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Currently, in connection with obtaining the unique properties of the surface layers of materials, special attention is focused on the theoretical and practical aspects of the technology of hardening and restoration, using both diffusion saturation and concentrated energy flows. The monograph deals with the issues of chemical-thermal and laser processing of tools and parts of transport and technological machines. It can be used in the study of disciplines "materials Science and technology of structural materials" and "Modern methods of strengthening materials" areas of training "Agroengineering" and "Technology of production and processing of agricultural products" (bachelor), as well as undergraduates, graduate students and specialists working in the field of agricultural engineering, mechanical engineering, metallurgy and surface engineering.

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Modern transport and technological machines operate under the seasonality conditions of agricultural operations and significant energy loads. Universal joints of unequal velocity, being part of mechanical power transmissions, work under adverse conditions and limit equipment reliability. It was established that the temperature mode of the bearing assemblies of the universal joints affects the wear rate of their working surfaces. When the temperature in the friction zone increases due to mechanical operation and heating from the environment and adjacent heat sources, boundary friction and temperature conditions exceeding the level of material self-tempering occur. As a result of research, the universal joints (RU199508) were designed to ensure the intensification of cooling its bearing units directly in the maximum heat generation zone during the universal joint operation. Numerical simulation was performed according to the thechinque of calculating radiators for a universal joint with a cross K 040 GOST 13758-89 on needle bearings No. 804704 K5. The results showed the size of the outer surface area that is sufficient for its cooling. When the maximum values of the fracture angle of the universal joint, torque, angular velocity, and efficiency of 0.99 are combined, its bearing units are effectively cooled. It has been found that if the efficiency of the bearing assemblies is less than 0.952, their surface is no longer sufficient to provide efficient cooling and maintain thermal balance conditions in the friction zone. The use of the radiator can increase the heat transfer area by 19%. The radiator ribs fixed on the side surfaces of the yoke eyes with a thickness of 2 mm and a distance of 4 mm and a total area of 166.1 cm2 will ensure the operability of the bearing units. It will remain satisfactory even if their efficiency decreases to 0.943 as a result of mechanical wear.

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