| 摘要 |
<p>A hydraulic power steering system (10) for turning steerable wheels of a vehicle. The system (10) comprises a steering gear (12) including a hydraulic motor, actuatable to turn the steerable vehicle wheels, and a steering valve, for controlling actuation of the hydraulic motor by controlling fluid flow to the hydraulic motor. The steering gear (12) has an inlet (38) in communication with a fluid source and an outlet (40) for directing the fluid from the hydraulic motor back to the fluid source. The steering gear is susceptible to pressure fluctuations that cause noise during steering. The system (10) further comprises a pressure relief valve (14) having an unactuated condition and actuated conditions. The pressure relief valve (14), in the unactuated condition, restricts fluid flow through the pressure relief valve (14). In an actuated condition, the pressure relief valve (14) permits fluid flow through the pressure relief valve (14). The pressure relief valve (14) progressively moves from the unactuated condition to an actuated condition as a pressure differential between the inlet (38) and the outlet (40) of the steering gear (12) increases. The pressure relief valve (14), in an actuated condition, providing fluid communication between the inlet (38) and the outlet (40) of the steering gear (12) while circumventing the steering gear (12) to minimize the pressure fluctuations in the steering gear (12).</p> |
