Thermal diagnostics of mechanical gear elements of combine harvester

The work carried out practical testing of the technology of thermal diagnostics of belt gear elements of the grating mill drive of the combine harvester. The basis of the technology is the principle of using the coefficient of the temperature ratio on the surface of the diagnosed unit and temperature in the friction zone, expressed through the coefficient of proportionality of the finite element model. The peculiarity of the thermal diagnostics, in this case, is to compare the temperature in the friction zone with the maximum allowable temperature for the direct contact zone in the mechanical transmission unit. The object of the study is the tensioning roller of the drive of the grating mill of the first stage of the CLAAS TUCANO 580 combine harvester with 6203-2RS TIMKEN bearings. The result of the numerical experiment showed a significant effect on the temperature in the friction zone of the operational parameters - radial force and rotational speed. The use of 3D-modeling made it possible to determine the key parameter of the proposed thermal diagnostics technology - the proportionality coefficient of the finite-element model k=0.489. The temperature of the bearing assembly of the tension roller was measured periodically, using a non-contact method during harvesting in the 2020 season. For the period of regular observations of 128 moto-hours, the value of the maximum temperature growth rate in the friction zone Vτ=0.025 °C/min and the maximum temperature in the friction zone 69.5 °C, taking into account the ambient air temperature, were determined. No failures of the diagnosed unit were found. In the process of application of thermal diagnostics technology, no errors of the first kind are recorded, which indicates the effectiveness of the proposed technology.

Historic Building Thermal Diagnostics Algorithm Presented for the Example of a Townhouse in Lviv

This paper presents a proposal for a historic building thermal diagnostics algorithm for the example of a historical townhouse located in Lviv, Ukraine. The authors proposed a testing and diagnostics procedure that should precede design and renovation work associated with improving the energy standard of the buildings under discussion. The procedure was presented using a case study of a selected historical building. The scope of the study included an assessment of the building’s technical condition, thermal vision diagnostics, wall moisture, and water absorption in the context of protection against rain. Sample thermal and hygrothermal calculations were performed for a sample architecture element. The calculations included simulations of partition envelope behaviour after planned thermal retrofitting had been carried out. Performing the presented thermal diagnostics methods in three interlinked blocks (A, B, and C) shall ensure the proper thermal retrofitting of historical buildings in the context of their further occupancy.

DEVELOPMENT OF A METHOD FOR THERMAL DIAGNOSTICS OF RADIOELECTRONIC DEVICES USING AN ARTIFICIAL NEURAL NETWORK

The current level of development of science and technology allows us to speak about the high quality and stable operation of electronic devices used in the manufacturing industry, which, in turn, ensures compliance with technological requirements and reduce production costs.

THERMAL CONTROL INVESTIGATION OF ROLLING-STOCK SHOE BRAKES BY SIMULATION METHOD

The development of heavy speed freight train communications in the Russian Federation results in the increased thermal loading of braking system elements of rolling-stock, in particular, in shoe brakes. Taking into account the requirements of branch program documents on wheel life increase, it is evident that the further development of freight communications requires a complex application of thermal diagnostics means for auto-brake equipment of rolling-stock during a train motion. The statistics shows that the fifth part of wheel pair failures is connected with thermal-mechanical damages and the situation goes on to be aggravated. In view of this hardware and software means for thermal diagnostics of shoe brakes require further improvement. The purpose of this paper is the process investigation of shoe brake thermal control by method of computer simulation and the estimate of infrared optics position impact upon control results. There is considered a model for the definition of a scanning path and computation of a signal level being part of a complex simulation model of wheel thermal control. The model offered is based on the methods of solid dynamics system investigations in the basis of which there is an application of theorems on mass center motion and changes of a solid kinetic moment. The model is used for finding a form and a spot area at every time moment of scanning by a solution of a problem on a dynamic spatial intersection of a wheel surface with the control area. There are considered different versions of optics orientation to an object of control for each of which for the first time there are obtained calculated thermal signals from the object under control. The analysis has shown that at the optics orientation to wheels from the outside a wheel tread appears to be in the control area that allows defining a maximum temperature of a wheel. But at the realization of emergency brake application a sharp short-time temperature increase of a tread is possible which indicates an improper operation of a brake unit. The optics orientation to a wheel from its inner side allows excluding false alarm indices at emergency brake application. The correctness of the results shown in the paper is confirmed by convergence with the results of wheel heating monitoring and environmental tests of experimental complexes of thermal control means of shoe brakes.