摘要 |
An electric motor includes a magnet rotor which is placed with an air gap interposed between it and a stator and has a magnetic pole portion formed from a plastic magnet which swells by hydrogen bonds, an inverter circuit, a DC-voltage conversion portion, a driving logic control portion, a supply current value control portion, a current value designation portion, a reference current value designation portion, and a correlation designation portion, wherein the correlation designation portion determines an average current value by changing the average current value linearly or non-linearly with respect to a reference current value, and the magnetic pole portion absorbs moisture to swell, thereby making the air gap smaller, at higher humidity than a reference humidity. |