Hydraulic servo motor for motor vehicle steering systems has working piston with piston and seal on either side, and sensor in transmission are, for immediate detection of seal failure

摘要

The double-acting servo moor has a working piston (4), defining two working chambers (6,6') in a cylinder (2), and engaging via a toothing (9) with a steering shaft (10). On each side of the toothing, the working piston has a piston (5,5') and a seal (7,7') between piston and cylinder, so that both working chambers are sealed fluid-tight relative to the transmission area (8). The transmission area is filled with hydraulic fluid, pref. with the fluid used to operate the servo motor. It contains a pressure sensor, to detect a rise in pressure due to failure of the seal.