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:
Sep. 26, 2000
Filed:
Sep. 23, 1998
Harushige Osawa, Kusatsu, JP;
Nidec Corporation, Kyoto, JP;
Abstract
The present invention discloses a disk drive motor comprising a rotary member having an annular space formed therein coaxially with the axis of rotation, and ring-shaped balancing members accommodated in the annular space and capable of changing its mass distribution circumferentially along the circle of the annular space. In case of any imbalanced rotation occurring during the rotation, the balancing members temporarily gather at a portion of the annular space where the mass imbalance is taking place. When the motor speed exceeds the value at which resonance takes place due to coincidence between the frequency of the vibration of each of the balancing member and the natural frequency of the motor, the balancing members move to a position symmetrical with the point of mass imbalance to eliminate the mass imbalance, thereby reducing motor run-out.