No 1 (2020)

Articles

Stabilization of the load mode of the internal combustion engine of the tractor through the use of a hybrid power plant

Rakov V.A., Litvinov V.I.

Abstract

It is known that the main costs in the operation of agricultural machinery are associated with fuels, lubricants and spare parts. The attempts are made to improve the performance of the machinery by reducing operating costs. This happens due to the increasing competitive requirements of the final product. For example, during daily operation of the MTZ-82 tractor, the most widespread tractor in the Eurasian Economic Union, when delivering feed and driving a feeder for a year of operation, just the fuel costs will amount to approximately 20 % of its initial cost (300 thousand Russian rubles). In addition, to ensure the tractor is in a working condition, it will require spare parts and other consumables for another hundreds of thousands of rubles in Russian currency. The diesel engine used in tractors idles most of the time and, as a result, is underloaded. In peak loads, on the contrary, more power is required and, accordingly, it is necessary to create a sufficient energy reserve. This in turn inevitably leads to increased fuel consumption. Hence, there is a need to stabilize the load mode of the engine, reduce its operation in underloaded modes and at maximum loads. This problem can be solved in various ways. One of them is a combination of a diesel engine and an electromechanical transmission. Such power plants are usually called combined or hybrid. Among several typical structural schemes in agricultural machinery, hybrid power plants of the mild hybrid type and full hybrid type were most widely used. The presented methodology will allow to analyze the proposed schemes of a hybrid power plant, assess possible losses and calculate the required engine power, and ultimately determine a more rational scheme for the given operating conditions. The authors also presented the results of a comparative calculation of the required power of an internal combustion engine of hybrid power plants.
Tractors and Agricultural Machinery. 2020;(1):3-9
pages 3-9 views

The study of the performance of a diesel nozzle on mixed fuels with insufficient low-temperature properties

Plotnikov S.A., Buzikov S.H., Kozlov I.S.

Abstract

Today, the properties of rapeseed oil, affecting the fuel supply processes in a tractor diesel, are density, kinematic and dynamic viscosity, as well as surface tension. The purpose of this research is to expand the limits of the fuel base of tractor diesel engines by using mixed fuels with insufficient low-temperature properties. In this regard, the determination of the optimal composition of mixed fuel for the operation of the fuel supply equipment of tractor diesels is a very urgent task. To solve this problem, theoretical studies were conducted to determine the effect of rapeseed oil additives on the properties of mixed fuels, as well as testing a diesel fuel injector. As a result of the studies, the dependences of the viscosity of the mixed fuel, the pressure of injection beginning, the tightness of the locking cone, and the hydro-density of the spray nozzle on the addition of rapeseed oil with an additive were determined. Based on theoretical calculations, the value of the viscosity of mixed fuel that meets the requirements of the manufacturer's specifications for fuel injectors is obtained. An analysis of the experimental dependences showed that with an increase in the proportion of rapeseed oil in mixed fuel from 0 to 100 %, there increased: the pressure at the beginning of injection from 20,88 to 21,08 MPa, the time until a drop of fuel comes off from the nozzle of the spray from 18 to 104 s, and pressure reduction time decreased from 5,2 to 11,3 s. Tests shown that for all mixed fuel compositions, the injection start pressure, tightness on the locking cone, spray water density and spray needle mobility meet the requirements of GOST 10579-2017, however, the spray quality corresponds to mixed fuel compositions with rapeseed oil up to 60 %. Thus, the use of the proposed fuel compositions will improve the low-temperature properties of mixed fuels with additives of rapeseed oil, and thus expand the fuel base of tractor diesels.
Tractors and Agricultural Machinery. 2020;(1):10-16
pages 10-16 views

Justification of a new technical solution for the development of potato harvesting machines

Alatyrev S.S., Kruchinkina I.S., Alatyrev A.S.

