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. 15, 1991
Filed:
Dec. 19, 1989
Noriyuki Osada, Tokyo, JP;
Yasushi Hisabe, Kanagawa, JP;
Toshihiro Ohtani, Kanagawa, JP;
Toshiya Kanamori, Kanagawa, JP;
Ebara Corporation, Tokyo, JP;
Abstract
A rotation supporting device of a polygon mirror comprising a stationary shaft provided with a shaft sleeve around its circumference, a rotary assembly rotatably mounted around the circumference of the shaft sleeve and having a radial circumferential surface of a polygon made to serve as mirror surfaces and having a magnet member, thrust plates for suppressing the motion of a rotary assembly in the axial direction. The rotary assembly comprises a first rotor rotatably mounted at the outer circumference of the shaft sleeve, a second rotor having a circumferential surface of a polygon made to serve as mirror surfaces and being disposed at the outer circumference of the first rotor, and a yoke secured on the outer circumference of the first rotor. The first rotor is made of a ceramic material, the second rotor is made of aluminum and the yoke is made of steel. Radial dynamic pressure bearing is included between the outer circumference of the shaft sleeve and the rotary assembly. Dynamic thrust pressure bearings are included between the end surfaces of a rotary assembly and the thrust plates.