Journal of Environmental Treatment Techniques
2020, Volume 8, Issue 1, Pages: 196-201
under the unsteady nature of the load is largely determined by
its dynamic qualities, scientific research aimed at creating
mathematical models has been developed (11, 23, 24, 25).
With their help, transient processes are studied during faults
and load shedding, and, based on frequency methods,
technical and economic indicators of IC engine in dynamic
modes (4, 11).
Mathematical method in the form of linear and nonlinear
differential equations is widely used in these works. Some
authors focus on the frequency method using statistical
models of random processes as an input signal (4, 18, 23).
The unsteady nature of the load influences the energy
processes in the engine-transmission installation as a whole.
Due to fluctuations in the rotational speed of the shafts,
additional power losses due to friction and slipping in
kinematic pairs are formed. The nature of the losses has
received a fairly complete interpretation in the works (20,
systems composed of components of a different physical
nature (electrical, hydraulic, mechanical).
In general, from a review of analytical methods for
studying the dynamic properties of power transmission, it can
be concluded that the scope of existing methods is limited to
one specific physical nature (mechanical, hydraulic,
electrical). It can be noted as a drawback that they do not
consider complex dynamic systems consisting of a set of
heterogeneous elements.
The features of power transmissions of various physical
nature and the related features of the methods do not allow
the use of the latter as universal ones in substantiating the
rational type of continuously variable transmission (33-37).
The analysis of trends in modern tractor engineering
allows us to conclude that one of the main goals of improving
tractors as the main energy tools for mobile crop production
is to increase their productivity. Therefore, the industry has
developed a direction of research work related to the search
for ways to more fully load the diesel engine, to improve the
dynamics of the tractor in operating conditions and, in
general, to increase the fuel economy and productivity of the
MTA. Currently, the following paths have been identified:
the introduction of progressive power transmissions, the
correction of the static and dynamic characteristics of internal
combustion engines. It implies stepless hydrodynamic,
hydrostatic, electric transmissions and an increase, within the
limits of the steepness of the corrector, of the speed
characteristic of the internal combustion engine.
According to experts, the situation in the field of
improving the manufactured equipment and developing
promising modifications of tractors and agricultural machines
can be seriously improved by providing designers and
researchers with universal engineering methods for
calculating the energy and dynamic indicators of MTA,
which are invariant to the physical heterogeneity of the
mechanisms of the unit, allowing for their static and. dynamic
characteristics, speed and load conditions of the machine-
tractor unit and ultimately, giving the opportunity at the
design stage of new technology to obtain reliable
comprehensive information about the MTA indicators of
interest in the probabilistic nature of the external load.
2
6).
The next group of theoretical methods is associated with
the study of mathematical models composed of equations
describing equivalent circuits of dynamic systems. The first
theoretical works devoted to the study of the dynamic
properties of mechanical systems, based on the principles and
principles adopted in electrical engineering, appeared in the
3
0s (27, 28, 29, 30, 31). These studies substantiate the
possibility of using electromechanical analogies when
considering issues related to the study of oscillatory processes
in mechanical systems. This approach made it possible to
transfer to the ready-made mechanical system a number of
conclusions obtained in some well-developed branches of
electrical engineering (for example, in the theory of four-
terminal networks, in the theory of electric filters, etc.). In the
papers under consideration, the concept of equivalent circuits
is given and methods for constructing them are shown. The
equivalence of two systems - electrical and mechanical - is
justified by the identity of the Lagrange equations presented
in generalized coordinates. From them equations are derived
that describe mechanical systems and are similar to
Kirchhoff's equations. So, for example, an electric circuit
composed of inductance L, capacitance C and resistance R is
described by the equation of the second Kirchhoff law.
Similarly, a mechanical system is described by equations
obtained on the basis of the de Alambère principle. These
works give an idea of the fundamental possibilities of an
approach based on the formation and study of equivalent
circuits of mechanical systems.
The analysis of technological processes carried out both
on industrial and agricultural machine-tractor aggregates
suggests that the maximum spectral density of load
fluctuations falls precisely on the low-frequency region.
In (32), there is a classification of processes occurring in
a dynamic system. High-frequency vibrations seem to be
associated with individual mechanical links, which constitute
a separate type element through hard links. It is argued that
low-frequency oscillations occur in a system of typical
elements and cause fluctuations in the speed of rotation of the
shafts. A common drawback of all the theoretical works
discussed above is that they do not reveal at all or weakly
reveal the questions of studying the dynamic properties of
Let us give a physical interpretation to the procedure for
calculating the energy indicators of a machine-tractor unit
using the spectral density of a random process. As is known,
spectral density is a function that characterizes the frequency
distribution of elementary dispersions (38). From here, in
accordance with (39), one can proceed to the frequency
distribution of the amplitudes of harmonic processes:
ΔА(ɷ) = √ꢀꢁ ꢂꢃꢄ .
(1)
So, the input variables in a random process obeying the
arcsine distribution can be represented by a set of amplitudes
of harmonic oscillations distributed over a frequency (Figure
1
), and then it is legitimate to talk about the frequency
characteristics of the mathematical expectation of the
effective power of the internal combustion engine and other
indicators. M - dependence of the torque on the shaft of an
k
internal combustion engine (ICE) on the speed of rotation of
the shaft; N is the dependence of the effective power on the
k
1
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