Speed controlled machine tool

USRE43636E1 · kind E1 · reissue

Assignee

• Toshiba Kikai Kabushiki Kaisha · JP

Inventors

• Koichi Katoh · Yokohama, JP
• Yasunori Katoh · Fuji, JP

Key dates

• Filing date: Sep 10, 2007
• Grant date: Sep 11, 2012
• Expiry date: Sep 10, 2027

Classification

• Technology area (CPC —): General

Abstract

A tool, attachable to a spindle of a machine tool and capable of changing independently a rotational speed of a cutting tool from that of the spindle, provided with a cutting tool for machining a workpiece, an electric motor for driving the machining tool, a generator for generating electric power to drive the electric motor by the rotation of the spindle, a tool holding part for rotatably holding the cutting tool, a casing for holding the electric motor, the generator, the tool attachment part, and the tool holding part, and a locking part for preventing rotation of the casing by engagement with a non-rotating part of the machine tool. A tool includes an AC generator, an AC motor and a case holding the generator and motor such that the generator and the motor are arranged in the case along a center axis and a longitudinal direction of a rotatable portion of the generator. A rotation speed of an output shaft of the motor is based on a rotation speed of an input shaft of the generator and a ratio, between a number of poles of the generator and a number of poles of the motor.