Search results

The paper describes the physical nature of the occurrence of disturbing forces in traction gears during intermating teeth and determination of the amplitude-frequency content of the spectrum. In addition, the experimentally determined defects arising elements locomotive traction gearing.

The article is devoted to the analysis of the quality of materials for the manufacture of fasteners for rolling stock. The paper presents the results of studies of parts destroyed during operation that are used for fastening the undercarriage assemblies, spring suspension and impact-traction devices of rolling stock. The purpose of the work is to establish the probable causes of the destruction of parts under the action of static and dynamic loads during movement on the track. The paper describes the methodology and sequence of examination of materials based on the analysis of the chemical composition of metals, the assessment of mechanical properties and the study of the surfaces of fractures of parts. The results of spectral analysis of the metal of the investigated parts, measurements of hardness and analysis of the surface of fractures of the parts are presented, which allowed to establish the possible nature, sequence and causes of their destruction. The results obtained in the course of the research showed that the main reason for the breaks in the fasteners of rolling stock is the impact on them of loads exceeding the tensile strength of the metal. It was found that the brand used in the production of metal does not meet the requirements of the normative-technical documentation for the product and is not intended for the manufacture of fasteners. Thus, the findings confirm the need to tighten the quality control of materials used in the manufacture of fasteners for rolling stock, and can be used in machine-building enterprises specializing in the production of components and spare parts for railway rolling stock. The main conclusion of the work is the need to use in the production of fastening parts of the responsible components and assemblies of rolling stock, structurally reasonable steels and alloys.

The paper describes a mathematical model of gas-dynamic movement through the through defects in the body of the boiler tank cars. The mathematical model allows to take into account the processes of gas flow at low pressure drop and the impact of the level of roughness of the inner surface of the through channel formation jet escaping gas. The comparison of the results of theoretical modeling and experimental studies of the velocity of the gas flow and temperature under different conditions. The study identified the laws of gas flow through a series of classic models through defects. Shows the dependence of the temperature of the escaping gas flow from the exhaust velocity and the level of roughness of the internal surface of the through channel, which allows us to estimate the nature of gas flow and temperature gradient. The obtained results allow to adjust the level of sensitivity to rejection temperature during thermal leakage control boilers railway tanks.

This article contains results of experimental studies on the formation of corrosion products as a result of aggressive environment and electric currents action on the reinforced concrete structures. There are discussed a method of creating models with artificial electrocorrosion under conditions close to real working. The results of testing models using the X-ray method and modeling their strength characteristics are presented.

The expediency of introducing dynamic models of defect development into the practice of vibration diagnostics of rotor mechanical units is substantiated. It is shown that as a basis for the creation of models it is advisable to use empirical data. An example of a dynamic model of a small gear defect of a wheel-gear unit is given. The approximate amount of work on the creation of dynamic models is determined. Methods of realization of dynamic models of defects "in the big" are offered.

The article presents the results of the research conducted by the authors, the purpose of which was to development a model for recognizing defects in axle caps of a wheel-motor block of a locomotive in order to implement automatic advance notification of management structures about the need for maintenance or repair operations to eliminate defects at an early stage of their occurrence. The research used the following interdisciplinary and mathematical methods: computer and mathematical modeling, methods of mathematical statistics, methods of the theory of artificial intelligence and parametric reliability. As a result of the research, a mathematical formalization of the model for recognizing one of the defects in the axle caps of the wheel-motor block of the locomotive - the groove (chipping) of the babbitt layer was obtained. With the help of the obtained model, it is possible to implement automatic recognition of defects, pre-failure states not only of axle caps, but also of other units of technical systems. The developed model can be used in monitoring systems, control, diagnostics of the technical condition of the locomotive fleet, in order to reduce downtime in repairs and forced costs for scheduled operations. The proposed model solves the range of problems described in the development concept of JSCo Russian Railways associated with the implementation of the actual repair system for the current technical condition of the locomotive, as well as with the digitalization of the company's advanced areas.

The urgency of the task of creating test signals of vibration. Described possible ways of implementation of the test vibration signals. A method of forming a test signal by adjusting amplitudes of the individual harmonic components of the vibration signal. Showing the results of modeling. Shows the possible effect of using the proposed method.

