Introduction. A decrease of damaging loose grains by threshing tools when combing standing plants is an urgent scientific problem. The aim of the research is to develop a technical solution and experimentally confirm the possibility of loose grains pre-separation from the stripped grain heap before it enters the threshing chamber of the combine harvester. Materials and Methods. The most promising technical solution to minimize the damaging of loose grain is an inclined chamber containing an oblong-hole lattice bottom, under which inclined augers are mounted. The experimental studies had two stages. In the first series of experiments, in laboratory conditions there were determined the optimal sizes of the lattice bottom holes to ensure the maximum passage of loose grains. In the second series of experiments, the degrees of separating and damaging loose grains were evaluated in real field conditions. Results. According to the results of laboratory studies, it was found that the maximum passage of loose grains through the holes of the lattice bottom is 68.7% with the width of holes 8 mm and their length 160 mm. According to the results of field experiments, it was found that the average passage of loose grains through the holes of the lattice bottom is 90%. At the same time, damaging grains in the inclined chamber did not exceed 0.5%, and in the hopper 1.75%. Damaging grains in the bunker was in the range of 5.25% when the combine operated without pre-separation of the combed grain heap on the lattice bottom of the inclined chamber. Discussion and Conclusion. Pre-separation of loose grains from the combed heap makes it possible to reduce damaging grains at least three times, and also reduces the power consumed by the drive of the threshing machine by 11–12%.

The results of theoretical studies confirming the possibility of carrying out preliminary separation of free grain from the stripped grain pile before it enters the threshing chamber of a combine harvester are presented. The prospect of a separating device mounted directly in front of the threshing drum, consisting of longitudinal rods, over which an additional scraper conveyor is mounted, has been established. The cross section of each strip of the grating is narrowed downwards to increase the intensity of separation of the device and eliminate the possibility of clogging the holes with passing particles of the heap. The optimal length of the openings of the pre-drum type separating device, its spatial orientation were determined, and the quality indicators of the work were evaluated. Theoretical studies of the separation process on winter wheat of the “Moskovskaya 56” variety with a grain size of 3.9x6.5 mm were performed. The speed of the scraper conveyor was 3 m/s, and the angle of inclination of the separating device varied within 0-45 degrees. It has been established from the results of research that with an increase in the angle of inclination of the separating surface, the length of the sieve openings increases, and the separation speed decreases. Since the horizontal grate provides a higher separation rate of free grain, compared to an inclined surface, the use of a pre-drum type separating device is most preferable in relation to the grate bottom of the feeder house of a combine harvester in terms of its performance. It has been established that the length of the separating holes should be at least 0.08 m. Such a technical solution allows minimizing not only the crushing of free grain by the working bodies of the threshing machine, but also to reduce the metal consumption of the separating device.

SUBJECT OF THE STUDY: Is the process of preliminary separation of loose grains from combed grain heap on the slatted bottom of the feed elevator of a combine harvester. AIMS: Is an efficiency evaluation of the combed grain heap separation on the slatted bottom of the inclined chamber of a combine harvester in the field and to compare the degree of crushing of free grain depending on its supply to the threshing device or directly to the cleaning system. METHODS: All studies were carried out on winter wheat of the Moskovskaya 56 variety with a yield of 30 c/ha. Plant height varied within 0,60,9 m with a grain ripeness of at least 98% and a moisture content of 14%. The serial grain header ZHO-5 OZON manufactured by PJSC Penzmash was aggregated by the Niva-Effect combine harvester with a constant speed of 8 km/h and a stripping cylinder speed of 485 min-1. The field experiments were divided into two stages. The first series of experiments was devoted to evaluating the efficiency of preliminary separation of combed grain heap on the slatted bottom of the experimental feed elevator. During the second series of the experiment, grain was harvested with a serial feed elevator without its preliminary separation. RESULTS: According to the results of the first series of studies, it was found that the passage of loose grain through the holes of the slatted bottom of the inclined chamber is 91,6%. At the same time, grain crushing in the feed elevator did not exceed 0,5%, and in the bunker 1,75%. During the operation of the combine with a serial feed elevator without preliminary separation of the combed grain heap, the crushing of the bun-ker grain was within 5,25%. CONCLUSION: The practical implementation of such a technical solution makes it possible to 3 times the grain crushing in a bunker by the working bodies of the threshing machine.

The results of the study of the mechanical properties of the soil, relevant from the point of view of the effective use of slatted rollers, are given in the article. It has been established that the most important technological property of the soil is its anisotropy. As a result, the limiting stresses sufficient for the destruction of the soil differ by 6-10 times with different methods of impact on it. The minimum is the tensile strength and the ultimate bending strength of the soil derived from it. It is the most important way of influencing the arable layer, since it provides the minimum energy intensity of soil crumbling. In particular, the slatted roller destroys soil clods by the combined action of bending and compression. In this regard, a study was made of loamy soil of different moisture content for its resistance to bending and crumbling. It has been established that the strength of the soil increases with a decrease in its moisture content. At the same time, the minimum limiting stress is typical for a moisture content of 20-23%. With a further increase in moisture, the strength of the soil again slightly increases. In general, the dependence of soil strength on moisture both in bending and in compression is described by a quadratic equation. To determine the magnitude of the bending stress, a new version of the calculation of the moment of resistance to bending of a rectangular section of the sample is proposed, taking into account the anisotropy of the soil. Instead of the middle layer, the surface (upper) layer was used as a “neutral” layer. This is due to the fact that with the existing difference in the tensile and compression strength of the soil, the upper layer practically does not deform until the destruction of the lower layer. As a result, it is advisable in the calculation to take the cross section as a composite one, shifted from its geometric axis by half the height.

Introduction. Reducing the distance of throwing soil into the zone around bushes and maintaining a leveled surface between rows of berry crops are urgent scientific problems. Aim of the Article. To identify the basic parameters for the interaction of a spherical disk with waterlogged soil and on this basis to develop the technical solution for reducing the distance of soil throwing away in space between rows of berry crops. Materials and Methods. The object of research is an orchard disc harrow equipped with a protective shield mounted in front of the outermost disc of the tool front panel. The subject of the research is the process of interaction of the end disc of the front harrow plate with the waterlogged soil in berry plantations. The length of the protective shield and its spatial orientation were chosen as optimization parameters for field experiments. The quality evaluation of intertillage of the berry plantations was carried out by profiling their surfaces. Results. Based on the results of theoretical studies, it was found that the angle of inclination of the protective shield in the horizontal plane should be within 53–54°, and with respect to the movement of the harrow – 50–58°. The results of field experiments have confirmed the theoretical conclusions. It has been established that only a protective shield, the length of which is 450 mm and the installation angle of 50°, allows completely eliminating the side throw of the soil beyond the width of the tool. In addition, these parameters ensure the stable operation of the disc tool in almost any soil moisture and weed infestation of space between berry bushes. Discussion and Conclusion. The use of a modernized tillage tool made it possible to exclude the soil throwing into the bush zone to increase the speed of the unit by 25%.