How to accelerate the process of forming a varnish film on rings and collectors of electric machines.

The switching conditions are largely characterized by the specifics of the intermittent nature of the brush contact with each collector plate. The current distribution in the brush contact is determined by the lapping of the working brush to the collector and the state of the varnish film, which determines the nature of the "mirror" on the working surface of the brushes. A varnish film on the working surface of the collector or the current-collecting ring is a prerequisite for ensuring satisfactory switching of electric machines. An important aspect in this regard is the structure of the varnish film. The structure of the varnish film is determined both by the composition of the atmosphere in which it is formed (gas composition, humidity, salinity), and by the electrical processes occurring in intermittent contact in the sliding current collector unit. In some cases, the varnish film may not form and thus significantly degrades the sliding friction and current transfer conditions. Under these conditions, the wear of the brush – collector pairs (current-collecting ring) – increases significantly. Therefore, it is important (in the conditions of a weak protective varnish film or its absence) to use the techniques of its artificial guidance. The article considers a variant of directing a varnish film using an active oxidation catalyst. This solution may be of considerable interest for electric machines operating in the conditions of a discharged atmosphere and the atmosphere of workshops with low oxygen content. [ABSTRACT FROM AUTHOR]