2-Speed Disconnect AWD System with Pinion Coupler

Abstract

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

Description

Technical Field

[0001] Cross - reference to related applications

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 359,217, filed on July 8, 2022, the disclosure of which is hereby incorporated by reference in its entirety.

[0002]

[0002] The present invention relates to a disconnect assembly for an all - wheel - drive (AWD) vehicle. More particularly, the present invention relates to a power takeoff unit (PTU) and a rear drive module (RDM) for an all - wheel - drive (AWD) vehicle.

Background Art

[0003]

[0003] An all - wheel - drive (AWD) vehicle can be driven mainly by a front axle powered by the vehicle's engine through a gearbox. An AWD vehicle can include an all - wheel - drive system (AWD system) including a power takeoff unit (PTU) and a rear drive module (RDM). Power can be transmitted to the rear axle by the power takeoff unit (PTU), a drive axle, and the rear drive module (RDM). It is generally known that the PTU can selectively transmit power to the RDM through a gear set within the PTU. Additionally, it is generally known that the PTU can include an optional low - range mode in which it can shift into a low gear range.

[0004]

[0004] The RDM converts the rotational power 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, through the pinion gear, through the ring gear, and through the rear differential. The output shaft is driven by the side gears of the rear differential that are driven by the rotation of the ring gear. It is generally known that a vehicle includes a disengagement assembly engaged between the ring gear and the differential pinion gear to connect or disconnect the ring gear and the differential pinion gear. It is generally known that the disengagement assembly is operable by an actuator assembly such as a hydraulic or electric clutch, solenoid, etc.

[0005]

[0005] It is generally known that a vehicle includes a differential lock to prevent one driven wheel from rotating relative to the other driven wheel. This is typically achieved by locking one differential side gear to the differential housing, thereby preventing rotation of the side gear relative to the differential housing. It is also known to provide a hydraulic or electric clutch to lock or unlock one of the side gears of the rear differential or the output shaft relative to the differential housing. Additionally, it is generally known that the RDM includes an optional low range mode in which the RDM can shift to a low gear range.

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0006]

[0006] It is desirable to provide an AWD system that can disconnect the PTU from the RDM and stop the rotation of specific components within the AWD system. To prevent power from being transmitted from the input shaft to the RDM, it is also desirable to disconnect the input shaft to the PTU from the gear set. Additionally, it is desirable for the PTU to include a single actuator to selectively transmit power to the RDM and to selectively shift into an optional low range gear.

[0007]

[0007] In addition, it is desirable to disconnect the RDM at the clutch drum to prevent power from being transmitted between the clutch drum and the drive axle. Further, it is desirable to provide a disconnect assembly that is operated by a single actuator configured to lock / unlock the differential lock and selectively shift into an optional low range gear.

Means for Solving the Problem

[0008] According to one embodiment, a power take-off device for a vehicle is provided. The power take-off device includes an input shaft configured to receive power supplied to the power take-off device, a main shaft, and a main ring gear non-rotatably coupled to the main shaft and rotating in response to rotation of the main shaft. The power take-off device also includes a hypoid pinion gear meshing with the main ring gear and a pinion shaft non-rotatably coupled to the hypoid pinion gear, the hypoid pinion gear and the pinion shaft rotating when the main ring gear rotates. In addition, the power take-off device includes a take-out shift collar slidable axially 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 take-out shift collar is in the engagement position, the power received by the input shaft is transmitted through the take-out shift collar to the main shaft, and through the main ring gear and the hypoid pinion gear to the pinion shaft. When the take-out shift collar is in the disengagement position, the main shaft is disconnected from the input shaft.

[0009] According to another embodiment, a rear-wheel drive module for a vehicle is provided. The rear-wheel drive module includes an input hub configured to receive power, a clutch drum, and a torque transmission coupling configured to selectively transmit power between the input hub and the clutch drum when in an engaged state, and the input hub is disengaged from the clutch drum when in a disengaged state. The rear-wheel drive module also includes a hypoid pinion shaft non-rotatably coupled to the clutch drum, a hypoid pinion gear non-rotatably coupled to the hypoid pinion shaft, the hypoid pinion gear rotating with the clutch drum, and a main ring gear meshing with the hypoid pinion gear. The rear-wheel drive module also includes 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 housing, and opposing first and second side gears meshing with the pinion gears so that power can be transmitted from the differential housing to the pinion gears and then transmitted. In addition, the rear-wheel 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 rear-wheel drive module also includes a sun gear non-rotatably coupled to a sun shaft non-rotatably coupled to the main ring gear, a planetary ring gear disposed radially outside the sun gear, and a planetary carrier assembly including a planetary carrier rotatably supporting one or more planetary gears, the planetary carrier engaging with the planetary gears to rotate together, and the planetary gears rotating between the sun gear and the planetary ring gear when the planetary carrier rotates.The rear wheel drive module also includes a shift collar splined to the differential shaft so as to rotate with the differential shaft while being axially slidable relative to the differential shaft, connecting the sun shaft to the differential shaft and transmitting the power received from the hypoid pinion gear to the differential housing at a 4HI position, and connecting the planetary carrier to the differential shaft and transmitting the power received from the planetary carrier to the differential housing at a 4LO position, the shift collar being axially slidable between the 4HI position and the 4LO position, the 4HI position being axially spaced from the 4LO position and including the shift collar.

[0010] According to another embodiment, a rear wheel drive module for a vehicle is provided. The rear wheel drive module includes an input hub configured to receive power, a clutch drum, and a torque transmission coupling configured to selectively transmit power between the input hub and the clutch drum when in an engaged state, and to disconnect the input hub from the clutch drum when in a disengaged state. The rear wheel drive module also includes a hypoid pinion shaft non-rotatably coupled to the clutch drum, a hypoid pinion gear non-rotatably coupled to the hypoid pinion shaft, the hypoid pinion gear rotating with the clutch drum, and a main ring gear meshing with the hypoid pinion gear. The rear wheel drive module also includes a differential housing configured to rotate in response to rotation of the main ring gear, a differential shaft non-rotatably coupled to the differential housing, opposed pinion gears rotatably connected together by a pinion shaft mechanically connected to the differential housing, and a differential including opposed first and second side gears meshing with the pinion gears so that power can be transmitted from the differential housing to the pinion gears and then transmitted. The rear wheel 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 transmission coupling also includes a friction clutch including a plurality of friction plates axially positionally changeable between an engaged state coupling the clutch drum to the input hub and a disengaged state disconnecting the clutch drum from the input hub, a hydraulic piston configured to axially selectively apply pressure to the friction plates to change the position of the friction plates to the engaged state, and a return spring configured to bias the friction plates toward the disengaged state. When the pressure is removed from the friction plates, the return spring disengages the friction clutch and axially separates the friction plates to disconnect the clutch drum from the input hub.

[0011]

[0011] Advantages of the present invention will be readily appreciated as being better understood by reference to the following detailed description when considered in connection with the accompanying drawings.

Brief Description of the Drawings

[0012]

Figure 1

[0012] FIG. 1 is a cross-sectional side view of a power take-off unit (PTU) for an all-wheel drive system (AWD system) for use in a vehicle according to a first embodiment of the present invention.

Figure 2

[0013] FIG. 2 is a cross-sectional side view of a rear-wheel drive module (RDM) for an AWD system according to a first embodiment of the present invention.

Figure 3

[0014] FIG. 3 is a partial cross-sectional side view of the PTU of FIG. 1 showing that the take-off shift collar is in a disengaged position corresponding to a disengagement mode and that the range shift collar is in a high position corresponding to a high gear mode for supplying high gear range power to the front differential.

Figure 4

[0015] FIG. 4 is a partial cross-sectional side view of the PTU of FIG. 3 showing that the take-off shift collar is in a disengaged position and that the range shift collar is in a high position.

Figure 5

[0016] FIG. 5 is a partial cross-sectional side view of the PTU of FIG. 4 showing that the take-off shift collar is in an engaged position corresponding to an engagement mode and that the range shift collar is in a high position.

Figure 6

[0017] FIG. 6 is a partial cross-sectional side view of the PTU of FIG. 5 showing that the take-off shift collar is in an engaged position and that the range shift collar is in a neutral position disengaged from the front differential.

Figure 7

[0018] FIG. 7 is a partial cross-sectional side view of the PTU of FIG. 6 showing that the take-off shift collar is in an engaged position and that the range shift collar is in a low position corresponding to a low gear mode.

Figure 8

[0019] A perspective view of a part of the PTU of FIG. 1 showing a barrel cam actuator assembly according to an embodiment of the present invention.

Figure 9

[0020] A perspective view of the barrel cam actuator assembly of FIG. 8.

Figure 10

[0021] A partial cross-sectional side view of the RDM of FIG. 2 showing that the shift collar is in the 4HI position corresponding to the 4HI mode.

Figure 11

[0022] A partial cross-sectional side view of the RMD of FIG. 10 showing that the shift collar is in the 4HI position.

Figure 12

[0023] A partial cross-sectional side view of the RDM of FIG. 11 showing that the shift collar is in the neutral position.

Figure 13

[0024] A partial cross-sectional side view of the RDM of FIG. 12 showing that the shift collar is in the 4LO position corresponding to the 4LO mode.

Figure 14

[0025] A partial cross-sectional side view of the RDM of FIG. 13 showing that the shift collar is in the 4LO lock position corresponding to the 4LO lock mode.

Figure 15

[0026] A cross-sectional side view of a power take-off unit (PTU) for an all-wheel drive system (AWD system) for use in a vehicle according to a second embodiment of the present invention, showing that the range shift collar is in the high position corresponding to the high gear mode and that the take-out shift collar is in the engaged position corresponding to the engaged mode.

Figure 16

[0027] A cross-sectional side view of the PTU of FIG. 15 showing that the take-out shift collar is in the engaged position and that the range shift collar is in the neutral position corresponding to the neutral mode.

Figure 17

[0028] A cross-sectional side view of the PTU of FIG. 16 showing that the take-out shift collar is in the engaged position and that the range shift collar is in the low position corresponding to the low gear mode.

Figure 18

[0029] A partial cross-sectional view of the PTU of FIG. 17 showing that the extraction shift collar is in the disengagement position corresponding to the disengagement mode and showing that the range shift collar is in the high position.

Figure 19

[0030] A cross-sectional side view of a power take-off unit (PTU) for a four-wheel drive system (AWD system) for use in a vehicle according to a third embodiment of the present invention, showing that the extraction shift collar is in the engagement position corresponding to the engagement mode.

Figure 20

[0031] An enlarged cross-sectional side view of a part of the PTU of FIG. 19 showing that the extraction shift collar is in the engaged position.

Figure 21

[0032] An enlarged cross-sectional side view of the PTU of FIG. 20 showing that the extraction shift collar is in the disengagement position corresponding to the disengagement mode.

Figure 22

[0033] A cross-sectional side view of a rear-wheel drive module (RDM) for an AWD system according to a second embodiment of the present invention.

Best Mode for Carrying Out the Invention

[0013]

[0034] FIGS. 1-22 show the components of a disconnecting all-wheel drive (AWD) system 10 for use in an automobile according to the embodiments described herein. References to directions such as top, bottom, upper, lower, upward, downward, longitudinal direction, lateral direction, left, right, etc., used or shown in the Best Mode for Carrying Out the Invention, the figures, or the claims are relative terms used to facilitate the description and are not intended to limit the scope of the present invention in any way. Referring to the figures, like numbers indicate like or corresponding parts throughout several of the figures.

