Abstract:For highspeed induction motors,the common squirrel cage rotor structure is difficult to withstand its huge centrifugal force,which requires solid rotor to meet the structural strength required by the motor in highspeed operation.But even the solid rotor can not guarantee its stable structure strength at high speed.Due to the influence of huge centrifugal force,the solid rotor will produce slight radial expansion displacement when it works,which will lead to the change of airgaps size of induction motor,thus the electromagnetic performance of the motor is reduced.In order to avoid this design defect,the structural strengths of four solid rotors were simulated and analyzed by using Workbench.The influences of the slot width,slot depth,slot number,rotational speed,external diameter and other factors on the radial expansion displacement of solid rotors during operation were explored.The research results will provides reference for air gap design of highspeed motors to improve the performance of motors.