Self-propelled plate compactors are surface-action soil compaction machines with a flat working device set in a state of oscillatory motion by means of a vibration exciter. The most effective way to ensure self-propelled plate compactors is to use the energy of the vibrational motion of the vibratory plate itself. In recent decades, various designs of self-propelled plate compactors have been industrially produced, but existing studies cover only two groups of plate compactors: forward plate compactors with a single-shaft vibration exciter of cir-cular oscillations and reversible plate compactors with a two-shaft vibration exciter of directional oscillations. At the same time, an increase in the number of unbal-ances and/or a change in their location relative to each other makes it possible to solve more complex problems of vibratory plate control, namely, the implementation of remote control, movement to the sides or along an arc, movement along a slope, etc. The aim of the study was to collect and analyze data on industrially produced models of self-propelled vibratory plates. It was found that the most widely used are forward plate compactors with a single-shaft exciter of circular oscillations and reversible plate compactors with a two-shaft exciter of circular oscillations. At the same time, the main trends of recent decades are an increase in the number of unbalance shafts and the introduction of designs that provide remote control of the vibratory plate. An increase in the number of unbalance shafts also allows achieving higher values of the driving force.

The quality of fractional preparation of solid fuel, implemented in agglomeration production using roller crushers, depends on many factors, one of which is ensuring the required interroller gap in the process of crushing the material, for the substantiation of which a mathematical model of a roller crusher with corrugated rolls has been developed. Formulas are proposed for determining the forces acting on the working surface of the corrugated roll in the process of crushing the material, on the basis of which a dependence is obtained for the preliminary tightening of the spring set of the shock-absorbing device of the roller crushing machine to ensure the required gap in the crushing process. According to the technological requirements of the agglomerate sintering process, recommendations are given for preliminary adjustment of the shock-absorbing device of the upper corrugated rolls of the four-roll crusher CFS 900×700, used in the agglomeration shop of LLC «SMMC» for fractional preparation of blast-furnace coke and dry-quenching coke. According to the results of preliminary tests in the process of fractional preparation of solid fuel in the crusher CFS 900×700 using the recommended operating parameters for adjusting the inter-roll gap, it was found that the content of undesirable small –0,5 mm and large +3,0 mm fractions in the finished product decreased by 6,5% and 4,5%, respectively.

The article deals with the following aspect of the work of the developed combined compacting equipment for asphalt concrete mixtures: research and substantiation of the optimal direction of rotation of working bodies from the point of view of the quality of the finished pavement. It is proposed to use smooth rollers of multiple impact rotating around their own axes with eccentricity as working bodies under consideration. The presented data and schemes give a visual representation of the most important processes and phenomena affecting the ejection of material in front of the working body and, as a consequence, the size of the wave formation prism. This parameter is chosen as an indicator of quality assurance of the finished coating. A laboratory bench was designed and constructed, which allowed to conduct a number of experiments on the formulated methods. The design of the stand, due to its flexibility and a wide list of adjustable parameters, allows for in-depth analysis and observation of the work of the compacting organ in the form of a roller with an offset axis of rotation. Two experiments with five repetitions each were conducted, and the results were recorded and systematized. The analysis of the obtained results confirms the hypothesis that compaction by rotating working body should be performed from the unconsolidated material to the compacted one. This will reduce the number of coating defects (such as cracks), increase the evenness and smoothness of the coating, and reduce the delamination of the compacted material.

Designing multi-drive belt conveyors is a rather labor-intensive process, provided that even this process is implemented based on a significant number of accepted restrictions and simplifications. This article proposes a concept of a mobile design environment — a universal software solution based on database technologies for designing and calculating various mechanical engineering objects, capable of quickly deploying in various conditions and adapting to new design objects. Using the example of the procedure for traction calculation of a multi-drive belt conveyor, the features of constructing conceptual diagrams of mobile design environments are shown, generalized elements characteristic of other mechanical engineering objects are defined. The use of mobile design environments and their further development allows for the implementation of large-scale digital experiments on various design objects based on the accumulation and analysis of large arrays of parameters of synthesized possible design solutions with subsequent implementation of the choice of the fi-nal rational option.

The practice of operating self-propelled jib cranes indicates their insufficient stability in the process of loading and unloading operations as a result of sub-sidence of supports in the ground. Evidence of this is the accidents of cranes as a result of their overturning, and the average statistical indicators of which have practically not changed over the past twenty years. The existing methods of increasing the bearing surface (shoes) of outriggers are characterized by a low production culture and are associated with high time costs and, as a result, leading to a decrease in productivity. The proposed fundamentally new development of the outrigger of a self-propelled jib crane, the shoe of which allows you to change the area of its bearing surface in conditions of uneven distribution of forces under the supports. The purpose of the work is to describe the design features, selection, evaluation of operating positions and the method of determining the parameters of the main structural elements of the proposed outrigger. The obtained dependencies make it possible to determine the ratio of the lengths of the links of the proposed design and change them depending on the type of bearing capacity of soils or the stroke of the hydraulic cylinder rod, which is equal to the width of the opening of the shoe elements with an increase in the area of their supporting surface hydraulic cylinder rod. The proposed shoe design is easy to manufacture and maintainable and allows you to increase the stability of lifting cranes, construction machines, etc. during loading and unloading and construction works.

