Electric actuator control apparatus
AssigneeNippon Gear Co., Ltd.
InventorSusumu Watanabe
Life of this patent
Estimating the term…
Abstract
When abnormal torque occurs in a valve, water gate, etc., it changes speed of a load shaft in a reduction gears, which is transmitted from a worm to a rotary encoder via a main shaft connected to an electric motor and gears. An electric signal is fed from the rotary encoder to a microcomputer in which the abnormal torque is identified to stop the elctric motor. The microcomputer also identifies a full-opening point and a complete-closing point of the valve to stop the electric motor.
Claims8
A control apparatus in an electric actuator for actuating driven material requiring relatively large initial torque, with output form an electric motor via reduction means, the motor providing reduced torque with increase of rotation of the output of the motor, the apparatus comprising:
- rotation amount detecting means to detect an input rotation amount of the reduction means digitally at an absolute level from a certain reference position;
- load torque control means connected in electrical communication with the rotation amount detecting means for detecting load torque from rate of change of the detected input rotation amount and identifying magnitude of the detected load torque to control the electric motor;
- operation position control means connected in electrical communication with the rotation amount detecting means for identifying the detected input rotation amount by measuring an operation position of said driven material at the absolute level of the input rotation amount of the reduction means and controlling the electric motor at operation points;
- and
- said rotation amount detecting means being one of an incremental rotary encoder and an absolute rotary encoder with a backup battery.
Dependencies are inferred from the claim text.