| 摘要 |
PURPOSE:To lower necessary capacity of an electric motor and a driving controlling device in driving a steel billet transportation roller table by operating the induction motor at constant torque characteristic in low speed range and at constant output characteristic in high speed range. CONSTITUTION:In low speed range, large torque is ncessary for an electric motor to make the billet get over a roller. In high speed range, however, as the biller get over the roller easily by inertial force, the motor is operated at constant output. From energy balance, the point of changing speed is above about 60 (gh)<1/2> (m/min) in transporting speed. Accordingly, by changing from constant torque operation to constant output operation when the number of revolutions of the induction motor exceeds a specified value, the maximum necessary output of the motor can be lowered. |