[0014]

[0035] Referring to FIGS. 1 and 2, the vehicle AWD system 10 consists of a power take-off unit (PTU) 12 and a rear wheel drive module (RDM) 14, and the AWD system 10 can disconnect the PTU 12 from the RDM 14 and stop the rotation to improve fuel efficiency. The AWD system 10 disconnects the input shaft 16 from the PTU gear set 18, while the RDM 14 disconnects the connection at the clutch drum 20. The AWD system 10 includes an optional low gear mode in which both the PTU 12 and the RDM 14 can shift to the low gear range.

[0015]

[0036] Referring to FIG. 1, the PTU 12 consists of a front wheel power flow that transmits power from the input shaft 16 to a front differential (in other words, a differential device) 22 that drives the front wheels (not shown). The PTU 12 includes a range shift mechanism 24 that enables the front wheel power flow to shift from the high gear range (i.e., normal) to the low gear range or to neutral. The PTU 12 includes a second power flow through the PTU gear set 18 connected to a propeller shaft 26 that sends power to the rear wheels (not shown). The second power flow can be selectively connected or disconnected from the input shaft 16, and the torque flow to the rear wheels can be disconnected using an actuator assembly 28 that also operates the range shift mechanism 24. It will be appreciated that the propeller shaft 26 can be any type of propeller shaft, drive shaft, drive line, etc., known in the art for transmitting power from the PTU 12 to the RDM 14, or a combination thereof.

[0016]

[0037] The PTU 12 is provided in a vehicle (not shown). The PTU 12 may be referred to as a part of a vehicle axle, as will be understood from the following description. The PTU 12 includes a fixed housing 32 that defines an internal compartment in which a PTU gear set 18 and a front differential 22 are received. Additionally, the fixed housing 32 is fixedly supported on the vehicle. The PTU 12 is operably connected to a drive shaft or a vehicle drive train, and an engine or a motor, and an input shaft 16 is rotatably driven by the drive train.

[0017]

[0038] As depicted in FIG. 3, the front differential 22 includes a pinion gear assembly 34 rotatably supported within a fixed housing 32. The pinion gear assembly 34 includes opposing differential pinion gears 36, a pinion shaft 38, a differential housing 40, and opposing first and second side gears 42, 43. The pinion gears 36 are rotatably connected together by a pinion shaft 38 mechanically connected to the differential housing 40. Additionally, the differential pinion gears 36 mesh with the first and second side gears 42, 43 such 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, 43. The pinion shaft 38 rotatably supports the differential pinion gears 36 at its ends and rotates with the differential pinion gears 36 as the differential pinion gears 36 move around the first and second side gears 42, 43. The front differential 22 further includes a connector pin (not shown) fixedly coupling the pinion shaft 38 to the differential housing 40 such that the pinion gear 36, pinion shaft 38, and differential housing 40 of the front differential 22 all move together around the same shaft axis as the side gears 42, 43. The differential housing 40 is supported radially and axially by bearings 44, 46 and can rotate freely within the fixed housing 32.

[0018]

[0039] Differential side gears 42, 43 are supported by differential housing 40 and operate to transmit torque to any combination of left and right output shafts 50, 52 (i.e., first and second output shafts), which may be any type of side shaft, half shaft, link shaft, etc. as known in the art. Thereby, output shafts 50, 52 rotate with the wheels of the connected vehicle and selectively drive the wheels. Differential housing 40 includes a housing end flange 54 and a cover end flange 56 that are open so that output shafts 50, 52 attached to side gears 42, 43 can extend axially from side gears 42, 43 to drive the wheels. When the wheels rotate due to the connection of output shafts 50, 52 and side gears 42, 43 to the wheels, output shafts 50, 52 and side gears 42, 43 rotate. Side gears 42, 43 are in meshing engagement with pinion gear 36, and input shaft 16 is engageable with differential housing 40, such that torque is transmitted from input shaft 16 through differential housing 40, pinion gear 36, and then side gears 42, 43, thereby being able to drive output shafts 50, 52.

[0019]

[0040] PTU 12 also includes a planetary gear set 58 configured to selectively supply power in high and low ranges to the front differential 22. The planetary gear set 58 defines separate paths for transmitting torque between the input shaft 16 and the front differential 22 corresponding to the high and low ranges. The planetary gear set 58 includes a sun gear 60, a planetary ring gear 62, a set of planetary gears 64, and a planetary carrier 66. The sun gear 60 is rotatably supported on the outer periphery of the left output shaft 52 and is integrally formed with the sun shaft 67. The planetary ring gear 62 is fixed to the fixed housing 32, is concentric with the sun gear 60, and is arranged in a radially spaced and opposed relationship. The set of planetary gears 64 are radially meshed with the sun gear 60 and the planetary ring gear 62. The planetary gears 64 are attached to and supported by the planetary carrier 66 to form a planetary carrier assembly 68 rotatably supported on the output shafts 50, 52. The planetary carrier 66 has an outboard carrier portion 70, an inboard carrier portion 72, and support shafts 74 arranged at circumferential intervals for rotatably supporting the planetary gears 64. The outboard carrier portion 70 is supported on the inboard end of the housing end flange 54, either integrally or as a separate component, such that the differential housing 40 rotates when the planetary carrier 66 rotates.

[0020]

[0041] To selectively drive the planetary carrier 66, the inboard carrier portion 72 preferably includes a drive formation formed as drive teeth 76 shown in FIGS. 3 and 4. The carrier drive teeth 76 are formed around the inner periphery of the inboard carrier portion 72 and face radially inward. However, it will be recognized that the carrier drive teeth 76 may be formed in alternative configurations, such as facing radially outward, radially inward, or axially, without changing the scope of the present invention.

[0021]

[0042] To selectively drive the sun gear 60, the sun shaft 67 preferably includes a drive forming portion formed as a drive tooth 78. In FIG. 3, the sun drive tooth 78 is formed around the outer diameter or surface of the sun shaft 67 and is shown facing radially outward. However, it will be appreciated that the sun drive tooth 78 may be formed in an alternative configuration, such as facing radially outward, radially inward, or axially, without changing the scope of the present invention.

[0022]

[0043] To switch the PTU 12 between a high gear range and a low gear range, the input shaft 16 also includes an end flange 80, and the end flange 80 includes an input drive tooth 82 formed on its outer periphery or surface. The input drive tooth 82 faces radially outward and extends axially. However, it will be appreciated that the input drive tooth 82 may be formed in an alternative configuration, such as facing radially outward, radially inward, or axially, without changing the scope of the present invention. The PTU 12 also includes a range shift collar 84, and the range shift collar 84 is splined to the input shaft 16 such 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 movable between three axially spaced positions corresponding to a high gear mode (high position, FIGS. 3-5), a low gear mode (low position, FIG. 7), and a neutral (neutral position, FIG. 6). Referring to FIG. 1, the range shift collar 84 is axially movable by a suitable actuator assembly 28, such as a hydraulic actuator, an electromechanical actuator, and a solenoid, which is electrically controlled by a vehicle controller.

[0023]

[0044] As depicted in FIG. 4, the range shift collar 84 includes a body formed with an inner drive forming portion 86, which is formed as drive teeth formed on the inner circumference or surface and faces radially inward. However, it will be appreciated that the carrier inner drive forming portion 86 may be formed in an alternative configuration, such as facing radially outward, radially inward, or axially, without changing the scope of the present invention. The inner drive forming portion 86 meshes and engages with the input drive teeth 82 of the end flange 80 of the input shaft 16 while enabling the range shift collar 84 to be axially movable along the input drive teeth 82 so as to maintain the state where the range shift collar 84 is engaged with the input drive teeth 82 in both the high gear mode (high position) and the low gear mode (low position).

[0024]

[0045] In addition, the range shift collar 84 includes a low drive formation 88 shown in FIG. 4. The low drive formation 88 is formed as drive teeth that face radially inward from the inner circumference or surface and are axially spaced from the inner drive formation 86. However, it will be appreciated that the low drive formation 88 may be formed in an alternative configuration, such as facing radially outward, radially inward, or axially, 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 and supply low gear range power to the front differential 22, the low drive formation 88 is configured to mesh with the sun drive teeth 78 of the sun shaft 67. The range shift collar 84 includes a recess 90 axially spaced between the drive formation 86 and the drive formation 88. The recess 90 provides a radial gap between the range shift collar 84 and the sun drive teeth 78 when the range shift collar 84 is axially moved while the engagement between the range shift collar 84 and the sun shaft 67 is disengaged. The range shift collar 84 also includes a high drive formation 92 shown in FIG. 4. The high drive formation 92 is formed as drive teeth that face radially outward from the outer circumference or surface of the range shift collar 84. However, it will be appreciated that the high drive formation 92 may be formed in an alternative configuration, such as facing radially outward, radially inward, or axially, without changing the scope of the present invention. When the range shift collar 84 is axially repositioned to transmit power through the planetary carrier 66 to provide a high gear range to the front differential 22, the high drive formation 92 is configured to mesh with the carrier drive teeth 76 of the planetary carrier 66.

[0025]

[0046] In addition, the range shift collar 84 includes a range channel 93 that extends circumferentially around the outer circumference or surface of the range shift collar 84. The range channel 93 is operably coupled to the actuator assembly 28 and is configured to axially reposition the range shift collar 84 between a high position (high gear mode), a low position (low gear mode), and a neutral position (neutral). The drive teeth 76, 78, and drive formations 86, 88, 92 may be formed like gear teeth, but it will be recognized that other configured drive formations may be provided without changing the scope of the present invention. Generally, the sun drive tooth 78 and the inner drive formation 86 are disposed at the same or substantially the same radial distance from a central axis extending through the input shaft 16, the left output shaft 52, and the right output shaft 50, although that distance may be varied to change torque transmission characteristics. Further, the carrier drive tooth 76 and the high drive formation 92 are disposed radially offset from the other drive teeth 78, 82 and the other drive formations 86. However, it will be recognized that the radial positions of the carrier drive tooth 76 and the high drive formation 92 may be varied without changing the scope of the present invention.

[0026]

[0047] In FIGS. 3 - 5, the range shift collar 84 is shown in the high position (high gear mode). Referring to FIG. 4, the range shift collar 84 is axially arranged such that the high drive forming portion 92 meshes with the carrier drive teeth 76 of the planetary carrier 66, as indicated by arrow 94, thereby supplying high gear range power to the front differential 22. The low drive forming portion 88 is axially spaced from the sun drive teeth 78, and the inner drive forming portion 86 meshes with the input drive teeth 82 of the input shaft 16. More specifically, when the range shift collar 84 is in the high position, power is transmitted from the input shaft 16 to the range shift collar 84, the planetary carrier 66, and then to the differential housing 40 (arrow 94). Next, the power is transmitted from the differential housing 40 through the differential pinion gears 36 to the differential side gears 42, 43, and then to the left and right output shafts 50, 52.

[0027]

[0048] In FIG. 6, the range shift collar 84 is shown in the neutral position. Referring to FIG. 6, the range shift collar 84 is axially arranged to disengage from both the sun gear 60 and the planetary carrier 66 so that power is not transmitted to the front differential 22. In the neutral position, the high drive forming portion 92 is axially spaced from the carrier drive teeth 76, the low drive forming portion 88 is axially spaced from the sun drive teeth 78, and the inner drive forming portion 86 meshes with the input drive teeth 82 of the input shaft 16. Thus, power is transmitted from the input shaft 16 to the range shift collar 84, as indicated by arrow 95, without power being transmitted to the front differential 22. When the range shift collar 84 changes position between the high and low positions, the range shift collar 84 is moved through the neutral position so that the engagement between the planetary gear set 58 and the front differential 22 is disengaged before the range shift collar 84 engages with the carrier drive teeth 76 or the sun drive teeth 78.

