Overview
Closeup |
Linear motors are used for machine tools, carrier devices and so forth,
so it is very important for them to move smoothly and response quickly.
To do so, cogging needs to be reduced, since cogging causes the variation
in thrust force and speed. One method to reduce cogging is to skew the
magnet. This note presents the use of magnetic field analysis to obtain
the magnetic flux density distribution and cogging of a moving coil linear
motor with a skewed magnet. |
Magnetic Flux Density Distribution
Closeup |
Figure 1 shows the magnetic flux density distribution at the translation
distance of 36mm. By skewing a magnet, magnetic circuit is seen to be changed.
This change of the magnetic circuit is assumed to affect the cogging. |
Cogging Waveform
| Figure 2 shows the cogging waveform. By skewing a magnet, cogging is reduced
about 40 percent at the peak value. |
Closeup |
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