Analysis And Optimization Of Vibration Characteristics Of Spindle-Rotor-Bearing Multi Source Nonlinear System

Spindle rotor bearing system is the central mechanism of large rotating machinery transmission device.It often operates under high-speed and heavy load working conditions.Coupled with the coupling of bending and torsional vibration caused by the unbalanced mass of parts,the system vibration shows complex nonlinear vibration characteristics,which further affects the function realization and safety and stability of the transmission system.Therefore,the research on the nonlinear vibration characteristics of the spindle rotor bearing system is of great engineering significance to suppress the vibration of the system and improve the efficient and stable operation of the transmission device.The research object of this paper is the spindle rotor bearing system of a special vehicle integrated transmission device.Due to the interaction of multi-source excitation caused by bending and torsion coupling,coupled with the structural asymmetry defect,the right end of the main shaft breaks at the starting condition.Therefore,this paper carries out the research on the inherent characteristics of the main shaft system,the steady-state and the nonlinear vibration response at the starting and shifting conditions The influence of key parameters on the nonlinear vibration stability of the system and the parameter optimization of the spindle structure are studied.The main contents of this paper are as follows:(1)The main shaft rotor bearing system has internal nonlinear excitation such as unbalanced mass,bearing nonlinear Hertzian force,spline misalignment force,and external excitation such as load excitation and engine fluctuating torque.Based on the lumped mass method,the multi-source nonlinear dynamic model of the main shaft rotor bearing system is established,and the structural parameters of related components are determined,which can provide reference for the follow-up research The research laid the foundation.(2)Based on the nonlinear vibration model of the spindle rotor bearing system with multi-source excitation,the stiffness matrix method is introduced and the natural frequency of the system is solved.The influence of the spindle stiffness on the natural frequency of the system is analyzed.The Runge Kutta method is used to simulate the steady-state response of the system and the transient response of the system during shifting;(3)Based on the spindle rotor bearing model,the effects of key parameters such as spindle speed,mass eccentricity,spindle stiffness,static misalignment of spline and bearing clearance on the dynamic load of the spindle are obtained by numerical simulation under rated conditions.The effects of these parameters on the stability of the system are analyzed by non-linear vibration analysis methods such as bifurcation diagram,phase diagram and Poincar é section diagram;(4)Aiming at the problem that the traditional particle swarm optimization(PSO)is easy to converge to the local optimal solution prematurely,an improvement is proposed.Based on the analysis results of parameter sensitivity,the improved PSO algorithm is applied to optimize the vibration suppression of the spindle system under multiple working conditions.