Scientific Journal of KubSAU

Polythematic online scientific journal
of Kuban State Agrarian University
ISSN 1990-4665
AGRIS logo UlrichsWeb logo DOAJ logo

Name

Kravchenko Vladimir Alekseevich

Scholastic degree


Academic rank

professor

Honorary rank

—

Organization, job position

Don state agrarian University
   

Web site url

—

Email

—


Articles count: 20

2373 kb

THE RATIONALE OF THE RIGID CHARACTERISTICPARAMETERS OF THE COMBINE HARVESTERS OF HIGH PERFORMANCE

abstract 1521908022 issue 152 pp. 257 – 274 31.10.2019 ru 227
The purpose of the study was to substantiate the rigid parameters of tyres in propulsion units for the combine harvesters of high performance. A research method is analytical with the use of a mathematical model of the combine harvester in which damping and rigidity of the drive axle tyres in circumferential and radial directions are taken into account. Values of the rational rigid characteristics of the pneumatic tyre have been generally determined by the ability of the tyre to be deformed so that to reduce the angular, vertical and horizontal skeleton oscillations of a combine harvester to ensure the high-quality technological process of the threshing and harvesting. The specified circumstance gains the special importance at the development and introduction of the new tyre modes for the combine harvesters of high performance. The analysis of the conducted analytical researches has been showed the expediency of using the threads of a cord in the propulsion unit of combine harvesters instead of diagonal or radial tyres of the same standard size with an original position of them. The offered pneumatic tyre of 30.5E-32 used as the leading one, and promotes the reduction of the angular oscillation amplitude and operating speed of a combine and also angular and vertical accelerations up to 1.42 times
389 kb

COMPARATIVE ANALYSIS OF THE DE-FORMATION IN TIRES 30.5-32 WITH A DIF-FERENT INTERNAL STRUCTURE

abstract 1511907011 issue 151 pp. 116 – 129 30.09.2019 ru 290
The objective of the research was to study the patterns of deformation with the different internal structure in a tire envelope with the standard size of 30.5-32 in propulsion units for modern mobile farm vehicles. The research method is experimental with the use of «a tire tester» and specially developed devices for determining the deformations of the tire envelope concerning the rim in circular and radial directions. Output indicators of a wheel with the pneumatic tire are determined by the ability of the tire to be deformed so that at small hysteresis losses in the rubber-cord envelope the largest area of the contact with a substructure have been created. This circumstance has special significance when developing the tires for mobile farm vehicles with the high power saturation, the patterns of deformation of which are poorly studied now. The analysis of the carried out experimental researches has shown the expediency of application of the experimental tires with the same standard size, offered in the work, on the propulsion units of the mobile farm vehicles instead of diagonal and radial tires. The rolling resistance of the experimental tires 30.5E-32 is lower than the rolling resistance of serially produced tires, and the developed area of contact is higher and that provides the decrease in the condensing impact on the soil
585 kb

THE DEVELOPMENT AND TEST RESULTS OF AN AUTOMATIC GEAR BOX FOR A TRACTOR OF CLASS 5 WITH AN ELASTIC DAMPER MECHANISM IN TRANSMISSION

abstract 1481904001 issue 148 pp. 1 – 15 30.04.2019 ru 351
The aim of the work is to establish rational parameters on the basis of analytical and experimental research, in terms of obtaining the maximum performance of the unit based on a class 5 tractor, an automatic gear shift system. We have proposed a device for automatic gear shifting, in which the pressure of the working fluid in the pneumatic-hydraulic accumulator installed in the power transmission of the tractor of the elastic-damping mechanism, equivalent to the engine torque, was used as an input signal. The task of optimizing the tracking device and the actuator of the automatic shift system is the definition based on the theory of automatic regulation of the rational flow cross section of the damper throttle and the time delay of the system response to ensure the input signal with the necessary filtering in frequency and phase. The study presents the results of the tests carried out under laboratory conditions, which showed that the automatic gear shift system provides gear shifting at an external load frequency in the range from 0 to 0.24 s-1, direct assessments of the quality of the automatic gear shift system: oscillation (0), overshoot (0%) and time of the transition process (2...4 s), meet the requirements for their work. The analysis of the results obtained in experimental studies showed that the productivity of the machine-tractor plowing unit with a class 5 tractor-model equipped with the developed system of automatic gear change is higher by 10.6%, and the specific fuel consumption is 8.1% lower compared to the serial version
277 kb

