Adaptivity of thermal diagnostics method of mechanical transmission assemblies

Abstract

Determination of the real technical condition of mechanical transmissions is a key problem of diagnosing in the course of maintenance and repair of transport and technological machines in operation. The most reliable method of determining the technical condition of mechanical transmission assemblies taking into account the prospect of digitalization is thermal diagnostics based on the change in the intensity of infrared radiation of the heat source under normal conditions and under pre-failure condition. The aim of the research is practical testing of the method of thermal diagnostics based on the development of the analytical model of thermal stress and simulation of temperature loads by the method of finite-element analysis taking into account the resource bench tests on the example of the joints of drive lines. Research object -the cardan joint as per GOST R 52923-2008 (type 3 row IV, bearings 804707K4S10). The method of research includes: analytical study of cardan joint heat generation at three hierarchical levels of elementary joint "crosspin-bearing", crosspiece assembly and cardan joint assembly taking into account heat generation of adjacent parts and assemblies; simulation technique of stress-strain state taking into account thermal loading of parts on the basis of 3D-model of the joint using CAD-technology COMPAS 3D and CAE-technology APM FEM; comparative analysis of analytical and simulation technique results on the basis of data of resource bench tests on dynamics of radial play in the joint and temperature of bearing units at the level of extreme operational loading modes. As a result of the studies, the adequacy of the analytical mathematical model of the thermal stress of the cardan joint was confirmed, the method of simulation technique was verified and the operability of the complex method of thermal diagnostics for determining the real technical condition of mechanical transmission units was evaluated.

Thermometric diagnostics of elements of reaper drive for sunflower harvesting

“…Obviously, the obtained data are poorly approximated (R 2 = 0.00004), and the temperature value in the friction zone is significantly different from the theoretically calculated one. Earlier bench tests showed convergence of results [9]. Obviously, the results of the measured diagnostic temperature are influenced by an unaccounted factor, which is probably solar radiation.…”

“…The dependence obtained in the study [9] is used to calculate the temperature of the first hierarchical level ΘF. The design parameters for the EUROCARDAN cardan joint were determined by measuring the dimensions of its parts, as well as studying the manufacturer's catalogs on the website www.eurocardan.it.…”

“…The obtained dependence makes it possible to determine the value ΘF, and compare it with the maximum allowable temperature of ΘL = 250 ºC by the value of the measured diagnostic temperature ΘD. The results of bench tests [9] made it possible to establish such dependence, DOI: 10.22616/ERDev.2021.20.TF008 however, in real operation, the temperature model is inevitably influenced by more factors, which include the intensity of solar radiation.…”

“…The most effective tool for developing temperature models of technical objects is the finite element method, which allows both modeling and predicting the behaviour of the studied models, which is confirmed in studies in relation to rolling bearings [8]. The authors developed an adaptive temperature model of the cardan joint, including a mathematical model of the first hierarchical level and finite-element models for the second and third levels [9]. The results of bench tests showed the adequacy of the developed mathematical model, so it is necessary to carry out operational testing of the thermometric control technology.…”

Analysis of Bearing Assemblies Refit in Agricultural PTO Shafts

“…The damage surfaces of the cross shafts (shown in Fig. 12a and 12b) fit into the research of the calculated temperature fields on the cardan joint that were shown in the research [33], Fig. 15.…”