MATHEMATICAL MODELING OF A MULTI-INERT OSCILLATORY MECHANISM

It is noted that the free harmonic vibrations of a classical pendulum are due to the mutual conversion of the kinetic energy of the load intothe potential energy of the spring. Oscillators with a different nature of energy exchange have been developed, for example, by converting the kinetic energy of a load into the energy of a magnetic field of a solenoid or the energy of an electric field of a capacitor. All these oscillatory systems and the like were a prerequisite for the creation of a biinert oscillator,in which the acceleration of one load occurs due to the braking of another, i. e. only kinetic energies are exchanged. The aim of the work is mathematical modeling of a multi-inert oscillatory mechanism. The main research methods in the framework of this work are methods of mathematical modeling and analysis. The methods used make it possible to obtain a reliable description of the studied objects. Inthe proposed multi-inert oscillator, inert bodies of mass m each carry out harmonic oscillations due to the mutual exchange of kinetic energy. The potential energy of the springs is not requiredfor this. Body vibrationsare free. A feature of a multi-inert oscillator is that the frequency of itsfree oscillations is not fixed and is determined mainly by the initial conditions. This feature can be very useful for technical applications, for example, for self-neutralization of mechanical reactive (inertial) power. n-gon, formed by inert bodies, carries out complex motion – orbital rotation around the center of coordinates and spin rotation around its axis passing through the center of the n-gon. Moreover, each load performs linear harmonic oscillations along its guide. With the arrangement of the guiding weights not in the form of a star, but in parallel to each other, the angles between the corresponding cranks must be 360/n degrees.

EXPERIMENTAL DETERMINATION OF THE HOLE AXIS DEFLECTION WHEN WORKING WITH A COUNTERSINK WITH CARBIDE BLADES

This article discusses the developed mathematicalmodel that takes intoaccount the errors of sharpening and assembling the cutting blades of a countersink tool with carbide blades. This allows you to determine the actual area of the cut sections of the allowance for each blade and calculate the cutting forces acting on them. The resultant cutting forces leads to lateral displacements of the axis of the tool during machining of the hole. The mathematical model makes it possible to determine the errors of processing holes (axis retraction, split and shape accuracy) with a countersink with a carbideblades. To check the adequacy of the mathematical model, fullscale experiments were performed on blanks madeof various materials. The method of conducting a full-scale experiment was developed. Recommended cutting modes and a countersink with three blades are selected. Processing was performed at the MM800 Fanuc processing center. Using modern automation tools – the Renishaw system and additive technologies using the Range Vision Spectrum 3D scanner, the drift of the hole axis was measured after processing with a vertical drill with carbide blades. This device allows you to get the desired result in a very short time. A compact sensor was used to measure the deflection of the hole axis, allowing for very accurate results. Substituting the part processing data into the mathematical model, the calculated values (theoretical) of the hole axis withdrawal during processing for the prototypes are obtained. The theoretical results and the results of the field experiment are compared. Comparing the obtained theoretical results – the results of a mathematical model, and the results of a full-scale experiment, it was concluded that the developed mathematical model is adequate and can be used in production by technologists in the development and computer debugging of technological processes.

DEVELOPMENT OF A BENCH FOR SEMI-FULL-SCALE MODELING OF A CONTROL SYSTEMFOR THE MOVEMENT OF A TRACKED VEHICLE WITH A HYDROSTATIC TRANSMISSION

The article presents the results of the development of a bench for a semi-full-scale simulation of the motion control system of a tracked vehicle with a hydrostatic trans-mission, intended both for teaching programming of logical controllers and for testing control algorithms at the stage of their development. The analysis of technical solutions known on the market with the identification of their main shortcomings is performed. In the framework of the concept of semi-full-scale modeling, a structure has been drawn up and implemented. A mathematical model of the control system for the movement of a tracked vehicle with hydrostatic transmission is presented. It is made on the basis of an industrial tracked tractor of traction class 15 tons manufactured by JSC Ural Road Construction Equipment Plant and adapted to the needs of the stand. A set of control algorithms has been formed, which includes an algorithm for controlling the movement of a caterpillar vehicle, an algorithm for activating the running-side brake when there is a risk of skidding, and an algorithm for activating the brake of the lagging side when the hydrostatic mechanism is overloaded by pressure. To organize the input of initial data, as well as observations of the simulation results, the Altair Embed software package developed a visualization system that includes an operator panel mimic diagram demonstrating changes in the basic parameters of the tracked vehicle's motion (center of gravity speed; center of gravity trajectory; pump flow control pa-rameters; curvature of the trajectory (set and current); track rotation speed on the left and right sides; soil resistance coefficient under each track), a panel settings the algorithms for motion control of a tracked vehicle, a panel of adjustment of parameters of the soil and the selection panel motion path of the tracked vehicle.

