Study of the influence of the parameters of the working body on the performance of the excavator

This paper emphasizes the importance of estimating actual productivity and presents a way to achieve it. The excavator actual productivity refers to the maximum possible productivity in real construction site conditions

Forecasting the Life of a Structure Relative to the Operating Mode

The question of forecasting the service life of transport machines designed by taking into consideration the load spectrum, that is close to the real one, is an important problem at the calculation. One of the ways to simulate real operating conditions at the design calculation is a method of randomization quasirandom loads. Methods of randomization are widely used in many areas of science and technique. In the article, the numeric comparison of different ways of randomization is shown at the calculation for determining the service time using two techniques: the use of a standardized function of randomization in the high-level programming language of the and the law of normal distribution at its different parameters. The use of the law of normal distribution makes the more exact fatigue calculation because it makes it possible to simulate the quasirandom process that corresponds to the real operation picture to a greater degree. The results presented in the work make it possible to fulfill the calculation of the service time of the metallic structure that is under cyclic asymmetric loads, at the well-known nature of the application of loading to it. © 2021 Institute of Physics Publishing. All rights reserved

On preventing resonance condition in operation of rotary excavators

The article examines the causes of forced vibrations of the rotor. It was found that the increased tendency of rotary excavators to oscillate is caused by the frequency of scooping, which leads to self-oscillation. The frequencies of natural and forced rotor vibrations during the digging of different soils are determined depending on the speed of rotation of the working body and the depth of digging. The dynamic stability of the movement of the working body under the horizontal elastic pliability of the structure is investigated. The condition of occurrence of resonant phenomena during operation of a trench rotary excavator is determined. © 2020 IOP Publishing Ltd. All rights reserved

Developing a digital control system for the main drives of an open-pit excavator as a major field of increasing the efficiency of excavator operation

The specifics of rock excavation using a front-shovel operational equipment are addressed in the paper. Excavation, carried out by actuating (thrusting and lifting) mechanisms of an excavator, is shown to form a leverage mechanism which consists of operational equipment elements and connects the main actuating mechanisms with the bucket, thus forming a common transmission mechanism for their drives. Mechanical energy of the main drives is converted to energy-force parameters realized at the cutting edge of the bucket (its teeth) in agreement with kinematic properties of the mechanism. Expressions for transfer functions of the leverage, which define relations between the energy-force parameters at the cutting edge and operating parameters (velocities of operating motions), were obtained. A flow chart for calculating the operating parameters was developed. A digital control system on its basis would allow to increase the excavating efficiency. © Published under licence by IOP Publishing Ltd

Evaluation of Single-Bucket Excavators Energy Consumption

AbstractIt is shown that with the increase in capacity and weight of excavators their specific indices of functioning remain practically at the same level corresponding to the energy consumption value (available power) for excavators of each type (electromechanical or hydraulic). That value depends on the type of operational equipment, the ratio between linear and weight parameters and other factors. New layout of the operational equipment is suggested, featuring an internal closure of workloads within its operating element. The layout includes the operating element in the form of two oppositely arranged buckets and the closure mechanism. Energy efficiency index for single-bucket excavators is proposed

Specifics of drives functioning in main mechanisms of open-pit excavator

Specifics of functioning for the drives of main (lifting and thrusting) mech-anisms in an open-pit excavator were determined for their joint action during the process of excavation. It was shown that the operation forms a two-crank lever-age transmission mechanism (connecting the main mechanisms and the excavator bucket) and a common transmission mechanism of the drives (consisting of the main mechanisms and the leverage). It was also established that an initial link of the common transmission mechanism would be a stick-bucket link whose co-ordinates determine positions of every other link in the mechanism in relation to the stand (a boom). Dependencies were derived for finding kinematic transfer functions of the leverage, that is relations between lifting and thrusting velocities and an excavation velocity when the bucket (its cutting edge) is moved along a given trajectory in the process of pit development. The results of the research could be used for the purposes of designing a control system for the main drives of an excavator. © Published under licence by IOP Publishing Ltd

Increasing power efficiency of open-pit excavators

It is shown that a working process of rock excavation realized by an open-pit front-shovel excavator is characterized by an increased power intensity due to counteraction of its main actuating mechanisms (lifting and thrusting), whose operational parameters have to be properly matched during their joint action to provide more efficient excavation. A computational experiment allowed to determine an actual work of lifting and thrusting forces immediately involved in developing an excavated face. It was further established that power inputs depend on the bucket position relative to the working area of an excavator, and such regions of that area where those inputs are higher were determined. Differentiated calculation of the inputs was carried out, based on the type of a conducted operation-power inputs originating from excavating, from counteraction of the main mechanisms, and from lifting operational equipment parts and rock. The power intensity of excavation was estimated for various regions of the workspace of the excavator. The proposed method for calculating the power inputs of rock excavation using the operational equipment of an open-pit excavator would allow to determine an energy characteristic of the excavator for specific mining and technical conditions of operation. © Published under licence by IOP Publishing Ltd

Оптимізація галузевої структури агроекосистем на меліорованих землях Правобережного Полісся

The article shows the economic evaluation of different use cases agroresources capacity of the reclaimed territories of the right Bank Polissya, it was conducted on the simulation results of prospective scenarios of development of a typical agricultural enterprise. It is established that the maximum profitability to be achieved in the formation of the infrastructure with the growing and processing of flax, high-performance animal getting ready to eat food, bioenergy and organic fertilizers in terms of effective regulation of water-air regime in the reclamation system.У статті наведено економічне оцінювання різних варіантів використання агроресурсного потенціалу меліорованих територій Правобережного Полісся, що проводилось за результатами імітаційного моделювання перспективних сценаріїв розвитку типового сільськогосподарського підприємства. Встановлено, що максимальна прибутковість підприємства досягатиметься за формування інфраструктури з вирощуванням і переробкою  продукції льонарства, високопродуктивним тваринництвом з отриманням готових до споживання продуктів харчування, біоенергії і органічних добрив за умови ефективного регулювання водно-повітряного режиму на меліорованих землях

Impact of damping on decay time of free oscillations in metal structures

The problem of increase of durability of the bearing thin walled metal structures of hoisting- A nd-transport machines maybe solved by means of structural damping which allows to increase the logarithmic decrement of the damped oscillations. In the work there are given the results of modelling and experimental check of the advantages of usage low-modulus foam materials as fillers at a structural damping of thin walled elements of metal structures. With the help of computational package SolidWorks there was conducted a numerical study to define amplitude-frequency characteristic of laboratory machine and then there were run the tests of model structure with building vibrorecord. As a result if research there was revealed a significant increase of the logarithmic decrement and reduction of the time of decay of natural oscillation of the foamed structure. Consequently, there are shown the advantages of the further researches to use energy-intensive foam materials to dampen the elements of the structures of handling machinery. © Published under licence by IOP Publishing Ltd