the differential housing being configured to rotate in response to the rotation of the main ring gear; a differential shaft, the differential shaft being non-rotatably coupled to the differential housing; opposing pinion gears, the pinion gears being rotatably connected together by a pinion shaft mechanically connected to the differential housing; and opposing first and second side gears, the first and second side gears being meshingly engaged with the pinion gears so that power can be transmitted from the differential housing to the pinion gears and then to the first and second side gears. The rear drive module also includes a first output shaft non-rotatably coupled to the first side gear and a second output shaft non-rotatably coupled to the second side gear. The torque transmitting coupling also includes a friction clutch including a plurality of friction plates that are axially repositionable between an engaged state coupling the clutch drum to the input hub and a disengaged state separating the clutch drum from the input hub, a hydraulic piston configured to selectively apply pressure to the friction plates in the axial direction to reposition the friction plates to the engaged state, and a return spring configured to bias the friction plates toward the disengaged state. When pressure is removed from the friction plates, the return spring disengages the friction clutch by axially separating the friction plates, separating the clutch drum from the input hub. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Advantages of the present invention will be better understood by referring to the following detailed description when considered in conjunction with the accompanying drawings, in which:

[0013] Figure 1 is a cross-sectional side view of a power take-off unit (PTU) of an all-wheel drive system (AWD system) for a vehicle according to a first embodiment of the present invention;

[0014] Figure 2 is a cross-sectional side view of a rear drive module (RDM) for an AWD system according to a first embodiment of the present invention;

[0015] Figure 3 for Figure 1a partial cross-sectional side view of a PTU in FIG. 1 showing an all-wheel drive (AWD) output shift collar in a disengaged position corresponding to a disengaged mode and showing a range shift collar in a high position corresponding to a high range mode providing high range power to a front differential;

[0016] Figure 4 for Figure 3 A partial cross-sectional side view of the PTU in FIG. 1 showing the output shift collar in the disengaged position and the range shift collar in the high position;

[0017] Figure 5 for Figure 4 A partial cross-sectional side view of the PTU in FIG. 1 showing the output shift collar in an engaged position corresponding to an engaged mode, and the range shift collar in a high position;

[0018] Figure 6 for Figure 5 a partial cross-sectional side view of the center PTU showing the output shift collar in an engaged position and the range shift collar in a neutral position disengaged from the front differential;

[0019] Figure 7 for Figure 6 a partial cross-sectional side view of the mid PTU showing the output shift collar in an engaged position and the range shift collar in a low position corresponding to a low gear mode;

[0020] Figure 8 for Figure 1 A perspective view of a portion of a PTU showing a barrel cam actuator assembly according to one embodiment of the present invention;

[0021] Fig. 9 for Figure 8 A perspective view of a barrel cam actuator assembly;

[0022] Fig.10 for Figure 2 A partial cross-sectional side view of the RDM of , showing the conversion collar in a 4HI position corresponding to a 4HI mode;

[0023] Fig.11 for Fig.10 A partial cross-sectional side view of the middle RMD showing the conversion collar in the 4HI position;

[0024] Fig.12 for Fig.11 a partial cross-sectional side view of the RDM showing the shift collar in the neutral position;

[0025] Fig.13 for Fig.12a partial cross-sectional side view of the middle RDM showing the conversion collar in the 4LO position corresponding to the 4LO mode;

[0026] Fig.14 for Fig.13 a partial cross-sectional side view of the RDM showing the translation collar in a 4LO-locked position corresponding to a 4LO-locked mode;

[0027] Fig.15 is a cross-sectional side view of a power take-off unit (PTU) of an all-wheel drive system (AWD system) for a vehicle according to a second embodiment of the present invention, showing a range shift collar in a high position corresponding to a high gear mode, and an output shift collar in an engaged position corresponding to an engaged mode;

[0028] Fig.16 for Fig.15 a cross-sectional side view of the PTU showing the output shift collar in an engaged position and the range shift collar in a neutral position corresponding to a neutral mode;

[0029] Fig.17 for Fig.16 a cross-sectional side view of the PTU showing the output shift collar in an engaged position and the range shift collar in a low position corresponding to a low gear mode;

[0030] Fig.18 for Fig.17 a partial cross-sectional view of the mid PTU showing the output shift collar in a disengaged position corresponding to the disengaged mode and showing the range shift collar in a high position;

[0031] Fig.19 is a side cross-sectional view of a power take-off unit (PTU) for an all-wheel drive system (AWD system) for use in a vehicle according to a third embodiment of the present invention, showing an output shift collar in an engaged position corresponding to an engagement mode;

[0032] Fig. 20 for Fig.19 an enlarged cross-sectional side view of a portion of the PTU in FIG. 1 showing the output conversion collar in an engaged position;

[0033] Fig.21 for Fig. 20 an enlarged cross-sectional side view of the PTU showing the output shift collar in a disengaged position corresponding to the disengaged mode; and

[0034] Fig. 22 FIG. 1 is a cross-sectional side view of a rear drive module (RDM) for an AWD system according to a second embodiment of the present invention. DETAILED DESCRIPTION

[0035] Figure 1-22 Components of a disconnected all-wheel drive (AWD) system 10 for a motor vehicle are shown according to an embodiment described herein. Directional references used or shown in the specification, drawings, or claims, such as top, bottom, upper, lower, upward, downward, longitudinal, lateral, left, right, etc., are relative terms used for convenience of description and are not intended to limit the scope of the present invention in any aspect. Referring to the drawings, like numerals indicate like or corresponding parts throughout the several views.

[0036] refer to Figure 1 and Figure 2 The vehicle AWD system 10 is composed of a power take-off unit (PTU) 12 and a rear drive module (RDM) 14, wherein the AWD system 10 is capable of disengaging the PTU 12 and the RDM 14 and stopping rotation to improve fuel economy. The AWD system 10 disconnects the input shaft 16 from the PTU gear set 18, and the RDM 14 is disconnected at the clutch drum 20. The AWD system 10 includes a selectable low range mode in which both the PTU 12 and the RDM 14 are capable of shifting to a low range.

[0037] See also Figure 1 , the PTU 12 consists of a front wheel power flow that transfers power from the input shaft 16 to a front differential 22 that drives the front wheels (not shown). The PTU 12 includes a range shifting mechanism 24 that allows the front wheel power flow to be shifted from a high gear range (i.e., normal) to a low gear range or neutral. The PTU 12 includes a second power flow that is connected to a propeller shaft 26 through a PTU gear set 18, and the propeller shaft 26 transmits power to the rear wheels (not shown). The second power flow can be selectively connected to or disconnected from the input shaft 16, and the torque flow is separated to the rear wheels using an actuator assembly 28 that also actuates the range shifting mechanism 24. It should be understood that the propeller shaft 26 can be any type or combination of propeller shafts, drive shafts, transmissions, etc. as known in the art for transmitting power from the PTU 12 to the RDM 14.

[0038] The PTU 12 is disposed on a vehicle (not shown). As will be appreciated from the following description, the PTU 12 may also be referred to as part of an axle. The PTU 12 includes a fixed housing 32 defining an interior compartment in which the PTU gear set 18 and the front differential 22 are housed. In addition, the fixed housing 32 is fixedly supported on the vehicle. The PTU 12 is operably connected to a drive shaft or vehicle transmission system and an engine or motor, wherein the input shaft 16 is rotatably driven by the transmission system.

[0039] like Figure 3As shown, the front differential 22 includes a pinion gear assembly 34, which is rotatably supported in a fixed housing 32. The pinion gear assembly 34 includes opposing differential pinions 36, a pinion gear shaft 38, a differential housing 40, and opposing first and second side gears 42 and 43. The pinion gears 36 are rotatably connected together by the pinion gear shaft 38 mechanically connected to the differential housing 40. In addition, the differential pinion gears 36 are meshingly engaged with the first and second side gears 42 and 43 so that torque (i.e., power) can be transmitted from the differential housing 40 to the differential pinion gears 36, and then to the first and second side gears 42 and 43. The pinion gear shaft 38 rotatably supports the differential pinion gears 36 at its ends, and when the differential pinion gears 36 travel around the first and second side gears 42 and 43, the pinion gear shaft 38 rotates together with the differential pinion gears 36. The front differential 22 also includes a connecting pin (not shown) that fixedly couples the pinion shaft 38 to the differential case 40 so that the pinion gears 36 of the front differential 22, the pinion shaft 38, and the differential case 40 all travel together about the same axis as the side gears 42, 43. The differential case 40 is radially and axially supported by bearings 44, 46 and can freely rotate within the fixed case 32.

[0040] The differential side gears 42, 43 are supported by the differential case 40 and operate to drive torque to any combination of the right output shaft 50 and the left output shaft 52 (i.e., the first output shaft and the second output shaft), which can be any type of side shaft, half shaft, coupling shaft, etc. as known in the prior art. The output shafts 50, 52 thereby rotate with the wheels connected thereto and selectively drive the wheels. The differential case 40 includes a case end flange 54 and a cover end flange 56, which are open to allow the output shafts 50, 52 attached to the side gears 42, 43 to extend axially therefrom for driving the wheels. Due to the connection of the output shafts 50, 52 and the side gears 42, 43 to the wheels, when the wheels rotate, the output shafts 50, 52 and the side gears 42, 43 will also rotate. The side gears 42 , 43 are in meshing engagement with the pinion gears 36 , and the input shaft 16 is engageable with the differential housing 40 such that torque can be transferred from the input shaft 16 through the differential housing 40 , the pinion gears 36 , and then the side gears 42 , 43 to drive the output shafts 50 , 52 .

[0041] The PTU 12 also includes a planetary gear set 58, which is configured to selectively provide power to the front differential 22 in a high range and a low range. The planetary gear set 58 defines an alternative path for torque transmission between the input shaft 16 and the front differential 22, which corresponds to the high range and the low range. The planetary gear set 58 includes a sun gear 60, a planetary ring gear 62, a set of planetary gears 64, and a planet carrier 66. The sun gear 60 is rotatably supported on the outer circumference of the left output shaft 52 and is integrally formed with the sun shaft 67. The planetary ring gear 62 is connected to the fixed housing 32 and is concentric with the sun gear 60 in a radially spaced, opposite relationship. The set of planetary gears 64 radially meshes with the sun gear 60 and the planetary ring gear 62. The planetary gears 64 are mounted to and supported by the planet carrier 66 to form a planet carrier assembly 68 rotatably supported on the output shafts 50, 52. The planet carrier 66 has an outer carrier segment 70, an inner carrier segment 72 and circumferentially spaced support shafts 74 for rotatably supporting the planet gears 64. The outer carrier segment 70 is supported on the inner end of the housing end flange 54, either integral therewith or as a separate component, so that rotation of the planet carrier 66 causes the differential housing 40 to rotate.

[0042] In order to selectively drive the planet carrier 66, the inner carrier segment 72 includes a drive structure, which is preferably formed as a drive tooth 76, such as Figure 3 and Figure 4 The rack drive teeth 76 are formed around the inner circumference of the inner rack segment 72 and face radially inward. However, it will be appreciated that the rack drive teeth 76 may be formed in alternative configurations, such as facing radially outward, facing radially inward, or in an axial direction, without changing the scope of the present invention.

