A theoretical and experimental study of combined agricultural gantry unit with a mineral fertiliser spreader

Saabunud / Received 06.07.2020 ; Aktsepteeritud / Accepted 03.08.2020 ; Avaldatud veebis / Published online 03.08.2020 ; Vastutav autor / Corresponding author: Jüri Olt e-mail: [email protected] to apply mineral fertilisers to the soil are an important part of practically every form of agricultural technology. The current global trend of transitioning to bridge and gantry-type agricultural systems leaves the unanswered relevant question of the effectiveness of the technological process of applying mineral fertilisers to the soil. This is relevant because, in gantry agriculture, a section of the arable soil is separated as an engineering area. This is why the main difference in gantry agriculture from traditional methods of the bulk spreading of fertiliser onto a field is that, with gantry systems, the amount of fertiliser that lands within the engineering zone are limited. This significantly affects the manufacturing costs involved in the entire area of agricultural technology and, as a result, the production costs of the end product. This study aimed to research the patterns that are apparent in affecting the parameters involved in the use of gantry-type equipment when applying fertiliser with the parameters and operational modes of a specially-developed electric spreader of mineral fertilisers. The physical object of the study was the agricultural gantry equipment that had been developed by the authors. This equipment, which is used for spreading fertiliser, was in the form of a tractor-mounted, suspended, single-disc spreader which was known as JarMet, and which had especially been modified to run from an electrical supply. The study indicated that the biggest influence on the speed of rotation of the centrifugal disc in the mineral fertiliser spreader stems from its height above the ground, the distance of track of the agricultural gantry itself, and the aerodynamic coefficient of the fertiliser. It was determined that, for the agricultural gantry with a distance of tracks of 3.5 m, a sufficient angular speed of the single-disc centrifugal tool is 15.5 rad·s−1, with a power demand for driving this at 0.35 kW·h. When using agricultural gantries of this type with an extended track width of up to 6 m, the necessary angular speed of the centrifugal tool for spreading fertiliser increases exponentially, to 318.2 rad·s−1, with the power demand for driving it increasing to the third power

Theory of Vibrating Lifting Tools of Sugar Beet Harvesters

The cultivation and harvesting of sugar beets (roots and haulm) is one of the most labour and energy consuming work processes in the agricultural industry. The improvement of the qualitative indicators of the sugar beet harvesting process as the final operation in the work flow of its production represents a multi-faceted research-and-engineering problem, which is to be solved basing on the search for new implement design concepts and overall beet harvester design layouts, the thorough theoretical substantiation of their design and process parameters, the experimental verification of the completed theoretical research with the ultimate objective of the analysis and synthesis of their rational parameters. Theoretical research must play a fundamental role in the mechanical and technological substantiation of the root lifting process. It must be used as the basis for developing rational kinematic and dynamic operation conditions in order to achieve the required quality of the performed work process as well as the streamlined energy consumption. The book can be considered as one of the first solid analytical studies of the process of vibrational digging of sugar beet roots. It offers the analysis of up-to-date engineering solutions of vibrational digging tools and experimental investigations of the first vibrational lifters, the equation of oscillating motions of digging shares

Research into the parameters of a potato harvester's potato heap distributor, and the justification of those parameters

Saabunud / Received 28.05.2021 ; Aktsepteeritud / Accepted 22.06.2021 ; Avaldatud veebis / Published online 22.06.2021 ; Vastutav autor / Corresponding author: Jüri Olt [email protected] low levels of efficiency and general quality when it comes to the use of potato harvesters in difficult soil and climatic conditions substantiate the relevance of the problem which is faced in terms of research by technologically advanced equipment and tools. They are looking to increase the efficiency of potato harvesters. This paper serves to justify the formation of the design and technical parameters of the V-type distributor, which directly acts on the undermined mass to increase the ability of the potato harvester to separate the soil. Preliminary experimental studies have shown that to achieve efficient technological processing in terms of the distribution of the general soil and potato heap, the distributor must possess the appropriate technological and design parameters. Calculations which have been carried out by using as a basis the theoretical dependencies that have been obtained serve to allow us to determine the optimum speed of progress through the heap, using the following design and kinematic parameters: Vel = 2.0 m s–1, А = 0.35 m, hv = 0.22 m, Δ = 0.08 m, bel = 1.2 m. The allowable speed for heap movement will be [V] = 1.62 m s–1, which will ensure the prevention of any heap clogging in front of the distributor. An analysis of the dependencies which have been obtained during the work shows that rational values for the distributor wing’s fitting angle fall within the range of α = 40°

The effect of a lateral airflow created on nozzle tip on the spray droplets deposition

Saabunud / Received 02.09.2021 ; Aktsepteeritud / Accepted 11.12.2021 ; Avaldatud veebis / Published online 11.12.2021 ; Vastutav autor / Corresponding author: Jüri Olt [email protected] application efficacy of a plant protection products by using a pneumatic device to change the dispersion of spray droplets is depended on the intensity of crosswind. The laboratory investigations of the spraying process of plants by means of the nozzles of a pneumatic system determined the quality indicators of pressure in the injection process of 0.4 MPa – the droplet coating density of 19–46 pcs cm2 –1 for the weighted mean droplet diameters (WMD) in the other experimental variants was within 304–543 μm. These indicators were compared with those for the standard, anti-drift and air injection nozzle types in which the droplet coating density was 23–59 pcs cm2 –1 and the weighted mean droplet diameters (WMD) were in the range of 350 to 485 μm. An analytical dependence was obtained of the influence of the lateral airflow and air pressure in the pneumatic system upon the amount of the deposited spray liquid

Research of possibilities for efficient use of wide span tractor (vehicle) for controlled traffic farming

