The motors eliminate the need for an encoder in mediumaccuracy applications, produce torque equal to the next larger frame size of a standard ac motor, and deliver 25 to 40% higher efficiency. Enclosed in an aluminum housing, the motors have a three-phase stator winding with custom-designed rotor with permanent magnets embedded in the stack for a perfectly sinusoidal magnetic field and even flux distribution. The perfectly sinusoidal back-EMF signal from the motor lets sensorless drive controllers calculate speed and position without an encoder. Typical accuracy is under 1° when coupled to a gearbox, or ±5° at the motor shaft.
The embedded permanentmagnets produce a higher dynamic for faster response/acceleration with better speed control. The design also allows field weakening for overspeed use at lower output torque, while the high efficiency delivers longer battery life between charges.
ABM Drives Inc.
2000 Ford Circle, Suite E
Milford, OH 45150