Study of the collector profile technical condition influence on the performance of the collector-brush assembly of rolling stock traction electric motors

The article is devoted to assessing the influence of diagnostic parameters for assessing the technical condition of the collector profile of rolling stock traction motors on the value of the mechanical force in the «brush-collector» contact. The results of the experimental studies of the parameters of the collector profile for traction motors EK810Ch of mainline electric locomotives 2ES6 are presented. Four-stage numerical experimental studies were carried out for the following conditions: the first stage - the height differences of the lamellas and harmonics were taken into account; the second stage - the height differences of the lamellas are taken into account without the influence of harmonics (with reduced beating); the third stage - harmonics are taken into account without the influence of differences in the heights of the lamellas (with reduced beating); the fourth stage - harmonics are taken into account without the influence of differences in the heights of the lamellas (with a multiplying factor up to a given beat). Using a mathematical model of brush movement along the collector, a degree of relationship was established between the diagnostic parameters that characterize the state of the traction motor collector profile, with the value of the mechanical force in the «brush - collector» contact. A diagnostic parameter is proposed that characterizes the spread of mechanical force values in the «brush - collector» contact of a traction motor, determined from the ratio of the force of elastic interaction of the brush with the collector and the average value of this force. An analysis of the results of the numerical experiment showed that the contact instability coefficient is largely determined by the value of the standard deviation of the lamella drops and, to a small extent, depends on the values of the harmonic amplitudes. The harmonic composition of the collector profile has practically no effect on the value of the contact instability coefficient at small values of the lamella drops. It is concluded that it is possible to use diagnostic parameters for assessing the state of the traction motor commutator surface to determine possible poor contact between the brush and the commutator. It is proposed to evaluate the quality of repair of collectors of traction motors taking into account the standard deviation of the differences of the lamella.