A drive force transfer device is mounted on a four-wheel-drive vehicle having main drive wheels and auxiliary drive wheels. A cam mechanism presses a main clutch in the axial direction. An electromagnetic clutch mechanism actuates the cam mechanism and has an electromagnetic coil and a pilot clutch. When the electromagnetic coil is not energized, the pressing force of the cam mechanism, which is generated because of drag torque of the pilot clutch in the case where a output rotary member rotates faster than a input rotary member, is smaller than that generated because of drag torque of the pilot clutch in the case where the input rotary member rotates faster than the output rotary member.

A brake torque distribution system for a vehicle can include a braking system and a controller. The controller can be configured to signal a clutch of the vehicle powertrain to move to the engaged position such that the front wheels are rotationally coupled to the rear wheels and the brake torque applied to the front wheels by the braking system is transmitted to the rear wheels. The controller can be configured to signal the clutch to move to the engaged position based on an inclination angle signal received by the controller and indicative of an angle of inclination of the vehicle, a selected gear signal received by the controller that is indicative of the reverse gear ratio being selected in the powertrain, and a load signal received by the controller and indicative of a load applied to a portion of the vehicle adjacent to the rear wheels.

Methods and systems for a differential assembly are provided herein. In one example, a diagnostic method includes generating a clutch fault according to a variance between an initial engagement position and a lock point position of a clutch motor that occur during engagement of an interaxle differential (IAD) locking clutch coupled to the clutch motor. In the IAD system, an actuation assembly is coupled to the clutch motor and the IAD locking clutch.

An all-wheel-drive vehicle includes a primary drive axle, a secondary drive axle, and an all-wheel-drive powertrain configured to selectively power the primary and secondary axles. The powertrain includes a powerplant and a clutch that couples the powerplant to the secondary axle when engaged and that decouples the powerplant from the secondary axle when disengaged. A controller is programmed to disengage the clutch to disable all-wheel drive and propel the vehicle solely with the primary drive axle based on repeated occurrence of power output of the powertrain being less than a value.

Provided is a torque control device for a four-wheel-drive vehicle that can stably output a minimum torque required to start or drive the vehicle to the auxiliary wheel side under a road surface condition that main driving wheels are stuck in the idling state or under a road surface condition equivalent thereto. When front wheels Wf1, Wf2 are judged to be stuck in the idling state, a current rear torque TrCMD is raised step by step. And, when a brake operates in the state in which the four wheels are at stop after raising the command torque TrCMD step by step, the command rear torque TrCMD is released. And, the command rear torque TrCMD is raised step by step when the command rear torque TrCMD continues to be released for a second threshold time.

A method for controlling a driving dynamics function of a working machine with at least two vehicle axles. A current actual wheel rotational speed of at least one wheel is detected and sent to a control unit for comparison with an acceptable wheel rotational speed of the same wheel and wheel slip is calculated from that comparison. The control unit emits a control signal to lock at least one differential gear system if the wheel slip has an unacceptable value. For the differential gear system (4, 5, 6, 7, 8) concerned, an unlocking control signal is periodically emitted and the wheel rotational speeds are compared afresh. A control signal to lock the differential gear system concerned is emitted again if the value of the wheel slip is still unacceptable, and a trajectory is detected with reference to detection elements, along which the value of the wheel slip of the at least one wheel has been unacceptable.

A wheel disconnect clutch includes a housing attachable to a knuckle and a clutch sleeve slidably supported for axial movement within the housing and having first teeth configured to couple with a wheel hub and second teeth configured to couple with a half shaft. The clutch sleeve is slidable between an engaged position in which the first teeth are coupled to the wheel hub and a disengaged position in which the first teeth are decoupled from the wheel hub. A drive ring is connected to the clutch sleeve and supported within the housing to be axially slidable and rotationally fixed relative to the housing. An actuator ring is disposed adjacent to the drive ring, supported for rotation within the housing, and axially fixed relative to the housing. The driver ring moves the clutch sleeve between engaged and disengaged positions.

The electronic IWE actuator includes an electric motor, a worm gear connected to the electric motor, a ball ramp including a worm wheel configured to engage with the worm gear, a clutch ring configured to engage with a wheel hub of the vehicle, and a shift fork configured to engage with the clutch ring and the ball ramp and move linearly in a direction along an axis of the wheel hub in response to a rotation of the ball ramp. The clutch ring is configured to engage with the wheel hub in response to a rotation of the worm gear in a first direction, and disengage from the wheel hub in response to a rotation of the worm gear in a second direction that is opposite to the first direction.

A front-and-rear-wheel-drive vehicle includes an electric motor; a speed change mechanism; a first output rotation shaft that transmits a drive force of the electric motor that has been transmitted to an intermediate output member, to one of a front wheel side and a rear wheel side; and a second output rotation shaft that transmits the drive force that has been transmitted to the intermediate output member, to another of the front wheel side and the rear wheel side. The first and second output rotation shafts are disposed coaxially with the intermediate output member. The electric motor is disposed such that a rotation axis of a motor shaft is positioned in parallel with a rotation axis of the intermediate output member and the first and second output rotation shafts and vertically above the rotation axis of the intermediate output member and the first and second output rotation shafts.

A front-and-rear-wheel drive vehicle includes a front wheel-side driveshaft, a rear wheel-side driveshaft, and a driving force distribution device that distributes the driving force of a driving source to the front wheel-side driveshaft and the rear wheel-side driveshaft. The driving force distribution device includes a first rotating member, a second rotating member, an annular driving force transmission medium that transmits the driving force from the first rotating member to the second rotating member, and a motor driving force-rotated member that is rotated by the driving force of an electric motor. The motor driving force-rotated member is passed inside the driving force transmission medium, between the first rotating member and the second rotating member.