The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 16, 1991
Filed:
Feb. 21, 1990
Osamu Beppu, Odawara, JP;
Toshihiro Moribe, Chigasaki, JP;
Youjiro Tezuka, Hiratuka, JP;
Akira Chuma, Ashigarakami, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A motor for a disc drive unit is spatially separated from an enclosure housing the magnetic disks and read-write heads. The disks are mounted on a hub that is fixed to a shaft extending through the hub, having bearings at either end of the shaft. One end of the shaft extends outside of the enclosure, the rotor of the motor is fixed to this end of the shaft and is concentric therewith. The rotor has a rotor housing that is cup-shaped, with an opening facing away from the interior of the enclosure. Inwardly of the rotor housing is a stator mounted on a supporting member. The supporting member is detachably mounted to the enclosure for easy access to the stator. Further, a circuit board having control elements for the motor, including a Hall element mounted thereon, is provided on the supporting member for easy access to the circuit board. Each of the coils of the stator is divided into windings, and the controller for the motor switches the number of windings used so that more of the windings are used for each coil during start-up than during the running condition, when less work is needed.