Abstract

Currently used potato harvesters with bar and screening screening devices, based on intense impact on the soil layer, significantly injure the potato tubers in the process of separation from the soil. In addition, structural elements operating in an abrasive environment without lubrication wear out intensively, prone to sticking to plant residues. In this regard, proposed and justified theoretically constructive-technological scheme of the new potato harvester, containing a frame with support wheels, a sieve consisting of longitudinal bars, kinematically connected by a rear part by a drive shaft by means of eccentric pins, located in antiphase with respect to each other, mounted by the front part with the guide on the axis with rollers and fixed rigidly through one to the shares, as well as from the beaters located in the slots between the rods. The paper analyzes the kinematic mode of the machine. As a result, it was established that the layer of soil on the separating rods is cyclically subjected to bending, compression and stretching. This contributes to its intensive crumbling and screening between the rods. For more efficient operation of the machine, it is recommended to adopt the angular velocity of rotation of the eccentric shaft of the separating device ω1 = 10...15 s-1.
Tractors and Agricultural Machinery. 2020;(1):17-23
pages 17-23 views

Study of a device for implementing diesel engine fuel supply skipping

Harisov D.D., Gajsin E.M.

Abstract

The article discusses the problem of increasing the fuel efficiency of diesel engines at low load and idle modes by turning off the cylinders. The method is one of the effective ways to increase fuel economy in these modes. But its inherent disadvantages do not allow to fully obtain fuel economy. The method of skipping fuel supply is presented, which consists in the fact that when the diesel engine switches to low load and idle modes, the fuel supply stops not in the same cylinder, but in all cylinders alternately. To implement this method of regulation, the diesel fuel system must allow the skipping of individual cycle feeds. This is only possible with electronic fuel control. Many currently operating diesel engines are equipped with electronically controlled fuel supply systems, however, due to design features, it is not always advisable to reconfigure the system to work with a fuel supply skipping. In this regard, the most interesting are electronically controlled devices (valves), which can be implemented in a standard fuel supply system. The practical interest have the ring-type valves, where the split ring itself performs the function of the power and locking element, and the cylindrical surface serves as a socket for the ring. A fuel flow skipping device based on an electromagnetic-controlled valve of the annular type is proposed. Theoretical studies have made it possible to optimize the shape and size of the valve, in particular, to improve performance with a small section of the ring, to reduce the opposing forces and to obtain a large power of the electromagnet. Bench tests showed the efficiency of the proposed device with different numbers of skipped fuel supplies.
Tractors and Agricultural Machinery. 2020;(1):24-29
pages 24-29 views

The experimental evaluation of the effectiveness of the regenerative drive of the working bodies of a combine harvester

Dubovik D.A., Pershukevich N.P., Pribyl'skij V.I., Baran O.A., SHantyko A.S., Vyrskij A.N.

Abstract

In grain self-propelled harvesters, when performing technological processes of mowing grain crops and cleaning grain, the oscillating working bodies are used. Having advantages in carrying out technological processes, they are a source of alternating load caused by the inertia forces of the masses of the elements of these organs and leading to the dynamic loading of their drives and vibration of the combine frame. One way to overcome these shortcomings is the recovery of energy in the drives of the working bodies. The authors of the article have proposed a method that, due to the use of a regenerative drive, can reduce its dynamic loading, as well as reduce the vibration of the machinery frame. Based on the proposed method, a method for balancing a single-knife cutting apparatus has been developed. For an experimental assessment of the legitimacy of the theoretical developments underlying the presented technical solution, a prototype drive of oscillating working bodies was developed and manufactured, which allows simulating the operation of traditional and regenerative cutting machine drives. The experimental studies of the prototype model confirmed the validity of the theoretical background of the developed method for balancing a single-knife cutting apparatus and allowed to deepen the theoretical and empirical knowledge in the field of regenerative drives. An analysis of the results of experimental studies of prototype samples showed that, compared with a traditional drive, a regenerative drive can reduce the load and vibration activity by more than 1,5 times. The factors affecting the efficiency of the regenerative drive of a single-knife cutting device have been established, which include: the presence of higher harmonics in the law of motion of the knife provided by the rolling washer mechanism, resonance phenomena in the drive of oscillating masses and structural elements of the header, simplification of the design of the drive of the recuperator counterweight.
Tractors and Agricultural Machinery. 2020;(1):30-38
pages 30-38 views

Vector analysis of the kinematic characteristics of two-joint cardan shaft

Kotov A.V.

