Dynamic analysis and mechanical structure improvement of submersible rotor

In order to enhance interference immunity and reduce the breakage of rotating shafts (rotors) which happens frequently especially in submersible permanent magnet synchronous motor (PMSM) applications, first a typical rotor structure is established serving as the comparative object, and then two improved schemes with optimal mechanical structure are proposed. Rotor strength, rotor stiffness, and the influence of unilateral magnetic pull on the rotor deflection are calculated analytically. The modal simulation, stress field simulation, and unilateral magnetic pull simulation are analyzed using finite element method (FEM). Position deviation and bending deformation of the rotor caused by the unilateral magnetic pulling force is taken into account to improve the simulation accuracy. The simulation results illustrate that the submersible rotor improved by the proposed schemes presents more excellent stiffness and strength performance compared with the traditional scheme, which indicates that the proposed schemes have important reference values for the structural design of submersible rotor.