A Hydraulic Pressure-Boost System Based on High-Speed On–Off Valves

A novel hydraulic pressure-boost system utilizing high-speed On-Off valves is studied in this paper. The hydraulic pressure-boost system is analogous to a boost converter in power electronics. High pressure is achieved by braking a hydraulic motor with inertia flywheel through the high-speed On-Off valve. The high pressure is stabilized by a hydraulic capacitor set at the motor output. The steady state and fluctuation characteristics of the pressure-boost system are studied. Research shows that the output pressure is always higher than system pressure and it increases with the duty ratio of pulse width modulation (PWM) signal supplied to the high-speed On-Off valve. It also shows the output pressure fluctuation is greatly influenced by the PWM signal frequency and the oil chamber volume. The hydraulic pressure-boost system was built and tested. It successfully boosted the system pressure from 50 to 116 bar at the PWM signal duty ratio of 0.7. The success of the experiment brings a new way to boost hydraulic pressure.