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DEVELOPMENT AND DEFINITION OF REQUIREMENTS FOR SMOOTHNESS CALCULATIONS THE COURSE OF TRACTORS..,
Kunduzov Sodirjon Ayubovich, candidate of the technical sciences, chief of the laboratory, Uzbek State Centre for Certification and testing of agricultural machinery and technology in Cabinet of Ministers of the Republic of Uzbekistan (UzGTsITT), Republic of Uzbekistan E-mail: [email protected] Khalmatova Zulfiya Turdukulovna, chief of the laboratory, Uzbek State Centre for Certification and testing of agricultural machinery and technology in Cabinet of Ministers of the Republic of Uzbekistan (UzGTsITT), Republic of Uzbekistan Khamzayev Mumin Kayumovich, senior researcher, Uzbek State Centre for Certification and testing of agricultural machinery and technology in Cabinet of Ministers of the Republic of Uzbekistan (UzGTsITT), Republic of Uzbekistan
DEVELOPMENT AND DEFINITION OF REQUIREMENTS FOR SMOOTHNESS CALCULATIONS THE COURSE OF TRACTORS WHEN AGGREGATING WITH WIDE-GRIP MACHINES
Abstract. Stable movement at a given operating speed is a prerequisite for ensuring the quality of the work of the machine units. When moving aggregates, impacts in the form ofvarious irregularities of the profile and obstacles affect its dynamic properties. Stability must also be ensured when making turns at the ends of corrals and turns.
The quality of the execution of technological processes of aggregates largely depends on and is characterized by the level of vibrations and vibrations that occur. The development of design models or schemes in the design, will determine the initial properties, characteristics and analysis of dynamic stability, as well as to establish the degree of vibration intensity and the development of remedies.
These issues are relevant in the development and design of high-clearance portal tractors aggregated with wide-gripping machines - sprayers, cultivators and others.
Keywords: aggregation, stability, smoothness, requirements, high clearance portal tractor, dynamic processes, vibrations, oscillatory movements.
One of the necessary conditions for ensuring the quality of the work of machine units with maximum performance is their steady movement at a given operating speed.
When moving aggregates in the field, appearing random kind of impact, in the form of various irregularities of the profile and obstacles, have an impact on its dynamic properties. Similar questions on sustainability are also raised when cornering at the ends of pens in the field and when cornering on roads in the transport position. The quality of the process is determined by the choice of mechanical and technological parameters of machines. In particular, these issues are relevant in the development and design of high-clearance portal trac-
tors aggregated with wide-gripping machines, such as sprayers, cultivators and others.
Providing mobile units of high dynamic qualities allows the implementation of working movements with the least deviations from the theoretically given straight motion. The implementation of the stable movement of the aggregates is carried out by selecting appropriate values of linear dimensions, mass, moments of inertia, used tire brand with stiffness coefficients.
Under certain functional conditions with given speeds used in tractor units, their constructive perfection, workmanship, quality of technological processes performance and in
Section 9. Technical sciences
many respects depend on the level of the resulting vibrations and vibrations.
As shown by preliminary studies [1; 2; 3], in the issues affecting the dynamic properties and safety of tractors and machines, the main sources of vibrations and vibrations are their engines.
Dynamic processes occurring under different operating conditions determine the performance and durability of the engines and the tractors themselves. A detailed examination of the tractors revealed that the main source of regular oscillations are disturbances arising during the working process in an internal combustion engine.
Analysis of studies [2; 3; 4] showed that in order to solve the problems of the dynamics of tractors and their dynamic loading from power effects, it is necessary to develop rational ways of schematization of disturbing properties.
The used aggregate method of assembling the power plants, in which the individual units making them (engine, transmission mechanism and other working units) are designed, calculated and tested independently and determine the relevance of dynamic calculations.
The tractor is an oscillatory system with its particular features and properties, consists of several masses [4; 5; 6]. The design includes elements, the gravity of which is not transmitted through the elastic device of the suspension: - non-suspended elements-frame (wreck), wheels, semi-axes on which all main components are mounted.
Wheeled tractors have semi-rigid under-spraying systems, we have to take into account trailed implements and other features.
Theoretical studies and methods for calculating the mechanical vibrations (vibrations) and the stability of modern equipment are of great importance in the field of mechanical engineering and, in particular, for the development and design of new agricultural machinery and tractors.
The areas of technology in which oscillations play a particular role are quite numerous. As in any object of technology, in any engineering design, real machines have a variety of physical properties and imperfections of all kinds, in connection with which may arise
"Harmful" vibrations - the occurrence of them leads to large stresses in the elements and nodes of the machine, which lead to loss of stability or harmful effects on people.
Therefore, the development of design models or schemes in the design of new equipment or machines will allow:
- to determine the initial properties and characteristics (for the oscillatory system, amplitude-frequency or phase-frequency characteristics) and the analysis of dynamic stability;
- establish the degree of vibration intensity for developing ways to eliminate or reduce their amplitude oscillations to prevent buckling.
In internal combustion engines, torsional vibrations of the crankshaft associated with a piston group are essential. The design model of the motor shaft is a torsional system of discretely located massive elements and elastic elements between them. To obtain a model corresponding to reality, it is necessary to consider a more complex design scheme, in which the engine has a somewhat limited power, and the working bodies of the machine in the process of work overcome considerable resistance forces. In the study a tractor can be represented as a system of elastically coupled solids.
In the study of cab torsional vibrations, tractor transmissions and other components, the crankshaft (elastic or rigid) with forces acting on it, the clutch, gearbox shafts, propeller shaft, axles and wheels are included in the calculation scheme. It was determined from the studies that the interdependence and interaction of these oscillations is due to the fact that the radii of the drive wheels change with the vertical oscillations of the body, the torsional and vertical oscillations are interrelated and the state of the system is determined by the balance of the oscillatory mode.
References:
1. Tayanowskiy Georgiy, Wojciech Tanas. Tractor vibrations dynamic evaluation in an aspect of the possibility of coupling and of loading its driving axle. MOTROL, 2006.- 8 A.- P. 271-279.
2. Korsun A. I. Dynamics of mobile cotton machine-tractor units.- Tashkent, 1983. - 153 p.
3. Lurie A. B. Statistical dynamics of agricultural units.- L., 1981.- 381 p.
4. Diementberg F. M. Fluctuations of machines, structures and their elements.- Vol. 3. // Vibrations in engineering.- M. "Mashinostroenie". 1980.- 544 p.
5. Mitschke M. Dynamik der Kraftfahrzeuge. - Berlin, Springer,1972.- 529 p.
6. Smirnov G. A. Theory of the movement of wheeled vehicles.- M. "Mechanical Engineering". 1990.- 352 p.