[0028]

[0049] In FIG. 7, the range shift collar 84 is shown in the low position (low gear mode). Referring to FIG. 7, the range shift collar 84 is axially arranged such that the low drive forming portion 88 meshes with the sun drive teeth 78 of the sun shaft 67, thereby supplying the power of the low gear range to the front differential 22, as indicated by arrow 96. The high drive forming portion 92 is arranged axially spaced from the carrier drive teeth 76 of the planetary carrier 66, and the inner drive forming portion 86 meshes with the input drive teeth 82 of the input shaft 16. More specifically, when the range shift collar 84 is in the low position, power is transmitted from the input shaft 16 to the range shift collar 84, the sun shaft 67, through the sun gear 60, through the planetary gear 64, to the planetary carrier 66, and then to the differential housing 40 (arrow 96). Next, the power is transmitted from the differential housing 40 through the differential pinion gears 36 to the differential side gears 42, 43, and then to the left and right output shafts 50, 52.

[0029]

[0050] Referring to FIGS. 1 and 3, when the AWD system 10 transmits power to the RDM 14, the PTU gear set 18 is configured to transmit power from the input shaft 16 to the propeller shaft 26. More specifically, the PTU gear set 18 includes a main shaft 97 that rotatably supports axially spaced bearings 98, 100, and the bearings 98, 100 rotatably support the input shaft. In addition, the main shaft 97 is radially and axially supported by axially spaced bearings 102, 104, and these bearings are supported by the fixed housing 32. The main shaft 97 also includes an inboard portion 106 formed with a main shaft drive forming portion 108, and the main shaft drive forming portion 108 is formed as drive teeth formed on the inner circumference or surface of the main shaft 97 and faces radially inward. However, it will be appreciated that the main shaft drive forming portion 108 may be formed in an alternative configuration, such as facing radially outward, radially inward, or axially, without changing the scope of the present invention.

[0030]

[0051] The PTU gear set 18 also includes a main ring gear 110 that is supported radially and axially on the inboard portion 106 of the main shaft 97 either integrally or as a separate component such that the main ring gear 110 rotates when the main shaft 97 rotates. It will be appreciated that the main ring gear 110 may be a hypoid ring gear, a spiral bevel gear, a straight bevel gear, etc. without departing from the scope of the present invention. As shown in FIG. 1, the PTU gear set 18 also includes a hypoid pinion gear 112 that meshes with the main ring gear 110. The PTU gear set 18 also includes a pinion shaft 114 that extends axially from the hypoid pinion gear 112 either integrally or as a separate component such that the pinion shaft 114 rotates when the hypoid pinion gear 112 rotates. The pinion shaft 114 is supported radially and axially in the fixed housing 32 by bearings 116, 118 that are axially spaced apart such that the pinion shaft 114 can rotate freely. The PTU 12 can also include a propeller shaft coupler 120 that 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 such that rotation of the pinion shaft 114 causes the propeller shaft 26 to rotate. It will be appreciated that the pinion shaft 114 may be operably coupled to the propeller shaft 26 using other known methods without departing from the scope of the present invention.

[0031]

[0052] As depicted in FIGS. 1 and 3 - 5, the PTU 12 also includes a removable shift collar 122, alternatively described as an all - wheel drive (AWD) shift collar 122. The removable shift collar 122 is splined to the input shaft 16 such that the removable shift collar 122 is axially slidable relative to the input shaft 16 while rotating with the input shaft 16. The removable shift collar 122 is axially movable between two axially spaced positions corresponding to a disengaged mode (FIG. 4) and an engaged mode (FIG. 5). The removable shift collar 122 is configured to selectively couple the input shaft 16 to the main shaft 97 in order to transmit power to the RDM 14. The removable shift collar 122 is axially movable by an actuator assembly 28 that is also configured to axially move the range shift collar 84. However, it should be recognized that the removable shift collar 122 may be axially moved by an actuator different from the actuator assembly 28 for the range shift collar 84 without changing the scope of the present invention.

[0032]

[0053] Referring to FIG. 4, the extraction shift collar 122 includes a body formed with an input drive forming portion 124. The input drive forming portion 124 is preferably formed as drive teeth formed on the inner circumference or surface and faces radially inward. The input drive forming portion 124 meshes and engages with the input drive teeth 82 of the end flange 80 of the input shaft 16 while enabling the extraction shift collar 122 to be axially movable along the input drive teeth 82 so as to maintain the state of being engaged with the input drive teeth 82 in both the disengaged mode and the engaged mode. In addition, the extraction shift collar 122 includes an output drive forming portion 126. The output drive forming portion 126 is formed as drive teeth facing radially outward from the outer circumference or surface of the extraction shift collar 122. However, it will be recognized that the output drive forming portion 126 may be formed in an alternative configuration, such as facing radially outward, radially inward, or axially, without changing the scope of the present invention. When the extraction shift collar 122 is axially repositioned to transmit power through the main shaft 97 to supply power to the RDM 14, the output drive forming portion 126 is configured to mesh and engage with the main shaft drive forming portion 108 of the main shaft 97. The extraction shift collar 122 also includes an extraction channel 128 extending circumferentially around the outer diameter or surface of the extraction shift collar 122. The extraction channel 128 is operably coupled to the actuator assembly 28 and is configured to axially reposition the extraction shift collar 122 between an engaged position and a disengaged position corresponding to the disengaged mode and the engaged mode, respectively. The input drive forming portion 124, the output drive forming portion 126, and the main shaft drive forming portion 108 may be formed like the teeth of a gear, but it will be recognized that drive forming portions of other configurations may be provided without changing the scope of the present invention.

[0033]

[0054] In FIG. 4, the take-out shift collar 122 is shown in the disengaged position. Referring to FIG. 4, the take-out shift collar 122 is axially arranged such that the output drive forming portion 126 is axially spaced from the main shaft drive forming portion 108 of the main shaft 97. Power is transmitted from the input shaft 16 through the input drive forming portion 124 to the take-out shift collar 122 as indicated by arrow 134. However, when the take-out shift collar 122 is in the disengaged position, the take-out shift collar 122 does not transmit power to the main shaft 97, which also prevents power from being supplied to the RDM 14.

[0034]

[0055] In FIG. 5, the take-out shift collar 122 is shown in the engaged position. Referring to FIG. 5, the take-out shift collar 122 is axially arranged such that the output drive forming portion 126 meshes with the main shaft drive forming portion 108 of the main shaft 97. In addition, the input drive forming portion 124 is meshed with the input drive teeth 82 of the input shaft 16. Therefore, power is transmitted from the input shaft 16 through the take-out shift collar 122 to the main shaft 97 as indicated by arrow 136. Next, the main shaft 97 transmits the supplied power to the hypoid pinion gear 112 through the main ring gear 110, and supplies power to the RDM 14 through the pinion shaft 114 and the propeller shaft coupler 120 as indicated by arrow 138 in FIG. 1.

[0035]

[0056] Referring to FIGS. 8 and 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). Additionally, the actuator assembly 28 is configured to axially reposition the removal shift collar 122 between a disengaged mode and an engaged mode. The actuator assembly 28 is a barrel cam actuator assembly and functions in a manner similar to a particular barrel cam actuator assembly that is generally known. The actuator assembly 28 includes a barrel cam 140, a barrel cam shaft 142, a barrel cam motor 144, a removal shift fork 146, and a range shift fork 148. In summary, the barrel cam 140 is supported by and configured to rotate with the barrel cam shaft 142. The actuator assembly 28 also includes a spring (not shown) operably coupled between the barrel cam shaft 142 and the barrel cam 140 and configured to apply force if the shifting operation is obstructed. The barrel cam 140 includes a removal cam slot 150 and a range cam slot 152, which are axially spaced apart, circumferentially extending, and each include a respective cam profile (in other words, a cam contour). The barrel cam motor 144 is operably coupled to the barrel cam shaft 142 and configured to selectively rotate the barrel cam shaft 142, thereby rotating the barrel cam 140. The removal shift fork 146 and the range shift fork 148 are slidably coupled to respective support shafts 154, 156. Additionally, the removal shift fork 146 and the range shift fork 148 are operably coupled to the removal cam slot 150 and the range cam slot 152, respectively, by pins 158, 160. As depicted in FIG. 8, the barrel cam 140, the barrel cam motor 144, and the support shafts 154, 156 are supported on the outer surface of the fixed housing 32. The removal shift fork 146 and the range shift fork 148 extend radially through a slot 161 that extends through the fixed housing 32.The slot 161 provides a gap for the take-out shift fork 146 and the range shift fork 148 to change their axial positions.

[0036]

[0057] Referring to FIGS. 7 and 9, the take-out shift fork 146 has a lower end portion 162 fixedly coupled to the take-out channel 128 of the take-out shift collar 122. In addition, the range shift fork 148 has a lower end portion 164 fixedly coupled to the range channel 93 of the range shift collar 84. During operation, the barrel cam motor 144 selectively rotates the barrel cam 140, whereby when the pins 158, 160 move along the cam surfaces of the respective take-out cam slots 150 and range cam slots 152, the pins 158, 160 change their axial positions, thereby causing the take-out shift fork 146 and the range shift fork 148 to change their axial positions along the support shafts 154, 156. The cam profile of the take-out cam slot 150 is selected to change the position of the take-out shift fork 146 and the attached take-out shift collar 122 between the engaged position (FIG. 5) and the disengaged position (FIG. 4). In addition, the cam profile of the range cam slot 152 is selected to change the position of the range shift collar 84 between the high position (high gear mode, FIG. 4) and the low position (low gear mode, FIG. 7). Therefore, the axial positions of the take-out shift fork 146 and the range shift fork 148 are controlled by the rotational position of the barrel cam 140. The barrel cam 140 is configured to change the position of the take-out shift collar 122 between the engaged position and the disengaged position. Further, the barrel cam 140 is configured to change the position of the range shift collar 84 between the high position, the low position, and the neutral position.

[0037]

[0058] The RDM14 is configured to receive power from the PTU12 and transmit that power to the rear wheels. Referring to FIG. 2, the RDM14 includes a fixed housing 168, a propeller shaft flange 170, an input hub 172, a torque transmission coupling 174, a clutch drum 20, and a hypoid pinion shaft 176. The fixed housing 168 includes an internal cavity for containing and supporting certain components of the RDM14. 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 supported radially and axially within the fixed housing 168 by bearings 177, 178 spaced axially apart and is free to rotate in response to the rotation of the propeller shaft flange 170 and the attached propeller shaft 26.

[0038]

[0059] The proximal end of the input hub 172 is operably coupled to the torque transmission coupling 174, which is configured to selectively transmit power from the input hub 172 to the clutch drum 20 when in an engaged state. The clutch drum 20 is non-rotatably coupled to the distal end of the hypoid pinion shaft 176. The torque transmission 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 spaced axially apart when in a disengaged state.

[0039]

[0060] The hydraulic motor 182 and the hydraulic pump 184 are configured to selectively supply hydraulic pressure to the hydraulic piston 179. By the hydraulic pressure applied to the hydraulic piston 179, the friction plate 185 frictionally engages with the adjacent friction plate 185, whereby the friction clutch 180 is engaged, and thus power can be transmitted from the input hub 172 through the friction clutch 180 to the hypoid pinion shaft 176. The torque transmission coupling 174 also includes a return spring 186 that disengages the friction clutch 180 by axially separating the friction plates 185 when hydraulic pressure is removed from the hydraulic piston 179 and the engagement is released. Therefore, the return spring 186 ensures that power is not transmitted between the clutch drum 20 and the input hub 172 unless the AWD system 10 activates the hydraulic motor 182, whereby the hydraulic pump 184 supplies hydraulic pressure to the hydraulic piston 179 to engage the friction clutch 180. The torque transmission coupling 174 is normally in a disengaged state that prevents the transmission of power between the input hub 172 and the clutch drum 20. To reduce the residual drag torque within the friction clutch 180 (compared to other known couplings), when hydraulic pressure is removed from the hydraulic piston 179, the return spring 186 further separates the friction plates 185 within the friction clutch 180. The return spring 186 can reduce the drag torque of the AWD system 10 to a level low enough to stop the rotation of the driveline components.

