1MB High-Speed Asynchronous Motors

1MB High-Speed Asynchronous Motors are Bosch Rexroth Indramat liquid-cooled kit motors designed to become part of the spindle itself rather than being installed as a conventional housed motor. The series combines a 1MS stator with a 1MR rotor, allowing the motor components to be built directly into the spindle housing and commonly positioned between the main spindle bearings for greater mechanical rigidity. This arrangement supports both main-spindle operation and C-axis positioning from the same drive system in applications such as CNC lathes. Water cooling through the stator removes motor heat and supports high power density, with the spindle cooling circuit carrying away stator losses and a significant share of rotor-generated heat. Rotor position is measured by a separate feedback assembly integrated into the spindle, supplying the drive controller with the information required for speed regulation and spindle positioning. The 1MB series is specified for conditions including 0 to 40 °C ambient operation, IC3W7 water cooling, IP00 construction, and open-ended electrical leads for power and temperature-monitoring devices such as KTY, NTC, and bimetal sensors.