Prediction And Analysis Of Lubrication Characteristics Of Piston Pump's Slipper/swashplate Pairs In Varying Ocean-depths

Axial piston pump is one of the most widely used deep-ocean power sources because it has high working pressure and is easy to adjust its fluid volume.While slipper/swashplate pair is the significant component of pump and its lubrication characteristics affects service life and operation performance of it.Therefore,the lubricant property of slipper pairs in piston pump under varying ocean-depth condition is researched.And influencing different parameters on lubrication characteristics of slipper pair is analyzed.Then,the surface structure of slipper is optimized by optimization function,and slipper pair which satisfies the requirement of environment condition of deep-ocean adaptability is obtained.This will provide guidance for property analysis and structure optimization of friction pair in pump under varying ocean-depth condition.Main contents in this paper are as follows:?1?Changing rule of oil viscosity in varying ocean-depth condition is explored.In comprehensive consideration environment factors such as pressure,temperature and heat changing,the changing model of oil viscosity under varying ocean-depth condition is established.The results show that the oil viscosity increases with enlarging of pressure,and decreases with the magnifying of temperature.When ocean-depth increases,the oil viscosity magnifies slowly.?2?The model of lubrication characteristics of slipper pair is established,and the concrete solving process is given.According to working principle of piston pump and slipper pair,solving process of lubrication characteristics on slipper under varying ocean-depth condition pair is established,including wedge-shape oil-film model,Reynolds equation of pressure model,energy equation of temperature model,thermal-elastic deformation solving and power loss function,and numerically simulated by MATLAB.This method lays a solid for numerical solution of theoretical model.?3?Evaluation method for lubrication characteristics of slipper pair is presented,and the influencing of each parameter on slipper pair is analyzed.It indicates that slipper pair can form effective fluid lubrication when oil-film thickness in[1.6?m,20?m],and the lower of oil-film deviation,the higher the stability.The lubricant characteristics coefficient L_CCC is proposed as a significant index for the comprehensive evaluation of the lubrication characteristics of slipper pair.The higher the value,the better the lubricant property.The influence of environment parameters,structural parameters and working parameters on slipper pair is analyzed.The result manifests that oil-film small but slipper can form effective fluid lubrication when in low speed,pressure and swashplate angle,and L_CC is lager,so slipper pair has benign lubrication characteristics.It is difficult to form effective fluid lubrication when diving depth in[5000m,7000m].?4?Structural optimization of slipper pair is conducted.With the goal of reduce loss of power,degree tilt and pressure in per unit area,slipper undersurface structure is optimized with multi-objective nonlinear function fgoalattain in MATLAB,and multi-ting structure slipper is obtained.By contrast with original slipper,the optimized slipper has good lubrication characteristics in power loss,degree tilt and pressure of per unit area and a polycyclic slipper pair is designed.Through comparison and analysis,lubrication characteristics of the optimized slipper are improved significantly.Power loss was reduced8.73%,the pressure was reduced by 5.14%per unit area,tilt of oil-film was decreased 9.42%,L_CC increased by 14.7%.This method provides theoretical significance and engineering application value for the optimization of friction pair.