THERMOMETRIC DIAGNOSTICS OF THE CARDAN JOINT OF THE HEADER DRIVE CERIO 770
The article contains the results of experimental testing of the technology of thermometric nondestructive testing of the cardan joint of the drive of the cake CERIO 770 combine CLAAS TUCANO 570 during the harvest campaign of 2019 in the farms of the Belgorod region and Krasnodar territory. The purpose of the work is to justify the process of thermometric diagnostics for mechanical transmission elements of agricultural machinery. The study is based on a systematic approach involving thermometric control at three interrelated hierarchical levels. Theoretical basis and methods of research are represented by analytical equation for determination of temperature in friction zone, temperature analysis of finite-element model of investigated unit, and practical observations taking into account operational factors. The system approach made it possible to determine the values of heat release for an elementary fuel element, for the node being diagnosed, and for the node being diagnosed, taking into account the heat release of external sources. The developed mathematical model, taking into account design, technological and operational factors, provides an adequate estimate of the amount of heat generated in the coupling as a result of friction for the first hierarchical level. The use of the finite element method made it possible to determine the value of the diagnostic temperature suitable for diagnostics at the second diagnostic level. To account for the influence of external heating factors on the third hierarchical level operational observations were made. Thermometric control of the bearing units of the cardan joint showed a significant impact of the change in the level of solar radiation on the results of temperature measurements. In order to account for this factor and compensate for the measured temperature values, an equation of thermal balance has been developed for the tested unit, including thermal energy from solar radiation, energy released to the environment, by convection and by radiation. The results and generalizations of the study prove the effectiveness of using thermometric nondestructive testing for cardan joint bearing assemblies.