Mechanism Research On High-Speed On/Off Valve Applied In Radial Variable Displacement Piston Motor

Digital Displacement Motor (DDM) have been shown to enable high-efficiency operation in a wide operation range, especially at part load. The key to obtain efficient part load operation with DDM lies in the development of high-speed On/Off valves with a corresponding low pressure loss.This paper proposed four new requirements based on the the DDM high-efficiency performance:high frequency response, high flow rate, low valve opening pressure difference, low throttling losses,based on this points,a new spool valve with hold stroke length and moving sleeve is presented in this paper, this present paper have verified its flow capacity by analying the valve static characteristics through CFD simulation software, as well as steady flow force. Then building a mathematical model of the movement of the valve sleeve and the CFD dynamic simulation model to verify its fast switching response.Obtained the displacement, velocity and acceleration curve at the different operating points of the valve sleeve.Determining the switching time of the valve sleeve at different working positions, and analyzing the direction and magnitude of the valve sleeve’s transient flow force.Obtained the oil pressure dynamics in the piston chamber when the sleeve moving through the fully opening and dead strokes length based the valve controling motor model,as well as the valve opening pressure drop,at different motor speed and different valve closing position.Obtained the valve throlling loss ratio when the sleeve fully opening,closing or openging at different motor speed. Obtained the best location to close the valve motor speed to match different based on the design idea:Low pressure drop, low throttling loss, the validity of sync correction median. At the same time,the open valve opening pressure is small,which is guaranteed by the validity of sync correction of dead strokes length.