Hydrostatic differential lock for motor vehicles

摘要

A hydrostatic differential lock for motor vehicles, in which the locking torque depends on the difference between the speeds of the driven wheels on the vehicle axle concerned or - in the case of four-wheel drive - on the difference between the speeds of the front and rear axle, has a hydrostatic coupling or respective hydrostatic couplings designed as planetary gear units for connecting the wheel drive shafts or the prop shaft to the differential gear case(s) (differential cage(s)). Arranged in the hydrostatic coupling, between the pressure spaces and the pressure balance space, are pressure relief valves which open at a particular excess pressure, to be determined beforehand, in the pressure spaces. By this means, the locking torque, which rises in linear fashion as the speed difference increases, is limited to a constant maximum value. This makes it possible to provide a differential lock for motor vehicles which avoids high restoring torques in the steering or oversteering of the vehicle (which is designed for understeering) and hence permits easy handling of the vehicle concerned.