bluuebunny/crossref_metadata_2025 huggingface dataset:
To the determination of heating temperature of an object of thermal influence in solar power plants
Authors: Kupreenko A. I , Komogortsev V. F , Isaev Kh. M , Chenin A. N , Shkuratov G. V
Published: April 2022

The aim of the paper is to find the mathematical dependence of heating temperature of the object of thermal influence of solar power plant on its usage time under conditions of variable external factors. The object of thermal influence can be, for example, the wet grain meant for drying, the fresh air for natural ventilation systems of livestock houses, the water to heat up etc. The variable external factors are the weather conditions needed for right operating of solar power plant, in particular the solar activity throughout the day. The object of this research is the grain heating process in drum solar dryer. It is known that grain heating above a required temperature may reduce its viability. Therefore, in this case, forecasting of temperature for grain heating is of great importance for ensuring the quality of drying as a technological process. The time of effective use of solar energy in the drum solar dryer for grain heating process is about seven hours per day for conditions of the Bryansk region. In the basis of analysis of available experimental data, it is accepted that there is a directly proportional dependence between temperatures of the drying agent (the warmed-up atmospheric air) and grains during drying process. The differential equation of heat-transfer between grain and drying agent is solved using the methods of variable separation and substitutions. The dependence of the temperature of the object of thermal influence of solar power plant on its usage time under conditions of variable external factors is obtained. The analysis of the obtained exponential dependence shows that temperature of the object of thermal influence is generally defined by its reference temperature, weight and a thermal capacity, heating duration, heat-transfer coefficient.
Measurement of tractive effort at the drawbar of tractor in aggregate with mounted agricultural machine
Authors: Parkhomenko S. G , Parkhomenko G. G
Published: April 2022

Dynamometer test is used in scientific researches and in operation of tillage machines. It is necessary for completing of tractor units, for setting of rate of production and fuel consumption, and also for ensuring the control of technical condition of tractors and agricultural machines and correctness of their regulation. Under operating conditions, dynamometer test consists in determination of a horizontal component of tractive resistance of tillage machines. According to these data, it is possible to give the general comparative assessment of power consumption of various machines. There are methods of dynamometer test with the use of dynamometer frames, and also with the use of load cells, which embed into linkages and pins of the three-point hitch. All these methods have several disadvantages. Main of them is the use of several force sensors, which provides the lack of possibility of direct measurement of the total forces and raw errors of determination of the sought quantities. The aim of the research is to develop a device for dynamometer test of mounted agricultural machines, allowing to make the necessary measurements using one force-measuring sensor, without design changes of tractor and mounted machine. Presented dynamometer automatic coupler is made on the basis of two standard automatic couplers with a force measuring sensor mounted between them. Experimental studies showed the operability of the presented dynamometer automatic coupler. The proposed device is universal, it can be used with any tractor and any mounted agricultural machine and does not require design changes of tractor and agricultural machine. The application of one force measuring sensor enables the measurement with high precision.
Estimation of use efficiency of automatic transmission of «torque converter - coupling - gearbox» type
Authors: Kotiyev G. O , Vasilyev V. V , Gorbatovskiy A. V
Published: April 2022

The paper describes a mathematical model for wheeled vehicle with automatic transmission of «torque converter - coupling - gearbox» type. In order to compare this type of transmission and mechanical one with same number of gears and ratios, optimal characteristics of torque converter for considered vehicle are selected. The paper presents the results of simulation of wheeled vehicle moving for both variants of gearbox in conditions involving variable resistance and moving velocity assigned by driver. Efficiency of hydromechanical transmission use is estimated.
Influence of the number of undercarriage axles of mobile agricultural machinery on the depth of track
Authors: Shilo I. N , Orda A. N , Romanyuk N. N , Nukeshev S. O , Kushnir V. G
Published: April 2022

The deterioration of soil properties as a result of repeated impact of undercarriage of tractor units leads to the reduction in crop yields. Increasing of soil density caused by the impact of movers of tractors and agricultural machines results in increase of soil hardness by 2-3 times. To forecast the indices of undercarriage impact on soil taking into account the type and condition of soil fertility, as well as to determine the promising ways of improvement of undercarriages’ designs and their agro-ecological characteristics, it is necessary to substantiate the regularities of accumulation of repeated soil settlements under the impact of undercarriage. It is also necessary to determine the regularity of rise of settlement deformer under repeated soil load. The deformation at each subsequent soil loading is followed by stress rise in the contact zone as compared to the previous one. This is due to the increase in load intensity under repeated deformations, in particular due to the reduction of contact area of wheels with soil during repeated passing of tracks. This paper observes some dependencies which allow to determine the deformation of soils with different physical and mechanical properties under various operating conditions and parameters of undercarriages of tractor units. For the soil with high degree of compaction, the depth of track should be reduced by increasing the number of axles of undercarriage. For the moist soil with low degree of compaction, the movers with larger width of wheels should be used to reduce the depth of track.
Development of combined working organ for graded subsurface tillage
Authors: Bozhko I. V , Parkhomenko G. G , Gromakov A. V , Kambulov S. I , Rykov V. B
Published: April 2022