[0043] In order to selectively drive the sun gear 60, the sun shaft 67 includes a drive structure, which is preferably a drive tooth 78. The sun drive tooth 78 is Figure 3 67 and face radially outward. However, it should be understood that the sun drive teeth 78 may be formed in alternative configurations, such as facing radially outward, facing radially inward, or in an axial direction, without changing the scope of the present invention.

[0044] In order to switch the PTU 12 between a high range and a low range, the input shaft 16 also includes an end flange 80, the end flange 80 including input drive teeth 82 formed on an outer circumference or outer surface of the end flange 80, the input drive teeth 82 facing radially outward and extending in an axial direction. However, it should be understood that the input drive teeth 82 may be formed with alternative configurations, such as facing radially outward, radially inward, or in an axial direction, without changing the scope of the present invention. The PTU 12 also includes a range shift collar 84 splined to the input shaft 16 so that the range shift collar 84 rotates with the input shaft 16 while being axially slidable relative to the input shaft 16. The range shift collar 84 is axially shiftable between three axially spaced positions corresponding to a high range mode (high position, low position). Figure 3-5 ), low gear mode (low position, Figure 7 ) and neutral (neutral position, Figure 6 ). Reference Figure 1 The range shift collar 84 is axially displaceable by a suitable actuator assembly 28 , such as a hydraulic actuator, electromechanical actuator, solenoid, etc., electrically controlled by a vehicle controller.

[0045] like Figure 4 As shown, the range shift collar 84 includes a body formed by an internal drive structure 86, which is formed as drive teeth formed on the inner circumference or inner surface, facing radially inward. However, it will be appreciated that the internal drive structure 86 may be formed in alternative configurations, such as facing radially outward, facing radially inward, or in an axial direction, without changing the scope of the invention. The internal drive structure 86 meshingly engages with the input drive teeth 82 on the end flange 80 of the input shaft 16 while allowing the range shift collar 84 to be axially displaceable along the input drive teeth 82 so as to remain engaged with the input drive teeth 82 in both the high gear mode (high position) and the low gear mode (low position).

[0046] Additionally, the range shift collar 84 includes a low drive structure 88 such as Figure 4As shown, it is formed as a drive tooth that faces radially inward from the inner circumference or inner surface and is axially spaced from the internal drive structure 86. However, it should be understood that the low drive structure 88 can be formed as an alternative configuration, such as facing radially outward, radially inward, or in an axial direction, without changing the scope of the present invention. When the range shift collar 84 is axially repositioned to transmit power through the sun gear 60 to provide a low gear range power to the front differential 22, the low drive structure 88 is configured to meshingly engage with the sun drive teeth 78 on the sun shaft 67. The range shift collar 84 includes a recessed portion 90 axially spaced between the drive structures 86, 88, and when the range shift collar 84 is disengaged from the sun shaft 67, when the range shift collar 84 is axially displaced, the recessed portion 90 provides a radial gap between the range shift collar 84 and the sun drive teeth 78. The range shift collar 84 also includes a high drive structure 92, which is Figure 4 8 and 9. The high drive structure 92 is shown as being formed as drive teeth that face radially outward from the outer circumference or surface of the range shift collar 84. However, it should be understood that the high drive structure 92 can be formed in alternative configurations, such as facing radially outward, facing radially inward, or in an axial direction, without changing the scope of the present invention. The high drive structure 92 is configured to meshingly engage with the carrier drive teeth 76 on the planet carrier 66 when the range shift collar 84 is axially repositioned to transfer power through the planet carrier 66 to provide a high gear range for the front differential 22.

[0047] In addition, the range shift collar 84 includes a range channel 93 that extends circumferentially around the outer circumference or outer surface of the range shift collar 84. The range channel 93 is configured to be operably coupled to the actuator assembly 28, allowing the range shift collar 84 to be axially repositioned between a high position (high gear mode), a low position (low gear mode), and a neutral position (neutral). It should be understood that the drive teeth 76, 78 and the drive structures 86, 88, 92 can be formed as similar gear teeth, but other configurations of drive structures can be provided without changing the scope of the present invention. Generally, the sun drive teeth 78 and the inner drive structure 86 are located at the same or approximately the same radial distance from the central axis extending through the input shaft 16, the left output shaft 52, and the right output shaft 50, although the distance can be changed to change the torque transmission characteristics. In addition, the carrier drive teeth 76 and the high drive structure 92 are located radially offset from the other drive teeth 78, 82 and the other drive structure 86. However, it should be understood that the radial positions of the carrier drive teeth 76 and the high drive structure 92 may be varied without altering the scope of the present invention.

[0048] exist Figure 3-5 84 is shown in the high position (high gear mode). Figure 4, the range shift collar 84 is axially positioned so that the high drive structure 92 meshingly engages with the carrier drive teeth 76 on the planet carrier 66, providing high gear range power to the front differential 22, as shown by arrow 94. The low drive structure 88 is axially spaced from the sun drive teeth 78, and the inner drive structure 86 meshingly engages with the input drive teeth 82 on the input shaft 16. In more detail, when the range shift collar 84 is in the high position, power is transmitted (arrow 94) from the input shaft 16 to the range shift collar 84, the planet carrier 66, and to the differential case 40. The power is then transmitted from the differential case 40 through the differential pinions 36 to the differential side gears 42, 43 and to the right and left output shafts 50, 52.

[0049] Figure 6 The range shift collar 84 is shown in the neutral position. Figure 6 , the range shift collar 84 is positioned axially disengaged from the sun gear 60 and the planetary carrier 66 so that power is not transferred to the front differential 22. In the neutral position, the high drive structure 92 is axially spaced from the carrier drive teeth 76, the low drive structure 88 is axially spaced from the sun drive teeth 78, and the inner drive structure 86 is meshingly engaged with the input drive teeth 82 on the input shaft 16. In this way, power is transferred from the input shaft 16 to the range shift collar 84, as shown by arrow 95, and power is not transferred to the front differential 22. When the range shift collar 84 is repositioned between the high position and the low position, the range shift collar 84 is moved through the neutral position so that the planetary gear set 58 and the front differential 22 are disengaged before the range shift collar 84 engages with the carrier drive teeth 76 or the sun drive teeth 78.

[0050] The range switching collar 84 is located Figure 7 The low position (low gear mode) is shown in . Figure 7 , the range shift collar 84 is axially positioned so that the low drive structure 88 meshingly engages with the sun drive teeth 78 on the sun shaft 67 to provide low range power to the front differential 22, as shown by arrow 96. The high drive structure 92 is axially spaced from the carrier drive teeth 76 on the planet carrier 66, and the inner drive structure 86 meshingly engages with the input drive teeth 82 on the input shaft 16. In more detail, when the range shift collar 84 is in the low position, power is transmitted from the input shaft 16 (arrow 96), into the range shift collar 84, into the sun shaft 67, through the sun gear 60, through the planet gears 64, into the planet carrier 66, and to the differential case 40. Next, power is transmitted from the differential case 40 through the differential pinions 36 to the differential side gears 42, 43, and to the right output shaft 50 and the left output shaft 52.

[0051] See also Figure 1 and Figure 3 , the PTU gear set 18 is configured to transfer power from the input shaft 16 to the propeller shaft 26 when the AWD system 10 transfers power to the RDM 14. In more detail, the PTU gear set 18 includes a main shaft 97 that rotatably supports and axially spaced bearings 98, 100, which in turn rotatably support the input shaft 16. In addition, the main shaft 97 is radially and axially supported by axially spaced bearings 102, 104, which in turn are supported by the fixed housing 32. The main shaft 97 also includes an inner portion 106 formed with a main shaft drive structure 108, which is formed as drive teeth formed on the inner circumference or inner surface of the main shaft 97 and faces radially inward. However, it will be appreciated that the main shaft drive structure 108 can be formed in alternative configurations, such as facing radially outward, facing radially inward, or in an axial direction, without changing the scope of the present invention.

[0052] The PTU gear set 18 also includes a main ring gear 110 that is radially and axially supported on the inner portion 106 of the main shaft 97, either integrally formed therewith or as a separate component, such that rotation of the main shaft 97 rotates the main ring gear 110. It should be understood that the main ring gear 110 can be a hypoid ring gear, a spiral bevel gear, a straight bevel gear, etc., without changing the scope of the present invention. Figure 1 As shown, the PTU gear set 18 also includes a hypoid pinion 112 meshingly engaged with the main ring gear 110. The PTU gear set 18 also includes a pinion shaft 114 extending axially from the hypoid pinion 112, and the pinion shaft 114 is either integral with the hypoid pinion 112 or as a separate component, so that rotation of the hypoid pinion 112 causes the pinion shaft 114 to rotate. The pinion shaft 114 is radially and axially supported on the fixed housing 32 by axially spaced bearings 116, 118, so that the pinion shaft 114 rotates freely. The PTU 12 may also include a propeller shaft coupler 120, which is non-rotatably coupled to the distal end of the pinion shaft 114 and is configured to be fixedly coupled (i.e., non-rotatably coupled) to the propeller shaft 26, so that rotation of the pinion shaft 114 causes the propeller shaft 26 to rotate. It should be appreciated that the pinion shaft 114 may be operably coupled to the propel shaft 26 using other known methods without altering the scope of the present invention.

[0053] like Figure 1 and 3As shown in FIG. 5 , the PTU 12 also includes an output conversion collar 122, which may alternatively be described as an all-wheel drive (AWD) conversion collar 122. The output conversion collar 122 is splined to the input shaft 16 so that the output conversion collar 122 rotates with the input shaft 16 while being axially slidable relative to the input shaft 16. The output conversion collar 122 is in a state corresponding to the disengagement mode ( Figure 4 ) and the engagement mode ( Figure 5 ) is axially displaceable between two axially spaced positions of the range shift collar 84. The output shift collar 122 is configured to selectively couple the input shaft 16 to the main shaft 97 so as to transmit power to the RDM 14. The output shift collar 122 is axially displaceable by the actuator assembly 28, which is also configured to axially displace the range shift collar 84. However, it should be understood that the output shift collar 122 can be axially displaced by an actuator other than the actuator assembly 28 used for the range shift collar 84 without changing the scope of the present invention.

[0054] See also Figure 4 The output conversion collar 122 includes a body that is formed of an input drive structure 124, which is preferably formed as drive teeth formed on the inner circumference or inner surface and faces radially inward. The input drive structure 124 meshingly engages with the input drive teeth 82 on the end flange 80 of the input shaft 16, while allowing the output conversion collar 122 to be axially displaceable along the input drive teeth 82 so as to remain engaged therewith in the disengagement mode and the engagement mode. In addition, the output conversion collar 122 includes an output drive structure 126, which is formed as drive teeth facing radially outward from the outer circumference or surface of the output conversion collar 122. However, it should be understood that the output drive structure 126 can be formed in alternative configurations, such as facing radially outward, facing radially inward, or in an axial direction, without changing the scope of the present invention. When the output conversion collar 122 is axially repositioned to transfer power through the main shaft 97 and provide power to the RDM 14, the output drive structure 126 is configured to meshingly engage with the main shaft drive structure 108 on the main shaft 97. The output conversion collar 122 also includes an output channel 128, which extends circumferentially around the outer diameter or surface of the output conversion collar 122. The output channel 128 is configured to be operably coupled to the actuator assembly 28, allowing the output conversion collar 122 to be axially repositioned between an engaged position and a disengaged position, the engaged position and the disengaged position corresponding to a disengaged mode and an engaged mode, respectively. It should be understood that the input and output drive structures 124, 126 and the main shaft drive structure 108 can be formed in a gear-like shape, but other configurations of drive structures can also be provided without changing the scope of the present invention.

