Praca łożysk tocznych przy rozruchu oraz przy niewielkich prędkościach obrotowych silnika indukcyjnego

Damages of bearings are the one of the most frequently reasons of induction motors failures. Application in power electronic systems causes that motors work in wide range of speed also at low speed. Running of motors at low speed causes a certain danger for bearings. There are introduced the properties of bearings in the paper. The investigations showed that the properties of bearings depend on the viscosity, lubricant temperature, speed and load. There are talked the results of bearings testing running at low speed in the paper. Between shaft and raceway of bearings it was turned on 0.4 V DC voltage from external source and it was observed waveforms of this voltage during starting of motors and low speed. Moreover it was determined the losses in bearing in induction motor fed from source with regulated frequency and for different positions of motors.