[0040]

[0061] As depicted in FIG. 2, the hypoid pinion shaft 176 is supported radially and axially within the fixed housing 168 by bearings 192, 194 spaced axially apart and can rotate freely in response to the rotation of the clutch drum 20. The RDM 14 also includes a hypoid pinion gear 196, and the hypoid pinion gear 196 is supported at the proximal end of the hypoid pinion shaft 176, either integrally or as a separate component, such that the hypoid pinion gear 196 rotates when the hypoid pinion shaft 176 rotates.

[0041]

[0062] RDM14 also includes a main ring gear 198, which meshes with a hypoid pinion gear 196 so as to rotate in response to the rotation of the hypoid pinion gear 196. It will be recognized that the main ring gear 198 may be a hypoid ring gear, a spiral bevel gear, a straight bevel gear, etc., without changing the scope of the present invention. The main ring gear 198 is supported radially and axially on the inboard portion of the ring gear hub 200, either integrally or as a separate component, such that the ring gear hub 200 rotates when the main ring gear 198 rotates. The ring gear hub 200 is supported radially and axially in the fixed housing 168 by a bearing 201. Referring to FIG. 10, the main ring gear 198 is also supported by bearings 202 and 203, which will be described later.

[0042]

[0063] RDM14 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 supply power in high and low gear ranges to the rear differential 205, which transmits power to the left output shaft 206 and the right output shaft 208. Referring to FIG. 10, the left output shaft 206 is supported radially and axially by a bearing 210, which is supported by the fixed housing 168. The right output shaft 208 is supported radially and axially within the fixed housing 168 by a contact journal formed on the outer surface of a differential cover 212, which will be further described below. The differential cover 212 is supported radially and axially by a bearing 202. The output shafts 206, 208 may be any combination of output shafts, half shafts, link shafts, etc., as is known in the art. Thereby, the output shafts 206, 208 rotate with the wheels of the connected vehicle and selectively drive the wheels.

[0043]

[0064] As depicted in FIG. 10, the rear differential 205 includes a pinion gear assembly 214 rotatably supported within a fixed housing 168. The pinion gear assembly 214 includes opposed differential pinion gears 216, a pinion shaft 218, a differential housing 220, and opposed differential side gears 222, 224. The differential pinion gears 216 are rotatably connected together by a pinion shaft 218 mechanically connected to the differential housing 220. Additionally, the differential pinion gears 216 mesh with the differential side gears 222, 224 such that torque can be transmitted from the differential housing 220 to the differential pinion gears 216 and then to the differential side gears 222, 224. The pinion shaft 218 rotatably supports the differential pinion gears 216 at its ends and rotates with the differential pinion gears 216 as the differential pinion gears 216 move around the differential side gears 222, 224. The rear differential 205 further includes a connector pin 226 that fixedly couples the pinion shaft 218 to the differential housing 220 such that the pinion gear 216, the pinion shaft 218, and the differential housing 220 of the rear differential 205 all move together around the same shaft axis as the side gears 222, 224. The differential housing 220 is supported radially and axially by bearings 201, 202, and 203 and can rotate freely within the fixed housing 168. It will be appreciated that the bearings 201 and 202 may be tapered roller bearings or alternative known types of bearings.

[0044]

[0065] Referring to FIG. 10, differential side gears 222, 224 are supported by differential housing 220 and operate to transmit torque to any combination of left output shaft 206 and right output shaft 208. Thereby, output shafts 206, 208 rotate with the wheels of the connected vehicle and selectively drive the wheels. Differential housing 220 includes housing end flange 230 and differential cover 212. Differential housing 220 also includes differential shaft 233 that extends axially from the inboard end of housing end flange 230, either integrally or as a separate component, such that housing end flange 230 rotates when differential shaft 233 rotates. Differential shaft 233, housing end flange 230, and differential cover 212 are open so that output shafts 206, 208 attached to side gears 222, 224 can extend axially from side gears 222, 224 to drive the wheels. Differential shaft 233, housing end flange 230, and differential cover 212 are rotatably supported by bearings 201, 202 that support rear differential 205. Differential shaft 233, housing end flange 230, and differential cover 212 also support right output shaft 208. To selectively drive rear differential 205, differential shaft 233 includes flange portion 234, and flange portion 234 preferably has a drive formation formed as drive teeth 235 around the outer periphery or surface of flange portion 234 that faces radially outward and extends axially.

[0045]

[0066] Referring to FIG. 2, bearings 201 and 202 are tapered roller bearings that support differential housing 220 and differential cover 212 in the radial and axial directions, respectively. Bearings 201, 202, and 203 also support main ring gear 198 in the radial and axial directions. Main ring gear 198 and differential housing 220 are in a stacked arrangement between bearings 201 and 202. In addition, hypoid pinion gear 196, hypoid pinion shaft 176, friction clutch 180, input hub 172, and clutch drum 20 are generally axially aligned with a space therebetween between bearings 201 and 202.

[0046]

[0067] When the wheels rotate due to the connection between output shafts 206, 208 and side gears 222, 224 and the wheels, output shafts 206, 208 and side gears 222, 224 rotate. Torque is transmitted from ring gear hub 200 through planetary gear set 204, differential housing 220, differential pinion gears 216, and then through side gears 222, 224 so that output shafts 206, 208 can be driven. Side gears 222, 224 are meshed with pinion gears 216, and ring gear hub 200 is engageable with differential housing 220.

[0047]

[0068] Also, as shown in FIG. 10, the planetary gear set 204 defines alternative paths for torque transmission between the ring gear hub 200 and the rear differential 205 corresponding to high and low gear ranges. The planetary gear set 204 includes a sun gear 236, a planetary ring gear 237, a set of planetary gears 238, and a planetary carrier 240. The sun gear 236 is integrally formed with a sun shaft 241 that is rotatably supported on the outer periphery of the differential shaft 233 by bearings 242, 244. In addition, the sun shaft 241 is supported on the ring gear hub 200, either integrally or as a separate component, such that the sun shaft 241 rotates when the ring gear hub 200 rotates. To selectively drive the rear differential 205, the sun shaft 241 includes a drive formation portion formed as drive teeth 246 adjacent to the inboard end. In FIG. 10, the sun drive teeth 246 are formed around the outer periphery or surface of the sun shaft 241 and face radially outward. However, it will be appreciated that the sun drive teeth 246 may be formed in alternative configurations, such as facing radially outward, radially inward, or axially, without changing the scope of the present invention.

[0048]

[0069] The planetary ring gear 237 is fixed to the fixed housing 168, is concentric with the sun gear 236, and is arranged in a radially spaced and opposing relationship. A set of planetary gears 238 are radially meshed with the sun gear 236 and the planetary ring gear 237. The planetary gears 238 are attached to and supported by the planetary carrier 240, thereby forming a planetary carrier assembly 248 that is rotatably supported by the sun gear 236. The planetary carrier 240 has an outboard carrier portion 250, an inboard carrier portion 252, and support shafts 254 that are circumferentially spaced apart for rotatably supporting the planetary gears 238.

[0049]

[0070] To selectively drive the rear differential 205, the outboard carrier portion 250 includes a drive formation portion formed as drive teeth 258 adjacent to the outboard end. In FIG. 10, the carrier drive teeth 258 are formed around the inner circumference or surface of the outboard carrier portion 250 and face radially inward. However, it will be appreciated that the carrier drive teeth 258 may be formed in alternative configurations, such as facing radially outward, radially inward, or axially, without changing the scope of the present invention.

[0050]

[0071] To selectively lock the left output shaft 206 and prevent the left output shaft 206 from rotating relative to the right output shaft 208, the left output shaft 206 includes lock drive teeth 260 that face radially outward from the outer circumference or surface of the left output shaft 206, as shown in FIG. 10. However, it will be appreciated that the lock drive teeth 260 may be formed in alternative configurations, such as facing radially outward, radially inward, or axially, without changing the scope of the present invention. The RDM 14 also includes a shift collar 262 that is splined to the differential shaft 233 such that the shift collar 262 is axially slidable relative to the differential shaft 233 while rotating with the differential shaft 233. The shift collar 262 is axially movable between three axially spaced positions corresponding to the 4HI mode (4HI position, FIG. 11), the 4LO mode (4LO position, FIG. 13), and the 4LO lock mode (4LO lock position, FIG. 14). When the shift collar 262 moves between the 4HI mode and the 4LO mode, the shift collar 262 passes through a neutral position (FIG. 12).

[0051]

[0072] As depicted in FIG. 2, the shift collar 262 is axially movable by a suitable actuator assembly 264, such as a hydraulic actuator, barrel cam actuator, solenoid, etc., which is electrically controlled by a vehicle controller. An exemplary actuator assembly 264 is a barrel cam actuator assembly as generally known in the art. The actuator assembly 264 includes a barrel cam 266, a barrel cam shaft 268, a cam driver 269, a barrel cam motor 270, a block spring 271, a shift fork 272, and a pin 274. The barrel cam 266 is fixedly coupled to the barrel cam shaft 268 and rotates with the barrel cam shaft 268. Additionally, the barrel cam 266 includes a circumferentially extending cam slot 280. The barrel cam motor 270 is operatively coupled to the cam driver 269, and the cam driver 269 is operatively coupled to the barrel cam shaft 268 via the block spring 271. The barrel cam motor 270, the cam driver 269, and the block spring 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 operatively coupled to the cam slot 280 by the pin 274. Additionally, the shift fork 272 has a fork end 284 fixedly coupled to a fork channel 286 that extends circumferentially around the outer periphery or surface of the shift collar 262. The axial position of the shift collar 262 is determined by the rotational position of the barrel cam 266 when the pin 274 moves along the cam slot 280. The barrel cam motor 270 selectively rotates the cam driver 269, which rotates the block spring 271 and the barrel cam 266 to change the position of the shift fork 272 and the attached shift collar 262 among the 4HI, 4LO, and 4LO lock positions. When the shift fork 272 is prevented from changing position in response to the actuation of the barrel cam motor 270, the block spring 271 is forced by the movement of the cam driver 269 to apply a rotational pressure to the barrel cam 266.When the shift fork 272 becomes axially free to move (i.e., "unobstructed"), the barrel cam 266 rotates due to the tension of the block spring 271, changing the axial position of the shift fork 272, thereby changing the position of the shift collar 262.

[0052]

[0073] Referring to FIG. 10, the shift collar 262 includes a body formed as drive teeth formed on the inner circumference or surface and having an output drive forming portion 288 facing radially inward. However, it should be recognized that the output drive forming portion 288 may be formed in an alternative configuration, such as facing radially outward, radially inward, or axially, without changing the scope of the present invention. The output drive forming portion 288 enables the shift collar 262 to be axially movable along the differential drive teeth 235 of the differential shaft 233 while maintaining engagement with the differential drive teeth 235 in the 4HI mode, 4LO mode, and 4LO lock mode. Thus, the shift collar 262 can transmit power through the differential shaft 233 to the housing end flange 230 and then to the differential housing 220. In addition, the lock drive teeth 260 of the left output shaft 206 are radially aligned with the drive teeth of the differential shaft 233. The shift collar 262 is axially slidable, whereby the output drive forming portion 288 can simultaneously mesh and engage with both the lock drive teeth 260 and the differential drive teeth 235, enabling the 4LO lock mode shown in FIG. 14.

