Study of reliability of grain harvesters

To assess the reliability of combine harvesters, studies were conducted of their operation during seasonal field work and a classification of failures was performed by key characteristics: by the cause of occurrence, by changes in parameters over time, by the relationship of failures, by complexity groups. The studies were conducted in the period 2018-2023. The research program includes a justification for the number of objects of observation, a methodology for collecting information on failures, a methodology for recording the time of eliminating the consequences of failures. The article presents data on the number of failures by brand of combine harvesters, by failure characteristics, by severity groups of consequences, by structural elements of combine harvesters, by the time of restoration of operability after failure. Among the identified failures, the majority are classified as operational (54.9%), by the cause of occurrence - to sudden (91.2%), by depen-dence - to independent (69.8%), and to the first group by complexity (49.4%). The largest number of failures occurred in the reaping section (38.1%), the smallest in the engine and chassis - 1.5% and 1.1%, respectively. Elimination of failures in the reaping section takes up to 30 minutes on average, and failures in the motor unit and chassis - 5.8 hours and 4.2 hours, respectively. The time of elimination of the consequences of failures is significantly affected by the time of delivery of the element to the workshop for repair or the time of purchase and delivery of the failed element for replacement, as well as the arrival time of the service team of the dealer center. The results of the research allow us to determine ways to reduce downtime, increase the reliability of grain harvesters and optimal ways to organize maintenance and repair.