Critical Speed And Unbalance Re- Sponse Analysis Of Wet Rotor System Of Aviation Axial Piston Pump

High speed,high pressure and high power to weight ratio have become the main development direction of aviation axial piston pump with the increasing pressure system of aircraft hydraulic system.However,the performance of axial piston pump in our country is still far behind that in foreign countries.The oil between the cylinder block and the shell of the axial piston pump rotates at high speed,forming the gap circulation.The interaction between the gap circulation and cylinder block produces complex fluid-structure interaction,which aggravates the vibration and noise of the pump,and seriously affects the life and safety of the equipment.The critical speed and unbalanced response of the aviation pump dry/wet rotor system are analyzed by using the rotor dynamics theory.The influence of gap circulation on the dynamic characteristics of air pump was investigated.This is of great significance for improving the performance of aviation pumps and realizing the localization.The main research contents are as follows:(1)The aviation pump is taken as the research object.The rotating parts are extracted and the aviation pump dry rotor system is established.On this basis,considering the effect of gap circulation,the aviation pump wet rotor system is established.The discrete wet rotor system consists of disc,shaft,bearing and gap circulation.The motion equation of each element is analyzed and the correlation coefficient is determined.The overall motion equation of the aviation pump dry/wet rotor system is established.The program for solving the dynamic characteristics of the rotor system is compiled by using MATLAB software.(2)The nodes number of the aviation pump rotor system will seriously affect the calculation accuracy and analysis resources.The critical speed and analysis time of the aviation pump dry rotor system under various nodes partitioning strategies are studied by using the program.Based on the analysis,the best node partitioning strategy is obtained.The strategy is used to divide the aviation pump dry/wet rotor system,which is convenient for the subsequent critical speed and unbalanced response analysis.(3)The dynamic fluid excitation force generated by the gap circulation can be equivalent to the additional matrix,which will change the coefficient matrix of the system.Therefore,the dynamic characteristics of the rotor system also change.The critical speed and unbalanced response of the aviation pump dry/wet rotor are analyzed by means of mathematical model and finite element simulation.The effect of gap circulation on the dynamic characteristics of rotor system is discussed.(4)The critical speed test was completed on the MFS-RDS experimental platform.For the experimental rotor system model,the mathematical model is used to analyze its critical speed.Compare with the experimental test results to verify the correctness of the theoretical analysis method.The vibration test of the dry/wet rotor system was completed on the wet rotor system test platform.The experimental test results were compared and analyzed.The action law of the gap circulation on the rotor system was studied to verify the correctness of the theoretical analysis method.