[0053]

[0074] As depicted in FIG. 10, the shift collar 262 is also formed as drive teeth on the inner circumference or surface and includes a lower drive forming portion 290 that faces radially inward. However, it should be recognized that the lower drive forming portion 290 may be formed in an alternative configuration, such as facing radially outward, radially inward, or axially, without changing the scope of the present invention. The lower drive forming portion 290 meshes with the sun drive teeth 246 of the sun shaft 241 when the shift collar 262 is axially arranged such that it transmits power from the main ring gear 198 and supplies 4HI power to the rear differential 205.

[0054]

[0075] As shown in FIG. 10, the shift collar 262 is also formed as drive teeth on the outer circumference or surface and includes an upper drive forming portion 292 that faces radially outward. However, it should be recognized that the upper drive forming portion 292 may be formed in an alternative configuration, such as facing radially outward, radially inward, or axially, without changing the scope of the present invention. The upper drive forming portion 292 is configured to mesh with the carrier drive teeth 258 of the outboard carrier portion 250 when the shift collar 262 is axially arranged such that it transmits power from the planetary carrier 240 and supplies 4LO power to the rear differential 205. In addition, the shift collar 262 is axially slidable from the 4LO position to the 4LO lock position. When the shift collar 262 is in the 4LO lock position, while maintaining the upper drive forming portion 292 in an engaged state with the carrier drive teeth 258 of the outboard carrier portion 250 and maintaining the output drive forming portion 288 in an engaged state with the differential drive teeth 235 of the differential shaft 233, the output drive forming portion 288 meshes with the lock drive teeth 260 of the left output shaft 206.

[0055]

[0076] The drive teeth 246, 235, 258, 260 and the drive forming portions 290, 288, 292 may be formed like the teeth of a gear, but it should be recognized that drive forming portions of other configurations may be provided without changing the scope of the present invention. Generally, the lock drive teeth 260, the differential drive teeth 235, and the output drive forming portion 288 are arranged at the same or substantially the same radial distance from the central axis extending through the left output shaft 206 and the right output shaft 208, but that distance may be changed to vary the torque transmission characteristics. Further, the carrier drive teeth 258 and the upper drive forming portion 292 are arranged radially offset from the lock drive teeth 260, the differential drive teeth 235, and the output drive forming portion 288. In addition, the lower drive forming portion 290 and the sun drive teeth 246 are arranged radially offset from the remaining drive teeth 258, 235, 260 and the drive forming portions 288, 292. However, it should be recognized that the radial and axial positions of the drive teeth 246, 258, 235, 260 and the drive forming portions 290, 288, 292 may be changed without changing the scope of the present invention.

[0056]

[0077] During operation, the AWD system 10 selectively supplies power to the main shaft 97 of the PTU 12 when the removal shift collar 122 is in the engaged position, as shown by arrow 136 in FIG. 5. Referring to FIG. 1, the power supplied to the main shaft 97 is transmitted to the propeller shaft 26 through the main ring gear 110 and the hypoid pinion gear 112, as shown by arrow 138. As depicted in FIG. 2, the power is transmitted from the propeller shaft 26 to the input hub 172 of the RDM 14, as shown by arrow 294. While the torque transmission coupling 174 is disengaged, power is not transmitted between the input hub 172 and the clutch drum 20.

[0057]

[0078] To engage the RDM14 and transmit power from the propeller shaft 26 to the rear differential 205, the AWD system 10 activates the hydraulic motor 182, whereby the hydraulic pump 184 applies hydraulic pressure to the hydraulic piston 179, thereby applying pressure to the friction clutch 180 to engage the friction clutch 180. After the friction clutch 180 is engaged, the power supplied to the input hub 172 is transmitted through the friction clutch 180 to the clutch drum 20, as indicated by the arrow 296 in FIG. 2, and then transmitted to the main ring gear 198 through the hypoid pinion shaft 176 and the hypoid pinion gear 196.

[0058]

[0079] The AWD system 10 is configured to selectively position the RDM 14 in the 4HI, 4LO, and 4LO lock modes by axially repositioning the shift collar 262 between three spaced positions, namely the 4HI, 4LO, and 4LO lock positions. In FIG. 11, the RDM 14 is shown in the 4HI mode with the shift collar 262 in the 4HI position, transmitting the power of the 4HI range to the rear differential 205. In the 4HI mode, the lower drive formation 290 of the shift collar 262 meshes with the sun drive teeth 246, the output drive formation 288 meshes with the differential drive teeth 235, and is axially spaced from the lock drive teeth 260. Additionally, the upper drive formation 292 of the shift collar 262 is axially spaced from the carrier drive teeth 258. More specifically, when the RDM 14 is in the 4HI mode shown in FIG. 11, the power supplied to the hypoid pinion gear 196 (arrow 296 in FIG. 2) is transmitted through the main ring gear 198, the sun shaft 241, and through the sun drive teeth 246 meshed with the lower drive formation 290 to the shift collar 262. Next, the power of the 4HI range is transmitted from the shift collar 262, through the output drive formation 288 meshed with the differential drive teeth 235, to the differential shaft 233, the housing end flange 230, as indicated by arrow 298, then to the differential housing 220, through the differential pinion gear 216 to the side gears 222, 224, and finally to the output shafts 206, 208.

[0059]

[0080] In FIG. 13, RDM14 is shown in the 4LO mode where the shift collar 262 is in the 4LO position, and the power in the 4LO range is transmitted to the rear differential 205. In the 4LO mode, the upper drive forming portion 292 of the shift collar 262 is meshed and engaged with the carrier drive teeth 258, the output drive forming portion 288 is meshed and engaged with the differential drive teeth 235, and is axially spaced from the lock drive teeth 260. In addition, the lower drive forming portion 290 of the shift collar 262 is axially spaced from the sun drive teeth 246. More specifically, when RDM14 is in the 4LO mode shown in FIG. 13, the power supplied to the hypoid pinion gear 196 (arrow 296 in FIG. 2) is transmitted through the main ring gear 198 and the sun shaft 241, and is transmitted to the planet carrier 240 through the sun gear 236 and the planet gear 238. Next, the power in the 4LO range is transmitted from the outboard carrier portion 250 to the shift collar 262 through the carrier drive teeth 258 meshed and engaged with the upper drive forming portion 292. Next, as indicated by arrow 300, 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 forming portion 288 meshed and engaged with the differential drive teeth 235, and is transmitted to the differential housing 220, and is transmitted to the side gears 222, 224 through the differential pinion gear 216, and finally is transmitted to the output shafts 206, 208.

[0060]

[0081] When shifting between 4HI mode and 4LO mode, the shift collar 262 is axially repositioned to the neutral position as shown in FIG. 12 before moving to the 4HI position or the 4LO position. In the neutral position, the carrier drive tooth 258 is axially spaced from the upper drive forming portion 292, the sun drive tooth 246 is axially spaced from the lower drive forming portion 290, the output drive forming portion 288 is engaged with the differential drive tooth 235, and the output drive forming portion 288 is disengaged from the lock drive tooth 260. The shift collar 262 can be repositioned to either the 4HI position or the 4LO position after the shift collar 262 is disengaged from both the carrier drive tooth 258 and the sun drive tooth 246. The output drive forming portion 288 of the shift collar 262 maintains engagement with the differential drive tooth 235 when the shift collar 262 is axially moved between the 4HI position and the 4LO position.

[0061]

[0082] In FIG. 14, RDM14 is shown in the 4LO lock mode where the shift collar 262 is in the 4LO lock position, transmitting 4LO power to the rear differential 205 and locking the left output shaft 206 to the rear differential 205. By locking the left output shaft 206 to the rear differential 205, rotation of the left output shaft 206 relative to the right output shaft 208 is prevented, and power can be transmitted directly from the shift collar 262 to the left output shaft 206, or through the rear differential 205 to the right output shaft 208, whether traction of the wheels is limited or not on the opposite side. In the 4LO lock mode, the upper drive formation portion 292 of the shift collar 262 meshes with the carrier drive teeth 258, and the output drive formation portion 288 meshes with both the differential drive teeth 235 and the lock drive teeth 260. Additionally, the lower drive formation portion 290 of the shift collar 262 is axially spaced from the sun drive teeth 246. When RDM14 is in the 4LO mode, RDM14 can be repositioned to the 4LO lock mode by axially sliding the shift collar 262 from the 4LO position to the 4LO lock position. The upper drive formation portion 292 maintains engagement with the carrier drive teeth 258 when the shift collar 262 is axially repositioned between the 4LO position and the 4LO lock position. Additionally, the output drive formation portion 288 maintains engagement with the differential drive teeth 235 while the shift collar 262 is axially repositioned such that the output drive formation portion 288 meshes with the lock drive teeth 260.

[0062]

[0083] More specifically, when RDM14 is in the 4LO lock mode shown in FIG. 14, the power supplied to the hypoid pinion gear 196 (arrow 296 in FIG. 2) is transmitted to the planetary carrier 240 through the main ring gear 198, sun shaft 241, sun gear 236, and planetary gear 238. Next, the 4LO power is transmitted from the outboard carrier portion 250 to the shift collar 262 through the carrier drive tooth 258 meshed with the upper drive formation portion 292. Next, the 4LO power is transmitted from the shift collar 262, as indicated by arrow 302, through the output drive formation portion 288 meshed with the differential drive tooth 235 to the differential shaft 233 and the housing end flange 230, and then transmitted to the differential housing 220, through the differential pinion gear 216, to the side gears 222, 224, and finally transmitted to the output shafts 206, 208. However, in addition to the upper drive formation portion 292 being meshed with the carrier drive tooth 258, the shift collar 262 also has the output drive formation portion 288 meshed with both the lock drive tooth 260 and the differential drive tooth 235, thereby rotationally locking the left output shaft 206 to the differential shaft 233 and the planetary carrier 240. Therefore, the 4LO power is also directly transmitted to the left output shaft 206, as indicated by arrow 304.

[0063]

[0084] A second embodiment of the PTU 12’ is shown in FIGS. 15-18, and like reference numerals representing like elements as above are used with a prime symbol. Referring to FIG. 15, in this modified PTU 12’, the range shift collar 84’ includes an inner drive formation 86’ splined to the input drive teeth 82’ of the input shaft 16’, similar to the embodiment shown above in FIG. 3. Additionally, the range shift collar 84’ includes a drive formation 92’ configured to mesh engage with the carrier drive teeth 76’ to supply high gear range power to the front differential 22’ when the range shift collar 84’ is in the high position (FIG. 15). Further, the drive formation 92’ is also configured to mesh engage with the sun drive teeth 78’ to supply low gear range power to the front differential 22’ when the range shift collar 84’ is axially repositioned to the low position (FIG. 17). In contrast to the embodiment shown in FIG. 3, the input drive formation 124’ of the takeout shift collar 122’ is splined to an upper drive formation 306 formed on the range shift collar 84’. The takeout shift collar 122’ also includes an output drive formation 126’ configured to mesh engage with the drive formation 108’ of the main shaft 97’. Only the important differences between the two embodiments are reflected in the figures and the following description.

[0064]

[0085] More specifically, the modified PTU 12’ shown in FIG. 15 operates substantially the same as the previous PTU 12, and the range shift collar 84’ transmits power from the input shaft 16’ through the planetary gear set 58’ to the front differential 22’, and the left and right output shafts 50’, 52’. The planetary gear set 58’ includes a planetary gear 64’ rotatably supported by a planetary carrier 66’ and radially meshing engaged with a sun gear 60’ and a planetary ring gear 62’. The PTU 12’ also includes a PTU gear set 18’ having a main ring gear 110’ supported by the main shaft 97’, including the hypoid pinion gear 112 and the pinion shaft 114 shown in FIG. 1.

