Title :
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
fDate :
9/1/1999 12:00:00 AM
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;
Journal_Title :
Magnetics, IEEE Transactions on
