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US 4,363,984 AGranted
Digitally controlled brushless motor
AssigneeFuji Electrochemical Co., Ltd.
InventorsMichihiro Torii, Masanao Okuda, Yuzuru Suzuki
Life of this patent
Estimating the term…
Abstract
A brushless motor actuated by a predetermined frequency and driven at constant speed with less wow and flutter component in accordance with a pulse signal of the frequency applied. The motor has a rotor enclosed in a stator, the latter having driving windings. The rotor includes a rotor shaft and a flywheel connected to the shaft. The flywheel is housed in a motor case.
Claims8
A pulse-controlled brushless motor of constant speed, comprising:
- a rotor rigidly mounted on a rotary shaft, said rotor having an integral inertia ring,
- a stator having driving windings and inner and outer yokes, said yokes each having a plurality of polar teeth projecting inwardly at a constant interval, said windings being mounted within said inner and outer yokes,
- first means for rotatably supporting at least one of said rotor and said stator, said first means having a casing and a bearing at the center of said casing, to thereby rotatably support an end of said rotary shaft,
- second means for rotatably supporting the other one of said rotor and said stator, said second means having a bearing for rotatably securing said shaft, and a cover member fixed to said bearing of the second means, said cover member and said casing shielding a magnetic flux of said yokes, and
- an annular magnet concentric with said rotary shaft and fixed to said rotor, said magnet being permanently magnetized in a multi-pole fashion to have a plurality of north and south poles alternately arranged along its circumference,
- whereby said rotor is rotated smoothly and constantly when electric pulses of a predetermined frequency are supplied to said driving windings.
3 more elements
A pulse-controlled brushless motor of constant speed comprising:
- a rotor mounted on a rotary shaft, said rotor having an integral inertia ring,
- a stator having driving windings and inner and outer yokes, said yokes each having a plurality of polar teeth projecting inwardly at a constant interval, said windings being mounted within said inner and outer yokes,
- an annular magnet concentric with said rotary shaft and fixed to said rotor, said magnet being permanently magnetized in a multi-pole fashion to have a plurality of north and south poles alternately arranged along its circumference, and
- a casing and a cover member for containing therein the rotor, the stator and the annular magnet,
- wherein said integral inertia ring has a permanent magnet at a surface opposing said casing, said casing having a permanent magnet at a surface opposing said integral inertia ring, said permanent magnet of the integral inertia ring attracting said permanent magnet of the casing,
- whereby said rotor is rotated smoothly and constantly when electric pulses of a predetermined frequency are supplied to said driving windings.
3 more elements
Dependencies are inferred from the claim text.