Electric motor and electrical apparatus equipped with same
AssigneePanasonic Corporation
InventorMasayuki Takada
Life of this patent
Estimating the term…
Abstract
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.
Claims10
An electric motor comprising:
- a magnet rotor which is rotatably placed with an air gap interposed between the magnet rotor and a stator around which a driving coil is wound, the magnet rotor having a magnetic pole portion formed from a plastic magnet which swells by a hydrogen bond;
- an inverter circuit including an upper-stage switching device and a lower-stage switching device which are connected to each other in a bridge manner;
- a DC-voltage conversion portion which is formed from a chopper circuit adapted to apply a DC voltage to the inverter circuit;
- a driving logic control portion adapted to supply the DC voltage generated by the DC-voltage conversion portion to the driving coils through the inverter circuit, in a successive full-wave energization manner according to a predetermined direction and in a predetermined order;
- a supply current value control portion adapted to control an average current supplied to the inverter circuit to be constant;
- a current value designation portion adapted to designate an average current value for which the supply current value control portion controls to be constant;
- a reference current value designation portion adapted to set a reference current value to be designated by the current value designation portion, when the DC voltage generated by the DC-voltage conversion portion is a predetermined voltage;
- and
- a correlation designation portion adapted to provide the current value designation portion with designation of a correlation between the reference current value and the average current value according to a voltage value of the DC voltage generated by the DC-voltage conversion portion, wherein
- the correlation designation portion determines the average current value by changing the average current value linearly or non-linearly with respect to the reference current value, and
- the magnetic pole portion absorbs moisture to swell to make the air gap smaller, at a higher humidity than a reference humidity.
Dependencies are inferred from the claim text.