Modular motors give users a choice
Siemens was not the only company to unveil a modular motor technology at the recent Hannove Fair. SEW-Eurodrive, which claims to have introduced the world’s first commercial motors to use diecast copper rotors in 2002, has developed a range offering buyers a choice of "second generation" copper rotors or conventional rotors, to provide standard, high or premium efficiencies. The standard motors span ratings from 0.09-200kW, while the more efficient machines cover ratings from 0.75-200kW.
A modular brake design gives users a choice of two or three brake sizes for each model of motor in the new DR series (shown above). For example, inverter-controlled brake motors need smaller braking torques and can therefore use smaller brakes.
Another choice is the type of encoders supplied. SEW has developed a pair of low-cost, integrated encoders for simple positioning and speed detection tasks. These encoders offer a resolution of 1-100 pulses/rev. A rotation counter will be added to the range soon.
For applications requiring greater precision, sin/cos encoders with simple connectors can be mounted directly on the motor shaft and fan guard, for four-pole machines rated from 7.5-55kW.
As well as the modular motors, SEW was showing a compact range of inverters being built for it in Wales by Invertek Drives. The Movitrac LTE drives (above) come in three sizes, covering ratings from 0.37-7.5kW, for 115/230/400V operation. The drives are available in IP20 and IP55 versions and offer 40 configurable parameters.