Nowadays the trend of development of combined units and devices for implementation of specified technological processes is widely spread. The use of combined working organs for graded subsurface tillage allows to reduce the energy and labor costs and to improve the technological process. Based on the comparison methods and monographic survey of existing designs of working organs, their shortcomings when using in arid conditions are revealed. It has been established that in such conditions it is advisable to apply graded subsurface tillage. The analysis of designs of working organs for graded tillage is performed, it allows to establish the advantage of curved elements for surface tillage. A number of shortcomings of subsurface cultivating working organs that have been revealed during years of researches allows for the conclusion about the prospects of replacing blades on curvilinear rippers for surface tillage. The data of content of valuable soil aggregates as a percentage of absolute dry chernozemic soil are given. Based on the analysis of the data, it is established that layer structure can be improved through the use of an element for surface tillage to the depth down to 16 cm in design of chisel working organ. The expediency of mounting of elements for deep and surface tillage on the same tine for graded subsurface tillage is proved. The scheme of a combined working organ is proposed: a chisel for deep tillage and a curvilinear ripper for surface tillage are mounted on its tine, which provides the required crumbling of layer.
Technology of accelerated processing of rough plant raw material and waste
Authors: Reznik E. I , Kartashov S. G
Published: April 2022

Analysis of domestic and foreign experience in obtaining of high-protein feed additives allowed to identify the most important technology and equipment for these purposes. It was revealed that traditional methods of preparation of these feed additives mostly include single-stage chopping and mixing. This is not enough for obtaining of homogeneous granulometric composition of high-quality mixture. The equipment in use has high energy and metal intensity. As a result of the study, innovative equipment is proposed, and physical models are made. The article suggests to use new effective methods of three-stage chopping of plant raw material and its transportation, as well as food waste grinding and two-stage mixing in aqueous media for obtaining homogeneous product. It is recommended to manufacture the equipment in modular construction, that allows to compose the series-produced technical means with new less energy-intensive ones for use on flow line. The main parameters of equipment operating modes are determined. The developed technical means involve the fundamentally new working organs, that provide three-stage chopping of low-value plant materials, their transportation and two-stage mixing with the use of adjustable blades. Such processing of raw material improves the performance characteristics of equipment, and allows to increase the production profitability in comparison with best foreign and domestic equivalents. For supplying of control systems with innovative technologies and equipment, it is recommended to use computer control system, created on the basis of mechatronic systems. Creation of equipment control system and application of new methods of chopping and mixing of rough plant and food waste allow to increase the performance of entire line by 35%, reduce the material and energy intensity by 34-40% with a payback period of 9 months.
Loading of tractor on drawbar test when pulling force is directed at the angle
Authors: Gorodetskiy K. I , Lavlinskiy A. M , Alendeev E. M
Published: April 2022

Foreign methods of tractor drawbar testing do not allow to evaluate the performance capabilities of movers and drive system in general with a number of other common characteristics, because of using a tar makadam as a surfacing. Methods of tractor testing used in Russia provide the experiments on real soils and aiming to a wide variety of the country's natural environments. But even these tests do not give a full picture of performance of a machine-tractor unit. Tractor is a multipurpose machine that aggregates with a variety of implements that have a wide range of draught resistance. Therefore, during aggregation it is necessary to load tractor’s axles efficiently. Tractor ballasting increases the rolling resistance force that affects negatively on the propulsive efficiency. In most cases, the front ballast is not removed and remains on a tractor permanently, which increases the fuel consumption. There is a search problem for technical solutions that would optimize the tractor performance without using front ballast. For solving this problem, it is proposed to improve the methods of drawbar testing by directing of pulling force at the angle. If this angle is controlled, it is possible to load a front axle without ballast. In this case, the rear axle is loaded, and its trailing weight is decreased. Additional loading of the rear axle is adjusted by adding ballast weights to the rear wheels or on a cross bar of lower arms. For each case of loading by pulling force, it is necessary to provide the proper rational weight distribution to achieve the highest propulsive efficiency.
Basics of safe drying of seeds
Authors: Golubkovich A. V
Published: April 2022

