Vol 88, No 3 (2021)


The development of tractor theory

Kut'kov G.M.


The article discusses the main developments of the author in the field of tractor theory, which were published at different times and in different editions of technical literature, including Tractors and Agricultural Machinery journal. These are traction dynamics of the tractor; modular energy technology facilities and block-modular tractor aggregation system; a method for optimizing the type of a tractor, as well as the combustion chamber of the D-75 engine implemented in production and GOST for testing agricultural tractors.
Tractors and Agricultural Machinery. 2021;88(3):6-19
pages 6-19 views

Experimental determination of the parameters of the characteristics of the seat suspension for automotive vehicles

Godzhayev Z.A., Lyashenko M.V., Shekhovtsov V.V., Potapov P.V., Dolotov A.A., Iskaliyev A.I.


This article describes the methodology and results of the experimental determination of the static-elastic damping characteristics of the Sibeco air suspension with a scissor guide mechanism. To implement the measurement procedure in laboratory conditions, bench equipment, including a compressor unit (power system) with a control pressure gauge, a measuring device (height gauge) for fixing linear displacements and reference weights, was used. The measurements were carried out stepwise at various fixed values of air pressure in the pneumatic elastic element, as well as in the presence or absence of a standard unregulated hydraulic shock absorber in the design of the considered seat suspension system. The whole process of obtaining the necessary parameters was held in accordance with the recommendations of the official domestic regulatory documentation, which establishes regulations on the general technical conditions for the design of seats for automotive vehicles. There were analyzed the obtained curves of the static characteristics of the seat suspension, including for the presence of a character of nonlinearity in different specific sections of the characteristic. Based on these results, the values of the parameters of stiffness, natural frequency and resistance forces (“dry friction” forces) were calculated during the compression and rebound strokes of the seat suspension for certain measurement conditions. Additionally, an assessment for the compliance of these parameters with the normative indicators of domestic technical standards was made. Also, the dependences of the instantaneous values of the stiffness of the considered air suspension of the Sibeco seat on deformation at various air pressures in the pneumatic elastic element were constructed and analyzed. Recommendations on the operation of this device for cushioning the seats of operators of motor and tractor equipment were given.
Tractors and Agricultural Machinery. 2021;88(3):20-26
pages 20-26 views

Compressor type engine brake

Verbitskiy V.V., Pogosyan V.M.


The accident rate in road transport remains unacceptably high, and in order to reduce it, it is necessary to take into account all the factors affecting this process. In this regard, the process of long-term braking deserves special attention, which negative processes require the creation of additional braking systems (retarder brakes) for vehicles operating in mountainous areas, primarily in the field of passenger transportation. Transmission retarder brakes that provide sufficient braking performance have a number of disadvantages that inhibit their use. Existing engine retarder brakes provide insufficient deceleration, and studies were carried out at the Kuban State Agrarian University (KubSAU) to improve their efficiency. After a theoretical analysis, the compressor brake mode was experimentally investigated. The increased pressure was created in the intake manifold and at the end of the compression stroke, air from the cylinder was released through a special valve back into the system, due to which the braking effect was created. The carried out experiments confirmed the possibility of a significant increase in the engine braking torque in the compressor brake mode, when both valves are closed - the exhaust after the exhaust manifold and the intake in front of the carburetor, and compressed air is supplied to the intake manifold at different pressures. Then the braking torque increases in comparison with engine braking by more than 3 times.
Tractors and Agricultural Machinery. 2021;88(3):27-30
pages 27-30 views

V-belt transmissions of agricultural machines

Balovnev N.P., Brovkina Y.I., Dmitrieva L.A.


The article is devoted to the analysis of design features and operating conditions of V-belt transmissions of agricultural machinery. When designing these gears, it is recommended to give preference to gears made according to an open circuit or with a tension roller located outside the belt contour, to avoid cross and semi-cross gears, as well as multi-pulley gears with crossing shaft axles. To make the wider use of more progressive types of belts. It was shown that the features of V-belt transmissions of agricultural machinery require clarification of the methods for calculating transmissions with progressive types of V-belts and automatic belt tensioning methods. It was noted that special attention should be paid to transmissions with multi-profile belts, which calculation has not been sufficiently reflected in domestic regulatory documents. The advantages of such belts are especially noticeable under variable and shock loading. Based on the analysis, the recommendations for clarifying the calculation of belt drives with multi-profile belts were given. Analytical dependencies are proposed for determining the value of the nominal power transmitted by one belt (stream) of a multi-profile belt, allowing automation of the calculation of V-belt transmissions of agricultural machinery. For gears with a tension or guide roller that add an extra (sometimes reverse) bend of the belt, it is proposed to determine the coefficient taking into account different degrees of bending on the pulleys according to a graph built taking into account the linear hypothesis of summation of damages. It is recommended to calculate gears with spring-loaded tensioning rollers and design tensioning devices for such transmissions using a special method that takes into account the belt tensioning method. At the same time, the required value of the pre-tension of the belt can be significantly reduced, which will have a positive effect on its resource, without losing the traction capacity of the transmission itself. Expressions are given for finding the value of the pre-tension of belts, both for gears with tension due to the elasticity of the belt, and for gears with spring-loaded tension rollers. Conclusions and directions for further research are formulated.
Tractors and Agricultural Machinery. 2021;88(3):31-36
pages 31-36 views

