| 摘要 |
A load sensing controller is disclosed of the type which may be used in a hydrostatic power steering system. The controller housing includes a valving arrangement (29) and a fluid meter (31), through which fluid is delivered to a steering cylinder (15). A controller housing (63) defines a load signal port (25) which is connected to a load sensing flow control valve (39) to vary the rate of fluid delivery to the controller. During normal operation, a steering load signal is sensed downstream of a variable flow control orifice (131) and communicated through a shuttle valve assembly (151) to the load signal port (25). When the steering cylinder is subjected to an overrunning load, an increased load signal is sensed upstream of a variable orifice (136) and the shuttle valve assembly communicates this increased load signal to the load signal port to increase the rate of fluid delivery to the controller to prevent cavitation. The resulting increased rate of flow through the fluid meter increases follow-up movement to the valving, thus reducing the flow area of the variable orifice (136) to restrict the discharge flow rate, which also aids in preventing cavitation. |