In seed-production farms, the temperature of drying agent is often limited by the maximum permissible temperature of heating; the simultaneous moisture removal is 3-6%; seeds are dried to a moisture content that exceeds the normal one by 2-3%; the layer is stirred several times during drying process. All of this increases the process cost and could lead to crop losses. The paper analyzes the essential factors influencing the safe drying of seeds in dense layer. It is found that along with the maximum permissible temperature of heating, account must be taken of the rate of dehydration, the specific surface of seeds, the heat transfer coefficient and the unevenness of moisture of basic material and of a dried-up one. The estimation of parameters for safe drying of seeds is carried out on the basis of mathematical models and well-known empirical expressions of the heat resistance and maximum permissible moisture removal. The article proposes the calculation of drying agent temperature that ensures the complete safety of the process, for breeder seeds also. Permissible temperature of drying agent is calculated by the expression that takes into account the specific surface of grain, the heat transfer coefficient, the heat of vaporization and the coefficient that depends on the permissible rate of dehydration, as well as the maximum permissible temperature of seeds heating. The maximum height of the layer of seeds being dried without stirring depends on the speed of drying agent, the diameter of grain, the porosity of layer, the mass transfer coefficient and the moisture content of drying agent before and after the layer. The maximum permissible temperature of seeds heating should be calculated according to the formula of S.D. Ptitsyn, but the maximum humidity of 10% of weighed portion should be used as a basis.
The use of term «sintered powder frictional material»
Authors: Il'yushchenko A. F , Leshok A. V , Rogovoy A. N , Sharipov V. M
Published: April 2022

Powder frictional materials are widely used in frictional couplings and brakes of tractors, automobiles and agricultural machinery. Today various terms are applied for these materials, such as: "ceramic-metal frictional material", "powder frictional material", "sintered frictional material". The term "ceramic-metal frictional material" is the most frequently used in scientific literature. Long-term experience of development and use of frictional materials indicates that the listed terms are not exact. There is the following definition of metal ceramics. It is the artificial material having heterogeneous composition of metals and alloys with nonmetals (ceramics). In modern sintered powder frictional materials the quantity of nonmetallic components could range from 10 to 30% of volume, including graphite, oxides, nitrides, sulfides and other components. For example, the volume of the most widespread composition of MK-5 sintered powder frictional material based on copper contains 23% of graphite that does not interact with the bronze base. According to earlier formulated definition of "ceramic-metal frictional material", the graphite should be qualified as ceramics, which is absolutely incorrect. When studying a microstructure of MK-5 sintered powder frictional material based on copper, it is established that graphite is uniformly distributed across the section surface. It does not interact with the components of frictional material and has the form of isolated particles. Therefore, it is incorrect to define this material as metal ceramics. For these materials it is suggested to use the term "sintered powder frictional materials" that indicates their application and production technology.
Loading conditions of pistons of internal combustion engines and causes of crack formation on combustion chamber edge
Authors: Gots A. N , Glinkin S. A
Published: April 2022

In order to develop the methods for assessment of durability of pistons of tractor diesel engines, it is necessary to conduct the research of causes of failures in their operation, in particular crack formation on the edge of combustion chamber. Tractor engines operate in transient regimes due to periodic changes of control organ position and resisting moment when tractor performs agricultural, logging and other works. In transient regimes, the stress-strain state of piston varies in time, which leads to the formation of fatigue cracks on the edge of combustion chamber. The paper reviews the studies on regularities of change in the rate of propagation of fatigue cracks on the edge of combustion chamber of tractor diesel engine. The peak values of heat flows passing through the heat-absorbing surface of piston head in transient regimes exceed by 2.5 times the same values in steady-state regimes. According to the researches, for the 4ChN 11/12.5 tractor diesel engine stress intensity on the edge of combustion chamber caused by temperature gradients equals to 92-98 MPa, and exceeds more than by 2 times the stresses caused by gas pressure forces in cylinder (38-42 MPa). With the increase of engine forcing, the edge of combustion chamber becomes a local concentrator of thermal stresses, that leads to elastic-plastic deformations of cyclical pattern and microdefects. Stresses appearing on the edge of combustion chamber under rapid change of loading modes typically exceed the values of yield stress of piston material. This leads to the appearance of plastic deformations on the edge of combustion chamber. The analysis of causes of crack formation on the edge of combustion chamber of piston of a tractor diesel engine shows that when assessing the durability of piston, the whole range of indicators and parameters of the engine should be taken into account.
Influence of ploughshare design and welding reinforcement on the hardness of its nose part
Authors: Denisov V. A , Kozhukhova N. Yu , Orekhova G. V , Mikhal'chenkova M. A
Published: April 2022

