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:
Dec. 03, 2013
Filed:
Mar. 13, 2013
Nidec Corporation, Kyoto, JP;
Hiroyuki Abe, Kyoto, JP;
Nidec Corporation, Kyoto, JP;
Abstract
A spindle motor of a disk drive apparatus includes a base unit, a stator, a covered cylindrical rotor hub, a rotor magnet, and a bearing mechanism. The rotor magnet is an Nd—Fe—B bond magnet. The thickness of the rotor magnet in the radial direction is about 0.7 mm or more and about 1.0 mm or less. The distance between the rotor magnet and the stator core in the radial direction is about 0.15 mm or more and about 0.20 mm or less. A torque constant Kt of torque generated between the stator and the rotor magnet is about 4 mN·m/A or more and about 6 mN·m/A or less. A motor constant Km is about 2 mN·m/(A·√Ω) or more and about 4 mN·m/(A·√Ω) or less.