1,721,125 research outputs found
Mathematical model of the movement of a potato body along the surface of a spiral separator
Full text linkThe potato is grown in over one hundred countries spread over all latitudes, with the most diverse climatic conditions, from the areas near the Arctic Circle to the southern end of the South American continent. The potato is an irreplaceable component of the food tradition of many countries and is the most cultivated species after cereals (wheat, rice and corn). The authors set up and developed a new clod and rubbish spiral separator for potatoes, which is protected by the patent of Ukraine. The operation modalities of this machine are briefly described in the paper. The aim of this study is the development of a mathematical model concerning the movement of a potato body along the surface the spiral separator. In particular, equations are found for determining the coordinates of the position of a potato tuber on the surface of a spiral separator depending on the parameters of the spiral (spiral line) and the size of the tuber. Furthermore, the velocity of tuber movement in the stream formed by the surfaces of two neighboring spirals in the direction of the horizontal, vertical and longitudinal axis are determined. The results of this study will be used in the future to analytically considering the dynamics of movement of a potato tuber on the surface of a spiral separator, taking into account the conditions that exclude its damage
The theory of sifting the soil mass when cleaning potatoes on a spiral separator
Full text linkThe removal of soil and impurities is an important problem when harvesting potatoes. and the main reason for this problem is due to the modalities employed to carry out the potatoes mechanical harvesting. The equipments currently implemented on potato harvesters do not always allow to obtain high levels of soil and impurities separation, mainly due to the gluing of the moist soil to the surfaces of the separating organs. The authors have developed a spiral separator of soil clods from potatoes heaps, patented in Ukraine. The purpose of this paper has been to analyze the theory of sifting the soil mass when a spiral separator is used. A mathematical model of the motion of an elementary body along the spiral surface of a potato heap separator has been built. The numerical solution of the model has highlighted that the lowest angular speed (10 rad s-1) of the cleaning rollers allows the greatest amount of sifted soil mass. Field tests carried out confirmed that the developed spiral separator is able to perform the task achieving meaningful values of the efficiency of separation and heap purity. Further field and laboratory tests will be executed in order to improve the set up mathematical model
Research into engineering and operation parameters of mineral fertiliser application machine with new fertiliser spreading tools
Full text linkThe output capacity of the machine for top spreading the soil with solid mineral fertilisers can be raised by means of increasing its working width. The authors have carried out field trials and field experiment investigations with the MVU-8 granulated mineral fertilizer spreading machine equipped with two prototype units of the centrifugal fertiliser spreading tool, in which the axis can be tilted at different angles to the vertical line. In accordance with the results of the completed investigations, it has been established that setting the axial tilt angle of the centrifugal operating device in the fertiliser spreading tool within the range of 25–30° provides for achieving a productivity of the combined tractor-implement unit for applying mineral fertilisers at a level of 35–40 ha per working shift hour. The best performance in the fertiliser application with regard to both the working width and the fertiliser placing distribution uniformity is ensured at angles of inclination of the disc in the fertiliser spreading tool with respect to the horizontal plane within the range of 25–30°. At these angles, the uneven distribution of the fertiliser over the working width is equal to 19.2%, the uneven distribution of the fertiliser along the unit’s line of travel is equal to 8.9%, while the deviation in the dosage of the applied fertilisers from the set value is equal to 7.5%
Reduction in Energy Consumption by Mitigation of Cultivation Resistance Due to the New Fallow Harrow Concept