The hardness of working surface of ploughshares is very significant for their abrasive wear resistance. Knowing this mechanical property is especially important for manufacturing and hardening of ploughshares, since their wear is not uniform. In this regard, the research problems include studying of hardness distribution in the most loaded nose part of ploughshare, depending on its design and on welding reinforcement as a hardening method. Ploughshares after reinforcement and ploughshares in as-delivered condition after their taking out of service are submitted as objects of the research. Reinforcement included bead welding in the area of share point perpendicularly to the leading edge with the pitch of 30-40 mm. The validity of results was provided by measurement of four parts on each object of research. The total number of tested ploughshares was eight. Hardness was measured with a mobile hardness gage. Measurement results were recorded on Rockwell hardness scale (HRC) with subsequent conversion to Brinell hardness (HB). It is shown that for ploughshares without hardening, the hardness distribution in considered part has the non-uniform character, that is caused by the non-uniformity of processes of recrystallization because of unequal thickness of walls in separate volumes of a product. The hardness values of ploughshares in as-delivered condition are not high (230 HB maximum) and cannot provide the proper abrasive wear resistance. The lowered value of hardness (175 HB) is noted on the deepening part of a ploughshare. Application of welding reinforcement increases hardness (by 200 HB on the deepening part), that is connected with manifestation of heat hardening due to the formation of hardening structures. Traces of reinforcing beads make positive impact on the increase in hardness, which contributes to the growth of abrasive wear resistance.
Rational choice of parameters of powered disk of a soil cultivation unit
Authors: Akimov A. P , Konstantinov Yu. V
Published: April 2022

The paper aims to show the advantage of solution of the non-formal problem of rational choice of parameters of powered disk of a soil cultivation unit when it is formalized as bi-criteria optimization problem in comparison with its formalization as one-criterion optimization problem. An earlier suggested mathematical model of interaction between disk and soil is used. This model allows to determine the driving force and power consumption required for disk motion in soil depending on the parameters determining its operating mode. The taken dimensionless parameters are: the kinematic coefficient equal to the ratio of peripheral disk speed to forward speed of soil cultivation unit, and the relative depth of disk equal to the ratio of its operating depth to its radius. The problem of rational choice of parameters of powered disk is formalized as optimization problems by the following criteria: the maximal driving force; the maximal efficiency coefficient of powered disk; the maximal driving force and efficiency coefficient; the maximal driving force and minimal power consumption for disk motion in soil. The solutions of these optimization problem are obtained. It is found that in the case of two bi-criteria problem statements the compromise curves are almost identical in the parameter plane. It is also shown that the advantage of formalization as bi-criteria optimization problems lies in the fact that it allows to find such values of parameters whereby the required driving force is achieved with maximal efficiency coefficient and minimal power consumption for disk motion in soil.
Influence of reinforcement of ploughshares surface on their thickness wear
Authors: Kozhukhova N. Yu , Sinyaya N. V
Published: April 2022

Wear intensity of working surface of a part is the major factor influencing its durability. To reduce the wear of parts of working organs of tillage machines, a number of processing methods of their hardening is created; one of them is welding reinforcement. The assessment of ploughshare thickness wear and of influence of its surface reinforcement on wear intensity is carried out. Ploughshares in as-delivered condition and ploughshares after reinforcement according to three processing methods are used as objects of the research. Wear of reinforcing beads height and wear of ploughshare thickness between them are determined. Attrition of the beads occurs unevenly along the length of sock because of the high pressure of soil on ploughshare sock. It is also necessary to consider the fan-shaped soil movement along the ploughshare sock. It is shown that reinforcing beads essentially slow down the abrasive wear of ploughshare thickness between them. That is related to the fact that riffles create the conditions for the formation of fluidized layer between them, and thereby less soil particles get into contacting area. The quantity of abrasive particles contacting with working surface and their pressure on ploughshare body are decreased. When attrition of welding bead is flush with working surface, the composite surface is formed; thereon the maximum hardness is observed, which contributes to the increase in abrasive wear resistance. Traces of reinforcing beads with high degree of hardness also have a positive effect. Due to breaking-in of surface and forming of composite surface, the wear intensity decreases.
Strategy for design improvement of a combine harvester
Authors: Ozherel'ev V. N , Nikitin V. V
Published: April 2022

