Mocowanie chorągiewek w silnikach prądu stałego dużej mocy

DC motors operate as high power drive systems in mining hoists and drive systems in the steel mills. These are multipolar motors with relatively low rated speed. The large difference in diameters of the rotor and of the commutator results in risers' length of up to one meter (riser is commutator part connecting winding end to the commutator bar). The risers, when the engine is working, are subjected to electromagnetic forces and inertia forces. Operational experience shows that the risers are the most-likelyto- fault engine points and often experience failures. Forces acting on the risers are illustrated together with the effect of type of attachment of the risers on their durability. Example used is rolling-mill motor with a rotor diameter D = 4500 mm, commutator diameter Dk = 2280 mm and the number of commutator bars K = 1050.