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:
Mar. 13, 2001
Filed:
Jul. 28, 1999
Chen-Hsiung Lee, San Jose, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A device for testing the take off speed of a thrust bearing in a disk drive spindle motor is disclosed. The device has a stationary torsion transducer that is used to support a drive shaft of the spindle motor. A load motor located adjacent to the transducer rotates the motor about the shaft while applying a radial load to the spindle motor through a belt. The load motor is attached to a linear stage which generates selected radial loads. In one version, the device also uses a ring magnet to attract the housing of spindle motor. The magnetic attraction imposes an axial force on the spindle motor and an equal reactive load on the thrust bearing. The axial load is such that the take off speed for the thrust bearing is much greater than that for the journal bearings. Under these conditions, the friction torque is dominated by the thrust bearing so that an accurate assessment of its quality may be assessed. As an alternative to the magnet, air jets may be used to apply a similar axial load to the thrust bearing.