Promising directions of design improvement of combine harvester by means of the maximal adaptation of algorithm of its impact on plants with different physical and mechanical properties are presented. The technological algorithm of work with grain heap is optimized. It is proposed to separate previously the light impurities directly in the stripper header, the rear wall of which should be equipped with inertial tilted-plate separator. The light impurities are removed along with excessive airflow from the stripper header, but heavier free grain and tailings remain inside. In the terms of design, such technical effect is achieved due to the fact that the separator is formed by a set of longitudinal plates mounted with overlapping and imbedding of greater part of the cross section of each of them into the body of stripper header. The cross section of the plate has a curved surface, and its concavity is oriented towards the rear wall of the body. Remaining grain heap (tailings and free grain) is subjected to the secondary separation on perforated bottom of grain conveyor. Elongated holes are made in bottom; they have a particular cross-sectional shape and are inclined from the motion direction of conveyor flights on acute angle. As a result, the awns of spikes do not catch hold of the rear edge of the hole, and climb up the angled surface to the level of bottom of grain conveyor. Implementation of set of these technical solutions in the design of modern combine harvester will increase its performance when stripping of standing plants with eliminating the possibility of free grain crushing by working organs of the threshing device.
Application of storage catalytic converters of nitrogen oxides for reducing exhaust toxicity of tractor diesel engines
Authors: Kaminskiy V. N , Loik A. V , Titchenko A. Yu , Alikin E. A , Nadareyshvili G. G , Shcheglov P. A
Published: April 2022

Reduction of harmful effects of agricultural machinery on the ecosphere is an important task; its solution requires extensive use of emission reducing devices. Compliance with up-to-date legal requirements causes the cost increase of systems of diesel exhaust gases aftertreatment. This applies especially the systems that require an additional reagent feeding into exhaust system. The cost factor determines the study aim that is the creation of prototype of alternative aftertreatment system for selected engine type with the possibility of rapid adaptation to other types of the same power class. The article considers the operating principles of a storage-type system of catalytic reduction of nitrogen oxides, the design features of the system for tractor engine. An important advantage of this system is the fact that there is no need for additional reagent. The experimental studies of converter prototype as part of series-production engine were conducted on the engine test bench. In addition, the tests of samples of catalyst bricks with different types of catalytic coating were carried out. As a result of testing and selection of optimal catalytic coating, the new fuel supply system with increased performance is obtained and the converter design recommended for agricultural machinery is modified. The storage catalytic converter system allows to reduce the nitrogen oxides emissions by 40-50 %. With such efficiency of the system, its cost is noticeably lower than the cost of the system of selective catalytic reduction. The proposed design allows to adapt the storage system to engines of any power class without change in systems and control algorithms. The optimal field of application of storage systems is determined.
Combustion and heat emission in the cylinder of tractor diesel engine operating on methanol-fuel emulsion
Authors: Likhanov V. A , Lopatin O. P , Romanov S. A , Paturov A. V
Published: April 2022

The article is devoted to the application of methanol-fuel emulsion as alternative motor fuel in the 4Ch 11.0/12.5 tractor diesel engine. The maximum concentration of methanol in the emulsion is determined; it should not exceed 25% to prevent the uneven diesel engine operation and misfiring in the cylinder. According to the study results of stability and the primary tests of engine, the optimal composition of methanol-fuel emulsion is accepted for 4Ch 11.0/12.5 tractor diesel engine: 25% of methanol, 0.5% of S-5A succinimide, 7% of water, 67.5% of diesel fuel. The results of experimental studies of influence of methanol-fuel emulsion on the indices of combustion process and the characteristics of heat emission of the 4Ch 11.0/12.5 diesel engine are given. In order to determine and optimize the main parameters of diesel engine operation on methanol-fuel emulsion, the bench tests including the full range of regulating, loading and speed characteristics were carried out. The values of combustion process indices and heat emission characteristics of diesel engine operating under nominal mode are determined: the maximum temperature of the cycle increases by 16.2% and equals to 2580 K; the maximum pressure increases by 0.4% and equals to 8.54 MPa; the severity of the combustion process increases by 74.5% and equals to 1.251 MPa/degree; the angle corresponding to the ignition delay period increases by 36.4% and equals to 30 degrees of crank angle change; the heat emission speed increases by 2 times and equals to 0.177; the heat emission value at maximum temperature increases by 12.6% and equals to 0.789; the heat emission value at maximum pressure increases by 14.7% and equals to 0.688.
GENERALIZED TRACTION INDICATORS OF AGRICULTURAL TRACTORS
Authors: Gorodetskiy K. I , Parfenov A. P , Lavlinskiy A. M
Published: April 2022