In part, the economic effect gained from the introduction of controlled traffic farming can be directly determined by the area of the field lost under the engineering (or traffic) zone of the vehicles involved. With a wide span tractor, as with other vehicles, the area lost under the traffic zone will depend upon how efficiently operations in the field are organised. The purpose of the present investigation is to substantiate the design and other parameters of the wide span tractor from a position of efficient land use in controlled traffic farming. Theoretical studies, synthesis of the construction diagram and parameters of the wide span tractor were carried out using computer simulation of its operation. These studies indicated that planning of the field for controlled traffic farming with the use of a wide span tractor should take into consideration its track width and its field operational parameters. The use of a contemporary design of wide span tractor with a track width more than 7.5 m results in field traffic zone losses of no more than 5 -6 %, which is quite acceptable. Practical use of a wide span tractor for controlled traffic farming needs automatic steering to reduce field traffic zone area losses by a factor of 1.5 times compared with manual steering

Research of a contact stresses in swivel elements of flexible shaft in screw conveyor for transportation of agricultural materials

Saabunud / Received 12.03.2022 ; Aktsepteeritud / Accepted 28.04.2022 ; Avaldatud veebis / Published online 28.04.2022 ; Vastutav autor / Corresponding author: Jüri Olt ; [email protected] paper presents the new design of the rotating part with ball-bearing swivel joints between its sections for flexible screw conveyors. The new design provides for the improvement of the operation efficiency and loading capacity, the enhancement of the technological capabilities and the reduction of the admissible curvature radius. The contact stresses in the swivel element as the most loaded area in the rotating part have been analysed. It has been established that the maximum contact stresses arise at the points of contact between the ball and the flat surface of the slot in the cylindrical bushing. The recommended design limitation range for the cavity cone angle is within about 30–50. The relation between the loads and the stresses depending on the operating conditions has been modelled with the use of computer modelling. The comparison of the computer modelling results and the obtained calculation data has proved that the difference between the respective values varies within the range of 11–26%

Study into movement of wide span tractors (vehicles) used in controlled traffic farming

Wide span tractors/vehicles have good prospects as the mechanisation means for controlled traffic farming. The efficiency of the practical application of wide span tractors (vehicles) depends on the availability of the substantiated scientific basis or the theoretical basis for the research into their key properties, including among other factors the smoothness of movement. The aim of the research is to improve the smoothness of movement of wide span tractors (vehicles) by substantiating their configuration, design-and-process and other parameters as well as the properties of the longitudinal profile of the agricultural background irregularities in the ruts of the laid-down process track. The smoothness of movement of the wide span tractor (vehicle) as a dynamic system travelling in the ruts of the permanent process track substantially depends on the structure of the latter’s longitudinal profile, the stiffness of tyres on the supporting wheels, while the dynamics of the vertical oscillations of the process section depends on its operating weight

Investigation of technological properties of wide span tractors for controlled traffic farming

Practical use of wide span tractors (vehicles) for controlled traffic farming needs further motivation of the principles of their automatic steering, allowing maximum reduction of area losses of the field under the engineering zone at least 1.5 times. The use of contemporary wide span tractors (vehicles) with a track width more than 7.5 m allows reaching a value of the area losses of the field under the engineering zone not more than 5…6 %, which is quite acceptable. The presented brands of such tractors are provided with various technological equipment and means of automation, the technological significance of which can be estimated only by means of objective assessment methods. The developed equation for the estimation of the potential efficiency of the wide span tractors makes it possible to conduct analysis of the degree of impact upon them made by their design parameters and indicators of technical characteristics. Estimation of the degree of potential efficiency, which the contemporary wide span tractors should have, showed that the result exceeds the potential efficiency of the conventional machine and tractor aggregates by 1.5-2 times

Theory of Vibrations of Sugar Beet Leaf Harvester Front-Mounted on Universal Tractor

The harvest and transport of sugar beet leaves during harvesting can be considered a current task in the area of sugar beet growing system development. A rotary sugar beet leaf cutting mechanism is used for achieving the significant increase in the harvester forward speed during harvest. This leads to intensive vibrations of the topping mechanism in the longitudinal vertical plane causing the decrease of harvest quality. Therefore, it is necessary to analytically determine the effect of kinematic and design parameters of the sugar beet topping mechanism front-mounted on the tractor and to discover the value of the amplitude of oscillations in the longitudinal vertical plane of its sugar beet topping mechanism. We have constructed a mathematical model of the estimated motion of this machine by means of dynamics equations in Lagrange II-kind form. A system consisting of two non-linear differential equations was obtained by developing the equivalent scheme of selected generalized coordinates and by performing the necessary mathematical transformations. This system describes the vibrations of the sugar beet topping mechanism in the longitudinal vertical plane. The optimal design and kinematic parameters of the sugar beet topper mechanism front-mounted on the tractor were determined by means of our own software and numerical solution of the differential equation system, which allows the reduction of mentioned vibrations

Investigations of the Dynamics of a Four-Element Machine-and-Tractor Aggregate

The paper presents a dynamic model of four-element machine-and-tractor designed on the basis of a combined soil-cultivating-sowing aggregate and a tractor with an articulated frame. The pseudo velocity of the first tractor half-frame was considered a generalised coordinate. The control impact upon the tractor was obtained by means of the bending angle of the tractor half-frames. The trajectories and movement speeds of the aggregate elements were calculated as a function of time for the driving mode along a straight-line path and the tractor movement according to the harmonic control law. By means of the measuring system, trajectories of the aggregate elements were obtained. It was established that the movement trajectories of the aggregate elements represent a complex assessment parameter of the mathematical model adequacy of the aggregate plane-parallel movement. There was found a regularity of the aggregate turning radius and the bending angle of the tractor half-frames