Fail=safe servo steering with two hydraulic circuits - has third standby servo pump on vehicle to replace defective pump

摘要

The servo assisted steering for the vehicle has separate servo pumps (2, 14) for the two steering circuits, with a control valve to apply either circuit to the steering linkage. A third, auxiliary pump (14) is fitted to provide failsafe steering if one of the other two circuits fails. The auxiliary pump is linked to the control valve by pressure control monitors which automatically apply its pressure to the failed circuit, or directly to the steering servos.