In 1972 G.G. Kolobov and A.P. Parfenov published the monograph «Traction characteristics of tractors». The monograph generalized numerous results of field tests of domestic wheeled and caterpillar tractors of that time, conducted by machine testing stations in various soil and climatic zones of the USSR. This had an impact on formulation and study of the issue of determining of tractors slippage, and in general, the study of their traction characteristics. Averaging of the experimental data was carried out according to the formulas and coefficients developed by the authors of the monograph. The obtained dependencies, hereinafter referred to as traction characteristics of tractors, establish the dependence of the coefficient of usable traction (specific traction force on the hook) on the slipping of tractors of various types on different soils. By now, the concept of the role of the studies in research of the interaction of a wheel and track with the surface has changed. The standards have been introduced to limit slipping of agricultural tractors, considering the negative impact of their propulsors on the soil. There is a need to clarify the terminology used earlier in order to unify the same meaning terms used in different, but related technical disciplines. Objectives of work are: rethinking of previous research results and assessing their relevance; distinction between the physical meaning and concepts of the traction coefficient and the coefficient of usable traction (specific traction force on the hook); determination of traction capabilities of wheeled and caterpillar tractors on natural agrotechnical and asphalt-concrete surfaces, considering current slippage limitations. It was proposed for the purposes of engineering calculations in assessing traction performance of tractors to use as a traction coefficient of various propulsors its value corresponding to the maximum slipping on the appropriate agro-technical background or dry concrete. It is also found that the limitations on slipping of tractors on metal caterpillars are overstated on all soil backgrounds, since they rather characterize the «stop» mode of the tractor, than the beginning of the unstable operation of the engine. The parameters of traction characteristics of 4x4 wheeled tractors require correction based on statistical replenishment with the initial data on traction tests of such tractors having a layout that considers the increased role of the front drive axle in creating the tractor pulling power. For 4x2 tractors traction characteristics are at the same time characteristics of traction performance of individual driving wheels (tires). Therefore, having such data on all available driving tires of different dimensions, it is possible, at the development stage, to determine traction properties of newly created different variants of machines, including all-wheel drive.
VARIANTS OF TWO-COUPLE GEAR SHIFTING ORGANIZATION ON TRACTORS
Authors: Alendeev E. M , Kryuchkov V. A
Published: April 2022

In recent years, we can see trend of increasing tractor transport and operating speeds, which is also accompanied by increasing of gears number in manual transmissions. Increasing of gears number in Powershift transmissions is achieved by using in gearbox construction a few operating ranges. Every range and every gear of such gearboxes are switched by separate friction clutch that gives opportunity to organize gear shifting without power interruption in all tractor speed range. However, such technical solutions lead to appearing gear shifting, requiring of pressure control in four friction clutches at once (two-couple gear shifting): two gear clutches and two range clutches. This article is dedicated to the questions of two-couple gear shifting process organization in agricultural tractor gearboxes. These questions had required to design mathematical model of this process in Matlab Simulink software. Modelling was implemented under conditions that transmission control system and engine control system had opportunity of data exchange between themselves, which allowed to define the load torque value, acting on engine, and to control engine speed. A few variants of two-couple gear shifting up and down organization were modelled and compared in parameters of clutch wear. The modelling results show that simultaneous high gear clutch and high range clutch slipping during gear shifting gives the same oncoming clutches accelerated synchronization as during gear shifting with engine control.
WHEEL ROLLING RADIUS WITH ELASTIC TIRE
Authors: Kopotilov V. I
Published: April 2022

The rolling radius of the wheel is considered as a result of normal and circumferential deformations of its pneumatic tire, caused respectively by the normal load and the torque applied to the wheel. Consideration of the normal deflection of the tire enabled the value of the rolling radius of the driven wheel to be represented as a function of the axial load per wheel and the radial rigidity of the tire. To assess the adequacy of the developed model, the example of the 26°-2° tire used in trucks is used to calculate the kinematic radius for different values of the normal load. Analysis of the calculation results shows that the kinematic radius of the driven wheel decreases linearly with increasing normal load. This is in good agreement with the results of previous experimental studies. When considering the action of torque, it is considered that it causes a tangential (circumferential) deformation of the tire, i.e. its twisting, as a result of which the rim of the wheel makes a certain turn relative to its periphery. In this case, this rotation of the rim is not accompanied by a longitudinal displacement of the axis of rotation of the wheel itself. Since the torque breaks the single-valued relationship between the linear and angular velocity of the wheel, this is reflected in the kinematic radius of the wheel. Based on the dependence of the twist angle and torque, an analytical dependence of the rolling radius on the algebraic magnitude of the torque and the torsional rigidity of the tire is established. Calculation of the rolling radius of the wheel, carried out according to this formula, shows that when the torque is applied, a linear decrease in the rolling radius occurs, and when the braking torque is applied, on the contrary, its linear increase is shown. Such a change in the rolling radius completely agrees with the results of experimental studies of various types of pneumatic tires.
SPECIALIZED MEASURMENT SYSTEM FOR EXPERIMENTAL RESEARCH OF SUSPENSION SYSTEM LOADING CONDITIONS OF A HIGH MOBILITY TRACKED VEHICLES
Authors: Dubin D. A , Nakaznoi O. A , Chizhov D. A , Shmakov A. Yu
Published: April 2022

