Yukihiro Okada

Analysis for permanent magnet motor taking account of magnetizing process

To calculate the cogging torque for a permanent magnet motor accurately, the magnetization distribution in the permanent magnet must be obtained. Therefore, the authors have developed an analysis method taking account of a magnetizing process. In this paper, this method is applied to a permanent magnet motor, and numerical results of the cogging torque are conformed with measured ones.

Analysis of claw-poled permanent magnet-stepping motor considering deterioration of material characteristics by remains stress

This paper describes an influence of material characteristics by remains stress in magnetic field analysis for claw-poled permanent magnet-stepping motors. The torque of the stepping motor has been calculated by using the magnetic characteristics of annealing and not annealing. In addition, some models using the different magnetic characteristics are compared.

Preparation method of rare earth bonded magnets with continuously controlled anisotropy directions

An advanced preparation method was carried out to obtain a highly dense radially anisotropic rare earth bonded magnet with continuously controlled anisotropy directions. An 8-pole/12-slot surface permanent magnet synchronous motor with a rotor 40.9mm in outer diameter, which comprised the above-mentioned magnet, was prepared, and it was found that the cogging torque decreases by approximately 20% and the back emf increases by 134% compared with those of a conventional isotropic Nd2Fe14B one with the same dimensions.

Development of optimizing method using quality engineering and multivariate analysis based on finite element method

Describes the method of optimization based on the finite element method. The quality engineering and the multivariable analysis are used as the optimization technique. In addition, this method is applied to a design of IPM motor to reduce the torque ripple.

Study of permanent magnet motor using a three-dimensional bend core

In this paper, to provide a reduction in size and weight of the motor, improvements to the torque density by the use of a three-dimensional bend core motor was examined. The motor using the three-dimension bend core can collect the flux leakage. The torque density was able to be improved by 20% by effectively using the magnetic flux. As a result, the reduction in size and weight of the motor becomes possible, and the performance gain of the automobile or robot can be expected.

Magnetic recording analysis of MIG head and medium in a flexible disc drive

The authors have developed a method of analysis which can examine the effects of the eddy currents and hysteresis in magnetic devices. In this paper, the method is applied to investigate the recording process of the metal-in-gap head and thin-film medium in a flexible disc drive. The effects of thickness and conductivity of thin sendust, and the recording current are clarified.