Studying the normal operation of grain harvesters within the warranty period

Introduction. Grain harvesters are used for no more than two months within a year. They must have maximum operating reliability, since even short downtime during the harvesting period result in large crop losses. The purpose of the study is to identify the causes of combine harvester failures within the warranty period. Materials and Methods. Identifying consequences of failures and ensuring the reliability of grain harvesters are based on an improved classification of failures. In the process of studying, there have been proposed the ways to solve the problem of combine harvester downtime based on the analysis of the time for grain harvester troubleshooting. The category of severity of failure consequences was taken into account. Results. Through monitoring in the period from 2018 to 2020, there were found failures of units and systems of grain harvesters with low reliability indexes within the warranty period. Most of the failures (59.2%) were found in Russian-manufactured combines, of which operational failures are 55.9%, structural failures - 26.7%, and production failures - 17.4%. The general patterns of changes in the average time for combine troubleshooting have been determined. A geometric model of a detail for the trouble-free operation of combines (header auger shaft) was created. The finite element analysis (ANSYS) was used to identify parts, which are subject to maximum workload. There have been identified units and parts, which fail to function within the warranty period, because of design and technological defects. Discussion and Conclusion. In order to reduce the time to find the consequences of failures, it is necessary to create a more extensive network of enterprises providing a wide range of services, improve the organization of technical service and expand direct links with the manufacturers of equipment in order to respond quickly and make the necessary design and technological decisions.