摘要 |
<p>Disclosed is a vehicle power steering system including a flow-sensing switch for energizing an electrohydraulic safety backup system for supplying fluid pressure to the steering motor of the vehicle when a main pump becomes inoperative to supply pressure fluid to the steering motor. The flow-sensing switch is in the form of a poppet valve including a valve element which is normally seated to complete an electrical circuit for energizing an electric motor for driving an auxiliary pump. The poppet valve element is held open by fluid pressure delivered by the main pump when the main pump is working properly. The output of the auxiliary pump is connected to the poppet valve element such that the fluid pressure delivered by the auxiliary pump aids in maintaining the poppet valve element in its closed position.</p> |