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. 05, 1991
Filed:
Apr. 09, 1990
Yasushi Hisabe, Kanagawa, JP;
Noriyuki Osada, Tokyo, JP;
Toshihiro Ohtani, Kanagawa, JP;
Masahiko Kishi, Kanagawa, JP;
Yoshio Sato, Kanagawa, JP;
Daisuke Konno, Kanagawa, JP;
Sachihiko Miwa, Kanagawa, JP;
Toshiya Kanamori, Kanagawa, JP;
Shunichi Aiyoshizawa, Tokyo, JP;
Kazuyuki Kasahara, Kanagawa, JP;
Kazuto Hirokawa, Kanagawa, JP;
Yumiko Noda, Kanagawa, JP;
Ebara Corporation, Tokyo, JP;
Abstract
A spindle motor comprising a stator including a support shaft positioned on a base, a cap-shaped rotor rotatably and concentrically disposed around the support shaft, thrust and radial bearings disposed between the stator and the rotor, a stator coil secured to the stator, and a rotor magnet member secured to the rotor opposing the stator coil. The thrust and radial bearings are hydrodynamic bearings. A movable piece that constitutes a part of the thrust bearing is secured to the lower end of a cylindrical portion of the rotor and extended outwardly or inwardly from the cylindrical portion, or is disposed above the rotor. The stator coil is secured to the outer peripheral portion of the support shaft above or below the radial bearing. The rotor magnet member is securd to the inner peripheral surface or inner top surface of the rotor. Either a radial or axial gap is provided between the stator coil and the rotor magnet member.