• Trial model of a combined machine for inter-row tillage in perennial crops

    pg(s) 19-21

    At the Institute of Soil Science, Agrotechnologies and Plant Protection – Sofia (IPAZR – Sofia) an experimental model of a machine for combined soil treatment in permanent plantations has been developed. The machine is designed to work using technology without turning the soil layer and at the same time at a sufficient depth for fruit plantations. Tests were conducted in laboratory and road conditions to verify the capabilities of the structure. Deficiencies have been identified, as a result of which the work must continue.

  • Assessment of machines in reliability test

    pg(s) 16-18

    The necessity of using the apparatus of mathematical statistics to obtain high reliability of the results of the evaluation of thereliability indicators of agricultural machinery in comparative tests is justified.
    Two models of plant protection machines have been tested and the main numerical characteristics of the indicator production till failure of the failure-free feature have been obtained.
    The application of the Student’s criterion for proving the statistical significance of the difference in the tested reliability indicator is justified.

  • Examining of Water Distribution Uniformity in Drip Irrigation Systems: A Review of Various Recent Studies Worldwide

    pg(s) 6-8

    This study was aimed to evaluate water application uniformity of emitters for drip irrigation systems. The data was obtained from our previous studies or some researches in the world relevant to watering performance of drippers. In results, reasons of poor watering performance of drip irrigation systems were inadequate design and mainly incorrect management of systems. Following recommendations were proposed for better distribution of water for crops / plants; 1- correct design and management of the systems, 2- applications of physical, chemical, and biological for preventing dripper clogging, 3- timely control of system components particularly emitters, and 4- participation of farmers courses about agricultural water management.

  • Mechatronic system for controlling the sowing rate

    pg(s) 3-5

    Maintaining the set sowing rate is important to obtain an accurate number of plants and guarantee good yields. This can be achieved by mechanical systems – variators and gear reducers or by electric drive (mechatronic systems). The object of the present work is the device of a mechatronic system for setting and maintaining the sowing rate when sowing cereals. Dependencies are derived for determining the transfer function in the control mechatronic system. Its principle and structural schemes are presented

  • Application of polymer composites in moving joints machines of the fat and oil industry

    pg(s) 94-96

    The expediency of using parts made of polymer composites in moving joints of machines in the oil and fat industry is shown. The use of experimental moving joints provided an increase in the resource from 500 hours to 1080 hours minimum. Diagnostics of experimental moving joints revealed that some of them have signs of transfer of the composite material to the steel shaft. This is explained by the following factors: the presence of the transfer effect and operation at high temperatures of 140 °C. The operating modes of the equipment are maintained. Most of the experimental parts made of polymer-composite material are in a running-in state, as wear has not been recorded in them.

  • Justification of the improved technological process and development of the construction of the cleaner of root tubers from impurities

    pg(s) 91-93

    The paper presents a new construction of a root ball cleaner from impurities, consisting of five wave-shaped working spirals, which are given oscillatory movements with appropriate amplitudes and frequencies in the longitudinal-vertical plane. It allows to considerably expand a working zone of separation of the potato heap arriving on clearing, and it will promote its better dispersion on a working surface of the cleaner, more intensive destruction of ground clods, and consequently, improvement of sifting of ground and vegetative admixtures and decrease of blocking of working spirals. All this ultimately increases the productivity and quality of the new root crop cleaner from impurities. To carry out experimental studies of the new construction of the cleaner of potato roots from impurities, we have developed a laboratory setup, which allows you to test and justify the basic constructional and kinematic parameters of this cleaner. The process of cleaning of root crops from soil impurities and plant residues indicated cleaner is due to the movement of the heap coils cantilevered spiral springs, which rotate at a certain angular velocity, and the oscillatory motion of the springs themselves, arising from the deflection of their longitudinal axes. In this case, soil and plant impurities are sifted through the separating gaps and coils of spirals, and the bodies of potatoes are transported by coils of spirals in the direction of the unloading conveyor. Calculations of the required power for the drive of the laboratory unit showed that it does not exceed 1.3 kW.

