Skew effect modeling and analysis for the vibration motor with skew rotor by the periodic convolution technique

In this paper, the vibration motor which is used in the mini-scale vibrating process control will be investigated. To avoid the large cogging torque, the motor is specially designed with skew rotor. The skew effect which causes the current ripple will be studied. Based on the proposed mathematical transient modeling, the current ripple and skew effect can be precisely observed. An equivalent circuit approach is used to analyze the motor in detail. Twelve commutation patterns are classified and analyzed carefully. In order to analyze the detailed skew effect coming from the skew rotor, a transient model with inductance matrix will be developed. Periodic convolution process is used to derive the associated inductance matrix for the current ripple. The skew effect has great influence on the cogging torque for the vibration motor. It is believed that this paper will be helpful to understand the skew effect for the vibration motor with skew rotor.