No full textOne of the best precursors for winter wheat is fallow. Its application aims to solve two important tasks: preserving and accumulating soil moisture and weed control. The authors of this paper have designed a new modular harrow for fallow tillage, which can work stably at a depth of 5–6 cm tillage while maintaining and even accumulating soil moisture. This article describes a method designed by the authors for a reasonable selection of the design parameters concerning the working devices mounted inside the new harrow, such as their length and working width, as well as the angles of vertical inclination ((Formula presented.)) and horizontal deviation ((Formula presented.)) of blades, depending on the accepted depth of the upper soil layer loosening. To reduce the soil tillage resistance of the harrowing unit resulting in a reduction in the tractor fuel consumption, the value of the inclination angle (ε) of its vertical blade should be chosen so that the corresponding change in the value of the deflection angle of the horizontal blade (γ) complies with the constrain of the product of tangents of these angles. Moreover, preference should be given to choosing the value of the angle ε with the subsequent determination of the angle γ value. It is demonstrated that proper use of the new type of harrow assures fuel savings and decreases carbon dioxide emissions even if fossil fuel alone is used. Additional reduction of CO2 emission can be achieved when biofuels are used as a replacement for fossil ones
Kinematic discrepancy between driving wheels evaluated for a modular traction device
No full textOne of the options for increasing the versatility of tractors is to use them as a part of a modular traction device (MTD). The model MTD-100 consists of a power-generator module and a technical module. The power-generator module is a tractor with a nominal traction force of 14–16 kN. The technical module is an additional axle with wheels driven by the power-generator module ground speed power take-off. For agricultural implements whose traction resistance does not exceed 16 kN, only the tractor is used. When the technical module is attached to it, the traction force of the entire MTD-100 increases. The MTD-100 makes it possible to tow implements with a traction resistance of up to 30 kN. Since the rear wheels of the power-generator module are connected by a locked drive to the wheels of the technical module, there is a kinematic discrepancy Kv between them. Our studies have established that the greater the Kv value, the greater is the inflation pressure of the tyres on the wheels of the MTD-100 power-generator and technical modules. If it is necessary to ballast the MTD-100 technical module, the inflation pressure of its tyres should be increased. This makes it possible to maintain the value of the kinematic discrepancy coefficient Kv unchanged. Replacement of the standard 16.9R38 tyres with15.5R38 tyres on the rear wheels of the power-generator module and the wheels of the technical module of the MTD-100 requires practically no adjustment to their inflation pressure
A mathematical model of the cutting process of the sugar beet leafy tops without a tracer
Full text linkA method is proposed for the assessment of the effect of the soil surface irregularities upon the loss of mass and the residues of the leafy tops during the sugar beet harvesting process. A new mathematical model is constructed and dependences of the loss of mass and the top residues are obtained depending on the distribution parameters of the soil surface irregularities. The established dependences of the loss of the root crop mass and the residues of the leafy tops on the root crops depending on the statistical distribution parameters of the soil surface irregularities and the cutting height of the tops without a tracer allowed justification of an agrotechnically acceptable level of mathematical expectation of the soil surface irregularities and the cutting height of the root crops without a tracer
A mathematical model of the plane-parallel movement of an asymmetric machine-and-tractor aggregate
Full text linkTechnological peculiarities of cultivation and harvesting of some agricultural crops make it necessary to use asymmetric machine-and-tractor aggregates. However, for the time being there is no sufficiently complete, analytical study of the steady movement of such machine-and-tractor aggregates. This necessitates the development of a theory of stable movement of the aggregates which would allow choosing their optimal kinematic and design parameters. On the basis of the results of mathematical simulation, a system of linear differential equations of the second order is obtained describing transverse displacement of the center of masses of the aggregating wheeled tractor and turning of its longitudinal axis of symmetry by some angle around the indicated center of mass, as well as the deviation angle of the rear-trailed harvester from the longitudinal axis of the tractor at any arbitrary moment of time. This system of differential equations can be applied for numerical calculations on the PC, which will make it possible to evaluate the stability of the movement of the asymmetric machine-and-tractor aggregate when it performs the technological process
Experimental research into uniformity in spreading mineral fertilizers with fertilizer spreader disc with tilted axis
