Infinitely variable speed squirrel-cage motor - has rotor section extending beyond stator laminated core and comprising choke, or saturable reactor, forming variable resistance element

摘要

A squirrel-cage induction motor is used. It has a closed secondary circuit (20) and the rotor extends, at least on one side, beyond the stator laminations stack in the axial direction. A resistor is fitted into the closed rotor circuit with the resistance value made variable by means of a control facility. The motor is designed to be continuously variable in speed. The heat losses are kept to as low a value as possible, commensurate with small expense on design features. the rotor section extending above the stator stack comprises a choke saturable reactor or transductor (30) that forms the variable resistance.