Loading of cushioning systems, as a condition caused by external influences and operating conditions, for highspeed tracked vehicles is determined by the characteristics of the track profile and motion modes. The most reliable estimate of the operational parameters of loading of parts and suspension assemblies is obtained experimentally using specialized measuring equipment. Within the conducted investigations for determining of kinematic and force parameters of loading of the elements of the cushioning system of a 14-ton tracked vehicle while driving on forest ground roads, a measuring system has been developed that realizes estimation of the loading characteristics by the angular position of the suspensions relative to the vehicle body. The measuring system consists of the hardware and software subsystems and records angles of twisting of torsion shafts as a function of time, with subsequent conversion and statistical processing of obtained data into the loading characteristics of elastic elements and suspension arms. According to received sample data, the software subsystem calculates average durability of torsion shafts in order to determine the most loaded suspensions. The advantage of the study is in relative simplicity and versatility. The hardware subsystem and rigging of the sensor equipment attachment do not require making changes in the construction of the undercarriage and allows to carry out investigations on most types of tracked vehicles. The software subsystem can be adapted for studies of loading of tracked machines of different weight categories. Reliability of the test equipment, as well as stability of formation and recording of measuring signals, was evaluated in polygon tests during motion of a tracked vehicle in difficult road conditions along 350 km tracks.
Substantiation of rational design parameters of variable pitch screw of an extruder
Authors: Priporov I. E
Published: April 2022

The analysis of effectiveness of methods of feed material (extrudate) preparation for feeding showed that the thermal method of its processing with the use of the KMZ-2 extruder is of most practical and academic interest. The studies carried out by V.V. Novikov showed that in the process of its formation the extrudate moves throughout the length of working chamber in the space between the screw flights and the inner surface of body, due to this the obtained mixture is heated and compacted. Based on the theoretical researches carried out by V.Yu. Frolov, it was found that the screw should have a variable pitch gradually decreasing with the movement of the processed feed material along its axis. During its movement the processed feed material is compacted and reaches the condition that allows to take the required shape in accordance with process requirements. Determination of rational parameters of variable pitch screw of extruder in areas for loading and pressing is a very important task on both practical and theoretical grounds. The aim of the article is to determine the rational design parameters of variable pitch screw of extruder in areas for loading and pressing of processed feed material on the basis of sunflower cake. At the initial stage, the design parameters of variable pitch screw of extruder in the area for loading of processed feed material were considered. At the next stage, the process of its compaction and compressing by means of screw was considered. As a result of theoretical researches of variable pitch screw of the KMZ-2 extruder, it was found that the density increasing of the processed feed material on the basis of sunflower cake is proportional to the decreasing of pitch of screw flight. The density of processed feed material depends on its physical and mechanical properties.
BRAKE OF THE FRONT DRIVE WHEELS OF THE TRACTOR "BELARUS"
Authors: Mel'nikov A. S , Bilyk O. V , Choy Ki-Yong , Mel'nikov A. A
Published: April 2022

The increase in the energy saturation of the new models of tractors "Belarus", as well as the mass of towed trailers and agro-technological tools that are mounted with them, required an increase in the efficiency of the tractor braking system. The purpose of the study is to increase the efficiency of the braking system of the wheeled tractor "Belarus MTZ" by creating wheel brakes for the front axle with minimal changes in its standard design. The developed drum brake with hydraulic drive of the front drive wheels of the tractor "Belarus MTZ-1221" does not require significant changes in the standard design of the front axle of the MTZ tractor and is adaptive to the anti-lock system, which operates on the basis of measurement and analysis of force factors. The design of the developed brake mechanism allows its adaptation to the anti-lock system, which operates on the basis of measuring and analyzing the forces that arise in the contact of the wheels of the front axle of the tractor with the supporting surface. The braking effect of the tractor "Belarus MTZ-1221" is provided by additional use of its coupling weight, which falls on its front axle. A set of design documentation for the drum brake for the front driving wheels of the tractor "Belarus MTZ-1221" was developed. The use of an additional traction weight of the tractor due to the wheel brakes of the wheels of the front axle of the tractor "Belarus MTZ-1221" will increase the efficiency of its braking, as well as increase the competitiveness of wheeled tractors produced by the JSC "Minsk tractor works". Bench tests confirmed the possibility of braking the calculated moments corresponding to the weight load on the front axle of the tractor "Belarus MTZ-1221". Consequently, the developed brake mechanism will ensure effective use of the tractive weight of "Belarus MTZ-1221" tractor.
INFLUENCE OF THE MACHINING OF EDGES OF BLADES OF TRACTOR TORQUE COVERTER IMPELLERS ON ITS CHARACTERISTICS
Authors: D'yachkov E. A , Fedyanov E. A
Published: April 2022

