| 摘要 |
Static frequency modulator control is used for a.c. motors employed in a continuous tube reduction mill. The mill consists of a number of stands one behind the other. Each three high stand has its own motor which is directly coaxially coupled with one of the rolls, the other rolls being driven via intermediate wheels. The stands are all open at one side and the motors are all on the same side of all stands. The motors of each group of successive groups of three roll stands are grouped in identical fan like patterns, and are equidistant and at the same angles relative to each other in each group as in DT. 1179172. The use of the above type of motor permits the placing of roll stands close together since the motors are small. The control permits the accurate control, of their rotational speed, the change of which does not alter the loading they are capable of taking. The cost of the motors is lower than that of d.c. motors conventionally used. |
