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:
Jan. 27, 2009
Filed:
Nov. 18, 2005
Tomoki Hiramatsu, Kanagawa, JP;
Takahisa Okada, Kanagawa, JP;
Takeji Sumiya, Kanagawa, JP;
Hitoshi Tsujino, Kanagawa, JP;
Tomoki Hiramatsu, Kanagawa, JP;
Takahisa Okada, Kanagawa, JP;
Takeji Sumiya, Kanagawa, JP;
Hitoshi Tsujino, Kanagawa, JP;
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
Embodiments of the invention provide, in a compact magnetic disk drive, a stable structure capable of reducing self-oscillation occurring from disk spinning, while suppressing generation of dust and dirt. In one embodiment, a magnetic disk is mounted on a hub of a spindle motor. A clamp is further attached to secure the magnetic disk in position. A plurality of opening portions are formed in the clamp around an axis. A counterweight formed of an elastic material is mounted in the opening portion by being press-fitted therein. The counterweight is less likely to generate dust and dirt through friction during insertion and looseness. A gap is provided between the clamp and the hub at locations near the opening portions. The counterweight has a protruded portion on a side surface of a circular column portion. The protruded portion slides into the gap between the clamp and the hub, counteracting a tendency of the counterweight to drop out of position.