[0055] The output conversion collar 122 is located at Figure 4See the disengaged position shown in . Figure 4 , the output transfer collar 122 is axially positioned so that the output drive structure 126 is axially spaced apart from the spindle drive structure 108 on the spindle 97. As shown by arrow 134, power is transmitted from the input shaft 16 to the output transfer collar 122 through the input drive structure 124. However, when the output transfer collar 122 is in the disengaged position, the output transfer collar 122 does not transmit power to the spindle 97, which also prevents power from being supplied to the RDM 14.

[0056] The output conversion collar 122 is located Figure 5 See the mating position shown in . Figure 5 , the output conversion collar 122 is axially positioned so that the output drive structure 126 meshingly engages with the main shaft drive structure 108 on the main shaft 97. In addition, the input drive structure 124 meshingly engages with the input drive teeth 82 on the input shaft 16. In this way, power is transmitted from the input shaft 16 to the main shaft 97 through the output conversion collar 122, as shown by arrow 136. Next, the main shaft 97 transmits the supplied power through the main ring gear 110 to the quasi-curved pinion 112, through the pinion shaft 114, and through the propeller shaft coupling 120 to the RDM 14, as shown. Figure 1 As shown by arrow 138.

[0057] See also Figure 8 and Fig. 9, the actuator assembly 28 is configured to axially reposition the range shift collar 84 between a high position (high gear mode) and a low position (low gear mode). In addition, the actuator assembly 28 is configured to axially reposition the output shift collar 122 between a disengaged mode and an engaged mode. The actuator assembly 28 is a barrel cam actuator assembly, which functions similarly to certain known barrel cam actuator assemblies. The actuator assembly 28 includes a barrel cam 140, a barrel camshaft 142, a barrel cam motor 144, an output shift fork 146, and a range shift fork 148. In short, the barrel cam 140 is supported on the barrel camshaft 142 and is configured to rotate therewith. The actuator assembly 28 also includes a spring (not shown) operably connected between the barrel camshaft 142 and the barrel cam 140, and the spring is configured to wind up when the shift actuation is blocked. The barrel cam 140 includes an output cam groove 150 and a range cam groove 152, which are axially spaced apart, extend in the circumferential direction, and include respective cam profiles. The barrel cam motor 144 is operably coupled to the barrel camshaft 142 and is configured to selectively rotate the barrel camshaft 142, which in turn rotates the barrel cam 140. The output switching fork 146 and the range switching fork 148 are slidably coupled to respective support shafts 154, 156. In addition, the output switching fork 146 and the range switching fork 148 are operably coupled to the output cam groove 150 and the range cam groove 152 by pins 158, 160, respectively. As shown in FIG. Figure 8 As shown, the barrel cam 140, barrel cam motor 144 and support shafts 154, 156 are supported on the outer surface of the fixed housing 32. The output shift fork 146 and the range shift fork 148 extend radially through a slot 161 extending through the fixed housing 32. The slot 161 provides clearance for the output shift fork 146 and the range shift fork 148 to be axially repositioned.

[0058] See also Figure 7 and Fig. 9 , the output shift fork 146 has a lower end 162 that is fixedly coupled to the output passage 128 in the output shift collar 122. In addition, the range shift fork 148 has a lower end 164 that is fixedly coupled to the range passage 93 in the range shift collar 84. In operation, the barrel cam motor 144 selectively rotates the barrel cam 140, which causes the pins 158, 160 to be axially repositioned as the pins 158, 160 travel along the cam surfaces in the respective output and range cam grooves 150, 152, resulting in the output shift fork 146 and the range shift fork 148 being axially repositioned along the support shafts 154, 156. The cam profile of the output cam groove 150 is selected to be in the engaged position ( Figure 5 ) and disengaged position ( Figure 4) between the output switching fork 146 and the attached output switching collar 122. In addition, the cam profile of the range cam groove 152 is selected to be in the high position (high gear mode, Figure 4 ) and low position (low gear mode, Figure 7 ) to reposition the range shift collar 84 between the high, low and neutral positions. In this way, the axial position of the output shift fork 146 and the range shift fork 148 is controlled by the rotational position of the barrel cam 140. The barrel cam 140 is configured to reposition the output shift collar 122 between the engaged position and the disengaged position. In addition, the barrel cam 140 is configured to reposition the range shift collar 84 between the high, low and neutral positions.

[0059] The RDM 14 is configured to receive power from the PTU 12 and transmit the power to the rear wheels. Figure 2 , the RDM 14 includes a fixed housing 168, a propeller shaft flange 170, an input hub 172, a torque transmitting coupling 174, a clutch drum 20, and a hypoid pinion shaft 176. The fixed housing 168 includes an internal cavity for housing and supporting certain components of the RDM 14. The propeller shaft flange 170 is fixedly coupled to the distal end of the input hub 172 and is configured to be fixedly coupled to one end of the propeller shaft 26. The input hub 172 is radially and axially supported within the fixed housing 168 by axially spaced bearings 177, 178 and is able to rotate freely in response to rotation of the propeller shaft flange 170 and the attached propeller shaft 26.

[0060] The proximal end of the input hub 172 is operably coupled to a torque transfer coupling 174, which in turn is configured to selectively transfer power from the input hub 172 to the clutch drum 20 when the torque transfer coupling is in an engaged state. The clutch drum 20 is non-rotatably coupled to the distal end of the hypoid pinion shaft 176. The torque transfer coupling 174 includes a hydraulic piston 179, a friction clutch 180, a hydraulic motor 182, and a hydraulic pump 184. The friction clutch 180 includes a plurality of friction plates 185, which are axially spaced apart when the friction clutch 180 is in a disengaged state.

[0061] The hydraulic motor 182 and the hydraulic pump 184 are configured to selectively provide hydraulic pressure to the hydraulic piston 179. The hydraulic pressure applied to the hydraulic piston 179 causes the friction plates 185 to frictionally engage with the adjacent friction plates 185, causing the friction clutch 180 to engage, allowing power to be transferred from the input hub 172 to the hypoid pinion shaft 176 through the friction clutch 180. The torque transmitting coupling 174 also includes a return spring 186 that disengages the friction clutch 180 by axially spacing the friction plates 185 when the hydraulic pressure is removed from the hydraulic piston 179 and the torque transmitting coupling is in a disengaged state. In this way, the return spring 186 ensures that power is not transferred between the clutch drum 20 and the input hub 172 unless the AWD system 10 activates the hydraulic motor 182, causing the hydraulic pump 184 to provide hydraulic pressure to the hydraulic piston 179 engaged with the friction clutch 180. The torque transmitting coupling 174 is normally in a disconnected state, which prevents power transfer between the input hub 172 and the clutch drum 20. When hydraulic pressure is removed from the hydraulic piston 179, the return spring 186 creates additional separation between the friction plates 185 within the friction clutch 180 to reduce the residual drag torque in the friction clutch 180 (compared to other known couplings). The return spring 186 allows the drag torque of the AWD system 10 to become low enough to stop the rotation of the driveline components.

[0062] like Figure 2 As shown, the hypoid pinion shaft 176 is radially and axially supported within the fixed housing 168 by axially spaced bearings 192, 194 and is free to rotate in response to rotation of the clutch drum 20. The RDM 14 also includes a hypoid pinion gear 196 supported on the proximal end of the hypoid pinion shaft 176, the hypoid pinion gear 196 being either integral therewith or as a separate component, such that rotation of the hypoid pinion shaft 176 causes the hypoid pinion gear 196 to rotate.

[0063] The RDM 14 also includes a main annular gear 198 meshingly engaged with the hypoid pinion 196, so that the main annular gear 198 rotates in response to the rotation of the hypoid pinion 196. It should be understood that the main annular gear 198 can be a hypoid annular gear, a spiral bevel gear, a straight bevel gear, etc., without changing the scope of the present invention. The main annular gear 198 is radially and axially supported on the inner portion of the annular gear hub 200, and the main annular gear 198 is either integral therewith or as a separate component, so that the rotation of the main annular gear 198 drives the annular gear hub 200 to rotate. The annular gear hub 200 is radially and axially supported on the fixed housing 168 by bearings 201. Referring to Fig.10 , the main ring gear 198 is also supported by bearings 202 and 203, which will be further described below.

[0064] The RDM 14 also includes a planetary gear set 204, a rear differential 205, a left output shaft 206, and a right output shaft 208. The planetary gear set 204 is configured to selectively provide power to the rear differential 205 in a high range and a low range, and the rear differential 205 transmits power to the left and right output shafts 206, 208. Fig.10 , the left output shaft 206 is radially and axially supported by bearings 210, which are in turn supported by the fixed housing 168. The right output shaft 208 is radially and axially supported in the fixed housing 168 by contact journals formed on the outer surface of the differential cover 212, which will be further described below. In turn, the differential cover 212 is radially and axially supported by bearings 202. The output shafts 206, 208 can be any combination of output shafts, half shafts, coupling shafts, etc. known in the art. The output shafts 206, 208 thus rotate with the wheels connected thereto and selectively drive the wheels.

[0065] like Fig.10 As shown, the rear differential 205 includes a pinion assembly 214 that is rotatably supported within the fixed housing 168. The pinion assembly 214 includes opposing differential pinions 216, a pinion shaft 218, a differential housing 220, and opposing differential side gears 222, 224. The differential pinions 216 are rotatably connected together via the pinion shaft 218, which is mechanically connected to the differential housing 220. In addition, the differential pinions 216 are meshingly engaged with the differential side gears 222, 224, so that torque can be transferred from the differential housing 220 to the differential pinions 216, and then to the differential side gears 222, 224. Pinion shaft 218 rotatably supports differential pinion 216 at its end, and rotates with differential pinion 216 as differential pinion 216 travels around differential side gears 222, 224. Rear differential 205 also includes connecting pins 226 that fixedly couple pinion shaft 218 to differential case 220, so that pinion 216, pinion shaft 218, and differential case 220 of rear differential 205 all travel together around the same axis as side gears 222, 224. Differential case 220 is radially and axially supported by bearings 201, 202, and 203, and can rotate freely within fixed housing 168. It should be understood that bearings 201 and 202 can be tapered roller bearings, or can be alternative known types of bearings.

[0066] See also Fig.10, the differential side gears 222, 224 are supported by the differential case 220, and operate to drive torque to any combination of the left and right output shafts 206, 208. The output shafts 206, 208 thereby rotate with the wheels connected thereto and selectively drive the wheels. The differential case 220 includes a case end flange 230 and a differential cover 212. The differential case 220 also includes a differential shaft 233 extending axially from the inner end of the case end flange 230, the differential shaft 233 being either integral therewith or as a separate component, so that rotation of the differential shaft 233 rotates the case end flange 230. The differential shaft 233, the case end flange 230, and the differential cover 212 are open to allow the output shafts 206, 208 attached to the side gears 222, 224 to extend axially therefrom for driving the wheels. The differential shaft 233, the housing end flange 230 and the differential cover 212 are rotatably supported by the bearings 201 and 202 that support the rear differential 205. The differential shaft 233, the housing end flange 230 and the differential cover 212 also provide support for the right output shaft 208. In order to selectively drive the rear differential 205, the differential shaft 233 includes a flange portion 234 having a drive structure, which is preferably formed as drive teeth 235 around the outer circumference or surface of the flange portion 234, and the drive teeth 235 face radially outward and extend in the axial direction.