[0065]

[0086] The range shift collar 84' is axially position changeable along the input drive teeth 82' of the input shaft 16' between a high position corresponding to the high range mode (FIG. 15), a neutral position disengaged from the front differential 22' (neutral mode, FIG. 16), and a low position corresponding to the low range mode (FIG. 17) while maintaining meshing engagement with the input drive teeth 82' of the input shaft 16'.

[0066]

[0087] Referring to FIG. 15, the input drive teeth 82' of the input shaft 16' are formed on the outer circumference or surface of the input shaft 16'. The carrier drive teeth 76' and the sun drive teeth 78' are formed on the outer circumference or surface of the inboard carrier portion 72' and the sun shaft 67', respectively, face radially outward, and are arranged axially spaced apart. The inner drive forming portion 86' and the lower drive forming portion 92' are formed on the inner circumference or surface of the range shift collar 84', are arranged axially spaced apart, and face radially inward. However, it will be appreciated that the input drive teeth 82', the carrier drive teeth 76', the sun drive teeth 78', the inner drive forming portion 86', and the lower drive forming portion 92' may be formed in alternative configurations, such as facing radially outward, facing radially inward, and / or facing axially, without changing the scope of the present invention.

[0067]

[0088] Generally, the drive teeth 76', 78', 82' and the drive forming parts 86', 92' are arranged at the same or substantially 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', but this distance may be changed to vary the torque transmission characteristics. Further, the upper drive forming part 306 of the range shift collar 84' and the input drive forming part 124' of the take-out shift collar 122' are arranged radially offset from the other drive teeth 76', 78', 82' and the other drive forming parts 86', 92'. In addition, the drive forming part 108' of the main shaft 97' and the output drive forming part 126' of the take-out shift collar 122' are arranged radially offset from the other drive teeth 76', 78', 82' and the other drive forming parts 86', 92', 124', 306. However, it will be appreciated that the radial positions of the drive teeth 76', 78', 82' and the drive forming parts 86', 92', 108, 124', 126', 306 may be changed without changing the scope of the present invention.

[0068]

[0089] When the range shift collar 84' is in the high position shown in FIG. 15, power is transmitted from the input shaft 16' to the range shift collar 84' through the input drive teeth 82' meshed with the inner drive forming part 86'. Next, the range shift collar 84' transmits power through the drive forming part 92' and the planetary carrier 66' meshed with the carrier drive teeth 76' of the inboard carrier part 72'. The planetary carrier 66' transmits the high gear range power to the differential housing 40' and the output shafts 50', 52' through the differential pinion gears 36', the side gears 42', 43' as indicated by the arrow 308.

[0069]

[0090] When the range shift collar 84' is in the neutral position shown in FIG. 16, the lower drive forming part 92' is axially spaced from both the carrier drive teeth 76' and the sun drive teeth 78'. Therefore, the power from the input shaft 16' is transmitted to the range shift collar 84', but is prevented from being transmitted to the front differential 22'.

[0070]

[0091] When the range shift collar 84' is in the low position shown in FIG. 17, power is transmitted from the input shaft 16' to the range shift collar 84' through the input drive teeth 82' meshed with the inner drive forming portion 86'. Next, the range shift collar 84' transmits power to the planetary carrier 66' through the drive forming portion 92' meshed with the sun drive teeth 78' of the sun shaft 67', through the sun gear 60' and the planetary gear 64'. The planetary carrier 66' transmits the power of the low gear range to the differential housing 40' as indicated by arrow 310, and transmits it to the output shafts 50', 52' through the differential pinion gears 36', side gears 42', 43'.

[0071]

[0092] The takeout shift collar 122' can be axially repositioned along the upper drive forming portion 306 of the range shift collar 84' between the disengaged position (FIG. 18) corresponding to the disengagement mode and the engaged position (FIG. 16) corresponding to the engagement mode while maintaining meshing engagement with the upper drive forming portion 306 of the range shift collar 84'. In FIG. 18, the takeout shift collar 122' is in the disengaged position where the output drive forming portion 126' is axially spaced from the drive forming portion 108' of the main shaft 97'. Power is transmitted from the input shaft 16' to the range shift collar 84' and then to the takeout shift collar 122' (arrow 312), but the power is not transmitted from the takeout shift collar 122' to the main ring gear 110'. Therefore, the power is also not transmitted through the PTU gear set 18', and the RDM 14 does not receive power from the propeller shaft 26.

[0072]

[0093] In FIG. 16, the takeout shift collar 122' is in an engagement position where the output drive forming portion 126' is engaged with the drive forming portion 108' of the main shaft 97'. When the takeout shift collar 122' is in the engagement position, power is transmitted from the input shaft 16' through the input drive teeth 82' engaged with the inner drive forming portion 86' of the range shift collar 84', through the upper drive forming portion 306 engaged with the input drive forming portion 124' of the takeout shift collar 122', through the output drive forming portion 126' engaged with the drive forming portion 108' of the main shaft 97', and to the main ring gear 110' as indicated by the arrow 314. The power is transmitted from the main ring gear 110' through the PTU gear set 18' to the propeller shaft 26 and supplied to the RDM 14 in the same manner as in the first embodiment. The takeout shift collar 122' can receive the power supplied by the range shift collar 84' from the input shaft 16' when the range shift collar 84' is in the high position, neutral position, and low position. In addition, the takeout shift collar 122' transmits the power received from the range shift collar 84' to the PTU gear set 18' when the takeout shift collar 122' is in the engagement position.

[0073]

[0094] A third embodiment of the PTU 12” is shown in FIGS. 19-21, and like reference numerals representing like elements as above are used with double-prime symbols. Referring to FIG. 19, this modified PTU 12” does not have the range shift clutches 84, 84’, planetary gear sets 58, 58’, front differentials 22, 22’, actuator assemblies 28, and output shafts 50, 50’, 52, 52’ of the previous PTU embodiments 12, 12’ described above. Instead, this modified PTU 12” is a single-speed PTU 12” and includes a link shaft 316 having left and right ends 318, 320 for driving the wheels. Additionally, the PTU 12” includes an input shaft 16” splined to the link shaft 316 for supplying power to the link 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 then to the RDM 14, similar to the previous embodiments. The PTU 12” also includes a takeout shift collar 122” for transmitting power from the input shaft 16” to the main shaft 97” and through the PTU gear set 18”. The axial position of the takeout shift collar 122” is controlled by a cam actuator 322 and a return spring 324 instead of the actuator assembly 28 described above. Only the significant differences between the two embodiments are reflected in the figures and the following description.

[0074]

[0095] Referring to FIG. 19, the main shaft 97” includes a main shaft drive formation 108” that faces radially inward on its inner circumference or surface. The main shaft 97” transmits the received power to the main ring gear 110” as previously shown by arrow 138 in FIG. 1, and the main ring gear 110” transmits that power to the hypoid pinion gear 112”. Additionally, the input shaft 16” includes input drive teeth 82” formed on the outer circumference or surface of the end flange 80” and facing radially outward. However, it will be appreciated that the main shaft drive formation 108” and the input drive teeth 82” may be formed in alternative configurations, such as facing radially outward, radially inward, or axially, without changing the scope of the present invention.

[0075]

[0096] Referring to FIGS. 19 to 21, the take-out shift collar 122” is formed on the outer circumference or surface and includes an output drive forming portion 126” facing radially outward. However, it should be recognized that the output drive forming portion 126” may be formed in an alternative configuration, such as facing radially outward, radially inward, or axially, without changing the scope of the present invention. The output drive forming portion 126” enables the take-out shift collar 122” to move axially along the main shaft drive forming portion 108” of the main shaft 97” while maintaining engagement with the main shaft drive forming portion 108” of the main shaft 97” so that the take-out shift collar 122” maintains engagement with the main shaft drive forming portion 108” at both the engagement position (FIG. 20) and the disengagement position (FIG. 21) corresponding to the engagement mode and the disengagement mode, respectively. In addition, the take-out shift collar 122” includes an input drive forming portion 124” formed on the inner circumference or surface and facing radially inward. The input drive forming portion 124” is engaged with the input drive teeth 82” of the input shaft 16” when the take-out shift collar 122” is in the engagement position shown in FIGS. 19 and 20. As shown in FIG. 21, the input drive forming portion 124” is axially spaced from the input drive teeth 82” of the input shaft 16” when the take-out shift collar 122” is in the disengagement position. However, it should be recognized that the input drive forming portion 124” may be formed in an alternative configuration, such as facing radially outward, radially inward, or axially, without changing the scope of the present invention.

[0076]

[0097] Referring to FIGS. 19 - 21, the cam actuator 322 is configured to change the position of the extraction shift collar 122” between an engaged position (FIG. 20) and a disengaged position (FIG. 21). The cam actuator 322 is a self - exciting type compact disconnect actuator used to connect and disconnect the extraction shift collar 122” from 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 shift cam 332. The electromagnetic coil 326 is selectively energized for engagement and disengagement of the extraction shift collar 122” and the input shaft 16”. The pilot clutch 328 can include one or more inner plates and outer plates and can be housed within an armature. The inner plates of the pilot clutch 328 are splined to the clutch cam 330. The outer plates of the pilot clutch 328 are splined to the fixed housing 32”. The clutch cam profile 333 of the clutch cam 330 contacts the cam profile 334 of the face of the shift cam 332. The shift cam 332 is supported by the extraction shift collar 122” formed integrally or as a separate component, such that when the shift cam 332 rotates, the extraction shift collar 122” rotates and the extraction shift collar 122” is axially re - positioned together with the shift cam 332. The shift cam 332 is operably connected to the main shaft 97” through the extraction 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 of the shift cam 332 has a bistable profile including both an engagement portion 334a and a disengagement portion 334b corresponding respectively to the engaged position and the disengaged position of the extraction shift collar 122”. The cam actuator 322 also includes a return spring 324 radially supported by the main shaft 97” and axially supported between the extraction shift collar 122” and the bearing 100” supporting the input shaft 16”.The return spring 324 biases the extraction shift collar 122" toward the engaged state with the input shaft 16", and biases the shift cam 332 toward the engaged state with the clutch cam 330.

[0077]

[0098] During operation, when the clutch cam profile 333 engages with one of the engagement cam portion 334a and the disengagement cam portion 334b, by operating the cam actuator 322, the rotation of the clutch cam 330 is stopped or the rotation speed is slowed down with respect to the shift cam 332. By changing the rotation speed of the clutch cam 330 with respect to the rotation speed of the shift cam 332, the clutch cam 330 engages with the other of the engagement cam portion 334a and the disengagement cam portion 334b, whereby the shift cam 332 converts the rotational movement of the shift cam 332 into an axial (linear) movement of the shift cam 332, and the extraction shift collar 122" changes its position between the engaged position and the disengaged position. When the extraction shift collar 122" is in the engaged position shown in FIG. 20, the power is transmitted from the input shaft 16" as shown by the arrow 336, through the input drive teeth 82" meshed with the input drive forming portion 124" of the extraction shift collar 122", and through the output drive forming portion 126" meshed with the drive forming portion 108" of the main shaft 97". Next, the power transmitted to the main shaft 97" is transmitted to the propeller shaft 26 through the PTU gear set 18" as shown by the arrow 138 in FIG. 1 above. When the extraction shift collar 122" is in the disengaged position shown in FIG. 21, since the input drive forming portion 124" is axially spaced from the input drive teeth 82" of the input shaft 16" as shown by the arrow 338, the power is not transmitted to the extraction shift collar 122".

[0078]

[0099] A second embodiment of the RDM14’ is shown in FIG. 22, and like reference numerals representing like elements as above are used with a prime symbol. Referring to FIG. 22, this modified RDM14’ does not have the shift collar 262, the actuator assembly 264, and the planetary gear set 204 of the RDM14 shown in FIG. 2. Thus, the RDM14’ is a single-speed RDM14’ rather than the two-speed RDM14 of FIG. 2. Only the important differences between the two embodiments are reflected in the figures and the following description.

