Investigation on skew rotor design for the DC servo spindle motor

This paper will investigate the effect of skew rotor structure for the DC servo spindle motor. Twelve commutation patterns are carefully illustrated to provide the pre-processing for the finite element analysis (FEA). The skew effect for the rotor design is discussed to assess the effect on current and torque. The FEA for each different rotating angle of the rotor is also discussed. By proper mechanical design of the skew angle for the rotor, it can be found that the current ripple and cogging torque waveforms can be made smoother. The cogging torque can be assessed by using FEA. Verification of the validity and feasibility of the technique is obtained from simulation and experimental results.