Eiki Morimoto

Design and Analysis of Magnetic-Geared Motor With Field Windings

Magnetic-geared motors have been attracting attention as a type of low-speed and high-torque motor. The maximum torque is, however, limited by the maximum transmission torque between the rotors. This paper proposes a magnetic-geared motor with field windings which can increase and decrease the maximum transmission torque. Its N-T curve is then calculated and compared with a magnetic-geared motor without field windings. The characteristics are determined using finite element analysis.

Magnetizing directions of the permanent magnets of the magnetic-geared motor

We have clarified that a magnetic-geared motor with permanent magnets in the high-speed rotor and stator slots shows a good performance in terms of the output power and transmission torque. This paper describes the influence of the magnetizing directions of the permanent magnets in the high-speed rotor and stator slots. The torque characteristics are computed using finite element analysis and are verified by carrying out measurements on a prototype.

Control method for a magnetic-CVT motor

Traction motors of electric vehicles require wide power band characteristics and high efficiency over wide rotation speed. To achieve these requirements, we proposed a magnetic-CVT motor being composed of a magnetic-CVT gear and brushless DC motor. However, this motor has some problems. First, the efficiency of the magnetic-CVT motor is very low because of the copper loss that originates from 6 phase currents. Second, the gear ratio of the magnetic-CVT motor cannot be maintained constantly. In order to solve these problems, a new control method is proposed and its effectiveness is verified using finite element analysis.