New technical device for traction tests of autotractor equipment

Habardin S.V., Polyakov G.N., Shukhanov S.N.


Advanced agricultural production is based on innovative scientific developments. The priority direction is given to the technical support of the agro-industrial complex, which makes it possible to significantly increase labor productivity in this sector of the economy, including the quality of products. Autotractor equipment is not an exception in this regard. Correct operation, which largely depends on its timely and qualified maintenance, including tests. Traction tests of machines make it possible to establish and test their traction characteristics, economy, high-quality performance indicators of the main units, as well as control systems. Proposed is a new technical facility (load support) for traction tests of autotractor equipment, which includes a base, a support-brake plate installed on it for placement on it of tested equipment and traction-brake device. The design of the support and brake plate is made in the form of a treadmill. The base is made with the possibility of mounting a traction-braking device in it and is made in the form of a recess with a small ledge in the bottom part. Traction-braking device consists of two posts and support boards made in the form of parallelepiped. Front post is secured from base front wall element. The rear post is mounted on a small ledge on the side of the rear wall of the base. The structures of the lower part of the front pillar, as well as the upper part of the rear pillar, are firmly attached to the spar by braces. To the left and to the right of the installed posts there are locks in the form of bars. The advantages of the new technical device for traction tests of autotractor equipment are expressed in the improvement of operational properties through reduced weight and size characteristics, simpler design, as well as a small amount of preparatory work.
Tractors and Agricultural Machinery. 2021;88(3):37-41
pages 37-41 views

Mathematical model of the cabin suspension system for grain and forage harvesters taking into account the dynamic properties of the supporting system

Sirotin P.V., Lebedinskiy I.Y., Zhileykin M.M.


The paper is devoted to the study of the vibrational state of the operator's workplace of a transport-technological machine with a supporting system that undergoes torsional and bending elastic deformations during operation. Based on the previously carried experimental studies, the relevance of the work was substantiated and the goal was set to develop a computational model of spatial vibrations of the cabin on a non-existent system in the form of elastic cantilever beams. An original mathematical model of cabin vibrations on an elastic foundation is presented. It takes into account the nonlinear elastic and dissipative properties of the supporting system structure. A variant of the implementation of the developed mathematical model using the example of the mathematical modeling environment Mathcad is proposed. As an example of calculating the dynamic properties of a bearing system, a case of using the MSC Adams software package with an integrated finite element calculation module Flex is shown. It is presented that taking into account the dynamic properties of the carrier system in the model makes it possible to calculate the vibration load of the cabin with high accuracy and reproduce the resonance phenomena caused by the natural modes of vibration of the carrier system and disturbances from technological sources. The results of the verification of the computational model based on the analysis of the convergence of the values of the full corrected vibration acceleration in the center of mass of the grain harvester cabin, as well as the vibration spectra in linear directions obtained by experimental and computational methods, are presented. Directions for the development of measures and technical solutions for improving the vibration load of operators of transport and technological machines who have active sources of power disturbances on board, as well as a supporting system that experiences elastic deformations during operation are proposed.
Tractors and Agricultural Machinery. 2021;88(3):42-52
pages 42-52 views

Physico-chemical characteristics of particulate contamination in the coolant for automobile and tractor engines

Dragomirov S.G., Eydel P.I., Gamayunov A.Y., Dragomirov M.S.


