Matsushita Electric Industrial Co., Ltd.

Muneo Yamamoto

Masahiro Yasohara

Hiromitsu Nakano

Hisataka Kato

Hiroshi Dohi

Noriyoshi Nishiyama

Akihiko Watanabe

Yukio Honda

Hiroyuki Oku

Sotomitsu Maeda

The object of the present invention is to provide a low-noise and low-vibration brushless motor and an electric applicance and a vehicle which have the brushless motor and increase in quietness, by optimizing a ratio of the number of poles on a rotor to the number of slots on a stator, the ratio being suitable for a driving circuit. The present invention is a brushless motor constituted by ten-pole rotor ( ), a stator ( ) having ( ) slots ( ) and making three-phase connection to the slots ( ), and a driving circuit ( ) for applying three-phase full-wave current to the stator ( ). Further, the conduction width of the driving circuit is set at an electrical angle of 135 to 180&deg;.

Brushless motor and electric appliance or vehicle equipped with the same

With a view to reduce vibrations generated by a motor and improve resistance to heat, reliability and vibration isolation properties without increasing the cost or the number of manufacturing steps in a rotor for a permanent-magnet motor, a rotor core is formed of an outer peripheral portion by which the permanent magnet is fixed, and a central portion by which a shaft is fixed, a clearance is provided between the outer peripheral portion and the central portion, and the outer peripheral portion is connected to the central portion by means of a plurality of fastening members. Thus, a rotor having excellent vibration isolation properties can be obtained. Since the rotor core is formed of laminated iron plates on which the outer peripheral portion, the central portion and the fastening members are all formed as one piece, resistance to heat, reliability and the vibration isolation properties can be enhanced without increasing the cost or the number of manufacturing steps.

Rotor for a permanent-magnet motor

A drive apparatus for use in a brushless motor with a rotor and a drive coil assembly. The drive apparatus comprises an energization-state instruction circuit for generating an energization-state instruction signal instructing an energization state of the drive coil assembly on the basis of the position detection signal indicative of a position of the rotor and an energization switching circuit for outputting an energization switching signal to successively switch the energization state of the drive coil assembly in accordance with the energization-state instruction signal and a duty control signal. A power circuit is coupled to a direct-current voltage source and is responsive to the energization switching signal so as to energize the drive coil assembly by means of a direct-current voltage from the direct-current voltage source in accordance with the energization switching signal therefrom. A duty control circuit is responsive to a speed instruction signal from a speed instruction circuit and a motor speed signal from a speed detecting circuit for outputting the duty control signal to the energization switching circuit so as to control a duty ratio of the energization-state instruction signal on the basis of the duty control signal so as to output the energization switching signal to be inputted to the power circuit.

Drive apparatus and speed control apparatus for brushless motor

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Takefu, Japan

Muneo Yamamoto