OBRABOTKA METALLOV

Introduction: One of the most important tasks of locomotive repair production of Russian Railways is to increase the service life of the rolling stock: locomotives and wagons. This paper discusses the use of a new method of repair of collector-brush unit of the electric locomotive, which will improve the switching characteristics, improve the reliability of electric traction motors (ETM) and increase the operating time of the entire electric locomotive as a whole. The purpose of the work is to improve the reliability and service life of ETM of electric locomotives. Methods: To reduce the coefficient of friction between the collector plates and brushes and increase the service life of the collector-brush unit, it is proposed to carburize the surface standing copper plates of the collector by means of electrical discharge machining (EDM). The method of electrical discharge machining, in comparison with traditional mechanical methods of repair of electric traction motors, is more preferable, because it allows increasing the wear resistance of the contact surface of the collector plates, which provides the required performance properties and increases the reliability of the collector-brush unit. Results: The article proposes a technological process of repair of the electric motor collector, characterized by the use of electrical discharge machining with the formation of a carbon surface layer on the contact surface of the collector. A device for the formation of a carbon layer on the working surface of the collector of electric traction motors by means of electrical discharge machining is presented. The results of atomic emission spectral analysis of carbonized copper sample, which showed that the proportion of carbon in the carbonized copper sample increased by 0.1% compared to the copper plate, not subjected to electrical discharge machining, are given. An evaluation model of the dependence of the depth of the composite layer on the voltage applied to the electrodes is presented. Discussion: the evaluation model Presented in the article allows: 1) to make a preliminary estimate of the dependence of the depth and thickness of the layers forming the composite structure of the surface subjected to EDM on the voltage applied to the electrodes; 2) based on this calculation, to conduct an experimental EDM of the collector surface of the ETM with the adjustment of the thickness and depth of the layers by means of the described technique; 3) to experimentally determine the processing modes for the samples.

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