Three dimensional analysis of magnetic force and torque in a BLDC motel due to the axial variation of yoke and pole

Author

Jang, G.H. ; Yoon, J.W.

Author_Institution

Hanyang Univ., Seoul, South Korea

Volume

35

Issue

5

fYear

1999

fDate

9/1/1999 12:00:00 AM

Firstpage

3694

Lastpage

3696

Abstract

The characteristics of magnetic force and torque due to yoke and pole patterns in the axial direction were analyzed by a 3 dimensional finite element method, Maxwell stress tensor and Fourier spectral analysis for a brushless DC (BLDC) motor. This research shows that the magnetic field in a small air gap produces not only the torque as a resultant of the tangential force, but also an axial resultant for an axially asymmetric motor, which has a yoke-ceiling or skew magnets. This axial resultant has driving frequencies corresponding to the integer multiple of the product of the number of poles and phases. The axial resultant may increase the possibility of mechanical resonance of the motor as well as the surrounding structure

Keywords

Fourier analysis; Maxwell equations; brushless DC motors; finite element analysis; machine theory; magnetic fields; magnetic forces; spectral analysis; torque; 3D FEM; Fourier spectral analysis; Maxwell stress tensor; axial resultant; axial variation; axially asymmetric motor; brushless DC motor; driving frequencies; magnetic field; magnetic force; mechanical resonance; pole patterns; skew magnets; small air gap; tangential force; torque characteristics; yoke patterns; yoke-ceiling; Brushless DC motors; Brushless motors; DC motors; Finite element methods; Magnetic analysis; Magnetic forces; Pattern analysis; Spectral analysis; Tensile stress; Torque;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.800634

Filename

800634