Influence of a new design of brush holders on the service life of traction electric motor brushes of electric locomotives

Abstract

The article is devoted to the solution of the actual task of improving the current collector unit of collector traction electric motors of electric locomotives, which currently constitute the overwhelming majority of electric vehicles of the electric rolling stock of Russia. Based on the classical theory of commutation and using O.G. Wegner's idea on the need to establish in advance the current of the switched section equal to the current in the parallel branch of the armature into which it enters, the justification is given for the application of a new design of the sliding contact for collectors of traction motors. The article analyzes the factors accompanying the changed configuration of the brush, such as the current density and heating in a new designed brush, and also reviews comparison of areas of sparkless operation of traction motors with standard and experienced brush holders. Also, the results of operational tests on the North Caucasian Railway of the VL80 electric locomotive no. 1676 are shown, one of the traction engines of which was equipped with experienced brush holders. Experienced brush holders provided a significant reduction in brush wear. On the basis of the conducted studies, it was concluded that the decrease in wear of brushes during the operation of the engine with experienced brush holders is mainly due to a decrease in the influence of mechanical factors on the sparking. During operation, under the influence of mechanical factors, the running edges of the brushes are subject to vibration, and significant current breaks off, which cause an increased spark wear of the brushes. Using the example of a new brush contact configuration, it is shown that the brush contact, namely its design and geometric dimensions, has a significant effect on the nature of current commutation in collector traction motors.