As brush motors are cost efficient and do not require control circuits, these familiar DC motors are used in a wide range of applications, from toys to industrial products.
Though brush motors have a relatively simple operating mechanism, performing an analysis on them is difficult, and the following items pose challenges.
- Since current flows by mechanical contact between a brush and a commutator, the model must take this brush-commutator contact into account.
- The axis length of the rotor core, magnet, and housing are all different, so magnetic flux in the axial direction cannot be ignored.
- Because the housing is thin, magnetic saturation has a large effect, leading to an increase in magnetic flux in the axial direction.
In this applied case, the structure of a 2D analysis model accounting for 3D geometry is evaluated through the comparison with a 3D analysis model. The modeling validity is proved by comparing these results.