[0067] See also Figure 2 , bearings 201 and 202 are tapered roller bearings that radially and axially support the differential case 220 and the differential cover 212, respectively. Bearings 201, 202, and 203 also radially and axially support the main ring gear 198. The main ring gear 198 and the differential case 220 are between the bearings 201, 202 in a stacked arrangement. In addition, the hypoid pinion 196, the hypoid pinion shaft 176, the friction clutch 180, the input hub 172, and the clutch drum 20 are generally aligned on an axis spaced apart between the bearings 201, 202.

[0068] Due to the connection of the output shafts 206, 208 and the side gears 222, 224 to the wheels, when the wheels rotate, the output shafts 206, 208 and the side gears 222, 224 will rotate. The side gears 222, 224 are meshingly engaged with the pinion gears 216, and the ring gear hub 200 is engageable with the differential housing 220, so that torque can be transmitted from the ring gear hub 200, through the planetary gear set 204, through the differential housing 220, the differential pinion gears 216, and then the side gears 222, 224, thereby driving the output shafts 206, 208.

[0069] Likewise Fig.10As shown, the planetary gear set 204 defines alternative paths of torque transmission between the annular gear hub 200 and the rear differential 205, which correspond to a high gear range and a low gear range. The planetary gear set 204 includes a sun gear 236, a planetary ring gear 237, a set of planetary gears 238, and a planet carrier 240. The sun gear 236 is formed integrally with a sun shaft 241, and the sun shaft 241 is rotatably supported on the outer circumference of the differential shaft 233 by bearings 242 and 244. In addition, the sun shaft 241 is supported on the annular gear hub 200, and the sun shaft 241 is either integral with the annular gear hub 200 or as a separate component, so that the rotation of the annular gear hub 200 causes the sun shaft 241 to rotate. In order to selectively drive the rear differential 205, the sun shaft 241 includes a drive structure formed as drive teeth 246 adjacent to the inner end. Fig.10 In the embodiment, the sun drive teeth 246 are formed around the outer circumference or outer surface of the sun shaft 241 and face radially outward. However, it should be understood that the sun drive teeth 246 can be formed in alternative configurations, such as facing radially outward, facing radially inward, or in an axial direction without changing the scope of the present invention.

[0070] The planetary ring gear 237 is connected to the fixed housing 168 and is concentric with the sun gear 236 in a radially spaced, opposed relationship. The set of planetary gears 238 radially mesh with the sun gear 236 and the planetary ring gear 237. The planetary gears 238 are mounted to and supported by the planetary carrier 240 to form a planetary carrier assembly 248, which is rotatably supported by the sun gear 236. The planetary carrier 240 has an outer carrier segment 250, an inner carrier segment 252, and circumferentially spaced support shafts 254 for rotatably supporting the planetary gears 238.

[0071] To selectively drive the rear differential 205, the outboard frame segment 250 includes a drive structure formed as a drive tooth 258 adjacent the outboard end. Fig.10 In the embodiment of the present invention, the carrier drive teeth 258 are formed around the inner circumference or inner surface of the outer carrier segment 250 and face radially inward. However, it should be understood that the carrier drive teeth 258 can be formed in alternative configurations, such as facing radially outward, facing radially inward, or in an axial direction, without changing the scope of the present invention.

[0072] In order to selectively lock the left output shaft 206 to prevent the left output shaft 206 from rotating relative to the right output shaft 208, the left output shaft 206 includes a locking drive tooth 260 that faces radially outward from the outer circumference or outer surface of the left output shaft 206, such as Fig.10As shown. However, it should be understood that the locking drive teeth 260 can be formed in alternative configurations, such as facing radially outward, facing radially inward, or in an axial direction, without changing the scope of the present invention. The RDM 14 also includes a conversion collar 262 that is splined to the differential shaft 233 so that the conversion collar 262 rotates with the differential shaft 233 while being axially slidable relative to the differential shaft 233. The conversion collar 262 is in a position corresponding to the 4HI mode (4HI position, Fig.11 )、4LO mode (4LO position, Fig.13 ) and 4LO-locked mode (4LO-locked position, Fig.14 ) is axially displaceable between three axially spaced positions. When the switching collar 262 moves between the 4HI and 4LO modes, the switching collar 262 passes through the neutral position ( Fig.12 ).

[0073] like Figure 2As shown, the conversion collar 262 is axially displaceable by a suitable actuator assembly 264, which is, for example, a hydraulic actuator, a barrel cam actuator, a solenoid, etc., which is electrically controlled by a vehicle controller. An exemplary actuator assembly 264 is a barrel cam actuator assembly known in the art. The actuator assembly 264 includes a barrel cam 266, a barrel camshaft 268, a cam driver 269, a barrel cam motor 270, a spring stopper 271, a conversion fork 272, and a pin 274. The barrel cam 266 is fixedly connected to the barrel camshaft 268 and rotates with the barrel camshaft 268. In addition, the barrel cam 266 includes a cam groove 280 extending in a circumferential direction. The barrel cam motor 270 is operably connected to the cam driver 269, and the cam driver 269 is further operably connected to the barrel camshaft 268 via the spring stopper 271. The barrel cam motor 270, cam driver 269 and spring stop 271 are configured to selectively rotate the barrel cam shaft 268 about the longitudinal axis of the shaft, as further described below. The shift fork 272 is operably coupled to the cam slot 280 via a pin 274. In addition, the shift fork 272 has a fork end 284 that is fixedly coupled to a fork channel 286 that extends circumferentially around the outer circumference or outer surface of the shift collar 262. As the pin 274 travels along the cam slot 280, the axial position of the shift collar 262 is determined by the rotational position of the barrel cam 266. The barrel cam motor 270 selectively rotates the cam driver 269, which in turn rotates the spring stop 271 and the barrel cam 266 to reposition the shift fork 272 and the attached shift collar 262 between the 4HI position, the 4LO position and the 4LO-locked position. When the shift fork 272 is blocked from repositioning in response to activation of the barrel cam motor 270, the spring stop 271 is wound up by the movement of the cam driver 269 and exerts rotational pressure on the barrel cam 266. Once the shift fork 272 is free to move in the axial direction (i.e., "unblocked"), the tension in the spring stop 271 causes the barrel cam 266 to rotate and reposition the shift fork 272 to a new axial position, which in turn repositions the shift collar 262.

[0074] See also Fig.10, the conversion collar 262 includes a body, the body is formed with an output drive structure 288, and the output drive structure 288 is formed as a drive tooth formed on the inner circumference or inner surface, facing radially inward. However, it should be understood that the output drive structure 288 can be formed as an alternative configuration, such as facing radially outward, facing radially inward, or in the axial direction, without changing the scope of the present invention. The output drive structure 288 meshingly engages with the differential drive teeth 235 on the differential shaft 233, while allowing the conversion collar 262 to be axially displaceable along the differential drive teeth 235 so as to remain engaged with the differential drive teeth 235 in the 4HI mode, the 4LO mode, and the 4LO-locking mode. In this way, the conversion collar 262 is able to transmit power to the housing end flange 230 and enter the differential housing 220 through the differential shaft 233. In addition, the locking drive teeth 260 on the left output shaft 206 are radially aligned with the drive teeth on the differential shaft 233. The shift collar 262 is axially slidable, allowing the output drive structure 288 to meshingly engage the lock drive teeth 260 and the differential drive teeth 235 simultaneously, providing Fig.14 4LO-locked mode shown.

[0075] like Fig.10 As shown, the conversion collar 262 also includes a lower drive structure 290, which is formed as drive teeth formed on the inner circumference or inner surface, facing radially inward. However, it should be understood that the lower drive structure 290 can be formed as an alternative configuration, such as facing radially outward, facing radially inward, or in an axial direction, without changing the scope of the present invention. When the conversion collar 262 is axially positioned to transfer power from the main ring gear 198 and provide 4HI power to the rear differential 205, the lower drive structure 290 meshingly engages with the sun drive teeth 246 on the sun shaft 241.

[0076] like Fig.10As shown, the shift collar 262 also includes an upper drive structure 292 formed as drive teeth on an outer circumference or outer surface, facing radially outward. However, it should be understood that the upper drive structure 292 can be formed in alternative configurations, such as facing radially outward, facing radially inward, or in an axial direction, without changing the scope of the present invention. When the shift collar 262 is axially positioned to transfer power from the planet carrier 240 and provide 4LO power to the rear differential 205, the upper drive structure 292 is configured to meshingly engage with the carrier drive teeth 258 on the outer carrier segment 250. In addition, the shift collar 262 is axially slidable from the 4LO position to the 4LO-locked position. When the shift collar 262 is in the 4LO-locked position, the output drive structure 288 meshingly engages with the locking drive teeth 260 on the left output shaft 206, while maintaining the upper drive structure 292 meshingly engaged with the frame drive teeth 258 on the outer frame segment 250, and maintaining the output drive structure 288 meshingly engaged with the differential drive teeth 235 on the differential shaft 233.

[0077] It should be understood that the drive teeth 246, 235, 258, 260 and the drive structures 290, 288, 292 can be formed as similar gear teeth, but can be provided as other configurations of the drive structures without changing the scope of the invention. Typically, the locking drive teeth 260, the differential drive teeth 235, and the output drive structure 288 are located at the same or approximately the same radial distance from the center axis extending through the left output shaft 206 and the right output shaft 208, although the distance can be changed to change the torque transmission characteristics. In addition, the frame drive teeth 258 and the upper drive structure 292 are located radially offset from the locking drive teeth 260, the differential drive teeth 235, and the output drive structure 288. In addition, the lower drive structure 290 and the sun drive teeth 246 are located radially offset from the remaining drive teeth 258, 235, 260 and the drive structures 288, 292. However, it should be understood that the radial and axial positions of the drive teeth 246, 258, 235, 260 and drive structures 290, 288, 292 may be varied without changing the scope of the present invention.

[0078] In operation, when the output shift collar 122 is in the engaged position, the AWD system 10 selectively provides power to the main shaft 97 in the PTU 12, such as Figure 5 As shown by arrow 136. Figure 1 The power supplied to the main shaft 97 is transmitted to the transmission shaft 26 through the main ring gear 110 and the hypoid pinion 112, as shown by arrow 138. Figure 2 As shown, power is transferred from the propeller shaft 26 to the input hub 172 in the RDM 14, as shown by arrow 294. When the torque transmitting coupling 174 is disengaged, power is not transferred between the input hub 172 and the clutch drum 20.

