Abstract: A new energy saving hydraulic system is put forward,in which a pressure convert device named switchmode hydraulic power supply is introduced. The entrances of switchmode hydraulic power supplies are all connected with the hydraulic power bus. Their output pressure could be boosted or bucked through PWM control to provide the proper consumed pressure and flow rate of each actuator. The throttle lost is decreased considerably, and the energy saving efficiency is optimal.

Key words: Dynamic efficiency, Hydraulic capacitor, Hydraulic inductor, Hydraulic power bus, Instantaneous efficiency, Pressure boost, Pressure buck with flow rate increase, Switchmode hydraulic power supply