STUDY OF ACCELERATION PROCESS OF A MACHINE-TRACTOR UNIT WITH ELASTICDAMPING MECHANISM IN A CLASS 5 TRACTOR TRANSMISSION

abstract 1211607018 issue 121 pp. 449 – 458 30.09.2016 ru 444
The aim of the work is theoretical and experimental confirmation of the possibility of improving the rate of acceleration of tractor units due to installing of elastic-damping mechanism with variable stiffness in tractor transmission. Speed tractors application in agricultural production meets a number of difficulties associated with the unsteady processes during acceleration of machine and tractor units. The resulting large inertial loads when accelerating result in loss of engine power, due to which the machinetractor unit is operating at reduced performance and efficiency. An analysis of published studies shows that the acceleration performance of tractor units is greatly influenced by the stiffness and damping properties of the transmission of energy resources. To provide smooth acceleration of the unit it is proposed to install elastic-damping mechanism with variable stiffness in tractor transmission. As a result, the tension of the acceleration process decreases. The results of analytical and experimental studies on the effect of elastic-damping mechanism installed in the class 5 tractor transmission, on acceleration capabilities of tractor units are given. The optimum parameters of elements of elastic-damping mechanism with variable stiffness for class 5 tractors are determined. It is proved that the use of elastic-damping mechanism with a variable stiffness in the tractor transmission improves acceleration indicators
310 kb

STUDY OF THE INFLUENCE OF EXTERNAL LINKS RIGIDITY OF A CLASS 1.4 WHEELED TRACTOR ON THE UNIT’S ACCELERATION

abstract 1251701024 issue 125 pp. 346 – 361 31.01.2017 ru 490
The aim of the article is theoretical and experi¬mental confirmation of the possibility to improve the acceleration performance of tractor units by in¬stalling a tow hitch with variable stiffness. Application of speed tractors in agricultural pro¬duction meets a number of difficulties associated with the unsteady processes, especially while accel¬erating of machine and tractor units. The resulting large inertial loads during acceleration lead to loss of engine power, due to which the machine and tractor unit operates with less performance and economy. Our analysis of published studies shows that the acceleration performance of tractor units is greatly influenced by the rigidity of external links in the form of coupling devices installed between the trac¬tor and the agricultural machine. The design of the tow hitch with variable nonlinear stiffness for class 1.4 tractors is offered. The results of theoretical and experimental studies on the effect of the proposed tow hitch with variable nonlinear stiffness on the acceleration capabilities of machine and tractor units based on class 1.4 tractor are shown. Based on the analysis of characteristics obtained by the analytical and experimental ways, it was proved that the use of the hitch with a variable non-linear stiffness on class 1.4 tractor helps to improve the acceleration performance of the machine and tractor unit
439 kb

