Abstract :
Direct-Current Mill Type Motor Motor drive for the auxiliary apparatus of steel mills, including tables, screw-downs, cranes, charging machines, etc., has been used for about twenty years. The application of motors to the various machines was naturally a very gradual process. The conditions were very unusual, as the work was of an extremely severe nature, requiring frequent starting and stopping, rapid acceleration and sudden stops. Motors had to operate in very hot and dirty places and in a majority of cases gear drive was used. The mills were operated for 24 hours a day, six days a week. The manually operated direct rheostatic controller was the only type available, and this meant heavy overloads during starting and reversing periods.
