Composite rotor for high-speed induction motors

In order to improve the dynamic characteristics of 3-phase AC induction motors, the squirrel cage rotor for a high speed built-in type motor spindle system was designed and manufactured with powder containing epoxy composite material and an aluminum squirrel cage. The Youngʹs modulus, coefficient of thermal expansion (CTE), resistivity and magnetic permeability of the epoxy containing ferrite powder and iron powder were measured with respect to powder volume fraction to determine the optimum powder volume fraction. Then the epoxy powder composite rotor was manufactured by embedding the aluminum squirrel cage into the composite. Finally, the dynamic and electrical performances of the AC induction motor equipped with the developed composite rotor were measured and compared with those of a conventional AC induction motor