Hydraulic fluid pressure control

摘要

A hydraulic fluid pressure control system is provided. The control system comprises: a hydraulic pump motor 2 having an electrical input configured to receive an AC input signal 7 and a hydraulic fluid output 9 configured to output a pressure proportional to the frequency of the AC input signal 7; and electronic control circuitry 8 connected to the electrical input. The electronic control circuitry 8 provides an AC input signal 7 of variable frequency and the electronic control circuitry 8 may comprise an inverter. The hydraulic fluid output acts as a hydraulic power source for a directio0nal control valve 12. The pressure of the hydraulic fluid output 9 is measured by a pressure sensor 10 which provides an electrical output 11 which controls the frequency of the AC input signal 7 from the inverter 8.