Development And Experimental Study Of Water Hydraulic Piston Pump Driven By Linear Motor

Water hydraulic transmission technology is a use of filtered fresh water or sea water instead of mineral oil as the working medium of the green hydraulic technology.Piston pumps are the key components in water hydraulics.The leakage,corrosion,cavitation,friction and wear are terribly serious in water hydraulic piston pumps in comparison with oil pumps.The traditional mature swash-plate piston plunger pump is inapplicable to deep-sea machinery because of the sharp decrease of volume efficiency under high confining pressure.The water hydraulic piston pump driven by linear motor is suitable to deep sea due to the elimination of the confining pressure effect on the swash plate and shaft seals.Since the transformation between the revolution and linear motion is cut off in linear direct drive,the linear-motor-driven pump is more efficient than the traditional rotary-motor-driven pump.As well,the infinitely-variable speed is easily controlled by varying the velocity of the slider of the linear motor,so that we can realize the stepless speed regulation of the pump.Linear motor and water hydraulic piston pump as the research object,based on the related research at home and abroad,the development and research status of hydraulic piston pump and direct drive pump are analyzed.A new type of water hydraulic piston pump driven by linear motor is designed and developed.By analyzing the stacking effect of triangular wave and trapezoidal wave under the hysteresis condition,the motion planning of the linear motor is established.The flow pattern of the piston pump is determined by AMESim modeling and simulation.Based on the analysis of the force and leakage of the plunger pair and the modeling of the permanent magnet synchronous linear motor,the driving characteristics of the linear motor are analyzed by constructing a single plunger test rig.The drive characteristics of linear motor are verified.316LStainless Steel and four kind of Polyether-ether-ketone were studied.The contact surface friction coefficient,temperature of friction pairs in water were investigated by using a MMW-1 vertical universal friction and wear tester.After the friction test the worn surface morphologies and wear extent were observed by a laser scanning confocal microscope and electronic scales.316L-PEEKHPV is determined as the appropriate counter materials of friction pairs water hydraulic motor,The principle prototype of water hydraulic piston pump is designed and made on the basic of these studies.Through the installation of the prototype test bench,carried out load test,and the results show that the actual output flow is 10.2 L/min,the volumetric efficiency is about 79.07%,the mechanical efficiency is about 93.5%,and the total efficiency is about 73.5%,satisfy the requirements of the research indicators.