Variable-pressure pump with direct drive valve of multi-body spool

To meet the requirement of higher power-to-weight ratio of new aircrafts, the pressure of hydraulic power system has been risen to 35MPa. Considering constant pressure pumps are mostly equipped as EDP(Engine-Driven-Pump) in aircrafts, the pressure of this type pump always maintain at a constant value. Long periods of high pressure running will cause energy waste and heat problems. In this paper, a variable-pressure pump with DDV(Direct-Drive-Valve) of multi-body spool is proposed. The design of multi-body spool and direct drive form can make manufacturing easier and structure compact. The mathematical and AMESim model are established to analyze the behavior of the variable-pressure pump. The results show that the output pressure of pump can continuously change between 21MPa and 35MPa with the command signal input, when the solenoid is power off, the pressure can still maintain at 21MPa, so the availability and reliability of the variable-pressure pump can be obtained.