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The results of the experimental study of the termal cycle of many-electrode welding of the solid wheel`s comb and its influences in work upon structurization in zone of the termal influence are presented.

To improve the reliability of the detection of a technical condition of the mechanical components of rail rolling stock and calculate the critical values of the parameters put forward the hypothesis of the homogeneity of groups of similar nodes mechanical electron-tropoezda. As part of an experiment to verify this hypothesis, carried out the collection of information about the values of vibration parameters of electric components in the movement; the technique and the statistical analysis of the measured vibration parameters for the same type of bonds-fishing.

The results of infrared studies of the process of heating parts collector and brush assembly dc electrical machines. Proved diagnostic parameters for assessing the technical condition of the collector-brush assembly of electric motors: the ratio of changes in the elevation of temperature in time and space.

The aim of the work, the results of which are presented in this article, is to identify effective parameter of the heating process in the collector-brush unit of DC traction motor. The article suggests a detailed equivalent thermal equation of DC traction collector-brush unit. An experiment in a laboratory according to the theory of experimental design in the central rotatable terms of the second order are held, and the analysis of the results are presented. A method for processing the results of thermographic study of the machine is described. The regression equation, reflecting the degree of influence of the mode parameters of the machine on the intensity of the heating area of traction motor collector-brush unit, is compiled. The correct use of mathematical apparatus is confirmed by quantitative calculations Student's criteria assessing the significance of the coefficients of equations and F-Fisher criterion within the 5 % significance level. The results can be used to supplement the methods of DC traction motors and collector-brush unit technical condition diagnostics.

The article presents statistical studies of acoustic control signals when diagnosing power transformers of the railway power supply system. Statistical processing of acoustic monitoring data was carried out on the example of transformers with different levels of insulation condition. Comparisons of histograms of the experimental distribution of amplitudes and dominant frequencies of signals with the nearest theoretical distribution laws, performed in the STATISTICA program according to control data obtained from the automated system. The conducted studies have shown a close correlation of defects registered by the acoustic method with the distribution of signals in the form of laws of distribution of random variables. It is shown that for power transformers with mechanical oscillations, both during the passage of the train and at idle, the distribution of amplitudes and dominant frequencies of the recorded signals corresponds to a uniform law. The distribution of amplitudes and dominant frequencies is not centered around a certain average value. For power transformers containing partial discharges, the cause of which is the deterioration of the insulating properties of the windings under the influence of high voltage, the best approximation, both amplitudes and dominant frequencies, showed the Lognormal distribution. The signals are centered around a characteristic mean value. When the train passes, the acoustic system registers both high-frequency signals from the PD and low-frequency signals from body vibrations. There are two components in the distribution law - uniform and lognormal distribution densities. Thus, by the type of distribution of the recorded signals, their amplitude and dominant frequency, it is possible to determine the presence of a defective state of the insulation of power transformers. The study was carried out with the financial support of the Russian Foundation for Basic Research within the framework of the scientific project No. 20-38-90231.