Research On 2-pole Large-power High-voltage Asynchronous Motor Rotor Structure

The 2-pole large power asynchronous motor is widely used because of its simple structure and the advantages of small size and high response speed compared with other motors with the same number of poles,however,the excessive vibration is a prominent problem for this kind of motors.The reliability of the motor rotor is critical to the safe operation of the motor,therefore the critical speed of the motor rotor and the rotor structure of the motor that affect the vibration of the motor must be analyzed and calculated.This paper mainly uses numerical analysis methods to study a 7600 k W-2P high-voltage asynchronous motor as an example.It calculates and simulates the critical rotational speed of the rotor of the motor and the strength and structure of the rotor-related components in order to provide a theoretical basis for the rotor design of the motor.Based on the basic theory of the motor rotor critical speed calculation,the traditional formula method,transfer matrix method and finite element analysis method are used to calculate the critical rotor speed.By the comparison of the calculated theoretical value and the measured value,and the reason analysis for the error between rotor critical speed calculated value and actual measured value,an optimal calculation method for calculating the critical rotor speed was obtained.The finite element analysis method was used to analyze and calculate the strength of the relevant parts of the rotor of the motor.A three-dimensional solution model of the rotor core and the rotor shaft was established respectively.In combination with the rotor dynamics theory of the motor,the strength of the rotor core and shaft of the motor was checked and calculated.The stress and deformation distribution of the rotor core and shaft was obtained,the maximum stress and deformation position was determined,so as to verify whether the rotor core and the shaft selected material satisfy the design requirements of the motor strength.The interference of the motor rotor end rings and retaining rings is optimized.By analyze the force and deformation conditions of the end rings and the retaining rings caused by different magnitude of interference,the variation rules for forces and deformations applied on the end rings and retaining rings are obtained,and finally get the optimum magnitude of interference.