Research On The Water Hydraulic Piston Pump With Check Valves And Reliability Analysis Of The Key Components

Aiming at the current condition that the water supply height of fires truck isinsufficient and the service life of pumps is unsatisfactory, a kind of water hydraulicpiston pump with check valves is designed in this thesis, and its innovative structuresare introduced; besides, much of the research has concentrated on the reliabilityanalysis of these key frictions pairs such as pistons、shoes and sliding bearings.By comparing the structures of the commonly used check valves, and combiningwith the performance requirements of the pump, poppet valve is applied to distributethe flow of the pump, and the parameters of check valves is preliminary designedaccording to the formula. The AMESim software is used to establish the componentmodel of axial piston pump with check valves, and simulate its working process.Clearance volume、valve quality and spring stiffness are discussed particularly toanalyze the impact on flow characteristics, and solutions are proposed accordingly,which provide theoretical basis for developing the pump.In order to improve the reliability of piston pairs, a new sealing structure ofautomatic clearance compensation with constant length of fit is proposed. Thecorresponding crafts and kinematics rules are discussed, and the position of the sealgrooves is determined preliminary. Alternating load is applied to different width ofthe ring seal grooves with the software of ANSYS, by comparing the correspondingradial deformation and stress of piston sleeve, the optimum width of ring seal groovesfor the piston sleeve with specified thickness is determined.Finally, comprehensive performance tests of the prototype are carried out.Theresults show that: the unloaded flow rate is12.8L/min at the speed of600r/min, thevolumetric efficiency is more than74%under the delivery pressure of16MPa and thenoise stabilizes85.8dB, respectively; as for the shortage of water absorption, a newimprovement is put forward correspondingly. Besides, pollution reliability modelunder uncertainty is developed and applied to a high pressure water cutting system(HPWCS) with a bypass filtration system, which provides a minimized total cost andfailure-risk level for the HPWCS.