A four-wheel drive force distribution apparatus for distributing drive forces to the wheels of a four-wheel drive vehicle, in which the distribution of drive force to the front inside wheel (2a) and the distribution of drive force to the rear inside wheel (3a) are adjusted based on a ground load of the front inside wheel (2a) and a ground load of the rear inside wheel (3a) when the vehicle is turning, and the distribution of drive force to the front inside wheel (2a) compared with distribution of drive force to the rear inside wheel (3a) is reduced the smaller the ratio of the ground load of the front inside wheel (2a) to the ground load of the rear inside wheel (3a) during turning.

A four-wheel drive force distribution apparatus for distributing drive forces to the wheels of a four-wheel drive vehicle, in which the distribution of drive force to the front inside wheel (2a) and the distribution of drive force to the rear inside wheel (3a) are adjusted based on a ground load of the front inside wheel (2a) and a ground load of the rear inside wheel (3a) when the vehicle is turning, and the distribution of drive force to the front inside wheel (2a) compared with distribution of drive force to the rear inside wheel (3a) is reduced the smaller the ratio of the ground load of the front inside wheel (2a) to the ground load of the rear inside wheel (3a) during turning.

A vehicle control device mounted on a four-wheel drive vehicle including a driving force transmission system includes an electronic control unit. The electronic control unit calculates a command torque based on vehicle information. The electronic control unit estimates a temperature of a heat generating location in the driving force transmission system based on the command torque. The electronic control unit estimates the temperature of the heat generating location based on an estimated value of a driving force input to an input rotating member, when it is not possible for the driving force corresponding to the command torque to be transmitted to auxiliary drive wheels due to a magnitude of the driving force generated by a drive source or occurrence of a wheel slip.

Methods and systems are provided for selectively engaging an electric machine to an electric axle of a vehicle. In one example, a method may include engaging or disengaging the electric machine to a differential of the electric-axle by adjusting pressure in a piston coupled to an axle shaft of the electric-axle via a disconnect clutch.

Methods and systems are provided for selectively engaging an electric machine to an electric axle of a vehicle. In one example, a method may include engaging or disengaging the electric machine to a differential of the electric-axle by adjusting pressure in a piston coupled to an axle shaft of the electric-axle via a disconnect clutch.

An agricultural work machine comprising a front axle and a rear axle, an internal combustion engine, at least one hybrid module, and a transmission device is disclosed. The internal combustion engine and the hybrid module are each operatively connected to the transmission device with both output power from the internal combustion engine and output power from the hybrid module absorbed via the transmission device. The output powers are transferred together to the rear axle so that rear wheels of the agricultural work machine arranged on the rear axle can be driven. The internal combustion engine is arranged in a front region of the agricultural work machine and the hybrid module is arranged in a rear region of the agricultural work machine. The output powers from the internal combustion engine and the hybrid module are supplied separately to the transmission device.

A utility vehicle includes: a power unit that outputs drive power; a drive shaft that receives the drive power transmitted from the power unit; a front axle that receives the drive power transmitted from the drive shaft; a right front wheel connected to the front axle; a left front wheel connected to the front axle; a right clutch configured to disable power transmission from the drive shaft to the right front wheel; a left clutch configured to disable power transmission from the drive shaft to the left front wheel; a clutch actuator that actuates the left clutch and the right clutch; and a controller that controls the clutch actuator.

A roller cage assembly for an overrunning clutch is provided. The roller cage assembly includes a roller cage, a plurality of rollers and a plurality of roller spring assemblies. The roller cage includes a plurality of spaced support members axially extending between disk shaped first and second end portions. The plurality of rollers are positioned within the roller cage. The plurality of roller spring assemblies engage the roller cage. The plurality of spring roller assemblies are configured to provide a bias force on each roller away from the roller cage. Each roller cage assembly extends between the first and second end portions of the roller cage. Each roller spring assembly further includes at least one pair of attachment members configured to engage a support member of the roller cage.

A driving force estimation apparatus includes a free rolling rotation speed output unit, an actual rotation speed detector, a slip rate calculation unit, a driving force estimation unit, a slip angle output unit, and a stiffness correction unit. The free rolling rotation speed output unit outputs free rolling rotation speeds of front and rear wheels in a free rolling state devoid of a braking or driving force. The slip rate calculation unit calculates slip rates of the front and rear wheels, from the free rolling rotation speeds and actual rotation speeds. The driving force estimation unit estimates driving forces of the front and rear wheels, using driving or braking stiffnesses of the front and rear wheels and the slip rates. The slip angle output unit outputs slip angles of the front and rear wheels. The stiffness correction unit corrects the driving or braking stiffnesses based on the slip angles.

A driving force estimation apparatus includes a free rolling rotation speed output unit, an actual rotation speed detector, a slip rate calculation unit, a driving force estimation unit, a slip angle output unit, and a stiffness correction unit. The free rolling rotation speed output unit outputs free rolling rotation speeds of front and rear wheels in a free rolling state devoid of a braking or driving force. The slip rate calculation unit calculates slip rates of the front and rear wheels, from the free rolling rotation speeds and actual rotation speeds. The driving force estimation unit estimates driving forces of the front and rear wheels, using driving or braking stiffnesses of the front and rear wheels and the slip rates. The slip angle output unit outputs slip angles of the front and rear wheels. The stiffness correction unit corrects the driving or braking stiffnesses based on the slip angles.