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:
Apr. 23, 1991
Filed:
Sep. 04, 1990
Fumio Kameyama, Nagoya, JP;
Chikamasa Hattori, Ichinomiya, JP;
Brother Kogyo Kabushiki Kaisha, Nagoya, JP;
Abstract
A machine tool with a spindle for machining a large-diameter workpiece in that a servo motor for moving a spindle in the axial direction and a variable reluctance motor for rotating the spindle are installed in a housing, and a synchronous controller for synchronizing and driving the above-mentioned servo motor and the variable reluctance motor is provided. The variable reluctance motor has a characteristic in that a large driving torque can be obtained in a low rotating speed. By using a variable reluctance motor as a spindle motor, therefore, it is possible to obtain a large torque without providing a large size motor, and also possible to realize a large-diameter machining by a small-size unit.