Axle drive
The axle transmission (or the final drive ) has in a motor vehicle the task from the change gear supplied drive power to the drive shafts to be transmitted to the drive wheels.
tasks
- Transfer torque between gearbox and drive wheels
- The speed ratio between the transmission and drive wheels by appropriate translation compensate
- Redirect the power flow, if necessary
- Enable axial offset, if necessary (axial offset means that the axes of the cardan shaft and drive shafts do not intersect, which is made possible by a single-stage hypoid or worm drive )
- Different speeds of the drive wheels during cornering by means of a differential gear compensate
Provide appropriate translation
The difference in speed between the engine and the drive wheels must be balanced out by means of a change gearbox and axle drive. So that the speed ratio (transmission) in the gearbox does not have to be too large, part of the speed reduction is relocated to the axle drive. The speeds converted by the gearbox are converted to slow speed by the constant ratio of the axle drive and the torque is increased accordingly. The overall ratio of the drive train is then calculated from the ratio of the gear engaged and the constant ratio of the axle drive.
Divert power flow
If the motor is arranged in the direction of the vehicle's longitudinal axis, the power flow must be deflected by 90 degrees, since the drive shafts are always perpendicular to the longitudinal axis of the vehicle. The power flow can be redirected using a bevel , hypoid or worm gear.
In the case of vehicles with motors arranged transversely to the vehicle's longitudinal axis, the direction of the power flow does not have to be deflected, but under certain circumstances an axis offset must be provided for structural reasons. Here one uses spur gear axle drives.