[0079] In order to engage the RDM 14 and transfer power from the propeller shaft 26 to the rear differential 205, the AWD system 10 activates the hydraulic motor 182, which causes the hydraulic pump 184 to apply hydraulic pressure to the hydraulic piston 179, which in turn applies pressure to the friction clutch 180, causing the friction clutch 180 to engage. After the friction clutch 180 is engaged, the power supplied to the input hub 172 is transferred to the clutch drum 20 through the friction clutch 180, through the hypoid pinion shaft 176, the hypoid pinion 196, and to the main ring gear 198, as shown. Figure 2 As shown by arrow 296 in FIG.

[0080] The AWD system 10 is configured to selectively place the RDM 14 in the 4HI, 4LO, and 4LO-locked modes by axially repositioning the shift collar 262 between three spaced-apart positions, namely, the 4HI, 4LO, and 4LO-locked positions, respectively. Fig.11 , the RDM 14 is shown in 4HI mode, wherein the shift collar 262 is in the 4HI position, and the RDM 14 transmits 4HI range power to the rear differential 205. In 4HI mode, the lower drive structure 290 of the shift collar 262 is meshingly engaged with the sun drive teeth 246, and the output drive structure 288 is meshingly engaged with the differential drive teeth 235 and axially spaced from the locking drive teeth 260. In addition, the upper drive structure 292 on the shift collar 262 is axially spaced from the carrier drive teeth 258. In more detail, when the RDM 14 is in Fig.11 In the 4HI mode shown, the power supplied to the hypoid pinion 196 ( Figure 2 296) is transmitted through the main ring gear 198 through the sun shaft 241 and to the shift collar 262 through the sun drive teeth 246 meshingly engaged with the lower drive structure 290. Next, the 4HI range power is transmitted from the shift collar 262 through the output drive structure 288 meshingly engaged with the differential drive teeth 235 to the differential shaft 233, to the housing end flange 230, to the differential housing 220, through the differential pinion 216 to the side gears 222, 224, and finally to the output shafts 206, 208, as shown by the arrow 298.

[0081] exist Fig.13, the RDM 14 is shown in 4LO mode, wherein the shift collar 262 is in the 4LO position, transmitting 4LO range power to the rear differential 205. In 4LO mode, the upper drive structure 292 on the shift collar 262 is meshingly engaged with the carrier drive teeth 258, and the output drive structure 288 is meshingly engaged with the differential drive teeth 235 and axially spaced from the locking drive teeth 260. In addition, the lower drive structure 290 on the shift collar 262 is axially spaced from the sun drive teeth 246. In more detail, when the RDM 14 is in Fig.13 In the 4LO mode shown, the power supplied to the hypoid pinion 196 ( Figure 2 296 in FIG. 29A ) is transmitted through the main ring gear 198, through the sun shaft 241, through the sun gear 236, the planet gears 238, and into the planet carrier 240. Next, the 4LO range power is transmitted from the outer carrier segment 250 to the shift collar 262 through the carrier drive teeth 258 meshingly engaged with the upper drive structure 292. Next, the 4LO range power is transmitted from the shift collar 262 to the differential shaft 233 and the housing end flange 230 through the output drive structure 288 meshingly engaged with the differential drive teeth 235, and is transmitted to the differential housing 220 through the differential pinion 216, to the side gears 222, 224, and finally to the output shafts 206, 208, as shown by arrows 300.

[0082] When transitioning between the 4HI mode and the 4LO mode, the shift collar 262 is axially repositioned to the neutral position before moving to the 4HI or 4LO position, as shown in FIG. Fig.12 As shown. In the neutral position, the carrier drive teeth 258 are axially spaced apart from the upper drive structure 292, the sun drive teeth 246 are axially spaced apart from the lower drive structure 290, the output drive structure 288 is engaged with the differential drive teeth 235, and the output drive structure 288 is disengaged from the locking drive teeth 260. After the shift collar 262 has been disengaged from the carrier drive teeth 258 and the sun drive teeth 246, the shift collar 262 can be repositioned to the 4HI position or the 4LO position. When the shift collar 262 is axially moved between the 4HI and 4LO positions, the output drive structure 288 on the shift collar 262 remains engaged with the differential drive teeth 235.

[0083] exist Fig.14, the RDM 14 is shown in a 4LO-locked mode, wherein the shift collar 262 is in a 4LO-locked position, which transmits 4LO power to the rear differential 205 and locks the left output shaft 206 to the rear differential 205. Locking the left output shaft 206 to the rear differential 205 prevents the left output shaft 206 from rotating relative to the right output shaft 208, and allows power to be transmitted from the shift collar 262 directly to the left output shaft 206, or to the right output shaft 208 through the rear differential 205, even if the opposite side has limited or no traction at the wheels. In the 4LO-locked mode, the upper drive structure 292 on the shift collar 262 meshingly engages with the carrier drive teeth 258, and the output drive structure 288 meshingly engages with the differential drive teeth 235 and the locking drive teeth 260. In addition, the lower drive structure 290 on the shift collar 262 is axially spaced from the sun drive teeth 246. When the RDM 14 is in the 4LO mode, the RDM 14 can be repositioned to the 4LO-locked mode by axially sliding the shift collar 262 from the 4LO position to the 4LO-locked position. When the shift collar 262 is axially repositioned between the 4LO and 4LO-locked positions, the upper drive structure 292 remains engaged with the carrier drive teeth 258. In addition, the output drive structure 288 remains in meshing engagement with the differential drive teeth 235 while the shift collar 262 is axially repositioned to meshingly engage the output drive structure 288 with the locking drive teeth 260.

[0084] More specifically, when the RDM 14 is in Fig.14 In the 4LO-locked mode shown, the supply to the hypoid pinion 196 ( Figure 2 296) is transmitted to the planet carrier 240 through the main ring gear 198, through the sun shaft 241, through the sun gear 236, through the planet gears 238. Next, the 4LO power is transmitted from the outer carrier section 250 through the carrier drive teeth 258 meshingly engaged with the upper drive structure 292, and to the transfer collar 262. Next, the 4LO power is transmitted from the transfer collar 262 to the differential shaft 233 and the case end flange 230 through the output drive structure 288 meshingly engaged with the differential drive teeth 235, and is transmitted to the differential case 220 through the differential pinion 216, to the side gears 222, 224, and finally to the output shafts 206, 208, as shown by arrows 302. However, because the output drive structure 288 is meshingly engaged with both the locking drive teeth 260 and the differential drive teeth 235 in addition to the meshing engagement of the upper drive structure 292 with the carrier drive teeth 258, the shift collar 262 also rotationally locks the left output shaft 206 with the differential shaft 233 and the planet carrier 240. In this way, the 4LO power is also directly transmitted to the left output shaft 206, as shown by arrow 304.

[0085] Figure 15-18 A second embodiment of a PTU 12' is shown in FIG. 1 , which uses the same reference numerals with an apostrophe (') to indicate similar elements as described above. Fig.15 In this modified PTU 12', the range shift collar 84' includes an internal drive structure 86' that is splined to the input drive teeth 82' on the input shaft 16', similar to the above-described Figure 3 In addition, the range shift collar 84' includes a drive structure 92' that when the range shift collar 84' is in the high position ( Fig.15 ), the drive structure 92' is configured to meshingly engage with the carrier drive teeth 76' to provide high range power to the front differential 22'. In addition, when the range shift collar 84' is axially repositioned to the low position ( Fig.17 ), the drive structure 92' is also configured to meshingly engage with the sun drive gear 78' to transfer low range power to the front differential 22'. Figure 3 In contrast to the illustrated embodiment, the input drive structure 124' on the output shift collar 122' is splined to the upper drive structure 306 formed on the range shift collar 84'. The output shift collar 122' also includes an output drive structure 126' that is configured to meshingly engage with the drive structure 108' on the main shaft 97'. Only the significant differences between the two embodiments are reflected in the drawings and the following description.

[0086] In more detail, Fig.15 The improved PTU 12' shown in FIG. 1 operates substantially the same as the previous PTU 12, wherein the range shift collar 84' transfers power from the input shaft 16' through the planetary gear set 58' to the front differential 22' and to the right output shaft 50' and the left output shaft 52'. The planetary gear set 58' includes planetary gears 64', which are rotatably supported by the planet carrier 66' and radially mesh with the sun gear 60' and the planetary ring gear 62'. The PTU 12' also includes a PTU gear set 18' having a main ring gear 110' supported on the main shaft 97' and includes Figure 1 The hypoid pinion 112 and the pinion shaft 114 are shown.

[0087] The range shift collar 84' is positioned along the input drive teeth 82' on the input shaft 16' in a high position corresponding to the high range mode ( Fig.15 ), a neutral position (neutral mode) disengaged from the front differential 22'. Fig.16 ) and the low position corresponding to the low gear mode ( Fig.17), axially repositionable while maintaining the internal drive structure 86' in meshing engagement with the input drive teeth 82' on the input shaft 16'.

[0088] See also Fig.15 , the input drive teeth 82' on the input shaft 16' are formed on the outer circumference or outer surface of the input shaft 16'. The carrier drive teeth 76' and the sun drive teeth 78' are formed on the outer circumference or outer surface of the inner side frame segment 72' and the sun shaft 67', respectively, facing radially outward and axially spaced apart. The internal drive structure 86' and the lower drive structure 92' are formed on the inner circumference or inner surface of the range shift collar 84', are axially spaced apart, and face radially inward. However, it should be understood that the input drive teeth 82', the carrier drive teeth 76', the sun drive teeth 78', the internal drive structure 86' and the lower drive structure 92' can be formed in alternative configurations, such as facing radially outward, facing radially inward and / or facing in an axial direction, without changing the scope of the present invention.

[0089] In general, the drive teeth 76', 78', 82' and the drive structures 86', 92' are located at the same or approximately the same radial distance from the center axis that extends through the input shaft 16', the left output shaft 52' and the right output shaft 50', although these distances can be changed to change the torque transmission characteristics. In addition, the upper drive structure 306 on the range conversion collar 84' and the input drive structure 124' on the output conversion collar 122' are positioned radially offset from the other drive teeth 76', 78', 82' and other drive structures 86', 92'. In addition, the drive structure 108' on the main shaft 97' and the output drive structure 126' on the output conversion collar 122' are positioned radially offset from the other drive teeth 76', 78', 82' and other drive structures 86', 92', 124', 306. However, it should be understood that the radial position of the drive teeth 76', 78', 82' and drive structures 86', 92', 108, 124', 126', 306 may vary without changing the scope of the present invention.

[0090] When the range switching collar 84' is in Fig.15 In the high position shown, power is transferred from the input shaft 16' to the range shift collar 84' through the input drive teeth 82' meshingly engaged with the inner drive structure 86'. Next, the range shift collar 84' transfers power through the drive structure 92' meshingly engaged with the carrier drive teeth 76' on the inner frame segment 72' and through the planet carrier 66'. As shown by arrows 308, the planet carrier 66' transfers the high range power to the differential case 40' through the differential pinions 36', the side gears 42', 43', and to the output shafts 50', 52'.

[0091] When the range switching collar 84' is in Fig.16 In the neutral position shown, the lower drive structure 92' is axially spaced from the carrier drive teeth 76' and the sun drive teeth 78'. Thus, power from the input shaft 16' is transmitted to the range shift collar 84', but is blocked from being transmitted to the front differential 22'.

