Overview
Closeup |
The orientation of magnets largely affects the characteristics of devices
that use permanent magnets. The most desirable magnetization may not be
obtained due to eddy currents in the magnetization yoke. Therefore, it
is advantageous to investigate these affects in advance. The characteristics
of the device can be analyzed by using the magnetization of the magnet
based on the magnetization field that is calculated in JMAG.
This note presents the use of a magnetic field analysis to compare the
differences in the magnetization distribution of magnets and the surface
magnetic flux density of a magnetization yoke that is entirely composed
of laminated steel sheet and a magnetization sheet that that does not use
laminated steel sheet at each end. |
Magnetization Distribution of the Magnets
| The magnetization distribution of Magnet A that is magnetized using the
device entirely made of laminated steel sheet and Magnet B that is magnetized
using the device that does not use laminated steel sheet at each end are
indicated in Fig. 1. A 1/4 model emphasizing the magnetization distribution
is indicated in Fig. 2. The magnetization distribution is uniform in magnet
A whereas the magnetization distribution varies at the top, bottom, and
center of magnet B, as indicated in Fig. 1. Furthermore, when magnet A
and B are compared, magnet B has a weaker magnetization at the ends of
the magnet with stronger magnetization focused in the center, as indicated
in Fig. 2. |
Closeup |
Closeup |
Surface Magnet Flux Density Distribution of the Magnets
The surface magnetic flux density distribution of magnet A magnetized by
the device entirely composed of laminated steel sheet and magnet B magnetized
by the device that does not use laminated steel sheet at each end is indicated
in Fig. 3 through Fig. 5. The position the magnetic flux density is measured
is indicated in Fig. 6.
The magnet flux density of magnet B is universally smaller than magnet
A as indicated in Fig. 3. The magnet is not sufficiently magnetized because
of the eddy currents flowing in the integrated core. The magnetic flux
density distribution is almost the same in Fig. 4 and Fig. 5. The eddy
currents to not affect the parts of Magnet B at z=9.0 and z=0.0 because
this area of the magnetization device uses laminated steel sheet. |
Closeup |
Closeup |
Closeup |
Closeup |
|
