Influence оf gravity and thermodynamics on the sliding electrical соntасt

•Model for wear particle detachment from a surface of electric brushes and collector.•Properties of contact area in dependence to deviation from land contour under gravity.•The Joule–Thomson effect has no real impact on the thermodynamics of contact layer.

The motivation behind this work is to develop a dynamical systems understanding of the wear processes. We present a model for wear particle detachment from a surface of electric brushes and slip ring (collector) in the commutator-and-brush assembly. The geometry of the contact area is analysed and debris shape modification is estimated. The investigation accounts for the dependence of the properties of the sliding contact layer on the deviation of this layer from land contour under Earth’s gravity and on the Joule–Thomson effect. With stochastic simulations we demonstrate that analytical model of the third body may explain the different lifetime of the electrical brush depending on it position relative to the slip ring axis, and we predict their durabilities.