P35.30-A015-79
1 | Multidisk clutch | 3 | Pinion | |
2 | Ring gear | 4 | Actuator motor |
Overview
This document contains information on:
General
Function
General
The rear axle differential distributes the engine torque of the drivetrain fully variably between the front and rear axles. Each rear axle shaft is assigned a multiplate clutch with actuator motor. In this way, the drive torques can be transferred between the front and rear axles and between the rear axle shafts depending on the operating status.
Function
Oil supply
The gear sets are lubricated by immersion.
Rpm compensation
The speed compensation between the front and rear axles and the rear axle shafts is achieved by controlled slip operation of the multiplate clutches.
The all-wheel drive control unit converts the driving dynamic requirements into two specified torques for the multiplate clutches.
The specified torques are converted into angle set values at the power output of the actuator motors via the stored characteristics map in the powertrain control unit. The clutch controllers have the following tasks:
Regulate specified angle as quickly as possible (actuator dynamics)
Regulate specified angle precisely (actuator accuracy)
Regulate target angle with lowest possible energy consumption (on-board electrical system load)
The current actual angle information and actuator motor speeds are obtained through incremental sensors. The incremental sensors are located on the armature shafts of the actuator motors.
Torque transmission
A transverse and longitudinal lock function is achieved by the corresponding actuation of the actuator motors, via the all-wheel drive control unit. The multiplate clutches distribute, depending on the operating status, the drive torques between the front and rear axles and between the left and right rear wheel. In this way, a rear wheel can transfer the entire drive torque to the roadway in as far as the other wheels are at a low friction value.