[0079]

[0100] Referring to FIG. 22, the differential housing 220’ of the rear differential 205’ is supported radially and axially by bearings 201’, 202’ spaced apart axially, and the bearings 201’, 202’ are supported by the fixed housing 168’. In addition, the differential housing 220’ is rotatably supported on the outer circumferences of the left and right output shafts 206’, 208’. The main ring gear 198’ is supported by the differential housing 220’ such that the differential housing 220’ rotates when the main ring gear 198’ rotates. The main ring gear 198’ and the differential housing 220’ are in a stacked arrangement between the bearings 201’, 202’. It will be appreciated that the bearings 201’, 202’ may be tapered roller bearings or other known types of bearings.

[0080]

[0101] RDM14' includes a propeller shaft flange 170' configured to be fixedly coupled to the propeller shaft 26, an input hub 172', and a torque transmission coupling 174'. The power received from the propeller shaft 26 by the propeller shaft flange 170' is transmitted to the input hub 172' as indicated by arrow 294'. When the torque transmission coupling 174' is in a non-operating state, the return spring 186' biases the hydraulic piston 179' away from the friction clutch 180', thereby disengaging the friction plates 185' within the friction clutch 180' and preventing the power from being transmitted from the input hub 172' to the clutch drum 20'. When the friction clutch 180' is disengaged, the power is also prevented from moving from the clutch drum 20' to the propeller shaft 26. When hydraulic pressure is removed from the hydraulic piston 179' so as to reduce the residual drag torque within the friction clutch 180' and thereby make the drag torque of the AWD system 10 low enough to stop the rotation of the driveline components, the return spring 186' further separates the friction plates 185' within the friction clutch 180'.

[0081]

[0102] To engage the RMD14' and transmit power to the left and right output shafts 206', 208', the hydraulic motor 182' is actuated, thereby causing the hydraulic pump 184' to apply hydraulic pressure to the hydraulic piston 179', thereby engaging the friction clutch 180'. After the friction clutch 180' is engaged, the power is transmitted from the input hub 172' through the friction clutch 180' to the hypoid pinion shaft 176'. Next, the power is transmitted from the hypoid pinion shaft 176' through the hypoid pinion gear 196' to the main ring gear 198' and then to the differential housing 220' of the rear differential 205'. The differential housing 220' transmits the power to the left and right output shafts 206', 208' through the differential pinion gears 216', side gears 222', 224' as indicated by arrow 338.

[0082]

[0103] As described above, the all-wheel drive (AWD) system 10 includes a power take-off unit (PTU) 12, 12', 12'' configured to selectively supply power to rear-wheel drive modules (RDM) 14', 14'' for driving the rear wheels of the vehicle through a propeller shaft 26. The AWD system 10 is configured to selectively disconnect the PTU 12, 12', 12'' and the RDM 14, 14' and stop the rotation of specific components within the AWD system 10. More specifically, the PTU 12, 12', 12'' includes extraction shift collars 122, 122', 122'' configured to selectively disconnect the input shafts 16, 16', 16'' from the main shafts 97, 97', 97'' to prevent power from being transmitted from the input shafts 16, 16', 16'' to the RDM 14, 14'. In addition, the PTU 12, 12' includes optional planetary gear sets 58, 58' for supplying high-range power and low-range power to the front differentials 22, 22' and range shift collars 84, 84' for selectively supplying high-range power or low-range power to the front differentials 22, 22'. Further, the PTU 12, 12' includes a single actuator for axially repositioning the extraction shift collars 122, 122', 122'' and the range shift collars 84, 84' to selectively transmit power to the RDM 14, 14' and selectively shift into an optional low-range gear. Further, the RDM 14, 14' includes torque transmission couplings 174, 174' configured to selectively disconnect the input hubs 172, 172' from the clutch drums 20, 20' to prevent power from being transmitted between the clutch drums 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, and the shift collar 262 is axially repositionable to supply 4HI power or 4LO power to the rear differential 205. The shift collar 262 is optionally repositionable to a 4LO lock position that supplies 4LO power to the rear differential 205 and locks one of the output shafts 206 to the differential shaft 233.

[0083]

[0104] Although the present invention has been described in an illustrative manner, it is to be understood that the terms used are not limiting but are intended to be essentially words of description. Many modifications and variations of the present invention are possible in light of the above teachings. Accordingly, it is to be understood that the present invention may be practiced otherwise than as specifically described within the scope of the appended claims.

Claims

1. A power take-off device for a vehicle, comprising: an input shaft configured to receive power supplied to the power take-off device; a main shaft; a main ring gear non-rotatably coupled to the main shaft and configured to rotate in response to rotation of the main shaft; a hypoid pinion gear meshing with the main ring gear and a pinion shaft non-rotatably coupled to the hypoid pinion gear, wherein the hypoid pinion gear and the pinion shaft rotate when the main ring gear rotates; a take-out shift collar axially slidable between an engagement position for operably coupling the input shaft to the main shaft and a disengagement position for disconnecting the input shaft from the main shaft; and when the take-out shift collar is in the engagement position, power received by the input shaft is transmitted to the main shaft through the take-out shift collar, and then transmitted to the pinion shaft through the main ring gear and the hypoid pinion gear; when the take-out shift collar is in the disengagement position, the main shaft is disconnected from the input shaft.

2. The main shaft includes a main shaft drive forming portion; the input shaft includes input drive teeth; when the take-out shift collar is in the engagement position, the take-out shift collar includes an output drive forming portion configured to mesh with the main shaft drive forming portion, and the take-out shift collar includes an input drive forming portion configured to mesh with the input drive teeth; when the take-out shift collar is in the disengagement position, one of the input drive forming portion and the output drive forming portion is disengaged from the input drive teeth or the main shaft drive forming portion, respectively; when the take-out shift collar is axially repositioned between the disengagement position and the engagement position, the other of the input drive forming portion and the output drive forming portion maintains engagement with the input drive teeth or the main shaft drive forming portion, respectively. The power take-off device according to claim 1.

3. The power take-off device according to claim 2, further comprising a cam actuator configured to selectively change the position of the extraction shift color axially between the engagement position and the disengagement position.

4. A differential comprising a differential housing, opposing pinion gears rotatably connected together by a pinion shaft mechanically connected to the differential housing, and opposing first and second side gears meshing with the pinion gears such that power can be transmitted from the differential housing to the first and second side gears after being transmitted to the pinion 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 comprising a sun gear non-rotatably coupled to a sun shaft, a planetary ring gear disposed radially outward of the sun gear, and a planetary carrier assembly comprising a planetary carrier rotatably supporting one or more planetary gears, wherein the planetary carrier engages with the planetary gears so as to rotate together, the planetary gears rotate between the sun gear and the planetary ring gear when the planetary carrier rotates, and the planetary carrier is non-rotatably coupled to the differential housing so that the differential housing rotates when the planetary carrier rotates. The power take-off device according to claim 1, further comprising a range shift collar rotatably and slidably coupled to the input shaft so as to rotate with the input shaft and be 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 planetary carrier to transmit power received from the input shaft to the planetary 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 take-off device according to claim 4, further comprising an actuator assembly configured to change the position of the extraction shift collar between the engagement position and the disengaged position, and configured to change the position of the range shift collar between the high position and the low position.

6. The actuator assembly is a barrel cam actuator, and the barrel cam actuator includes a barrel cam having a longitudinal axis, having an extraction cam slot and a range cam slot extending circumferentially around the barrel cam, and being rotatable around the longitudinal axis; an extraction shift fork fixedly coupled to the extraction shift collar and operably coupled to the extraction cam slot; a range shift fork fixedly coupled to the range shift collar and operably coupled to the range cam slot; a barrel cam motor operably coupled to the barrel cam, the barrel cam motor being configured to selectively rotate the barrel cam around the longitudinal axis, whereby the extraction shift fork axially changes the position of the extraction shift collar between the engagement position and the disengaged position, and the range shift fork axially changes the position of the range shift collar between the high position and the low position. The power take-off device according to claim 5, comprising

7. The input shaft includes input drive teeth. The sun shaft includes sun drive teeth for rotatably driving the sun gear. The planetary carrier includes carrier drive teeth for rotatably driving the planetary carrier. The range shift collar includes an input drive forming portion that meshes with the input drive teeth of the input shaft and is axially slidable relative to the input shaft between the high position and the low position, and an inner drive forming portion disposed at a distance from the input drive forming portion. When the range shift collar is in the low position, the inner drive forming portion meshes with the sun drive teeth to transmit the power received from the input shaft through the sun gear and supply the power of the low gear range to the differential housing. When the range shift collar is in the high position, the inner drive forming portion is engaged with the carrier drive teeth to transmit the power received from the input shaft through the planetary carrier and supply the power of the high gear range to the differential housing. The power take-off device according to claim 6.

8. The input shaft includes input drive teeth, The sun shaft includes sun drive teeth for rotatably driving the sun gear, The planetary carrier includes carrier drive teeth for rotatably driving the planetary carrier, The range shift collar includes an input drive forming portion that is engaged with the input drive teeth of the input shaft and is axially slidable relative to the input shaft between the high position and the low position, an inner drive forming portion disposed at an interval from the input drive forming portion, and a high drive forming portion disposed at a radial interval from the inner drive forming portion and the input drive forming portion. When the range shift collar is in the high position, the high drive forming portion is engaged with the carrier drive teeth of the planetary carrier to transmit the power received from the input shaft to the planetary carrier, and the inner drive forming portion is axially spaced from the sun drive teeth. When the range shift collar is in the low position, the inner drive forming portion is engaged with the sun drive teeth to transmit the power received from the input shaft through the sun gear and supply power to the differential housing, and the high drive forming portion is axially spaced from the carrier drive teeth. The power take-off device according to claim 6.

9. The input shaft includes input drive teeth, The main shaft includes a main shaft drive forming portion, When the take-out shift collar is in the engaged position, the take-out shift collar includes an output drive forming portion configured to be engaged with the main shaft drive forming portion. The extraction shift collar is meshed and engaged with the input drive teeth of the input shaft, and the output drive forming portion is meshed and engaged with the main shaft drive forming portion to transmit the power received from the input shaft to the main shaft through the extraction shift collar. The engaging position, and the output drive forming portion is axially spaced from the main shaft drive forming portion of the main shaft, thereby preventing power from being transmitted from the input shaft to the main shaft. The power take-off device according to claim 6, comprising an input drive forming portion that is axially slidable with respect to the input shaft between the disengaged positions.

10. The range shift collar includes an upper drive forming portion, The main shaft includes a main shaft drive forming portion, The extraction shift collar includes an input drive forming portion configured to be axially slidable with respect to the range shift collar between the engaged position and the disengaged position while meshing and engaging with the upper drive forming portion of the range shift collar. When the extraction shift collar is in the engaged position, the extraction shift collar includes an output drive forming portion configured to mesh and engage with the main shaft drive forming portion. When the extraction shift collar is in the disengaged position, the output drive forming portion is axially spaced from the main shaft drive forming portion. When the extraction shift collar is changed in position between the engaged position and the disengaged position, the input drive forming portion maintains engagement with the upper drive forming portion. The power take-off device according to claim 6.

