In order to accurately evaluate the structural strength of high-speed permanent magnet motor rotors under complex stress fields

a three-dimensional stress analysis model considering the influence of axial stress was proposed. Aiming at the rotor structure under the carbon fiber sheath of anisotropic materials

the stress and strain of the rotor of high-speed permanent magnet motor under the combined action of prestress

centrifugal force and thermal stress were analyzed by using the three-dimensional elastic mechanics theory

and the analytical expressions of the stress and strain of each rotor component in the radial

tangential and axial directions were derived. By comparing with the finite element simulation results

the accuracy of the 3D analytical derivation was verified. Taking a 24 kW

20 000 r/min high-speed permanent magnet motor as an example

the influencing factors of rotor strength are analyzed based on the derived analytical formula combined with the finite element

and the saliency and nonsignificance of the influencing factors were analyzed by using the analytical formula combined with the sensitivity algorithm

and the theoretical basis for the design of the rotor of the high-speed permanent magnet motor was obtained. According to the analytical formula

the feasible domain of the design range of the motor sheath was calculated

so that the assembled prototype can operate safely and stably

which indirectly verifies accuracy of analytical derivation.