S. A. Gubar (Pacific State University, Khabarovsk)
Method for determining the geometric characteristics of the contact in a cylindrical gear with arched teeth
A numerical method for studying the contact in engagement in relation to cylindrical gears with arched teeth is considered, which makes it possible, for a given convergence of the teeth and deformation of the surfaces, to outline the boundaries of the contact area and determine the error in the position of the driven link when the gear is operating with errors in the relative position of the wheels.
Keywords: cylindrical gears; arched teeth; envelope; field of calculated clearances; contact area; error of position of the output link.
K. V. Grigorovich (Institute of Metallurgy and Materials Science of the Russian Academy of Sciences, Moscow); P. A. Vityaz' (National Academy of Sciences of Belarus, Minsk, Belarus); V. L. Basinyuk, M. A. Levantsevich (Joint Institute of Mechanical Engineering of the National Academy of Sciences of Belarus, Minsk, Belarus); S. I. Platov, R. R. Dema, D. V. Terent'ev, O. R. Latypov (Magnitogorsk State Technical University (MSTU) named after G. I. Nosov, Magnitogorsk)
Modification of the working surfaces of tools for the manufacture of hardware by friction cladding
The article describes the experience of practical application of friction cladding with a tool – a rotating wire brush. The working surfaces of the replaceable tools of hardware assemblies for the production of nuts (slugger punches, cut-off knives, taps) are processed using the developed sectional rotating wire brush. Industrial experiments have shown that modification with the application of functional coatings to wear surfaces made it possible to increase their resource by 1,6–2,3 times.
Keywords: friction cladding; flexible tool cladding; rotating wire brush; tap; punch; cut-off knife; production of nuts.
A. V. Biletskaya (Founder and project manager of the Museum of History, Life and Blacksmithing of Anna Biletskaya, «Citadel of Altai Masters Anna Biletskaya», Belokurikha)
Alternative to the oil pump for pneumatic hammer MA4129A
In the article the author analyzes and finds a way to replace the oil pump with a homemade oil pump. The general characteristics of equipment for machine forging and hot stamping are given, since the pneumatic hammer is completely dependent on the operation of the oil pump. The source of information is the publications of various authors, their own methods and approaches to work on a pneumatic hammer. The article is designed for use by workers, craftsmen, technologists of industrial enterprises. It may be useful to students and teachers of higher and secondary technical educational institutions as a manual.
Keywords: pneumatic hammer MA4129A; hammer; oil pump; oil station.
Desta Abebe Bekele, M. A. Kovalev (Samara National Research University named after Academician S. P. Korolev, Samara)
Problems of diagnostics and evaluation of the technical condition of aircraft hydraulic systems
The article presents the results of the study of the current state, problems and prospects of development of methods of diagnostics and assessment of the technical condition of aircraft hydraulic systems. The analysis substantiates the relevance of the topic under consideration, which is associated with the high importance of hydraulic systems for flight safety and increasing complexity of their technical components in the context of widespread implementation of the achievements of the Fourth Industrial Revolution. Particular attention is paid to the evolution of diagnostic methods since the 1970s. The article presents a description of the evaluation systems that have been developed at the level of national states and NASA individually. The problems associated with the need to select diagnostic parameters, the task of systematization of the data obtained in the analysis, the high cost of procedures, the limited use of logistic schemes are also highlighted.
Keywords: diagnostics; aircraft; hydraulic system; evaluation.
R. U. Kamenov (Omsk State Technical University, Omsk)
Simulation of crack growth in high-speed grinding of ceramic materials by the peridynamic method
Diamond grinding of ceramic materials is a complex dynamic task. This process is influenced by many factors that directly affect the quality of the treated surface. One of the key issues in the processing of brittle materials such as ceramics is the issue of crack growth in the material being machined. The purpose of this work is to study the dynamic growth of a crack during high-speed grinding of ceramic materials. To achieve this goal, the following tasks were solved in the work: the process of grinding a ceramic material based on aluminum oxide with a single diamond grain was simulated, and the issues of the effect of cutting speed on the quality of the machined surface of ceramic materials were considered. The results of experiments on high-speed grinding of vacuum-tight ceramics VK 94-1 are presented. Based on these results, it was concluded that increasing the cutting speed significantly reduces the number of breakouts in the machined material and, as a result, improves the surface quality. The obtained results of the work allow substantiating the recommendations on the cutting modes of brittle ceramic materials by the method of high-speed grinding.
Keywords: ultra high speed grinding; surface quality; diamond grinding; crack growth simulation; peridynamic.
A. V. Kornilova (Moscow State University of Civil Engineering, Moscow)
On the question of methods for creating mathematical models when solving scientific, technical and engineering problems of metal forming by pressure
The article discusses methods for creating mathematical models when processing the results of experiments of various types. The necessity of a clear formulation of the field of definition of existing modeling methods has been proved. It is shown that the methods of experiment planning are adequate for an active experiment. For a passive experiment on operating technological equipment, it is recommended to apply the methods of group accounting of arguments, main components, Brandon's method. Examples are given. It is shown that the method of neural networks currently cannot replace traditional methods of mathematical modeling in solving scientific, technical and engineering problems of metal forming by pressure.
Keywords: mathematical modeling; active experiment; passive experiment; experiment planning; full factorial experiment; Brandon's method; neural networks.
A. K. Kenesbekova (Al-Farabi Kazakh National University, Alma-Ata, Kazakhstan)
Corporate VPN: how it works and an overview of solutions
The article discusses the principle of operation of a corporate VPN. The concept of a virtual private network (VPN) is given, the features of application in the corporate network of the enterprise are indicated. The second part of this paper is devoted to a brief overview of modern software and hardware solutions in the field of corporate VPN applications. Examples of both foreign and domestic systems are described. The paper shows how a corporate VPN fits into the general information security policy of a modern enterprise.
Keywords: virtual private network; VPN; corporate network; information security; Internet.