Theory of Vibrating Lifting Tools of Sugar Beet Harvesters
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Kuupäev
2022
Kättesaadav alates
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
MDPI
Abstrakt
The cultivation and harvesting of sugar beets (roots and leaves) is one of the
most labour and energy consuming work processes in the agricultural industry.
The most important task in sugar beet farming is to improve the quality of sugar
beet root crop harvesting and reduce energy costs for harvesting. This primarily
concerns reductions in losses and damage of root crops, as well as a reduction in
their contamination; in this case, the loss of fertile soil will be excluded, which will
be removed from the fields together with the contaminated root crops. These issues
present a multifaceted scientific and technical problem, which must be solved by
searching for new working elements of sugar beet harvesting machines. Despite
the modern level of construction of beet harvesters and their working bodies that
has been achieved, there is a need to find further ways to improve them. Further
research should deal with the improvement of general constructional schemes of
new beet harvesters, with thorough theoretical justification of their constructions
and technological parameters. The newly developed theories of functioning of
improved constructions of sugar beet harvesters and their working bodies require
thorough experimental verification. This will give grounds to use the obtained
theoretical dependences for the final goal—analysis and generalisation of their
rational parameters.
Theoretical research must play a fundamental role in the mechanical and
technological substantiation of the root lifting process. It must be used as the basis
for developing rational kinematic and dynamic operation conditions in order to
achieve the required quality of the performed work process as well as streamlined
energy consumption.
At the modern stage of the development of agricultural mechanisms, the methods
of mathematical model generation based on the use of the theoretical and analytical
mechanics and the application of up-to-date mathematical tools and computer
technology have to be employed in the analysis and synthesis of the parameters of
implements and agricultural machines overall.
Thus, the modern methods of theoretical research into the implements of sugar
beet harvesters have to be based, first, on the state-of-the-art perception of the
principles of the processes that take place when the roots are lifted from the soil
and, second, on the possibility of describing these processes more comprehensively
and systematically with the use of modern mechanical and mathematical methods.
Undoubtedly, such a description only has to be provided for the principal and essential
moments of the mentioned processes, while the insignificant and incidental factors
must be completely neglected. Further, on the basis of the analytically determined rational parameters of the lifting implements of sugar beet harvesters, which are
subsequently experimentally validated and refined, highly reliable prototypes must
be designed, which then have to be widely used by the agricultural engineering
plants and companies.
Therefore, this treatise presents the fundamentals of a new theory of the lifting
tools of sugar beet harvesters—in particular, vibrational lifters based on the modern
methods of mechanics and mathematics.
It has been a long time since the first attempts were made (in the 1970s) to
analytically describe the oscillating processes that take place during the vibrational
lifting of sugar beet roots from the soil. The theory of the vibrational lifting of root
crops has, overall, not been developed to a sufficient extent; the mathematical model
specifically used for the process of root extraction from the soil by the vibrational
lifter has not been devised. Until recently, it had been assumed that the experimental
methods of determining the amplitude and frequency of oscillation of the vibrational
faces—which could only have relatively limited values, subject to the reliability of
the vibrational actuator—completely ensured the optimality of this whole process.
However, at the present time, under the conditions of significant improvements in
the reliability of designs and changes in the kinematic parameters of harvesting (for
example, the increase in the travel speed to levels of up to 2.5 m·s−1 ), the obtained
values of the parameters of vibrational lifters can by no means be considered optimal.
Therefore, a goal has been set to develop, first of all, a new theory of vibrational
root lifting based on the generation of mathematical models, which would describe
the interaction between the digging shares on the one hand and the root’s body
and the soil on the other hand. At the same time, the theory has to provide the
mathematical descriptions of all stages of said interaction, starting from the stage
of the lifter approaching the root body fixed in the soil (as in elastic medium),
proceeding to the interaction of the root body with only one digging share of the
lifter (asymmetric gripping of the root), followed by the interaction with both the
share surfaces (symmetric gripping), and finally the eventual translation of the root
along the lifting tool’s throat towards the level of the soil surface. Additionally, as
a matter of principle, the theory needs to consider different (possible) directions of
the oscillating motions of the digging shares of the vibrational attachment—i.e., the
longitudinal and transverse ones.
Kirjeldus
Märksõnad
combine harvesters, vibration, harvesters, sugar beet, mathematical theories, differential equations, biomass