Standard series of direct-current motors for regulated electric drives

A standard series of d.c. motors for electric drives with speed and torque regulation has been developed. Thyristor-type converters for machine tools with digital program control are also being developed. Meeting future goals requires modification of the motor frame from the conventional round to a nearly square one, a larger ratio of armature stack length to diameter, better cooling, and insulation of a higher temperature class. In addition, it is necessary to laminate the housing partially or completely and to include a compensating winding. The basic motor configuration is 1 M 1001, according to Council of Mutual Economic Assistance (CEMA) Standard 246-78, with at least IP 23S protection and 1C 06 or 1C 05 cooling (shaft height from 112 mm up) and 1C 01 cooling (Shaft height or up to 250 mm). The series will be designed for a reference speed of 1500 rpm with not more than 15% armature current fluctuation, with speeds of 300-3000 rpm depending on voltage and motor size and torque regulation 1:200 (externally cooled motors) or 1;5, 1:10, 1:30 (self-cooled motors). Prototype motors with 132 mm and 355 mm shaft heights have already passed all tests.