Yokogawa Electric Corporation

Haruo Higuchi

Yutaka Ono

Yasuhiko Muramatsu

Mitsuhiro Nikaido

Shigeru Hashida

Koichi Sato

Yutaka Koizumi

Hideo Banzai

Susumu Ohta

Shotaro Shindo

Yoichi Kikukawa

Hiroyuki Shinomiya

Toshiyuku Takagi

A linear motor drive system which is substantially not influenced by deviations in shape of slits, uneveness of distribution of light, and high order high harmonic components of a sensor signal, and which comprises a linear optical encoder having high sensor accuracy and which enhances the position detecting resolution of the encoder without use of high frequency clock generator.The system comprises means for detecting the movement of the slider of the linear pulse motor by use of a linear optical encoder and means for feedback control of the motor based on the sensor signal, wherein a photodiode array is extended over a plurality of rows of slits on a scale plate; a diffuser is mounted between a light source and the scale plate, and n photodiodes are provided within one pitch of the slit, the width of one photodiode in the direction of the array is set at p.sub.0 /(n+1), and the width of a gap between the photodiodes is set at p.sub.0 .multidot.n(n+1). In another embodiment, a phase modulating encoder is provided and the position of the slider is found with an average value of several measured values of phase differences between the phase modulated signal outputted from the encoder and to which a dither signal is added and the reference signal whose phase is not modulated.

Linear motor drive system

A motor drive system used with industrial robots, processing machines, and the like comprising an external interface part ready for connecting a plurality of kinds of host controllers generating a command signal; a sensor interface part to which a motor rotation detecting sensor is connected; a main control part operating for feedback control of a motor according to signals provided by way of the interfaces; and a power amplification part for feeding a current to motor coils according to a control signal from the main control part and wherein the external interface part, the sensor interface part, the main control part, and the power amplification part are separate and modularized as cards. Advantageously, the various controllers, sensors and power systems are changeable to flexibly meet different user requirements.

Motor drive system

A direct drive motor for use with factory automation, wherein the motor is arranged to directly obtain rotary forces without using a final reduction gear. The direct drive motor has an inner stator, an outer rotor disposed outside the inner stator with a slight air gap formed therebetween, a cylindrical rotor hub to which the outer rotor hub is internally fixed and a bearing provided in an inner cylindrical portion of the rotor hub for rotatably supporting the rotor hub.

Direct drive motor

Growing community of inventors

Tokyo, Japan

Haruo Higuchi