[0092] When the range switching collar 84' is in Fig.17 In the low position shown, power is transferred from the input shaft 16' to the range shift collar 84' through the input drive teeth 82' meshingly engaged with the internal drive structure 86'. Next, the range shift collar 84' transfers power to the planet carrier 66' through the drive structure 92' meshingly engaged with the sun drive teeth 78' on the sun shaft 67' and through the sun gear 60' and the planet gears 64'. As shown by arrows 310, the planet carrier 66' transfers the low range power to the differential case 40' through the differential pinions 36', the side gears 42', 43', and to the output shafts 50', 52'.

[0093] The output shift collar 122' is coupled to the upper drive structure 306 on the range shift collar 84' in a disengaged position corresponding to the disengaged mode ( Fig.18 ) and the engagement position corresponding to the engagement mode ( Fig.16 ) while maintaining the output-input drive structure 124' in meshing engagement with the upper drive structure 306 on the range shift collar 84'. Fig.18 , the output shift collar 122' is in the disengaged position, wherein the output drive structure 126' is axially spaced apart from the drive structure 108' on the main shaft 97'. When power is transferred from the input shaft 16' to the range shift collar 84' and into the output shift collar 122' (arrow 312), power is not transferred from the output shift collar 122' to the main ring gear 110'. Thus, power is also not transferred through the PTU gear set 18', and the RDM 14 does not receive power from the propeller shaft 26.

[0094] exist Fig.16, the output shift collar 122' is in an engaged position wherein the output drive structure 126' meshingly engages with the drive structure 108' on the main shaft 97'. When the output shift collar 122' is in the engaged position, power is transferred from the input shaft 16' to the main ring gear 110' through the input drive teeth 82' meshingly engaged with the inner drive structure 86' on the range shift collar 84', through the upper drive structure 306 meshingly engaged with the input drive structure 124' on the output shift collar 122', and through the output drive structure 126' meshingly engaged with the drive structure 108' on the main shaft 97', as indicated by arrow 314. As in the first embodiment, power is transferred from the main ring gear 110' to the propeller shaft 26 through the PTU gear set 18' and supplied to the RDM 14. When the range shift collar 84' is in the high position, the neutral position and the low position, the output shift collar 122' can receive the power provided by the range shift collar 84' from the input shaft 16'. In addition, when the output shift collar 122' is in the engaged position, the output shift collar 122' transmits the power received from the range shift collar 84' to the PTU gear set 18'.

[0095] exist Figure 19-21 A third embodiment of a PTU 12" is shown, using like double quote (") reference numerals to represent like elements as described above. Fig.19 , the improved PTU 12" lacks the range shift collar 84, 84', planetary gear set 58, 58', front differential 22, 22', actuator assembly 28 and output shaft 50, 50', 52, 52' of the previous PTU embodiments 12, 12' described above. Instead, this improved PTU 12" is a single speed PTU 12" and includes a connecting rod shaft 316 having a left end 318 and a right end 320 for driving the wheels. In addition, the PTU 12" includes an input shaft 16" splined to the connecting rod shaft 316 for providing power to the connecting rod shaft 316. The PTU 12" also includes a PTU gear set 18" for transmitting power from the input shaft 16" to the propeller shaft 26 and the RDM 14, as in the previous embodiments. The PTU 12" also includes an output shift collar 122" for transferring power from the input shaft 16" to the main shaft 97" and through the PTU gear set 18". The axial position of the output shift collar 122" is controlled by a cam actuator 322 and a return spring 324, rather than by the actuator assembly 28 described above. Only the significant differences between the two embodiments are reflected in the drawings and the following description.

[0096] See also Fig.19The main shaft 97" includes a main shaft drive structure 108" on the inner circumference or inner surface, facing radially inward. The main shaft 97" transmits the received power to the main ring gear 110", and the main ring gear 110" transmits the power to the quasi-hypoid pinion 112", such as Figure 1 In addition, the input shaft 16" includes input drive teeth 82" formed on the outer circumference or surface of the end flange 80", facing radially outward. However, it will be appreciated that the main shaft drive structure 108" and the input drive teeth 82" can be formed as alternative structures, such as facing radially outward, facing radially inward, or in the axial direction, without changing the scope of the present invention.

[0097] See also Figure 19-21 , the output conversion collar 122" includes an output drive structure 126" formed on an outer circumference or outer surface, facing radially outward. However, it should be understood that the output drive structure 126" can be formed into alternative configurations, such as facing radially outward, facing radially inward, or in an axial direction, without changing the scope of the present invention. The output drive structure 126" meshingly engages with the spindle drive structure 108" on the spindle 97", while allowing the output conversion collar 122" to be axially displaceable along the spindle drive structure 108" so as to be in an engaged position ( Fig. 20 ) and disengaged position ( Fig.21 ) is engaged with the main shaft drive structure 108". In addition, the output conversion collar 122" includes an input drive structure 124" formed on the inner circumference or inner surface, facing radially inward. When the output conversion collar 122" is in Fig.19 and 20 In the engaged position shown, the input drive structure 124" meshingly engages with the input drive teeth 82" on the input shaft 16". Fig.21 As shown, when the output shift collar 122" is in the disengaged position, the input drive structure 124" is axially spaced from the input drive teeth 82" on the input shaft 16". However, it should be understood that the input drive structure 124" can be formed in alternative configurations, such as facing radially outward, facing radially inward, or in an axial direction, without changing the scope of the present invention.

[0098] refer to Figure 19-21 , the cam actuator 322 is configured to be in the engaged position ( Fig. 20 ) and disengaged position ( Fig.21) to reposition the output converting collar 122". The cam actuator 322 is a self-energizing compact disconnect actuator for connecting and disconnecting the output converting collar 122" with the input shaft 16", and is similar to other known cam actuators. The cam actuator 322 includes an electromagnetic coil 326, a pilot clutch 328, a clutch cam 330 and a converting cam 332. The electromagnetic coil 326 is selectively energized to engage and disengage the output converting collar 122" and the input shaft 16". The pilot clutch 328 may include one or more inner plates and outer plates and may be housed in the armature. The inner plate of the pilot clutch 328 is splined to the clutch cam 330. The outer plate of the pilot clutch 328 is splined to the fixed housing 32". The clutch cam profile 333 on the clutch cam 330 contacts the cam profile 334 on the surface of the converting cam 332. The shift cam 332 is supported by the output shift collar 122", or is formed integrally with the output shift collar 122" or as a separate component, so that rotation of the shift cam 332 rotates the output shift collar 122", and the output shift collar 122" is axially repositioned with the shift cam 332. The shift cam 332 is operably connected to the main shaft 97" via the output shift collar 122", and rotates with the main shaft 97", but is configured to move axially relative to the main shaft 97". The cam profile 334 on the conversion cam 332 has a bistable profile, which includes an engagement portion 334a and a disengagement portion 334b, which correspond to the engagement position and disengagement position of the output conversion collar 122", respectively. The cam actuator 322 also includes a return spring 324, which is radially supported by the main shaft 97" and axially supported between the output conversion collar 122" and the bearing 100" supporting the input shaft 16". The return spring 324 spring-biases the output conversion collar 122" toward a state of engagement with the input shaft 16", and spring-biases the conversion cam 332 to a state of engagement with the clutch cam 330.

[0099] In operation, when the clutch cam profile 333 engages with one of the engagement cam portion 334a and the disengagement cam portion 334b, the cam actuator 322 is activated to cause the clutch cam 330 to stop rotating or to reduce its rotational speed relative to the conversion cam 332. The change in the rotational speed of the clutch cam 330 relative to the rotational speed of the conversion cam 332 causes the clutch cam 330 to engage with the other of the engagement cam portion 334a and the disengagement cam portion 334b, causing the conversion cam 332 to convert the rotational motion of the conversion cam 332 into axial (linear) motion of the conversion cam 332, and causing the output conversion collar 122" to reposition between the engaged position and the disengaged position. When the output conversion collar 122" is in Fig. 20In the engaged position shown, power is transmitted from the input shaft 16" through the input drive teeth 82" meshingly engaged with the input drive structure 124' on the output conversion collar 122" and through the output drive structure 126" meshingly engaged with the drive structure 108" on the main shaft 97", as shown by arrow 336. Next, the power transmitted to the main shaft 97" is transmitted to the propeller shaft 26 through the PTU gear set 18", as previously described in Figure 1 As shown by arrow 138. When the output conversion collar 122" is in Fig.21 In the disengaged position shown, power is not transmitted to the output shift collar 122 ″ because the input drive structure 124 ″ is axially spaced apart from the input drive teeth 82 ″ on the input shaft 16 ″, as shown by arrow 338 .

[0100] exist Fig. 22 A second embodiment of the RDM 14' is shown in FIG. 1 , which uses like reference numerals with quotes (') to indicate like elements as described above. Fig. 22 , this improved RDM 14' lacks Figure 2 The RDM 14 shown has a shift collar 262, an actuator assembly 264 and a planetary gear set 204. Thus, the RDM 14' is a single speed RDM 14', rather than a Figure 2 Only the significant differences between the two embodiments are reflected in the drawings and the following description.

[0101] See also Fig. 22 , the differential housing 220' of the rear differential 205' is radially and axially supported by axially spaced bearings 201', 202', which are in turn supported by the fixed housing 168'. In addition, the differential housing 220' is rotatably supported on the outer circumference of the left output shaft 206' and the right output shaft 208'. The main ring gear 198' is supported by the differential housing 220', so that the rotation of the main ring gear 198' causes the differential housing 220' to rotate. The main ring gear 198' and the differential housing 220' are between the bearings 201', 202' in a stacked arrangement. It should be understood that the bearings 201' and 202' can be tapered roller bearings, or can be other known types of bearings.

[0102] The RDM 14' includes a propeller shaft flange 170' that is configured to be fixedly coupled to the propeller shaft 26, an input hub 172', and a torque transfer coupling 174'. Power received from the propeller shaft 26 through the propeller shaft flange 170' is transferred to the input hub 172', as indicated by arrow 294'. When the torque transfer coupling 174' is deactivated, the return spring 186' biases the hydraulic piston 179' away from the friction clutch 180', causing the friction plates 185' within the friction clutch 180' to disengage, which prevents power from being transferred from the input hub 172' to the clutch drum 20'. When the friction clutch 180' is disengaged, power is also prevented from traveling from the clutch drum 20' to the propeller shaft 26. When hydraulic pressure is removed from hydraulic piston 179', return spring 186' creates additional separation between friction plates 185' within friction clutch 180' to reduce residual drag torque on friction clutch 180', which allows AWD system 10 drag torque to become low enough to stop rotation of driveline components.

[0103] In order to engage the RMD 14' and transfer power to the left output shaft 206' and the right output shaft 208', the hydraulic motor 182' is activated, which causes the hydraulic pump 184' to apply hydraulic pressure to the hydraulic piston 179' and causes the friction clutch 180' to engage. After the friction clutch 180' is engaged, power is transferred from the input hub 172' to the hypoid pinion shaft 176' through the friction clutch 180'. Next, power is transferred from the hypoid pinion shaft 176' to the main ring gear 198' through the hypoid pinion 196' and into the differential case 220' of the rear differential 205'. As shown by arrow 338, the differential case 220' transfers power through the differential pinions 216', the side gears 222', 224', and to the left output shaft 206' and the right output shaft 208'.