Abstract

Using the example of a two-joint cardan shaft, a method is presented for analytically describing its kinematic characteristics based on the use of vector analysis, which the author has been successfully using for a long time in designing various lever mechanisms. The proposed vector analysis method is based on the spatial coordinate transformation method. In this method, to get a vector rotated in space, you must specify the source vector, the vector around which the rotation will be performed, the angle of rotation itself and if a new vector length is required. In the proposed vector analysis method for describing the kinematics of a two-joint cardan shaft, the coordinates of the points of the axes of the cardan shafts and the radius of the cross are the basic geometric data. The adequacy of the results of kinematic analysis by the vector method was tested in two ways. In the first case, the values obtained by the vector method for the coordinates of all the characteristic points of the two-joint cardan shaft were compared with the corresponding coordinates of the characteristic points of the identical parametric model built in the three-dimensional CAD package. In the second case, the angular velocities and accelerations of the shafts of the two-joint cardan shaft obtained by the vector method were compared with the analytical dependencies given in the well-known literature sources. As a result of all the checks, it was concluded that the proposed method of vector analysis of two-joint cardan shaft is absolutely adequate. The developed method of vector analysis of the kinematic characteristics of two-joint cardan shaft can be further used to find the vector-loads (forces and moments) acting in the cardan transmission elements in order to conduct subsequent strength calculations. The proposed vector analysis method of two-joint cardan shaft is universal and can be successfully applied to describe the kinematics not only of two-joint cardan shaft, but also for polycardan transmission of any complexity.
Tractors and Agricultural Machinery. 2020;(1):39-48
pages 39-48 views

Substantiation of rational constructive parameters of the chisel subsoiler for autumn tillage of stubble field to tractors of the 8 drawbar category

Polishchuk Y.U., Derepaskin A.I., Laptev N.V., Komarov A.P.

Abstract

The article presents the results of theoretical and experimental studies to substantiate a rational distance from the point of connection of the implement with the tractor to the axis of rotation of the support wheels and the distance from the axis of symmetry of the frame in the horizontal plane to the point of connection of the hitch with the frame in the vertical plane. Theoretical studies have established that the stability of the working bodies during the process of soil sowing (soil hardness of at least 6 MPa) will be provided at a distance from the point of connection of the implement with the tractor to the axis of rotation of the support wheels equal to 4,3-5,3 m. The distance from the axis of symmetry of the frame in the horizontal plane to the point of connection of the hitch with the frame should be in the range 0-300 mm. During experimental studies, the state of the soil at a processing depth of 0-30 cm corresponded to the following average indicators: soil hardness 4,8 MPa, humidity 16,3 %, bulk density 1,39 g/cm3. The tests in the farm conditions were carried out at the travel speeds of 7,2; 8,9 and 10,0 km/h. The depth of tillage with the chisel was 28,5-29,7 cm, with the disc tillage tools 8,8-9,5 cm. At the working width of 8.8 m and travel speed of 8,9 km/h the working capacity of the aggregate per 1 hour of the basic time is 7,8 ha, draught resistance is 82,3 kN. The fuel consumption per hour was 76,2 kg, while 9,7 kg is consumed per hectare. The power consumed to overcome the draught resistance of the implement is 203,5 kW. The stability of the technological process in terms of tilling depth and draught resistance indicates the validity of the selected constructive parameters of the chisel subsoiler for autumn tillage of stubble field.
Tractors and Agricultural Machinery. 2020;(1):49-55
pages 49-55 views

The results of experimental studies of the root crop chopper

Shukhanov S.N., Dorzhiev A.S., Kosareva A.V.

Abstract

An experimental setup was made to create a machine for the purpose of grinding root crops with specified dimensions. The object of study is the functioning of the root crop chopper. Experiments and analysis of the data obtained were carried out using the theory of experimental design. When conducting a statistical analysis, comparisons of the two groups on quantitative scales were based on the non-parametric Mann-Whitney test. To describe the quantitative indicators, the mean value and standard deviation in the format «M±S» were used. To use the ability to predict some target quantitative variable based on several independent variables (factors), the multiple regression analysis method was used. The value of static significance was fixed at a probability level of error of 0,05. Statistical data processing was performed using the Statistica 10 and SAS JMP 11 application software packages. One of the main indicators of the quality of a machine is its energy intensity. As a result of processing the experiments, regression dependences and response surfaces were obtained, which reflect describing the processes that take place. According to the results of the regression modeling of the response «Energy intensity of the process E, W», it can be concluded that the most important combination of factors is the set: «Root and tubers diameter», «X4⋅x5» and «X4⋅x4». The model has a high level of forecast quality (R2 = 98 %).
Tractors and Agricultural Machinery. 2020;(1):56-61
pages 56-61 views

The use of simple teeth surfaces in non-conjugate gears

Timofeev B.P., Kovalevich A.V., Sachkov M.Y.

