초록 ▼

An arrangement for controlling the operation of a fluid-displacement machine, such as a hydraulic pump or motor, which is equipped with an adjuster that adjusts the machine toward higher and lower throughputs in dependence upon the pressure of a control fluid acting thereon, includes a control valve

An arrangement for controlling the operation of a fluid-displacement machine, such as a hydraulic pump or motor, which is equipped with an adjuster that adjusts the machine toward higher and lower throughputs in dependence upon the pressure of a control fluid acting thereon, includes a control valve which communicates the adjuster either with a high-pressure zone or with a low-pressure zone of a control circuit in different ones of its terminal positions. In addition thereto, the arrangement includes a pressure-limiting valve interposed between the low-pressure and the high-pressure zones of the control circuit. Both the control and pressure limiting valves are acted upon by the control fluid, the pressure of which is controlled by a common regulating valve. The control and pressure-limiting valve as well as the associated equipment are so constructed that the magnitude of the force required to move the limiting valve toward the open position exceeds that of the force required to move the control valve toward that position in which the adjuster adjusts the machine toward lower throughputs.

대표청구항 ▼

In a fluid-flow system of the type including a high-pressure conduit, a throughput-adjustable fluid-displacement machine, a throughput-adjusting device for the machine, a control valve interposed between the throughput-adjusting device and the high pressure conduit, and a pressure-limiting valve com

In a fluid-flow system of the type including a high-pressure conduit, a throughput-adjustable fluid-displacement machine, a throughput-adjusting device for the machine, a control valve interposed between the throughput-adjusting device and the high pressure conduit, and a pressure-limiting valve communicating with the high-pressure conduit, the improvement comprising a regulating valve commonly associated with said throughput-adjusting device via said control valve and with said pressure-limiting valve; and said control and pressure limiting valves being so constructed that the magnitude of the force required to open said pressure limiting valve exceeds that of the force required to actuate said control valve to a position thereof in which said through-put adjusting device adjusts said machine toward lower throughputs.