Effects of Novel Skewed Rotor in Squirrel-Cage Induction Motor on Electromagnetic Force

Axial endplay problems often occur in electrical machines even in the conventional skew motor. In order to solve these problems, an improved skew rotor is proposed to weaken the ill-effect of the conventional skew motor by skewing the slots toward reverse directions. The space distributions of magnetic flux field and the Maxwell stress tensor on the rotor surfaces are analyzed by an analytical method. The time-step finite-element 3-D whole model of a novel skew squirrel-cage induction motor is presented for verification. The results indicate that the radial and the axial forces decrease, but the rotary torque remains unchanged. The validity of the improved method is verified by means of the comparison with the conventional one.