The production of impellers for hydrodynamic transmission of traction-transport machines is a complex technological task. Manufacturing of blades by punching with subsequent assembling and welding to toroidal surfaces ensures obtaining of specified angles of flow input and output, but does not provide an equidistant flowline of the working fluid in the intervane space, since the blades punched from sheet material have the same thickness along the length. Consequently, there is an increase in energy losses during the movement of the working fluid in the intervane channels and the coefficient of efficiency decreases. In the manufacture of impellers by casting provides the necessary spatial shape and variable in direction of flow thickness of the blade, but due to technological limitations, it is not possible to obtain the required thickness of the input and output edges. In addition, the forced turn cutting of blades eliminates the rounding of these edges. The required geometry of the edges can be achieved by their machining, but such an operation is undesirable due to its very high labor intensity. In large-scale and mass production, locksmithing operations should be excluded. In connection with said above, the question of level of influence of the impeller blade edges geometry on the characteristics of hydrotransmission is important. This article presents the results of experimental studies of the effect of machining of the torque converter impeller blade edges, manufactured by casting into the chill mold, on the efficiency coefficient and the converting properties of the hydrotransmission. The influence of blade edges machining is shown for each wheel separately and in aggregate. The conclusion is substantiated that the laborious operation of the metalworking of impeller blades' edges can be eliminated in the mass production of torque converters without significant degrading of the hydrotransmission characteristics.
POWER ANALYSIS OF DUAL-FLOW HYDROMECHANICAL GEARS
Authors: Sharipov V. M , Shchetinin Yu. S , Gaev S. V , Troshkin O. V
Published: April 2022

Dual-flow hydromechanical transmissions are becoming increasingly widespread in the designs of modern land transport and traction machines (tractors, automobiles and high-speed crawler vehicles). This happens mainly due to the desire to increase the efficiency of transmission, although the capabilities of dual-flow hydromechanical transmissions are broader. In order to select a dual-flow hydromechanical transmission scheme in relation to specific operating conditions, it is necessary to know the advantages and disadvantages of various schemes, their potential capabilities. The evaluation of the operation of each circuit can be made on the basis of their kinematic and force analysis. The article deals with 12 dual-flow schemes of hydromechanical transmission with a differential element in inlet and outlet with a mixed meshing of gears, the results of the power analysis are shown. For the estimated parameters of a double-flow hydromechanical transmission were taken: й - power ratio of a double- гмп flow hydromechanical transmission; ан - coefficient of loading of the pump wheel of the torque converter; ам -load factor of the mechanical branch of the closed transmission contour; аa - load factor of the solar gear of the three-link differential mechanism. For each of the schemes considered, analytical dependencies of the estimated parameters on the internal parameters of the hydromechanical transmission were obtained. For the parameters were used the characteristic k of planetary gear set, power йгт and kinematic игт gear ratios of torque converter. It is assumed that, at the boundaries of the range й = да and й = 0. Calculations have been performed to determine the parameters й , гмп гмп гмп ан , ам u аа for different values of k and й , results of which made possible to evaluate the potential transforming properties of the schemes of two-flow hydromechanical transmissions independently of the model of the used hydrotransformer.
DETERMINATION OF DIFFERENT METHODS OF TRACTORS DIESEL ENGINE PRE-START PREPARATION AT ITS STARTING CHARACTERISTICS
Authors: Bondar V. N
Published: April 2022

The article presents the results of an experimental study of a tractor diesel engine 4CHN15/20,5, equipped with various pre-start preparations tools, starting characteristics in a climate chamber at low ambient temperatures. The purpose of the study is the determination of different methods of tractors diesel engine pre-start preparation at its starting characteristics. Engine was sequentially equipped with electric starter system, together with the liquid starting preheater, and starter engine, which exhaust gases were used for oil heating in the crankcase of a diesel engine. On the engine was installed hydrotransformer that allowed to reproduce the actual conditions of engine operation more accurately. The study found out that engine with liquid starting preheater always starts at ambient temperature not lower than minus 30 ° C, but the pre-start preparation time is longer than one hour. Long warm-up time leads to discharge of even fully charged and warm batteries, which limits the start of diesel engine at lower temperatures. The use of a heater only for heating the coolant with heated oil in the diesel fuel tray with the exhaust gases of the heater slightly increases the rate of heating of the oil, compared with the use of water-oil heat exchangers, and has practically no effect on the speed of heating the coolant. Using the starter engine with forced coolant circulation and exhaust gases outlet for heating the crankcase and oil pump, allows to start diesel with cold batteries at minus 40 ° C during 30 minutes, that corresponds to the requirements of existing regulations. Results of the study were used for the modernization of production and development of new "Uraltrac" tractor diesel engines models and can be recommended for implementation in diesel engine companies.