THE CHARACTER OF DEFLECTION OF THE OVERSIZE TIRES WITH LOW PRESSURE IN TRACTOR PROPULSION UNITS OF CLASS 5

abstract 1321708098 issue 132 pp. 1231 – 1242 31.10.2017 ru 496
The aim of the article has been the study of deflection laws in tractor oversize low-pressure tires, intended for class 5 tractor propulsion. The research method was experimental. The "tire tester" and specially designed devices for determining the deflections of the inner and outer tube relative to the rim in the circumferential, radial and collateral directions have been used in it. A number of factors determine outcome indices of the wheel with pneumatic tyre. Among them the ability of the tire to deform so that at low - hysteresis losses in the rubber-cord casing and admissible stresses in it, based on resource, the largest area of contact with the supporting base has been created. This circumstance is of particular importance in the development of tractor tires of low pressure, deflection characteristics of which are poorly studied at present. Analysis of experimental studies showed the necessity of the feasibility of creating the tire with the cord orientation in its casing so that in the zone of perception of the vertical and longitudinal forces the cord threads would work in a mode close to the extension, but in the area of contact it would work in bending. These requirements will best meet the tire in which the cord threads are parallelly located in adjacent layers and directed at a predetermined angle in the direction of effect of the axial forces on the wheel in oncoming fibers
526 kb

THE INVESTIGATION OF THE ACCELERATION PROCESS OF A MACHINE AND TRACTOR UNIT ON THE BASIS OF CLASS 1,4 TRACTOR WITH A VARIABLE ROTATING MASS OF THE ENGINE

abstract 1131509077 issue 113 pp. 1061 – 1071 30.11.2015 ru 808
The aim of the work is theoretical and experimental confirmation of the possibility of improvement in tractor unit acceleration due to the variable inertia moment of the rotating masses of the engine. The use of high-speed tractors in agricultural production meets a number of difficulties associated with unsteady processes during acceleration of the tractor units. The emerging significant inertial loads during acceleration result in the loss of engine power because of what the machine and tractor unit is operating at reduced productivity and efficiency. An analysis of published works shows that the tractor unit acceleration is strongly influenced by the rotating mass of the engine. A device based on the application of additional rotating masses in a free flywheel connected or disconnected automatically to the main engine flywheel at appropriate stages is offered. As a result, the tension during acceleration is reduced. The results of experimental studies on the effect of the additional rotating masses on the engine acceleration characteristics of the machine and tractor units on the basis of Class 1.4 tractor are given. It is proved that the use of the tractor additional rotating mass connected or disconnected to the respective modes of movement of a machine and tractor unit to the flywheel of the engine, improves acceleration performance
305 kb

MATHEMATICAL MODELING OF MTU TENSILE LOAD

abstract 1011407024 issue 101 pp. 424 – 437 30.09.2014 ru 1129
The article is devoted to mathematical modeling of random process that occurred in tensile load of serial and experienced MTU. The efficiency of EDM application in transmission is discussed
329 kb

MATHEMATICAL MODEL OF A MACHINE AND TRACTOR UNIT WITH EDM IN TRANSMISSION OF A TRACTOR

abstract 1031409016 issue 103 pp. 251 – 261 30.11.2014 ru 1134
The developed mathematical model of the machine and tractor unit with the elastically damping mechanism in transmission of a tractor is given in the article. The analysis of mathematical model of the arable unit on the basis of a tractor with EDM in transmission showed that the MTU mathematical model can be considered as working
299 kb

REGULARITIES OF DEFLECTION IN THE DIAGONAL AND RADIAL TIRES OF THE GRAIN COMBINE PROPULSIONS

abstract 1341710014 issue 134 pp. 164 – 173 29.12.2017 ru 1134
The aim of the study is to investigate the regularities of deflection in the diagonal and radial tires for the grain combine propulsions of high productivity. The research method is experimental. The "tire tester" and specially designed devices for revealing the deflections of the inner and outer tube relative to the rim in the circumferential and radial directions have been used. The outcome indices of the pneumatic-tired wheel are determined with the tire capability to deflect so, that at low - hysteresis losses in the rubber-cord casing and its acceptable tensions, based on a resource, the largest area of contact with supporting base would be created. This circumstance acquires the particular significance developing tires for grain combines of high performance, the deflection regularities of which are poorly studied at present. The analysis of experimental studies showed the feasibility of using the grain combine propulsions instead of the diagonal radial tires of the same size. The resistance to rolling of radial tires 30.5 R-32 is lower than in diagonal tires 30.5 L-32, and the developed contact area due to the increase of length is higher, which reduces sealing effect on the soil
ßíäåêñ.Ìåòðèêà