[0104] As described above, the all-wheel drive (AWD) system 10 includes a power take-off unit (PTU) 12, 12', 12", which is configured to selectively provide power to a rear drive module (RDM) 14', 14" through a propeller shaft 26 for driving the rear wheels of the vehicle. The AWD system 10 is configured to selectively decouple the PTU 12, 12', 12" and the RDM 14, 14' and stop rotation of certain components within the AWD system 10. In more detail, the PTU 12, 12', 12" includes an output conversion collar 122, 122', 122", which is configured to selectively disconnect the input shaft 16, 16', 16" from the main shaft 97, 97', 97", to prevent power from being transmitted from the input shaft 16, 16', 16" to the RDM 14, 14'. In addition, the PTU 12, 12' includes an optional planetary gear set 58, 58' for providing high-range power and low-range power to the front differential 22, 22'; and a range shift collar 84, 84' for selectively providing high-range power or low-range power to the front differential 22, 22'. In addition, the PTU 12, 12' includes a single actuator for axially repositioning the output shift collar 122, 122', 122" and the range shift collar 84, 84' to selectively transfer power to the RDM 14, 14' and selectively shift to an optional low-range gear. In addition, the RDM 14, 14' includes a torque transfer coupling 174, 174', which is configured to selectively decouple the input hub 172, 172' from the clutch drum 20, 20' to prevent power from being transferred between the clutch drum 20, 20' and the propeller shaft 26. In addition, the RDM 14 includes a shift collar 262, a planetary gear set 204, and a rear differential 205, wherein the shift collar 262 is axially repositionable to provide 4HI power or 4LO power to the rear differential 205. The shift collar 262 is optionally repositionable to a 4LO-locked position, providing 4LO power to the rear differential 205 and locking one of the output shafts 206 to the differential shaft 233.

[0105] The present invention has been described in an illustrative manner, and it should be understood that the terms used are intended to describe the nature of the text rather than to limit it. In accordance with the above teachings, many modifications and variations of the present invention are possible. Therefore, it should be understood that within the scope of the appended claims, the present invention may be implemented in a manner different from that specifically described.

Claims

1. A power output unit for a vehicle, comprising: an input shaft configured to receive power provided to the power output unit; Spindle; a main ring gear non-rotatably coupled to the main shaft and rotating in response to rotation of the main shaft; a hypoid pinion gear and a pinion shaft, the hypoid pinion gear meshingly engaged with the main ring gear, the pinion shaft non-rotatably coupled to the hypoid pinion gear such that rotation of the main ring gear causes rotation of the hypoid pinion gear and the pinion shaft; and an output shift collar axially slidable between an engaged position operatively coupling the input shaft to the main shaft and a disengaged position disconnecting the input shaft from the main shaft; wherein when the output transfer collar is in the engaged position, power received by the input shaft is transmitted through the output transfer collar to the main shaft, through the main ring gear, the hypoid pinion gear to the pinion shaft, and wherein when the output transfer collar is in the disengaged position, the main shaft is separated from the input shaft.

2. The power take-off unit according to claim 1, wherein: The spindle includes a spindle drive structure; The input shaft includes input drive teeth; the output transfer collar including an output drive structure configured to meshingly engage with the spindle drive structure when the output transfer collar is in the engaged position and an input drive structure configured to meshingly engage with the input drive structure when the output transfer collar is in the engaged position; When the output conversion collar is in the disengaged position, one of the input drive structure and the output drive structure is separated from the input drive gear or the main shaft drive structure respectively; as well as When the output shift collar is axially repositioned between the disengaged position and the engaged position, the other of the input drive structure and the output drive structure remains engaged with the input drive teeth or the main shaft drive structure, respectively.

3. The power output unit according to claim 2, further comprising: A cam actuator is configured to selectively axially reposition the output shift collar between an engaged position and a disengaged position.

4. The power output unit according to claim 1, further comprising: A differential comprising: a differential case; opposing pinion gears rotatably connected together via a pinion shaft mechanically connected to the differential case; opposing first and second side gears meshingly engaged with the pinion gears so that power can be transferred from the differential case to the pinion gears and then to the first and second side gears; a first output shaft non-rotatably coupled to the first side gear; a second output shaft non-rotatably coupled to the second side gear; a planetary gear set including a sun gear non-rotatably coupled to a sun shaft, a planetary ring gear disposed radially outwardly of the sun gear, and a planetary carrier assembly including a planetary carrier having one or more planetary gears rotatably supported thereon, wherein the planetary carrier is engaged with the planetary gears so as to rotate together, and during rotation of the planetary carrier, the planetary gears rotate between the sun gear and the planetary ring gear, and the planetary carrier is non-rotatably coupled to a differential case such that rotation of the planetary carrier causes rotation of the differential case; as well as A range shift collar is rotatably and slidably coupled to the input shaft such that the range shift collar rotates with the input shaft and is axially slidable relative to the input shaft, the range shift collar being axially slidable between a high position connecting the range shift collar to the planet carrier to transmit power received from the input shaft to the planet carrier, and a low position connecting the range shift collar to the sun shaft to transmit power received from the input shaft to the sun gear.

5. The power output unit according to claim 4, further comprising: An actuator assembly is configured to reposition the output shift collar between an engaged position and a disengaged position and is configured to reposition the range shift collar between a high position and a low position.

6. The power take-off unit of claim 5, wherein the actuator assembly is a cartridge cam actuator comprising: a barrel cam having a longitudinal axis and having a range cam groove and an output cam groove extending circumferentially around the barrel cam, the barrel cam being rotatable about the longitudinal axis; an output shift fork fixedly coupled to the output shift collar and operably coupled to the output cam slot; a range shift fork fixedly coupled to the range shift collar and operably coupled to the range cam slot; and A barrel cam motor is operably coupled to the barrel cam and is configured to selectively rotate the barrel cam about the longitudinal axis, causing the output shift fork to axially reposition the output shift collar between an engaged position and a disengaged position, and causing the range shift fork to axially reposition the range shift collar between a high position and a low position.

7. The power take-off unit according to claim 6, wherein: The input shaft includes input drive teeth; The sun shaft includes sun drive teeth for rotatably driving the sun gear; The planet carrier includes carrier drive teeth for rotatably driving the planet carrier; the range shift collar including an input drive structure meshingly engaged with input drive teeth on the input shaft and axially slidable relative to the input drive teeth between a high position and a low position, the range shift collar also including an inner drive structure spaced from the input drive structure; the internal drive structure meshingly engaging the sun drive teeth for transmitting power received from the input shaft through the sun gear for providing low range power to the differential case when the range shift collar is in the low position; and When the range shift collar is in the high position, the internal drive structure meshingly engages the carrier drive teeth for transmitting power received from the input shaft through the planet carrier for providing high range power to the differential case.

8. The power take-off unit according to claim 6, wherein: The input shaft includes input drive teeth; The sun shaft includes sun drive teeth for rotatably driving the sun gear; The planet carrier includes carrier drive teeth for rotatably driving the planet carrier; the range shift collar including an input drive structure meshingly engaged with input drive teeth on the input shaft and axially slidable relative to the input drive teeth between a high position and a low position, the range shift collar including an inner drive structure spaced from the input drive structure, and including a high drive structure radially spaced from the inner drive structure and the input drive structure; When the range shift collar is in the high position, the high drive structure meshingly engages with the carrier drive teeth on the planet carrier for transmitting power received from the input shaft to the planet carrier, and the inner drive structure is axially spaced from the sun drive teeth; and When the range shift collar is in the low position, the inner drive structure meshingly engages the sun drive teeth for transmitting power received from the input shaft through the sun gear for providing power to the differential case, and the high drive structure is axially spaced from the carrier drive teeth.

9. The power take-off unit according to claim 6, wherein: The input shaft includes input drive teeth; The spindle includes a spindle drive structure; The output transfer collar includes an output drive structure configured to meshingly engage the spindle drive structure when the output transfer collar is in the engaged position; The output conversion collar includes an input drive structure meshingly engaged with input drive teeth on the input shaft and axially slidable relative thereto between an engaged position and a disengaged position; in the engaged position, the output drive structure meshingly engages with the main shaft drive structure for transmitting power received from the input shaft to the main shaft through the output conversion collar, and in the disengaged position, the output drive structure is axially spaced apart from the main shaft drive structure on the main shaft, which prevents power from being transmitted from the input shaft to the main shaft.

10. The power take-off unit according to claim 6, wherein: The range shift collar includes an upper drive structure; The spindle includes a spindle drive structure; the output shift collar including an input drive structure configured to meshingly engage an upper drive structure on the range shift collar while being axially slidable relative thereto between an engaged position and a disengaged position; as well as The output transfer collar includes an output drive structure that meshingly engages with the main shaft drive structure when the output transfer collar is in the engaged position, the output drive structure being axially spaced apart from the main shaft drive structure when the output transfer collar is in the disengaged position, and the input drive structure remaining engaged with the upper drive structure when the output transfer collar is repositioned between the engaged position and the disengaged position.

11. A rear drive module for a vehicle, comprising: an input hub configured to receive power; Clutch drum; a torque transmitting coupling configured to selectively transmit power between the input hub and the clutch drum when the torque transmitting coupling is in an engaged state, wherein the input hub is decoupled from the clutch drum when the torque transmitting coupling is in a disengaged state; a hypoid pinion shaft non-rotatably coupled to the clutch drum; a hypoid pinion gear non-rotatably coupled to the hypoid pinion shaft, wherein the hypoid pinion gear rotates with the clutch drum; a main ring gear meshingly engaged with the hypoid pinion gear; A differential comprising: a differential housing; a differential shaft non-rotatably coupled to the differential housing; Opposing pinion gears rotatably connected together by a pinion shaft mechanically connected to the differential case; opposing first and second side gears, the first and second side gears meshingly engaging with the pinion gears so that power can be transferred from the differential case to the pinion gears and then to the first and second side gears; a first output shaft non-rotatably coupled to the first side gear; a second output shaft non-rotatably coupled to the second side gear; a planetary gear set including a sun gear non-rotatably coupled to a sun shaft non-rotatably coupled to a main ring gear; a planetary ring gear disposed radially outward of the sun gear; and a planet carrier assembly including a planet carrier rotatably supporting one or more planet gears thereon, wherein the planet carrier is engaged with the planet gears so as to rotate together, and during rotation of the planet carrier, the planet gears rotate between the sun gear and the planetary ring gear; as well as A conversion collar, which is splined to the differential shaft so that the conversion collar rotates with the differential shaft and is axially slidable relative to the differential shaft, the conversion collar being axially slidable between a 4HI position connecting the sun shaft to the differential shaft for transmitting power received from the hypoid pinion to the differential housing, and a 4LO position connecting the planet carrier to the differential shaft for transmitting power received from the planet carrier to the differential housing, wherein the 4HI position is axially spaced from the 4LO position.

12. The rear drive module according to claim 11, wherein: The differential shaft includes differential drive teeth; and The shift collar includes an output drive structure meshingly engaged with the differential drive teeth and axially slidable relative to the differential drive teeth between a 4HI position and a 4LO position.

