Abstract: The goal of this paper is to present a novel application of filament winding to surface mounted high speed permanent magnet electrical motors. The surface-mounted magnets cannot support the ultra-high centrifugal force due to the high-speed rotation of the steel shaft of the rotor. The carbon-fiber overwrap wound with ultra-high tension was thus used as a protective sheath for providing the radial compressive stress resultant over the outer surface of magnets. An approach of calculating the residual stress deformation and radial compressive stress resultant according to superposition principle of elastic theory was proposed. The maximum fiber tension was determined due to winding experiments with different winding tension and the analytical algorithm applied to calculate the residual stress distribution with different tension models of filament winding. Then, the analytical solution was compared with the finite-element results. The static test at the radial compressive stress resultant was conducted. The results show that the proposed analytical solution can accurately predict the residual stress distribution of the composite sheath and the radial compressive stress resultant over the outer surface of magnets. The error between the analytical results and the finite-element results is very small, and the error between the analytical results and the test results is completely within the acceptable limits. So carbon fiber overwrap wound by ultra-high tension can satisfy the requirements of high speed permanent magnet rotors.

Key words: filament winding, winding tension, residual stress, high speed permanent magnet machine, radial compressive stress, carbon fiber