Study On A Servo Motor-pump Of Floating Valve Plate

At present,Electro-Hydrostatic Actuator(EHA)is a preferred technical approach to TVC(Thrust Vector Control)for future rockets.Servo motor-pump is the core power element of EHA-FPVM(Fixed-Pump-Displacement Variable-Motor-Speed).To a large extent,hydraulic performance of the servo motor-pump depends on distribution mechanism's working performance.The servo motor-pump frequently uses a valve plate to distribute flow.However,due to imbalanced forces and moments,floating pump cylinder body happens overturning and then wears the fixed valve plate.Floating plate distribution structure can significantly prevent the pump cylinder body overturning,improve the servo motor-pump's working reliability,and better solve hydraulic motors' overturning problems,so this paper carries out researches on feasibility of the servo motor-pump using the floating plate distribution structure.In this paper,a prototype is designed.Based on highly integrated design of a servo motor and a two-way fixed-displacement pump,the prototype uses the floating plate distribution structure to distribute flow.The floating plate distribution structure is installed on one side of the pump cylinder body,and the pump cylinder body is fixed on rotating shaft.The prototype's valve plate keeps floating by connecting sleeves and always presses to the pump cylinder body.This paper focuses on structural design of the floating plate distribution structure,including components' design.This paper carries on structure strength checks to the floating valve plate,the connecting sleeves and shaft assembly;and carries on flow field simulation analyses to floating valve plate's flow channel model and key seal structures' liquid film models to obtain flow information which experiment researches can't test.The flow field simulation analyses can examine the structural design's rationality.In this paper,experimental researches are carried out,including a sealing performance test and a prototype performance experiment.The sealing performance test can be used to verify rectangular sealing ring's effect,to determine the most suitable types of the connecting sleeves and compression springs,and to prepare for the prototype performance experiment.On one performance test platform of a servo motor-pump,the prototype performance experiment is tested.By the experiment,we can obtain actual working performance of the prototype and then to judge the floating plate distribution structure's feasibility.All researches show that the servo motor-pump can meet design requirements,and the design of the floating plate distribution structure is correct.This paper can provide some experience for the follow-up work.