Investigation of the Factors Affecting the Cogging Torque of a Permanent Magnet Brushed DC Motor

Abstract

Cogging torque disadvantages permanent magnet DC motors (PMDC), creating vibration and audible noises. This research investigates the factors affecting the cogging torque of a permanent magnet-brushed DC motor used to operate automobile windshield wipers by implementing some design changes by using the finite element analysis (FEA) based on Maxwell 2D software. These factors include changing the air gap length, slot opening, embrace factor, magnet edge inset (pole arc offset), skewing angle, and magnet type to study the amount of reduction and increase in cogging torque and its effect on the motor's efficiency. We conclude from the results of the FEM simulation that when changing the parameters of the factors, we will notice a clear effect on cogging torque and motor efficiency.

Keywords

• Cogging torque, Permanent magnet brushed DC motor, Finite element analysis, Maxwell 2D