13. The rear drive module according to claim 12, wherein: The sun shaft includes a sun drive gear; the shift collar including a lower drive structure configured to meshingly engage the sun drive teeth when the shift collar is in the 4HI position; and When the shift collar is spaced from the 4HI position, the lower drive structure is axially spaced from the sun drive gear.

14. The rear drive module according to claim 13, wherein: The planet carrier includes carrier drive gears; the shift collar including an upper drive structure configured to meshingly engage the carrier drive teeth when the shift collar is in the 4LO position; and When the shift collar is in the 4HI position, the upper drive structure is axially spaced from the carrier drive gear.

15. The rear drive module according to claim 14, wherein: The shift collar is axially slidable between a 4LO-locked position and a 4LO position while maintaining the output drive structure in meshing engagement with the differential drive teeth, the 4LO-locked position being axially spaced from the 4LO position, The first output shaft includes a locking drive tooth; When the shift collar is in the 4LO-locked position, the output drive structure meshingly engages the locking drive teeth and the differential drive teeth; as well as When the shift collar is in the 4LO position, the output drive structure is axially spaced from the locking drive teeth and meshingly engaged with the differential drive teeth.

16. The rear drive module according to claim 15, further comprising: An actuator assembly is configured to axially reposition the shift collar between a 4LO-locked position, a 4LO position, and a 4HI position.

17. The rear drive module according to claim 16, wherein: The actuator assembly is a barrel cam actuator comprising: a barrel cam having a longitudinal axis and having a cam groove extending circumferentially around the barrel cam, the barrel cam being rotatable about the longitudinal axis; a shift fork fixedly coupled to the shift collar and operably coupled to the cam slot; and A barrel cam motor is operably coupled to the barrel cam and configured to selectively rotate the barrel cam about the longitudinal axis, causing the shift fork to axially reposition the shift collar between the shift collar between a 4LO-locked position, a 4LO position, and a 4HI position.

18. The rear drive module of claim 11, wherein the torque transfer coupling further comprises a friction clutch, the friction clutch being configured to operably couple the clutch drum to the input wheel hub when the friction clutch is engaged and the torque transfer coupling is in an engaged state, wherein the friction clutch separates the clutch drum from the input wheel hub when the friction clutch is disengaged and the torque transfer coupling is in a disengaged state.

19. The rear drive module according to claim 18, wherein: The friction clutch further includes a plurality of friction plates that are axially repositionable between an engaged state coupling the clutch drum to the input hub and a disengaged state separating the clutch drum from the input hub; The torque transmitting coupling also includes a hydraulic piston configured to selectively apply pressure to the friction plates in an axial direction to reposition the friction plates to the engaged state, and a return spring configured to bias the friction plates toward the disengaged state; and When pressure is removed from the friction plates, the return spring disengages the friction clutch, allowing the clutch drum to separate from the input hub.

20. The rear drive module according to claim 11, wherein: The primary ring gear and differential are radially and axially supported between spaced bearings in a stacked arrangement.

21. A rear drive module for a vehicle, comprising: an input hub configured to receive power; Clutch drum; a torque transmitting coupling configured to selectively transmit power between the input hub and the clutch drum when the torque transmitting coupling is in an engaged state, wherein the input hub is decoupled from the clutch drum when the torque transmitting coupling is in a disengaged state; a hypoid pinion shaft non-rotatably coupled to the clutch drum; a hypoid pinion gear non-rotatably coupled to the hypoid pinion shaft, wherein the hypoid pinion gear rotates with the clutch drum; a main ring gear meshingly engaged with the hypoid pinion gear; a differential comprising: a differential housing configured to rotate in response to rotation of the primary ring gear; a differential shaft non-rotatably coupled to the differential housing; Opposing pinion gears rotatably connected together by a pinion shaft mechanically connected to the differential case; opposing first and second side gears, the first and second side gears meshingly engaging with the pinion gears so that power can be transferred from the differential case to the pinion gears and then to the first and second side gears; a first output shaft non-rotatably coupled to the first side gear; as well as a second output shaft non-rotatably coupled to the second side gear; wherein the torque transmitting coupling further comprises a friction clutch including a plurality of friction plates axially repositionable between an engaged state coupling the clutch drum to the input hub and a disengaged state separating the clutch drum from the input hub; a hydraulic piston configured to selectively apply pressure to the friction plate in an axial direction to reposition the friction plate into an engaged state; and a return spring configured to bias the friction plate toward a disengaged state; and Wherein when the pressure is removed from the friction plates, the return spring disengages the friction clutch by axially separating the friction plates, separating the clutch drum from the input hub.

22. The rear drive module according to claim 21, wherein: The primary ring gear and differential are radially and axially supported between spaced bearings in a stacked arrangement.

23. An all-wheel drive system for a vehicle, comprising: The power take-off unit of claim 1, adapted to selectively transmit power to a pinion shaft; a propulsion shaft having a first end operably coupled to the pinion shaft such that the propulsion shaft rotates in response to rotation of the pinion shaft; and a rear drive module comprising: an input hub non-rotatably coupled to a propeller shaft and configured to receive power from a power take-off unit; a clutch drum; a torque transmitting coupling configured to selectively transmit power between the input hub and the clutch drum; a second hypoid pinion shaft non-rotatably coupled to the clutch drum; a second hypoid pinion non-rotatably coupled to the second hypoid pinion; a second main ring gear meshingly engaged with the second hypoid pinion; a second differential comprising: a second differential case, a second differential shaft non-rotatably coupled to the second differential case, an opposing second pinion rotatably connected together by being mechanically coupled to the second pinion shaft of the second differential case, an opposing third side gear and a fourth side gear meshingly engaged with the second pinion so that power can be transmitted from the second differential case to the second pinion and then to the third side gear and the fourth side gear; a third output shaft non-rotatably coupled to the third side gear, a fourth output shaft non-rotatably coupled to the fourth side gear, the third side gear and the fourth side gear being coaxially arranged and rotatable relative to the second differential case; The second planetary gear set comprises a second sun gear, a second planetary ring gear, and a second planetary carrier assembly; the second sun gear is non-rotatably connected to the second sun shaft, the second sun shaft is non-rotatably connected to the second main ring gear, the second planetary ring gear is arranged radially outside the second sun gear, and the second planetary carrier assembly comprises a second planetary carrier rotatably supporting one or more second planetary gears thereon, wherein the second planetary carrier is engaged with the second planetary gears so as to rotate together, and during the rotation of the second planetary carrier, the second planetary gears rotate between the second sun gear and the second planetary ring gear; rear drive mode The block also includes a second transfer collar, which is splined to the second differential shaft so that the second transfer collar rotates together with the second differential shaft and is axially slidable relative to the second differential shaft, wherein the second transfer collar is axially slidable between a 4HI position and a 4LO position, the 4HI position connecting the second sun shaft to the second differential shaft for transmitting power received from the second hypoid pinion to the second differential case, and the 4LO position connecting the second planetary carrier to the second differential shaft for transmitting power received from the second planetary carrier to the second differential case, wherein the 4HI position is axially spaced from the 4LO position.

24. The all-wheel drive system of claim 23, wherein: The second differential shaft includes differential drive teeth; and The second shift collar includes an output drive structure meshingly engaged with the differential drive teeth and axially slidable relative to the differential drive teeth between a 4HI position and a 4LO position.

25. The all-wheel drive system of claim 24, wherein: The second sun shaft includes a sun drive gear; the second shift collar including a lower drive structure configured to meshingly engage the sun drive gear when the second shift collar is in the 4HI position; and When the second shift collar is spaced from the 4HI position, the lower drive structure is axially spaced from the sun drive gear.

26. The all-wheel drive system of claim 25, wherein: The second planet carrier includes carrier drive gears; the second shift collar including an upper drive structure configured to meshingly engage the rack drive teeth when the second shift collar is in the 4LO position; and When the second shift collar is in the 4HI position, the upper drive structure is axially spaced from the carrier drive gear.

27. The all-wheel drive system of claim 26, wherein: The second shift collar is axially slidable between a 4LO-locked position and a 4LO position while maintaining the output drive structure in meshing engagement with the differential drive teeth, the 4LO-locked position being axially spaced from the 4LO position, The third output shaft includes a locking drive tooth; When the second shift collar is in the 4LO-locked position, the output drive structure meshingly engages the locking drive teeth and the differential drive teeth; as well as When the second shift collar is in the 4LO position, the output drive structure is axially spaced from the locking drive teeth and meshingly engaged with the differential drive teeth.

28. The all-wheel drive system of claim 23, wherein the power output unit further comprises: The spindle includes a spindle drive structure; The input shaft includes input drive teeth; as well as the output shift collar including an output drive structure configured to meshingly engage with the spindle drive structure and an input drive structure configured to meshingly engage with the input drive teeth when the output shift collar is in the engaged position; wherein when the output conversion collar is in the disengaged position, one of the input drive structure or the output drive structure is separated from the input drive gear or the main shaft drive structure respectively; and Wherein one of the input drive structure or the output drive structure remains engaged with the input drive teeth or the main shaft drive structure, respectively, when the output shift collar is repositioned between the disengaged position and the engaged position.

29. The power take-off unit of claim 23, further comprising: A differential comprising: a differential case; opposing pinion gears rotatably connected together by a pinion shaft mechanically connected to the differential case; opposing first and second side gears, the first and second side gears meshingly engaging with the pinion gears so that power can be transferred from the differential case to the pinion gears and then to the first and second side gears; a first output shaft non-rotatably coupled to the first side gear; a second output shaft non-rotatably coupled to the second side gear; a planetary gear set including a sun gear non-rotatably coupled to a sun shaft, a planetary ring gear disposed radially outwardly of the sun gear, and a planetary carrier assembly including a planetary carrier having one or more planetary gears rotatably supported thereon, wherein the planetary carrier is engaged with the planetary gears so as to rotate together, and during rotation of the planetary carrier, the planetary gears rotate between the sun gear and the planetary ring gear, and the planetary carrier is non-rotatably coupled to a differential case such that rotation of the planetary carrier causes rotation of the differential case; as well as A range shift collar is rotatably and slidably coupled to the input shaft such that the range shift collar rotates with the input shaft and is axially slidable relative to the input shaft, the range shift collar being axially slidable between a high position connecting the range shift collar to the planet carrier for transmitting power received from the input shaft to the planet carrier, and a low position connecting the range shift collar to the sun shaft for transmitting power received from the input shaft to the sun gear.

30. The power output unit of claim 29, further comprising: An actuator assembly is configured to reposition the output shift collar between an engaged position and a disengaged position and is configured to reposition the range shift collar between a high position and a low position.

31. A power take-off unit according to claim 30, wherein: The actuator assembly is a barrel cam actuator comprising: a barrel cam having a longitudinal axis and having a range cam groove and an output cam groove extending circumferentially around the barrel cam, the barrel cam being rotatable about the longitudinal axis; an output shift fork fixedly coupled to the output shift collar and operably coupled to the output cam slot; a range shift fork fixedly coupled to the range shift collar and operably coupled to the range cam slot; and A barrel cam motor is operably coupled to the barrel cam and is configured to selectively rotate the barrel cam about the longitudinal axis to cause the output shift fork to axially reposition the output shift collar between an engaged position and a disengaged position and to cause the range shift fork to axially reposition the range shift collar between a high position and a low position.

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