Theoretical Derivation of Current Commutation Process during Electrical-Contact Sliding Movement in Model DC Motor

Concerning a direct current flowing through commutator-segments in a DC motor, first, this paper describes the attempt at constructing theoretical system to derive the direct-current commutation process during sliding movement. The theoretical system is based on (i) electrical circuit equations including concentration resistances, (ii) electric power balance equations taken into account of contact-part temperatures, and (iii) contact forces applied on sliding surfaces. Second, the constructed theoretical system is applied to an equipment for simulating brush and commutator segments to derive the current commutation process during the sliding movement and finally to evaluate a residual current.