  • Study of the oscillation processes of a front-mounted haulm harvester when it moves on the inequalities of the ground surface

    pg(s) 86-90

    In the article the calculated mathematical model of oscillations of the haulm-harvesting machine frontally attached to a wheeled tractor is constructed. A nonlinear differential equation is obtained, which describes the oscillations of a haulm-harvesting machine in the longitudinal-vertical plane during the movement of its pneumatic copying wheels along the unevenness of the soil surface. On the basis of the received theoretical results rational constructive and kinematic parameters of the front-mounted hoisting machine which provide decrease in amplitude of the specified fluctuations are defined. So, at translational speed of movement of the haulm-harvesting unit V = 3.0 m∙s–1, the amplitude of oscillations of the rotor of the haulm harvester decreases in 1.2…1.5 times in comparison with height of roughnesses of a surface of the field o h = ± 0.04 m. At the amplitude of oscillations of the lower ends of the knives of the rotary cutting device up to 4 cm, the loss of the tip does not increase significantly. However, when increasing the values of the amplitude of these oscillations to 7 cm or more, the loss of the branch increases significantly and the maximum values of which exceed 12%.

  • Theoretical investigation of the removal of halfrums from sugar beet root heads

    pg(s) 75-78

    Removal of the haulm from the heads of sugar beet to the roots during their harvesting (cutting the main mass) or separation of its residues (when finishing the heads) is a complex technological process associated with either a significant loss of sugar-bearing mass (low cut), or not complete removal of residues (high cut), which significantly degrades the quality of root crops. Therefore, ways to find a complete removal of haulm and its residues from the heads of root crops require research and development of such devices capable of performing this process qualitatively. However, first it is necessary to determine theoretically and experimentally the basic initial conditions under which high quality indicators will be achieved, and losses of sugar-bearing mass during cutting the haulm will be minimal, with the remaining haulm being as small as possible (or they will be absent at all). This paper theoretically and experimentally investigates and determines the loss of sugar mass and remnants of the bud on the heads of sugar beet roots during the separation of the bud and its remnants. It is established that in the interval of working heights of a cut which is equal to 20 … 60 mm deviation of theoretical calculations from experimental does not exceed on the average 1%.

  • Study of grinding corn stalks by a roller grinder with different knives positioning

    pg(s) 71-74

    The work is devoted to the study of the efficiency of the technological process of grinding corn stalks with a rollergrinder. Developed and manufactured roller-shredder, the design of which provides for the possibility of direct (left) and inverted at 1800 (right) installation of the cutting edge of the knives relative to their direction of rotation.
    It was noted that in the range of less than 50 mm the percentage of crushed stems in the cat with the right location of the knives was 20% higher than with the left layout of the knives. The total value of the percentage of crushed stem particles in the range of 0-100 mm for the right was 83.6%, for the left 81.9%. In the range of 101-150 mm the share of crushed stems in the roller with the left arrangement of knives was 11.0%, with the right 7.7%, in the range of 151-200 mm, respectively, 4.6% with the left, and 6.0% with the right, in the range over 201 mm, with the left 2.6%, with the right 3.1%.
    The average relative to the total weight percentage of crushed stem particles from the total weight of the fraction was for the range 0-50 mm – 20.3% for the right and 12.8% for the left, the range 51-100 mm – 23.8% for the right and 31.3 % for the left, range 101-150 – 14.8% for the right and 18.2% for the left, range 151-200 mm – 24.1% for the right and 16.8% for the left, in the range over 200 mm – 4 , 7% for the right and 20.9% for the left, respectively.

  • Ways to grow the efficiency of the harvesting and transport technological machine complex for grain crops

    pg(s) 66-70

    The article provides a rationale for an improved technological process for transporting grain from combine harvesters (GH) by a semitrailer-dump truck (STT), combined for field work with a tractor and a saddle trailer. As a result of the analysis, it was found that the minimum specific duration of harvesting and transport operations in the field is achieved when using a semi-trailer with a tractor to work with minimal time spent on the formation of transport units using a semi-automatic fifth wheel coupling.
    We offer a technical solution, which consists in the temporary redistribution of the grain mass in the back of the STT during its transportation in the field. At the same time, the rear wheels of the STT are partially unloaded and do not compact the soil, and the saddle trailer, equipped with wide-profile low-pressure tires, takes on additional load without significant soil compaction.
    The use of STTs operating by the semi-shuttle method in two parts: in the field and on the road section, increases the productivity of the harvesting and transport complex in 1.5 times.