Full text linkImproving the efficiency in the work process of mineral fertilizer dressing is a topical problem in today’s agricultural industry. The authors have developed a design of the fertilizer spreading tool with a tilted axis and carried out field experiment investigations on it. It has been established by the results of the investigations that the non-uniformity in the spreading of mineral fertilizers along the line of their departure from the fertilizer spreading tool with a tilted axis is most strongly affected by the disc rotation frequency. The obtained results provide for selecting the optimum parameters and modes of operation for the tool under consideration in the situation, when it is installed in fertilizer placing machines. Also, it has been established that increasing the spreading disc rotation frequency in such a tool from 600 to 800 rpm results in the growth of the effective range of mineral fertilizer spreading along the placing line at a level of 10.5 m. Increasing the disc’s angle of inclination to the horizontal plane to 20o results in the rise of the effective fertilizer spreading range at a level of the 48th tray (24 m) inclusive as well as the increase of the distance between the tool and the tray that contains the maximum share of the spread fertilizers (5.1%) to 24 trays (12 m). At a constant rotation frequency of the disc in the tilted-axis fertilizer spreading tool, in all its kinematic modes of operation, an increase in the angle of its disc’s inclination to the horizontal plane results in the rise of the indices representing the distribution of the mineral fertilizers over the trays along the line of their placing. The width of the mineral fertilizer spreading can be controlled by adjusting the rotation frequency of the disc in the tilted-axis fertilizer spreading tool, when it is set at an angle to the horizontal plane, similar to how it is done in state-of-the-art fertilizer placing machines with horizontally positioned discs in their centrifugal spreading tools. The rotation frequency of the disc in the tilted-axis fertilizer spreading tool has the most significant effect on the coefficient of variation incidental to the distribution of the mineral fertilizers along the line of their placing
Experimental study of the implement-and-tractor aggregate used for laying tracks of permanent traffic lanes inside controlled traffic farming systems
No full textTraffic-induced soil compaction is a serious drawback of modern agriculture. However, controlled traffic farming (CTF) systems, which have been adopted worldwide, are useful strategies of lessening this problem. In CTF systems, the crop zone is clearly separated from the permanent traffic lanes (PTL), which are used exclusively for the movement of the machine-and-tractor aggregates. The CTF systems are implemented both with and without the use of the GPS systems. When navigation-aid is not used, the first positioning of the PTL tracks is an essential operation, in which the aggregate intended for this task must perform a sufficiently straight movement. This paper reports the assessments concerning the PTL tracks laid by an experimental aggregate, which consisted of a four-wheel drive tractor and a tillage implement operating in the “push” mode. This aggregate formed tracks with a sufficiently small dispersion (10.30 cm2) and a fairly low (not more than 0.09 Hz) frequency of their fluctuations in a horizontal plane. Furthermore, during the tests, a rather close positive correlation between the bearing angle φ of the tractor and the turning angle α of its driven wheels was registered and the maximum value of the related correlation function was 0.9. Moreover, the phase (time) shift between the disturbing torque and the response to it by the tractor operator did not exceed 0.75 s. The use of the proposed aggregate allowed laying tracks with a depth of 21.2 ± 0.3 cm and vibrations in a longitudinal vertical plane, whose dispersion was not more than 2 cm2 and was concentrated in a fairly narrow frequency range from 0 to 1.78 Hz
Experimental investigation of the energy-power characteristics of the cleaner of the root crop heads from the haulm
Full text linkSugar beet haulm is a valuable animal fodder or a raw material for biogas generation. The most important indicator of the work of the cleaners is their energy-power characteristics since they affect the amount of the operating costs and the economic performance, on the whole. The purpose of the experimental investigations was to determine the nature of the change in the torque moment and power on the drive of the vertical cleaner, tractive power, as well as the draft resistance of the root crop head cleaner. Experimental investigations were carried out under the field conditions. In order to study the draft resistance of the working tool, the tensometry method was used. Dependences of the change in the tractive power and the torque moment upon the speed of the movement of the experimental root head cleaner from the haulm residues have been determined. The rational modes of operation of the cleaner are: the forward speed of its movement, equal to 1.5 m·s-1, the angular speed of rotation of the cleaning tool must be within 60.0...63.0 rad·s-1. The completeness of cleaning the root crop heads from the haulm residues by the experimental cleaner is 95.9 %, the degree of throwing of the haulm and the plant residues beyond the row is 99.96 %
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