Dumanchuk M. Improving the efficiency of manufacturing parts of elastic couplings

Object of research: technological processes of formation of protective coatings of surface layers of steel parts of machines against fretting corrosion. Subject of research: regularities of formation of protective coatings of surface layers of steel parts of elastic couplings, which form structurally different tribocouples, from fretting corrosion. The purpose of the study: to improve the quality of the surface layers of elastic coupling parts and their elements, by targeted selection of the most promising technological methods of their formation taking into account existing analogues, industry experience and recommendations in domestic and foreign literature. Research methods: The method of system analysis allowed to study the design and technological requirements for PM parts, as well as existing methods to improve their quality. The method of synthesis allowed the parts of elastic couplings to be divided into separate friction units (tribocouples), for which the increase of their wear resistance is achieved by various technologies. In developing the method of directed choice of technology for the manufacture of elastic couplings were used: graph theory, mathematical logic, Boolean algebra, mathematical modeling, as an optimization method used the method of minimum cross sections. Metallographic analysis of the samples was performed to assess the quality of the surface layer, its continuity, thickness and structure of the sublayer zones. Simultaneously, a durometric analysis was performed for the distribution of microhardness in the surface layer and along the depth of the section from the surface. The surface roughness was determined on a profilograph-profilometer mod. 201 plant "Caliber" by removing and processing profilograms. To study the distribution of elements in the depth of the layer, local micro-X-ray spectral analysis was performed using an X-ray spectroscope microenalyzer equipped with an electron microscope ISIS 300 Oxford Instruments. Theoretical and practical results: technologies for improving the quality of surface layers of elastic couplings and their elements have been developed. Scientific novelty: for the first time a system of purposeful choice of technology for manufacturing elastic couplings of rotary machines was developed, which allows to form contact surfaces of three-coupling parts: "shaft-half-coupling", flexible elements and fasteners with specified operational properties; for the first time a physically substantiated mathematical model of the process of wear of flexible elements of an elastic coupling at fretting corrosion is offered, which allows to determine the wear expressed by the change of surface roughness by the work of friction; further developed a method for determining the constants of the wear equation in fretting corrosion of the friction surfaces of flexible elements, which can serve as criteria for the selection of rational technologies to improve the quality of their surface layers; for the first time on the basis of studies of the stress-strain state of flexible elements of the coupling type MSK, solved the problem of their longitudinal-transverse bending, as well as a comparative assessment of their deflections from longitudinal-transverse bending and force due to misalignment of connected shafts.