Abstract: The carbon fiber composite has been widely applied to manufacture high speed flywheel rotor sheath for its high specific strength, specific stiffness, and absence of high frequency eddy current power loss. Moreover, compared with the press-fitted process, the large tension winding process is more suitable for applying the interference fit between the carbon fiber composite sheath and the metal hub. In this paper, the design and forming process of the large tension winding composite sheath of the flywheel rotor was discussed. A three-dimensional finite element model of composite flywheel rotor has been built. The filament winding tension was applied by using temperature difference method. And the winding and curing processes were simulated by the element deletion method. The influence of the winding tension and the interference between the hub and the shaft on the compressive stress at the interface of the rotor was analyzed at the speed of 30000 RPM and the different operating temperature. In addition, the specimens of composite sheath of high speed flywheel rotor were prepared by the large tension winding technology. The radial compressive stress of the sheath on hub and the radial strain of the hub were tested. The results show that the calculated values were in agreement with the measured values of specimens. The optimum geometry and technological parameters of the composite flywheel rotor were obtained. The maximum energy storage density was 44.5 Wh/kg, while the peripheral speed was 697 m/s. The results of this paper are of important significance to the design and manufacture of composite high speed flywheel rotor sheath.

Key words: composite materials, filament winding, flywheel rotor, large tension, high-speed rotation