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:
Oct. 18, 1994
Filed:
Feb. 25, 1993
Shunichi Aiyoshizawa, Tokyo, JP;
Kazuto Hirokawa, Kanagawa, JP;
Kazuyuki Kasahara, Kanagawa, JP;
Tohru Maruyama, Kanagawa, JP;
Ebara Corporation, Tokyo, JP;
Abstract
A spindle motor with an H-type pneumatic dynamic bearing has a high durability against repeated starts and stops of rotation. The H-type bearing is composed of a radial bearing member, thrust plates firmly fixed to opposite ends of the radial bearing member and a cylindrical radial sleeve, which form a radial pneumatic dynamic bearing and thrust pneumatic dynamic bearings. A stator core is fixedly secured around a rotary member, which is in turn fixedly secured around the cylindrical radial sleeve. A total thrust clearance a+a' of the thrust bearings is represented by an inequality of (a+a')/A< 2.5/10.sup.4 based on a sliding surface diameter A of each thrust plate, a and total radial clearance b+b' of the radial bearing is represented by an inequality of (b+b')/B<5/10.sup.4 based on a sliding surface diameter B of the radial bearing member.