THE STRUCTURE AND CONTENT OF THE TECHNOLOGICAL PASSPORT AND OPERATION PROCESS CHARTS OF GRAIN HARVESTERS
The work describes how parameters of grain crop stalk mass, combine harvester speed, coverage of swath headers and fi eld size infl uence the actual throughput of a grain harvester and the feasibility of its nominal throughput at threshing. The nominal throughput of a grain harvester is usually taken as the delivery of corn bulk in kilograms her second to a thresher with the level of grain loss of 1.5 percent and the standard moisture of grain and straw. In a production environment, the throughput of a grain harvester of the classical scheme increases by 1.45 times when the straw content in corn bulk goes down from 1.5 to 0.7 in unit fraction and decreases by 1.16 times when the straw content goes up from the standard value to 2.3. By regulatory standards the actual throughput of a grain harvester can only be 10 percent lower than its nominal throughput. When choosing harvesting strategy and tactics in the farm conditions, the technological passport of the 7 kg/s class grain harvester may be represented as a nomogram consisting of four quadrants. The procedure of using a technological passport was developed by harvesting grain crops with the yield of 1 to 2 tons per hectare by the 7 kg/s class grain harvester. According to the calculations for the normal weather conditions and the yield range mentioned above, such harvester will be fully loaded only at two-phase harvesting, threshing double swaths cut by reapers with the coverage of 10 and 6 m, and at the maximum allowable operating speed of the grain harvester. The coverage of the swath headers for the straight combine method is from 9 to 11 m, so the effi cient load of the 7 kg/s class grain harvester at maximum allowable operating speeds is achieved only at threshing grain crops with the yield capacity of over 2 tons per hectare. These fi ndings can be used to develop operation process charts for grain crop threshing in each fi eld by the straight or two-phase methods.