The article is devoted to the development of a methodology for monitoring the alignment and radial runout of the inner cylindrical seating surfaces of locomotive motor-axle bearings. The main reasons for the wear of the working surfaces of the bearings and the consequences of the influence of the clearances in the interfaces of the plain bearings and the axles of the wheelsets on the increase in the intensity of wear of the parts and the deterioration of the dynamic characteristics of the running gear of the locomotive are listed. The paper presents a basic diagram of the basing and control of deviations from alignment and radial runout of the inner cylindrical surfaces of bearings, describes the design and principle of operation of a special control device for measuring these deviations. The purpose of the work is to substantiate the feasibility of monitoring deviations from the shape and location of surfaces during the repair of motor-axial bearings. The paper describes the sequence of steps for measuring the alignment and radial runout of bearings and the interpretation of the measurement results. The features of the design of the control device are considered, the advantages of its use are listed in comparison with the existing analogues of the devices used to control the alignment of the holes of the body parts located on the same axis. At the same time, it was found that the control of alignment and radial runout must be carried out in order to assess the possible degree of misalignment of the traction motor frame and the axle of the wheelset of the locomotive after repair. Thus, the conclusions obtained confirm the need to tighten quality control of the restoration of locomotive motor-axle bearings by introducing into the production process the operations to control the alignment and radial runout of motor-axle necks and motor-axle bearing liners made of lead bronze, tin or lead-tin babbits.

The operational reliability of the electrification and power supply system and the associated traffic safety is mainly determined by the technical condition of the contact network-an element that is extremely difficult to reserve in any way. The state of the contact network devices of the East Siberian railway is indirectly characterized by periods of electrification of sections. The equipment of the contact network, put into operation in the 1960s and 1970s, has developed its design life, does not have the required load capacity enough and reduces the reliability of the electrified section. The article shows that the purpose of improving the reliability of electrical equipment in the operation of power supply devices is to predict the state of its elements, in particular the metal supports of the contact network, as an object of study. Correctly assess the state and resource of the contact network devices will allow the use of the latest diagnostic systems by personnel in practice, using mathematical apparatus and modeling methods. It is shown that by monitoring various parameters characterizing the support, it is possible to detect a change in the technical condition of the object of study in time and to carry out maintenance in the period of time when there are deviations of parameters beyond unacceptable limits. The statistical data on the state of the support economy at the VSZHD are summarized, the main types of damage to metal support and supporting structures are given. It is shown that new types of damage to metal structures, not classified earlier, are revealed, that qualitative and quantitative assessment of the state of metal supports of the contact network, which have various structural damage is possible using methods, modeling, simulation and evaluation of the state of structures. FEMAP, an independent computer-aided design system from Siemens PLM, is used as an independent full-featured environment for modeling, simulation and evaluation of the results of the analysis of the characteristics of metal supports of the M6/10 model

The article deals with the distribution of the electrostatic field around the garland of porcelain suspension insulators containing defects. Achieved the distribution simulation of the electrostatic field around insulators in the software package Elcut. We get a picture of field distribution around the insulators for the environment with different dielectric constants. A comparative analysis of simulation results and experimental studies on the basis of which revealed the possibility of diagnosing the parameters of insulators of the electrostatic field.

In connection with the negative effects caused by the fault of the insulators used in an overhead power transmission line of 6 - 10 kV, it is suggested controlling a condition of a post insulator by the device that responses when breakdown current goes through an insulator. The work of the device for identification of insulators defects is described. Equivalent circuits of an alarm device connection with an insulator in an overhead power transmission line are given. The basic processes, that occur in a system of a supporting insulator of an overhead power transmission line in a serviceable condition and if there is a defect in view of geometric capacitance, absorption current, steady leakage current and surface current of breakdown, are considered.

Data on corrosion fatigue damages of a sole of rails (defect 69) on the railroads of Russia are submitted. It is established that 69 the corrosion fatigue resulting from moistening of a sole in a zone of contact with subrail laying in combination with the high level of the stretching tension in a rail sole is the reason of breaks of rails on defect. The analysis of statistical data on refusals of rails on defect 69 in the West Siberian management of infrastructure showed that failure rate grows to an operating time of the tonnage of 800 million t gross and has fatigue character. On sites of a way with a complicated plan and a profile failure rate is 3 - 4 times higher, than on quiet Trans-Siberian to the course. Results of the analysis of data are shown and measures for increase of reliability of the rail lashes having tendency to formation of defects on a code 69 are offered.