Abstract

Nowadays, the dominant place in the practical use of rotational motion transmission mechanisms has conjugate, and, in particular, teeth gear. Reproduction of high-order surfaces used in conjugated gears requires the use of sophisticated and expensive equipment. An alternative to such gears are approximate gears. The paper analyzes the possibility of using gears with non-conjugate engagement when using the simplest surfaces - a plane, a cylinder and their various combinations, as the working surfaces of the teeth. It is shown that with the simplest outlines of the teeth it is possible to get the high-quality transmission. The results of mathematical modeling of approximate gears are presented. A comparison of the studied gears with the involute one in terms of the cyclic error of the tooth frequency is given. The resulting values of the position error and the gear ratio are minimal and, in particular, for multi-row gears can be negligible. The insensitivity of approximate gears to the errors in wheel manufacturing and gear assembly is shown. Several gear configurations and various motion transmission configurations are provided. Prospects for the use of gears with the simplest outlines of the teeth are associated with the lack of need for complex gear-processing equipment and the possibility of manufacturing and repair in the field conditions. In addition, such transmissions are indispensable for experimental installations because of the possibility of rapid changes in parameters that do not require significant time for design and manufacture.
Tractors and Agricultural Machinery. 2020;(1):62-70
pages 62-70 views

Improvement of the methods of operational management reliability of technical systems in agriculture

Lebedev A.T., Seregin A.A., Arzhenovskij A.G.

Abstract

In the process of operation, the interval coefficient of readiness of technical systems in the agro-industrial complex should correspond to the strategy of trouble-free operation in the interval of time required to perform the required amount of work, or technological operation in the production of agricultural products. Improving and maintaining the reliability of technical systems in the agro-industrial complex is largely determined by the perfection of methods and reliability management system. Currently, a lot of models of reliability management have been developed, which allow to quantify the results of management and purposefully influence these results in the required direction. The issues of reliability management at the stages of design and serial production of technical systems are most fully developed in them and much less - at the stage of their operation. However, the management of the reliability of technical systems at the stage of their operation, which consists in maintaining the level of reliability of the devices provided by the manufacturer, implemented by means of justification, appointment and execution for the available or specified time of the complex of measures for their technical and technological maintenance, is no less important task. The structural scheme of management of reliability of technical systems in agro-industrial complex, including strategic management of reliability, carried out at the stages of design and production of technical systems and operational management of reliability, carried out at the stage of operation of technical systems in the real conditions of agro-industrial enterprises. Introduced the concept of «Functional operational diagnosis» - a complex of measures, directed on increase of reliability of technical systems and their elements due to technology and means of rapid diagnosis, redundant from the point of view of classical domestic strategies of maintenance and repair of machinery, but is necessary to ensure absolute reliability interval. The block diagram of functional operational diagnostics of technical systems in the agro-industrial complex and their elements is developed.
Tractors and Agricultural Machinery. 2020;(1):71-76
pages 71-76 views

Tasks and problems of the revival of domestic agricultural engineering

Kolchin N.N., Zvolinsky V.N.

Abstract

The problems of supplying the population with quality products in sufficient quantities still remain in the focus of attention of all mankind. The soil and climatic features of our country pose the most difficult tasks for the mechanization of the cultivation, harvesting and preservation of the products obtained in a highly competitive environment. At the same time, the role of agricultural machinery is increasing not only as mechanical assistants, but also as tools that directly affect the means of production - the soil, plants, microorganisms, crops, and the environment. Therefore, the issues of technical level and quality of work of mechanization can be compared in complexity only with the choice of cultivation technology. Hence, the ever-increasing pace of implementation of automation, robotization, hydraulic and electrification of structures. Digital controls are increasingly used for machine controls. However, the changes taking place in our country significantly slow down the pace of implementation of these trends. Imports of foreign technology, in most cases carried out without the appropriate regional tests, with orientation only on advertising indicators. As a result, there is a growing understanding that the import of foreign equipment does not replace domestic agricultural engineering in all cases. A paradoxical situation arises - the more we import imported equipment, the more the demand for domestic standardized and unified developments grows. The nomenclature of agricultural machinery is due to the natural features, multi-zone and multi-pattern agriculture, a large number of different crops, differences in the technologies of their cultivation, variability of working conditions, etc. It is formed by periodic «machine systems» based on the complexes and sets of machines within the relevant technologies. In addition, a number of long-term state programs for the stabilization and accelerated development of the industry are being developed and implemented on the basis of promising resource-saving technologies and criteria for the innovative development of the national economy. The domestic agricultural machinery industry must have a scientific and technical system for creating and maintaining new equipment - the GSKB network, mainly at the leading manufacturers and special design bureaus by types of main machines and their mass aggregates. The STC network of SHT «VISHOM» - GSKB - SKB - KB needs to be revived at an accelerated pace with the preparation of relevant personnel for it, taking into account the experience of active research and production activities of the special complex of the VISHOM.
Tractors and Agricultural Machinery. 2020;(1):77-81
pages 77-81 views

