A system and method for controlling switching of an electric vehicle to four-wheel drive are provided. The system includes a first motor connected to main drive wheels and configured to output a first torque, a second motor connected to subsidiary drive wheels and configured to output a second torque, a disconnector mounted on an axle shaft for the subsidiary drive wheels, a driver requested torque detector configured to detect a driver requested torque, and a controller configured to release a set output limit of the first motor for a designated time and simultaneously release a set output limit of the second motor when the driver requested torque is greater than or equal to a reference requested torque, and control the first motor to output a maximum torque exceeding the set output limit to the main drive wheels until the disconnector is engaged.

A transfer device of a vehicle is provided, in which an auxiliary-drive-wheel output shaft extending in parallel with a main-drive-wheel output shaft is connected to a propeller shaft having a universal joint. An end part of the auxiliary-drive-wheel output shaft on a propeller shaft side is formed in a hollow shape and includes a fitting part configured to be spline-engaged with a joint part provided to the universal joint. The joint part is provided with a centering part which is inserted into a centering hole formed in a flange part provided to one side of the auxiliary-drive-wheel output shaft so that the joint part is centered on the auxiliary-drive-wheel output shaft. The flange part is sandwiched between a spacer and the joint part, and a bolt member is attached to a bolt hole formed in the centering part so that the propeller shaft is assembled to the auxiliary-drive-wheel output shaft.

A transfer device of a vehicle is provided, in which an auxiliary-drive-wheel output shaft extending in parallel with a main-drive-wheel output shaft is connected to a propeller shaft having a universal joint. An end part of the auxiliary-drive-wheel output shaft on a propeller shaft side is formed in a hollow shape and includes a fitting part configured to be spline-engaged with a joint part provided to the universal joint. The joint part is provided with a centering part which is inserted into a centering hole formed in a flange part provided to one side of the auxiliary-drive-wheel output shaft so that the joint part is centered on the auxiliary-drive-wheel output shaft. The flange part is sandwiched between a spacer and the joint part, and a bolt member is attached to a bolt hole formed in the centering part so that the propeller shaft is assembled to the auxiliary-drive-wheel output shaft.

Methods and systems are provided for controlling a multi-axle assembly in a vehicle. The multi-axle assembly may be operated according to a requested mode, where the mode includes providing torque at one, two, or no axles of the multi-axle assembly, and the requested mode may be selected based on vehicle speed. In this way, operation of the multi-axle assembly may be adjusted according to a fuel efficiency of the vehicle while the vehicle is in motion.

An axle assembly that has a lubricant reservoir. The lubricant reservoir may be disposed above a differential assembly and may capture lubricant that is splashed by the differential assembly. The lubricant reservoir may have at least one tank. The lubricant reservoir may optionally provide lubricant to a lubricant distribution trough.

An apparatus and method for diagnosing damage to drive-train hardware of a vehicle in which a disconnector may obtain speed of an auxiliary drive wheel motor of the vehicle and speed of a main drive wheel motor of the vehicle and determines damage to the drive-train hardware including the disconnector that controls whether to interrupt delivery of power through engagement or disengagement between auxiliary drive wheel motor-side drive-train hardware and auxiliary drive wheel-side drive-train hardware, based on whether a difference between the speed of the auxiliary drive wheel motor and the speed of the main drive wheel motor exceeds a threshold value, Accordingly, preventing divergence of motor RPM by diagnosing damage to the drive-train hardware of the vehicle.

An apparatus and method for diagnosing damage to drive-train hardware of a vehicle in which a disconnector may obtain speed of an auxiliary drive wheel motor of the vehicle and speed of a main drive wheel motor of the vehicle and determines damage to the drive-train hardware including the disconnector that controls whether to interrupt delivery of power through engagement or disengagement between auxiliary drive wheel motor-side drive-train hardware and auxiliary drive wheel-side drive-train hardware, based on whether a difference between the speed of the auxiliary drive wheel motor and the speed of the main drive wheel motor exceeds a threshold value, Accordingly, preventing divergence of motor RPM by diagnosing damage to the drive-train hardware of the vehicle.

A driving device of an electric-motor four-wheel drive vehicle includes a propeller shaft, a first differential mechanism, a second differential mechanism, a first decoupling mechanism, a second decoupling mechanism, a first motor, and a second motor. The propeller shaft transmits power between front wheels and rear wheels. The first differential mechanism is disposed in a drive shaft of the front wheels. The second differential mechanism is disposed in a drive shaft of the rear wheels. The first decoupling mechanism decouples the first differential mechanism from the propeller shaft. The second decoupling mechanism decouples the second differential mechanism from the propeller shaft. The first motor is coupled to the propeller shaft via a part closer to the front wheels than the first decoupling mechanism or a part closer to the rear wheels than the second decoupling mechanism. The second motor is coupled between the first and second decoupling mechanisms.

The present invention relates to a transfer gearbox having an input shaft, a first output shaft, a second output shaft, a friction clutch, by means of which, in a manner which is dependent on its engagement state, a variable proportion of a drive torque which is transmitted from the input shaft to the first output shaft can be transmitted to the second output shaft, and a rotationally driven actuator unit for controlling the engagement state of the friction clutch. Furthermore, the transfer gearbox has an electromagnetically actuable latch for locking the actuator unit as required.

A drive device for a vehicle axle of a two-track vehicle having a drive unit having in particular an electric machine, which outputs on the output side on at least one driveshaft leading to a vehicle wheel, which driveshaft is divided into a wheel-side shaft section and an axle-side shaft section which can be coupled to one another or decoupled from one another in a driving manner by means of a formfitting clutch, in order to avoid drag losses in the deactivated drive unit in driving operation with deactivated drive unit.