TANDEM ELECTRIC DRIVE Russian patent published in 1995 - IPC

FIELD: electric power engineering. SUBSTANCE: electric drive has two coaxially mounted electric motors, each provided with shaft-mounted internal magnetic circuit and external magnetic circuit. One pair of like-polarity magnetic circuits is rigidly interconnected and one of like-polarity magnetic circuits of other pair is installed in motionless position. Other magnetic circuit of the latter pair is mounted for rotation and functions as output element of electric drive. Drive may be found useful for various mechanisms as slow-speed gearless drive with comprehensive speed range at lower limit actually equal to zero (such as in sewing machines). EFFECT: improved torque at extremely low speed, as compared to standard induction motors; extended speed control range with lower limit practically equal to zero; enlarged functional capabilities. 3 cl, 7 dwg