A model for determining the operating costs of machine-tractor units for sowing, taking into account the duration of work and the size of the area

Starcev A.V., Alushkin T.E., Romanov S.V., Storozhev I.I.

Abstract

The article presents an analysis of the impact of the performance of machine-tractor units on the duration of technological work in crop production. The results of a survey among specialists of agricultural organizations of the Tomsk region, indicating a significant influence of the technical factor in general on the productivity of machinery (33,9 %), are presented. An interpretation of the survey results is given and, based on these data, a rationale is formulated to create a methodology for optimizing the technological parameters of sowing units. The aim of the work is to develop a methodology for optimizing the technological parameters of sowing units, compiled on the basis of different models of tractors by the criterion of minimum operating costs. The scientific novelty is the introduction of the indicator «unit operating costs of the sowing unit», which explains the choice of a tractor of a certain traction class taking into account the used sowing machines. As a result of the calculations, the fact of a nonlinear dependence of the productivity of the sowing units on the installed tractor power was confirmed. For the given conditions (sowing days, sown area), various sowing units were selected and the costs of their operation were calculated. As a result of mathematical modeling, the operating costs of various sowing units are determined in standard and reduced tractor engine power options. To assess the specific operating costs of the sowing unit for processing a unit area, an appropriate indicator and its graphical interpretation are proposed. The dependences of the indicator of specific operating costs on the power of the tractor engine with its installed (nominal) value and reduced to 15 % are obtained. If the engine power meets the set value, the optimal sowing machine and tractor unit according to the criterion of minimum specific operating costs is the unit based on a wheeled tractor with an engine power of 125 kW, which corresponds to 2 or 3 drawbar category. It was found that a decrease in tractor engine power by 15 % from the installed one, due to a change in its technical condition, provides an increase in unit costs for sowing by 28,4 %.
Tractors and Agricultural Machinery. 2020;(1):82-87
pages 82-87 views

The way to improve the quality of the application of lime fertilizers

Sedashkin A.N., Kostrigin A.A., Milyushina E.A.

Abstract

The article presents some results of comparative tests conducted at the N.P. Ogarev Mordovia State University of the unit when introducing pulverized calcareous fertilizers with serial and experimental centrifugal working body. The influence of the uneven distribution of fertilizers along the width of the capture unit was obtained. The observations showed that upon mechanical spreading (for example, a centrifugal disk) of fertilizers with different particle size characteristics, large particles fly further under the influence of the initial velocity acquired during the falling of the disk, and small (dusty) particles fall on the soil near the center of the disk. Therefore, it is proposed to use a differential feed, both mechanical and pneumatic, for the introduction of ameliorants. Many studies examine in detail the influence of kinetic energy on a fertilizer particle when it leaves the centrifugal working body, and there is insufficient research on the influence of the kinetic energy of an inclined air flow on the additional dispersal of dispersed particles and on the uniformity of their application. To test this hypothesis, the experiments to determine the uneven distribution of fertilizers along the width of the aggregate when introduced by the experimental and serial working body were conducted. For experiments, the base model of the MVU-6 spreader was taken. On this machine, a pneumocentrifugal working body developed by authors was installed in place of the serial working body. As experiments showed, the experimental working body allowed to increase the width of the capture from 6 to 10 m and reduce the uneven distribution of calcareous ameliorants on the total width of the capture from 45,0 to 25,0 %. Overlapping adjacent passages for the experimental setup with half or more of the total working width allows to obtain uniform distribution up to ± 25 %, and an increase in the working speed from 1,5 to 2,0 m/s at a working width of 8 m leads to a deterioration in the uniform distribution of fertilizers on the surface of the field.
Tractors and Agricultural Machinery. 2020;(1):88-91
pages 88-91 views

This website uses cookies

You consent to our cookies if you continue to use our website.

About Cookies