The article describes the results of a study of the physicochemical characteristics of solid particles of contaminants present in the coolant of automobile and tractor engines. The data on the fractional, physical and chemical composition of solid particles of contamination are given. It was established that the generalized reason for the appearance of contaminants of various nature in liquid cooling systems of engines is the physicochemical interaction of the coolant (antifreeze) with different elements and dissimilar materials of the cooling system. The use of absolutely pure coolant in the cooling systems of automobile and tractor engines is practically unrealistic, since there will always be operating conditions that contribute to the formation of contamination. A number of chemical elements (in an amount from 1 to 47% of each element) were found in the composition of solid particles of coolant contaminants: iron Fe, silicon Si, aluminum Al, lead Pb, tin Sn, zinc Zn, calcium Ca, magnesium Mg, copper Cu. In addition, at a level of less than 1.0% (wt.), Such chemical elements as potassium K, sodium Na, titanium Ti, phosphorus P, sulfur S, chromium Cr, molybdenum Mo, chlorine Cl, iridium Ir, nickel Ni, manganese Mn, etc. were found. The most dangerous contaminants are particles of iron Fe and silicon Si, contained in the coolant in an amount of up to 47 and 37%, respectively, and possessing significant hardness and angularity. The abrasive properties of Fe and Si particles create the danger of removing a thin oxide film on the inner surface of the walls of the cooling radiator channels, leading to their premature destruction. In this regard, it is concluded that high-performance engine coolant filters should be used in automobiles and tractors to remove these contaminants from the flow.
Tractors and Agricultural Machinery. 2021;88(3):53-61
pages 53-61 views

Installation of screw reduction UVO 20-50 for hardening and calibration of cylindrical parts and billets of agricultural machinery

Dement'yev V.B., Zasypkin A.D., Sterkhov M.Y., Churkin A.V.


A screw reduction unit UVO 20-50 (diameter of hardened products from 20 mm to 55 mm) with a closed cooling system for hardened rolled products with the ability to integrate equipment into a production line for manufacturing parts was developed. The UVO unit is intended for shaping and hardening of cylindrical parts by high-temperature thermomechanical treatment (HTMT) with metal deformation by screw compression (VO), ensuring the technical characteristics of products. It is known that some thermomechanical methods of hardening and production of rolled products, for example, steels HTMT, in comparison with conventional types of hardening heat treatment, provide a set of higher properties: strength, ductility and fracture resistance. Evaluating the efficiency of using the hardening thermomechanical treatment of long products for highly loaded parts, it is necessary to use the criteria of fracture mechanics, to study the resistance to brittle and cyclic fracture of steel under the action of stress concentrators, negative temperatures and other difficult test and operating conditions. Taking into account the increased properties of steels with HTMT, it becomes possible to use hollow sections instead of solid billets. The investigated materials and the revealed patterns allow authors to conclude that thick-walled hollow parts, which are used to save metal and lighten the weight of structures, should be considered not only as full-fledged substitutes for solid ones, but also as having an advantage over the latter, mainly due to their better hardenability at surface cold working and less sensitivity to stress concentration at cyclic loads, which makes them more reliable in operation. These research results substantiate the wider use of hollow profiles for such parts of agricultural machinery as track pins, shafts, axles, torsion bars and other parts for various purposes.
Tractors and Agricultural Machinery. 2021;88(3):62-68
pages 62-68 views

The influence of the reinforcement of the chisel-shaped area of the ploughshare on the change in the geometric parameters of radial wear during operation

Kozarez I.V., Mikhal'chenkova M.A., Lavrov V.I., Perepechina Y.I.


The formation of radial wear is a decisive factor in the removal of shares from service, i.e. this type of wear refers to the characteristics of the limiting state of the part. It is noted that the dynamics of its formation and development in a certain way affects the development of technical processes for the restoration of plowshares. However, the process of wear, in this case, cannot be considered fully studied, therefore the work is devoted to the study of the above issue. Experienced plowshares were used for research: as delivered; with a reinforced chisel-shaped part with elliptical rollers; with a reinforced chisel-shaped part with rollers perpendicular to the field edge; with a reinforced chisel-shaped part, rollers perpendicular to the field cut and surfacing of the buried part for a length of about 100 mm. As a result of experiments, the dependences of the change in the width of radial wear in the function of operating time and changes in the depth of radial wear in the process of plowing were obtained. An explanation of the process of wear during the formation of radial wear is given for all investigated technological options. It was revealed that the change in the geometric parameters of radial wear (width and depth) in the process of origin and development has a single character and is the same for all technological variants of hardening with surfacing reinforcement, while the greatest resistance to the formation of this defect is provided by reinforcement by forming beads perpendicular to the trajectory of soil movement with surfacing the deepening part to a length of 100 mm.
Tractors and Agricultural Machinery. 2021;88(3):69-75
pages 69-75 views

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