Research On Vibration Characteristics Of Variable-Diameter Multi-Disc Motor Rotor System

The rotor is one of the core components of the motor structure,and it is easy to vibrate when excited by loads such as unbalanced forces during high-speed operation.When this kind of vibration occurs near the critical speed,it will cause system resonance and,in severe cases,cause operating equipment to fail.Therefore,the study of the vibration characteristics of the motor rotor is of great significance to whether the motor can work stably under complex working conditions.Considering the application requirements of high-power drive motors in irregular working conditions such as conical space,this paper analyzes a variable-diameter multi-disc combined motor structure,and conducts research on the vibration characteristics of the rotor system of this type of motor.This paper takes the variable diameter multi-disk rotor system as the research object to establish the dynamic equation of the system.Based on this,the influence of each parameter on the critical speed and vibration response characteristics of the system was analyzed,and the established rotor was verified by ANSYS Workbench simulation calculation.Correctness of Systems Theory Models.The main tasks completed in this paper were as follows:(1)The dynamic model of variable diameter multi-disk rotor system was established.First,the key geometric parameters of the motor rotor system used in the conical space environment were calculated.The pose of the rotor disk was described based on the coordinate transformation theory.The dynamic relationship between the rotor disk and the rotor shaft was analyzed and the rotor shaft was discretized.Based on lagrangian equations,the dynamic equations of rotor shaft node element and rotor disk element are established respectively.Finally,the dynamic equations of all elements were integrated,and the coupled dynamic model of the system was obtained.(2)The critical speed characteristics of variable diameter multi-disk rotor system were studied.The first four critical speeds of the rotor system considering the gyro matrix were obtained.The influence of state parameters and structural parameters on the first four-order critical speed of the system was analyzed.The sensitivity values of the structural parameters to the first four-order critical speeds of the rotor system were obtained through orthogonal tests and significance tests.(3)The vibration response characteristics of variable diameter multi-disk rotor system were studied.The modal superposition method was used to decouple the dynamic equations of the rotor system.The displacement response curves of all rotor disks of the rotor system in the working speed range were obtained by MATLAB numerical calculation.The influence of different parameters(including excitation application method,unbalance amount,support bearing parameters and magnetic pull force)on the vibration response of the rotor system was analyzed,and the feasibility of the rotor system to safely pass the low-order critical speed was analyzed,and the stable operation of the rotor system was obtained.unbalance safety threshold.(4)The simulation of vibration characteristics of variable diameter multi-disk rotor system was studied.The simulation model of the rotor system was established based on ANSYS Workbench.The modal and unbalanced response tests were carried out on the model and compared with the theoretical calculation results to verify the correctness of the established theoretical model.