Back EMF characteristics analysis of brushless DC motor having polarly magnetized ring magnet according to the magnet dimension

摘要

This paper compares the characteristics of a ferrite bonded ring magnets having polar magnetization with those of radially magnetized magnet. The magnetization yoke is investigated to determine the magnetization status of the ring magnet. The surface flux densities of the polarly magnetized ring magnets and those of the radially magnetized ring magnets are analyzed. And the electromotive force (EMF) values of brushless DC motors with the magnets are investigated according to the pole number and thickness of the magnets.