The article considers the problem of creating controlled parameters of vibration fields necessary to take into account the physical, mechanical and rheological properties of the processed materials and to achieve maximum efficiency of vibration technics. The prospects of using a rotary vibration drive with a kinematically unbalanced mass in vibration machines, which has wide possibilities for controlling the parameters of the generated oscillations, are shown. The modeling of the process operation of rotary vibration-drive was carried out, analytical and graphical dependences of the oscillation parameters on the tuning parameters were obtained and the most effective and easy-to-use control parameters were determined. An analysis of possible vibration drive tuning modes was conducted, implemented during its operation. It was found that by changing the rotor speed it is possible to obtain both low-frequency oscillations of the rotor center of mass in the entire possible range of amplitude, and high-frequency oscillations. In addition, with different values of the rotor disk diameter, in the vibration drive can regulate the vibration amplitude at a constant frequency. The compelling force created in a rotary vibration drive, at one same rotation frequency and equal in size and mass dimensions of the rotor and mace, will be significantly greater in comparison with centrifugal vibration exciters. The adjustment of the directional shape of the rotor’s center of mass trajectory implemented in the vibration drive is achieved without the use of addition-al masses and elastic elements. The vibration machine with the proposed rotary vibration drive will significantly increase the possibilities for creating optimal parameters of vibration fields in technological processes.

Ground transport and technological machines are exposed to significant vibrations and impacts during operation. Therefore, the task of protecting their operators from these effects is relevant. In this work, we investigated non-harmonic impulse effects on the seat system with the operator in the form of upward or downward movement with a constant speed, which begins at zero time from the rest state of the system. A model computational verification of the made assumption that the vibration protection system of the seat with an asymmetric force characteristic is capable of providing better protection compared to systems with a symmetric linear static force characteristic was carried out. In the stud-ied single-mass vibration protection system of the seat on the vibration protection suspension with one translational degree of freedom, a piecewise linear two-segment force characteristic with different angles of inclination of the segments in the positive and negative areas of the values of the local coordinate of deformations of the vibration protection mechanism was used. Asymmetric kinematic excitation of the system motion was performed by giving the base a linear mo-tion in the vertical direction at a constant speed at the initial moment. In the computational experiment, the slope coefficients of the static force characteristic seg-ments in the positive and negative ranges of the local coordinate values were varied. The maximum corrected acceleration of the seat was used as an indicator for assessing the effectiveness of protection. The indicator was averaged for raising and lowering the seat base with the same speed. Vibration protection systems with single-segment and two-segment force characteristics were compared. Functional dependencies of the maximum corrected acceleration on the average maximum deformations of the vibration protection mechanism of the seat are given for the calculated cases of raising and lowering the base. The assumption about the advantage of vibration protection systems with an asymmetric force characteristic is confirmed. With small external impacts, the decrease in the maximum correct-ed acceleration is insignificant, with an increase in external impacts it is more significant.

Multi-axle wheeled chassis are widely used to solve various transport and logistics tasks in areas with difficult terrain, unfavorable soil conditions, the presence of natural obstacles and the lack of minimum necessary transport infrastructure. The object of the study is a mechanical transmission of a multiaxial wheeled chassis with several drive and non-driving axles. The purpose of the study is to create an engineering methodology for predicting the kinetics (changes over time or depending on mileage) of quantitative indicators of the reliability of the transmission as a whole and its key subsystems during the entire service life of the chassis. The methodology is based on the developed probabilistic mathematical model. It allows you to predict the kinetics of reliability indicators of both the mechanical transmission as a whole and its subsystems, taking into account the timing and volume of repair and restoration work. The calculation of the probabilities of finding the transmission and its subsystems in good condition at any given time is based on solving the Chapman-Kolmogorov system of linear differential equations. Periodic reformulation of this system of equations is provided at the time of scheduled repairs of the wheeled chassis. The results of a test calculation example and their analysis are presented in relation to the mechanical transmission of a 6-axle wheeled chassis with a 12×10 wheel formula.

The results of a study on the geological position and internal structure, petrographic and petrochemical features of the Beltau gabbro-peridotite massif are presented. Original data on the species and material composition of rock-forming minerals are presented. It is concluded that the massif is stratified due to crystallization-gravitational differentiation of primary basaltic magma, the products of which are represented by separate horizons of lherzolites, troctolites, olivine gabbro, titanavgite gabbro, gabbronorite, gabbropyroxenite, and anorthosite. It is confirmed by the internal structure of the intrusive massif — anorthosites and beolin-free leuko- and mesocratic gabbroids are located closer to the central part of the massif, hypsometrically higher than melano-cratic gabbroids and peridotites, and the latter gravitate to its peripheral and deeper parts. The forms of occurrence and material compositions of the main concentrating minerals and carrier minerals of iron, titanium, copper, nickel, cobalt, chromium, platinum, gold, silver, and other metals are determined. The geochemical specialization of peridotites is characterized by pronounced elevated contents of nickel and cobalt, which sharply exceed the contents of these elements than in melano- and mesocratic gabbro, leukograbbro and anorthiosites. Melanocratic, mesocratic gabbroids and their vein derivatives are relatively melliferous than other rocks of the massive

The article substantiates the need for an experimental study of static and dynamic loads in a single-row roller chain of roller conveyors for pallets. A small-sized wireless device based on a strain gauge and Arduino boards, designed on the principle of a full bridge, has been developed to measure forces in the outer plates of the drive roller chain of a pallet conveyor, which allows data to be received at different frequencies. The tests on a full-scale stand of a drive roller conveyor for pallets with a chain transfer, carried out in a reversible mode of operation, are described. The results of a series of experimental studies consisting of preliminary calibration, static and dynamic parts are presented. To filter the obtained results from high-frequency noise, the obtained results were processed using the fast Fourier transform in Excel. We also compared the initial, averaged, and filtered results on 25 repetitions of the experiment using different data acquisition frequencies. The obtained results of measuring forces in a drive roller chain are analyzed and conclusions and recommendations for further use of the device are the most appropriate data acquisition frequencies of 12.5 Hz and 16.7 Hz are presented.