11. An input hub configured to receive power, A clutch drum, A torque transmission coupling configured to selectively transmit power between the input hub and the clutch drum when in an engaged state, and when in a disengaged state, the input hub is disengaged from the clutch drum. A torque transmission coupling, A hypoid pinion shaft non-rotatably coupled to the clutch drum, A hypoid pinion gear non-rotatably coupled to the hypoid pinion shaft, the hypoid pinion gear rotating together with the clutch drum, A main ring gear meshed and engaged with the hypoid pinion gear, A differential comprising a differential housing, a differential shaft non-rotatably coupled to the differential housing, opposed pinion gears rotatably connected together by a pinion shaft mechanically connected to the differential housing, and opposed first and second side gears meshingly engaged with the pinion gears such that power can be transmitted from the differential housing to the pinion gears and then transmitted further. 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 comprising a sun gear non-rotatably coupled to a sun shaft non-rotatably coupled to the main ring gear, a planetary ring gear disposed radially outward of the sun gear, and a planetary carrier assembly comprising a planetary carrier rotatably supporting one or more planetary gears, wherein the planetary carrier engages with the planetary gears so as to rotate together, and the planetary gears rotate between the sun gear and the planetary ring gear when the planetary carrier rotates. A shift collar splined to the differential shaft so as to be axially slidable relative to the differential shaft while rotating with the differential shaft, the shift collar connecting the sun shaft to the differential shaft and being axially slidable between a 4HI position for transmitting power received from the hypoid pinion gear to the differential housing and a 4LO position for connecting the planetary carrier to the differential shaft and transmitting power received from the planetary carrier to the differential housing, the 4HI position being axially spaced from the 4LO position. A rear-wheel drive module for a vehicle, comprising the above components.

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

13. The sun shaft includes sun drive teeth, when the shift collar is in the 4HI position, the shift collar includes a lower drive forming portion configured to mesh and engage with the sun drive teeth, when the shift collar is disposed at a distance from the 4HI position, the lower drive forming portion is disposed at an axial distance from the sun drive teeth, the rear wheel drive module according to claim 12.

14. The planetary carrier includes carrier drive teeth, when the shift collar is in the 4LO position, the shift collar includes an upper drive forming portion configured to mesh and engage with the carrier drive teeth, when the shift collar is in the 4HI position, the upper drive forming portion is disposed at an axial distance from the carrier drive teeth, the rear wheel drive module according to claim 13.

15. while maintaining the output drive forming portion in a meshing engagement state with the differential drive teeth, the shift collar is axially slidable between a 4LO lock position and the 4LO position, the 4LO lock position being disposed at an axial distance from the 4LO position, the first output shaft includes lock drive teeth, when the shift collar is in the 4LO lock position, the output drive forming portion is meshed and engaged with the lock drive teeth and the differential drive teeth, when the shift collar is in the 4LO position, the output drive forming portion is disposed at an axial distance from the lock drive teeth and meshed and engaged with the differential drive teeth, the rear wheel drive module according to claim 14.

16. The rear wheel drive module according to claim 15, further comprising an actuator assembly configured to axially change the position of the shift collar among the 4LO lock position, the 4LO position, and the 4HI position.

17. The actuator assembly is a barrel cam actuator, and the barrel cam actuator has a longitudinal axis, has a cam slot extending circumferentially therearound, and a barrel cam rotatable around the longitudinal axis, is fixedly coupled to the shift collar and operably coupled to the cam slot, a shift fork A barrel cam motor operably coupled to the barrel cam, the barrel cam motor configured to selectively rotate the barrel cam about the longitudinal axis, whereby the shift fork axially repositions the shift collar among the 4LO lock position, the 4LO position, and the 4HI position The rear wheel drive module according to claim 16, comprising the same.

18. The torque transmission coupling further comprises a friction clutch configured to operably couple the clutch drum to the input hub when the friction clutch is engaged and the torque transmission coupling is in the engaged state, and to disengage the friction clutch from the input hub when the friction clutch is disengaged and the torque transmission coupling is in the disengaged state. The rear wheel drive module according to claim 11.

19. The friction clutch further comprises a plurality of friction plates axially movable between an engaged state in which the clutch drum is coupled to the input hub and a disengaged state in which the clutch drum is disengaged from the input hub. The torque transmission coupling further comprises a hydraulic piston configured to selectively apply axial pressure to the friction plates to position the friction plates in the engaged state, and a return spring configured to bias the friction plates toward the disengaged state. The rear wheel drive module according to claim 18, wherein when pressure is removed from the friction plates, the return spring disengages the friction clutch and disengages the clutch drum from the input hub.

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

21. An input hub configured to receive power; A clutch drum; A torque transmission coupling configured to selectively transmit power between the input hub and the clutch drum when in an engaged state and to disengage the input hub from the clutch drum when 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, the hypoid pinion gear rotating together with the clutch drum, A main ring gear meshingly engaged with the hypoid pinion gear, A differential housing configured to rotate in response to rotation of the main 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 housing, and opposing first and second side gears meshingly engaged with the pinion gears so that power can be transmitted from the differential housing to the pinion gears and then transmitted, a differential comprising: 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 rear-wheel drive module for a vehicle, comprising: The torque transmission coupling includes a friction clutch including a plurality of friction plates axially positionally changeable between the engaged state of coupling the clutch drum to the input hub and the disengaged state of disconnecting the clutch drum from the input hub, a hydraulic piston configured to selectively apply axial pressure to the friction plates to change the position of the friction plates to the engaged state, and a return spring configured to bias the friction plates toward the disengaged state, A rear-wheel drive module in which when pressure is removed from the friction plates, the return spring disengages the friction clutch and axially separates the friction plates to disconnect the clutch drum from the input hub.

22. The rear-wheel drive module according to claim 21, wherein the main ring gear and the differential are supported radially and axially between bearings arranged in a stacked arrangement with a gap therebetween.

23. A power take-off device according to claim 1, selectively transmitting power to a pinion shaft, A propeller shaft having a first end operatively coupled to the pinion shaft so as to rotate in response to rotation of the pinion shaft, A four-wheel drive system for a vehicle, comprising a rear-wheel drive module, The rear-wheel drive module is An input hub non-rotatably coupled to the propeller shaft and configured to receive power from the power take-off device; A clutch drum; A torque transmission 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 gear non-rotatably coupled to the second hypoid pinion shaft; A second main ring gear meshing with the second hypoid pinion gear, a second differential housing, a second differential shaft non-rotatably coupled to the second differential housing, a second pinion shaft mechanically connected to the second differential housing, a pair of opposing second pinion gears rotatably connected together by the second pinion shaft, and a pair of opposing third and fourth side gears meshing with the second pinion gear so that power can be transmitted from the second differential housing to the second pinion gear and then transmitted; a second differential; A third output shaft non-rotatably coupled to the third side gear; A fourth output shaft non-rotatably coupled to the fourth side gear, wherein the third side gear and the fourth side gear are rotatably arranged coaxially with respect to the second differential housing; a fourth output shaft; A second sun gear non-rotatably coupled to a second sun shaft non-rotatably coupled to the second main ring gear, a second planetary ring gear disposed radially outside the second sun gear, and a second planetary carrier assembly including a second planetary carrier rotatably supporting one or more second planetary gears, wherein the second planetary carrier engages with the second planetary gears so as to rotate together, and the second planetary gears rotate between the second sun gear and the second planetary ring gear when the second planetary carrier rotates; a second planetary gear set; A second shift collar splined to the second differential shaft so as to be axially slidable relative to the second differential shaft while rotating together with the second differential shaft, connecting the second sun shaft to the second differential shaft, and transmitting the power received from the second hypoid pinion gear to the second differential housing; and a 4HI position where the second planetary carrier is connected to the second differential shaft and the power received from the second planetary carrier is transmitted to the second differential housing. A second shift collar that is axially slidable between the 4LO position, and the 4HI position is axially spaced from the 4LO position. An all-wheel drive system for a vehicle comprising a second shift collar.

24. The second differential shaft includes differential drive teeth, The second shift collar meshes with the differential drive teeth and includes an output drive forming portion that is axially slidable relative to the differential drive teeth between the 4HI position and the 4LO position. The all-wheel drive system according to claim 23.

25. The second sun shaft includes sun drive teeth, When the second shift collar is in the 4HI position, the second shift collar includes a lower drive forming portion configured to mesh with the sun drive teeth, When the second shift collar is disposed at a distance from the 4HI position, the lower drive forming portion is axially spaced from the sun drive teeth. The all-wheel drive system according to claim 24.

26. The second planetary carrier includes carrier drive teeth, When the second shift collar is in the 4LO position, the second shift collar includes an upper drive forming portion configured to mesh with the carrier drive teeth, When the second shift collar is in the 4HI position, the upper drive forming portion is axially spaced from the carrier drive teeth. The all-wheel drive system according to claim 25.

27. While maintaining the output drive forming portion in the meshing engagement state with the differential drive teeth, the second shift collar is axially slidable between the 4LO lock position and the 4LO position, and the 4LO lock position is axially spaced from the 4LO position. The third output shaft includes lock drive teeth. When the second shift collar is in the 4LO lock position, the output drive forming portion is meshingly engaged with the lock drive teeth and the differential drive teeth. The all-wheel drive system according to claim 26, wherein when the second shift collar is in the 4LO position, the output drive forming portion is axially spaced from the lock drive teeth and meshingly engaged with the differential drive teeth.

28. The power take-off device includes: The main shaft including a main shaft drive forming portion; The input shaft including input drive teeth; The take-out shift collar including an output drive forming portion configured to mesh and engage with the main shaft drive forming portion and an input drive forming portion configured to mesh and engage with the input drive teeth when the take-out shift collar is in the engagement position; And further includes: When the take-out shift collar is in the disengaged position, one of the input drive forming portion or the output drive forming portion is disengaged from the input drive teeth or the main shaft drive forming portion, respectively. The all-wheel drive system according to claim 23, wherein when the take-out shift collar is repositioned between the disengaged position and the engaged position, the other of the input drive forming portion or the output drive forming portion maintains engagement with the input drive teeth or the main shaft drive forming portion, respectively.

29. The power take-off device includes: A differential including a differential housing, opposing pinion gears rotatably connected together by a pinion shaft mechanically connected to the differential housing, and opposing first and second side gears meshingly engaged with the pinion gears so that power can be transmitted from the differential housing to the pinion gears and then transmitted; 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 comprising a sun gear non-rotatably coupled to a sun shaft, a planetary ring gear disposed radially outward of the sun gear, and a planetary carrier assembly including a planetary carrier rotatably supporting one or more planetary gears, wherein the planetary carrier engages with the planetary gears to rotate together, the planetary gears rotate between the sun gear and the planetary ring gear when the planetary carrier rotates, and the planetary carrier is non-rotatably coupled to a differential housing such that the differential housing rotates when the planetary carrier rotates. A range shift collar rotatably and slidably coupled to the input shaft so as to rotate with the input shaft and be axially slidable relative to the input shaft, and the range shift collar is axially slidable between a high position connecting the range shift collar to the planetary carrier to transmit the power received from the input shaft to the planetary carrier and a low position connecting the range shift collar to the sun shaft to transmit the power received from the input shaft to the sun gear. The power take-off device according to claim 23, further comprising the above.

30. The power take-off device according to claim 29, further comprising an actuator assembly configured to change the position of the take-out shift collar between the engaged position and the disengaged position and configured to change the position of the range shift collar between the high position and the low position.

31. The actuator assembly is a barrel cam actuator, and the barrel cam actuator has a longitudinal axis, has a take-out cam slot and a range cam slot extending circumferentially around it, and a barrel cam rotatable around the longitudinal axis. A take-out shift fork fixedly coupled to the take-out shift collar and operably coupled to the take-out cam slot. A range shift fork fixedly coupled to the range shift collar and operably coupled to the range cam slot. A barrel cam motor operably coupled to the barrel cam, selectively rotating the barrel cam about the longitudinal axis, whereby the take-out shift fork axially repositions the take-out shift collar between the engaged position and the disengaged position, and the range shift fork axially repositions the range shift collar between the high position and the low position. The power take-off device according to claim 30, comprising the same.

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