Motor
AssigneeMitsubishi Electric Corporation
InventorsAtsushi Matsuoka, Kazuhiko Baba
Life of this patent
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Abstract
A drive device driving a power converter that includes a switching element formed from a wide bandgap semiconductor, includes a PWM-signal output unit that generates a drive signal that drives the switching element with PWM; an on-speed reducing unit that, when the switching element is changed from off to on, reduces a change rate of the drive signal; and an off-speed improving unit that, when the switching element is changed from on to off, draws charge from the switching element at a high speed and with a charge drawing performance higher than that at a time when the switching element is changed from off to on.
Claims5
A motor comprising:
- a stator;
- and
- a rotor arranged on a side of an inner diameter of the stator, having a magnet constituting a magnetic pole thereof, the magnet including a first magnet provided on an outer circumference of a rotation shaft and a plurality of second magnets arranged on an outer circumference of the first magnet, having a magnetic property higher than that of the first magnet,
- wherein the first magnet includes, on an outer circumferential surface thereof, concave portions that are formed at a regular pitch to a circumferential direction, the concave portions being formed so that the number thereof is identical to the number of the magnetic poles, and
- wherein each of the second magnets is arranged on each of the concave portions;
- and includes a center portion whose thickness with respect to the circumferential direction is formed to be larger than thickness of an edge portion, wherein the first magnet is oriented in polar anisotropy so that the magnetic poles appear on each of the concave portions in an alternate manner and a magnetic flux flows from one of adjacent concave portions to the other.
Dependencies are inferred from the claim text.