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.
Journal section: MECHANIZATION IN AGRICULTURE
Justification of the improved technological process and development of the construction of the cleaner of root tubers from impuritiespg(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 surfacepg(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%.
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%.
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 cropspg(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.
This study was carried out to determine the dust concentration values formed in the environment during the use of hazelnut threshing machines, determine the effects on the employees, and reveal solution suggestions to reduce the dust concentration value. The most distinctive difference that distinguishes Turkish hazelnut varieties from other country varieties is that the fruit husks of Turkish varieties are long and tightly wrap the fruit, and threshing is required. During the threshing process, dust particles (fine soil, sand, husk and grass particles, Etc.) are dispersed intensively from the husk-blowing unit of the machine and the air outlet of the fan. A handheld particle measuring device with a particle size range of 0.3…5 μm was used to determine the dust concentration emitted from the machine to the atmosphere during the blending process. As a result of the measurements, dust concentrations of PM1 (1 μm), PM2.5 (2.5 μm), and PM5 (5 μm) were determined in μg/m3 air. The dust levels formed in the environment during the hazelnut threshing machines were compared by considering the dust concentration threshold limit of 4 mg/m3 air specified in the occupational health and safety legislation and regulations.
Theoretical and experimental study of the operational reliability of small-sized agricultural machinery operating in the mountainous conditions of Adjarapg(s) 57-60
Adjara, with its diverse natural conditions, relief and soil and climatic features, is one of the distinctive regions of Georgia, dominated by mountainous terrain, steep slopes and small areas. Accordingly, the complex mechanization of agricultural processes by mobile agricultural machinery is inappropriate and therefore small-sized agricultural machinery is used. This technique works in difficult soil-climatic and dynamic conditions, it is constantly affected by significant dynamic forces, high humidity, abrasive particles in the environment, mountainous terrain and others. All these factors cause intensive wear and decrease in the reliability of the working bodies of machines. It should be noted that single and complex indicators of the operational reliability of small-scale mechanization equipment operating in the mountainous conditions of Adjara have not been studied and their establishment will contribute to the rational organization of technical service of small-scale mechanization machines.
The reliability indicators of motoblocks and motor cultivators, such as the probability of failure-free operation, time between failures, the failure rate parameter, the average resource, the coefficients of technical use and readiness, are considered, adequate probabilisticstatistical mathematical models are obtained, the least reliable nodes, types of failures are identified, and a set of measures is outlined to improve reliability
This paper presents the basic principles of building a mathematical model of trailer harvesting, for which an example of a trailed combine harvester is considered. To develop this mathematical model, all the components are given, starting with the assembly of an equivalent scheme of plane-parallel movement of this harvesting unit, which consists of a wheeled aggregate tractor of classic layout and trailed behind the combine. And behind the combine is attached a cart for the harvest. Differential equations of relative motion of the collecting unit are compiled and solved on the basis of the Lagrange equation of the second kind.
Analysis of physicochemical and operational performance of petroleum and alternative motor fuels showed that their lower heat of combustion can differ significantly. However, the heat of combustion of fuel-air mixtures of these fuels differs slightly. Therefore, the assessment of energy and fuel-economic performance of the engine during its operation on different fuels is proposed to do the calculation method for the consumption and heat of combustion of fuel-air mixtures. According to the developed method, engine power and fuel consumption during engine operation on biodiesel, biomethane and petroleum diesel fuel were determined. To determine the heat of
combustion of fuel-air mixtures, the lower heat of combustion of fuels was used. Fuel-air consumption was determined by engine displacement and crankshaft speed. The tests show that the highest power and lowest fuel consumption of the engine running on petroleum diesel fuel and slightly worse values of the engine running on biodiesel. The gas engine with spark ignition converted from diesel running on biomethane shows the lowest indicators.
A methodical approach to the evaluation of vibrations of passengers of electric bus 6K2 in the task of selecting a general layout and suspensionpg(s) 45-49
An improved methodological approach to assessing the vibration levels of passengers of a mobile car during its virtual tests on mathematical models in the design problem of choosing the parameters of the general layout and suspension of electric bus 6K2 is considered. When considering human vibrations in a machine, it is advisable to determine them taking into account the structure of the human body. Harmless vibration levels for different parts of the body are significantly different in amplitude and frequency. Vibration levels affecting a person be determined on the basis of two-mass and four-mass models of the human body, as recomended The International Organization for Standardization ISO. A computational experiment of parametric optimization of the suspension according to the proposed approach and criteria-rules allows you to find the required rational suspension parameters of the machine. The following considerations allow to carry out structural optimization of the layout of the passenger compartment of the electric bus, considering the effect of occupancy of the passenger compartment and schemes for random placement of passengers across the passenger compartment.
Cleaning of root crop bodies from impurities during their digging from the soil is a complex and energy-consuming technological process. Therefore, the development of new types of cleaners of root crop pile from impurities, in particular spiral type cleaners, allowing to intensify this process and improve the quality of cleaning is a step to successfully overcome this problem. The paper presents a study of the technological process of sifting soil particles during the cleaning of the heap of root crops with a spiral-type cleaner. In particular, a calculated mathematical model was constructed, which reflects the movement along the spiral of the body cleaner (soil particles) of variable mass. Using the differential equation of volume change, the differential equation of mass change, i.e. the mass that is sifted through the coils of the spiral cleaner was compiled. Based on the theoretical study, it was found that many factors influence the intensity of soil sifting on the spiral separator – the initial mass of particles, the design dimensions of the cleaner, frictional properties of the surface, angular parameters of body placement on the spiral surface and angular velocity of the spiral roller rotation, and the intensity of these parameters has been studied. Using PC, graphical dependences of the intensity of soil sieving on the angle of rotation of the cleaning spiral when changing the angular velocity of the spiral were constructed.