ASSESSMENT OF THE INFLUENCE OF MICROTEXTURING PARAMETERS ON THE HYDROMECHANICAL CHARACTERISTICS OF DIESEL CRANKSHAFT BEARINGS

The solution to the problem of increasing the motor resource of an internal combustion engine (ICE) is directly related to the reduction of energy losses due to overcoming friction in the elements of systems, mechanisms, and complexly loaded tribo-couplers (TC). Among the mechanical friction losses, a special place isoccupied by the hydromechanical friction losses in the internal combustion engine. The reduction of energy losses to overcome friction is achieved by reducing mechanical losses by limiting the level of loading of the rubbing surfaces, by increasing the proportion of the liquid friction regime for the most critical in terms of reliability resource-determining complex loaded vehicles. For complexly loaded vehicles, the time and magnitude of the acting loads are characteristic, at which the position of the movable element in conjunction is characterized by high eccentricities. Such complexly loaded vehicles include the main and connecting rod bearings of the crankshaft, the “piston guide – cylinder liner” and “piston ring – cylinder liner” couplings, the thrust and thrust bearings of the ICE turbocharger, etc. One of the ways to reduce oil starvation isto texturize the contacting surfaces, which will increase the bearing capacity of a complex bearing due to the creation of many “micro wedges”. In particular, the texturing of the surface of the bearing shells of the crankshaft can be performed in the form of elliptical micro-holes, which allow you to save oil on the friction surface under any operating conditions of the diesel engine. The article provides an overview of the main types of microtexturing of friction surfaces of TC. A calculation model has been created and a calculation analysis program has been developed for the internal combustion engine “crankshaft neck-liner” TC. The calculations ofthe hydromechanical characteristics (HMC) of the vehicle for various types of microtexture were performed using the connecting rod bearing of the diesel engine CHN 13/15 as an example.

ASSESSMENT OF RELIABILITY OF THE DRIVER – CAR – ROAD – ENVIRONMENT (DCRЕ) SYSTEM IN MOUNTAIN CONDITIONS

The article provides an assessment of the factors affecting the reliability of the DCRE system in mountain conditions. A more detailed classification of factors affecting the reliability of the DCRE system in mountain conditions is given for such groups of features as design and technological, operational and road-climatic. In addition, the article gives a classification of factors affecting the reliability of the DCRE system in mountain conditions based on controllability. In both classifications, particular importance is given to such factors as altitude, the reliability structure of the elements of the DCRE system, the reliability structure of the elements of the car, the subsystems of the DCRE system, the probabilistic nature of the influence of external influences on the elements of the car, the types and frequency of maneuvers, their dynamism, etc. The specifics of the influence of the main factors determining the reliability and durability of heavy-duty mining car in difficult and extreme conditions of cargo transportation in mountain conditions are analyzed and justified. To assess the influence of the stochastic nature of external influences that determine the dynamics of the interaction of the car with the roadway, depending on the sample size, the nature of the process, the state of the object under study and other factors, the most rational methods based on probability theory are substantiated. Three of them are recommended for an adequate assessment of the impact of external influences on the output indicators of the car, in particular to assess the process of interaction of the car with the roadbed, which has a probabilistic character. Among the recommended estimation methods are included such methods as the method of approximating the external load with a periodic function such as a sinusoid with certain values of the amplitude and period of oscillation, the method of expanding the periodic function in Fourier series and the probabilistic-statistical method, which is based on taking into account the action of many random factors characterized by stable frequency.

FORMATION OF GEARINGS FROMINVOLUTE-BEVEL GEARS

When designing modern machine drives based on traditional gears, in some cases there are problems associated with the complexity of the rational layout of the drive, and its load capacity. These problems can be solved using gears with involute bevel wheels. The involute bevel gear (IBG) is the most common case of gearwheel with an involute tooth profile. In IBG, when teeth are formed, the tool displacement coefficient varies linearly along the width of the gear rim. The geometry of the IBG and the gears made up of them was developed at the Department of Technical Mechanics, a branch of SUSU in Zlatoust. The article presents the main dependencies necessary for determining the size of the IBG and possible schemes for the formation of gears with the IBG. Gearings on the base can be formed at any position of the axles of the gears in space. This paper presents schemes for the formation of spatial (on intersecting axes), bevel (on intersecting axes), cylindrical (on parallel axes) transmissions with IBG. The advantages of gears with IBG (layout, operational, load) in relation to gears from traditional cylindrical and bevel wheels are shown. Thus, transmissions from the IBG on intersecting axes make it possible to transmit rotation at arbitrarily small distancesbetween the axles of the wheels with the required contact localization, up to obtaining a linearcontact in gearing of the teeth. Bevel gears with IBG are less sensitive to errors and can be formed at small interaxial angles, which is problematic for traditional bevel gears. Cylindrical gears with IBG differ from traditional ones in increased load capacity and smooth operation. In addition, they can be used as backlashless and single-sided gears. Thus, gears with IBG due totheir versatility and advantages over traditional gears can be successfully used in modern drives(aviation, space, automobile, etc.) with any arrangement of gear axles in space.

HYDROJET EJECTION HYDROMETER OF BULK MATERIALS. WORKFLOW AND CHARACTERISTICS

Among hydrodynamic machines, jet pumps are among the most common. The high demand for this type of pump is due to their following features: the absence of moving parts and the simplicity of the device, small overall dimensions and weight, high self-priming ability, the ability to pump aggressive media and hydraulic mixtures containing solid impurities. In the hydromechanical method of developing deposits of building materials (sand, gravel, etc.), jet pumps – hydraulic elevators are used for underwater mining and transportation of bulk materials to the sorting plant, and after classification of the sand-gravel mixture – hydraulic transport of sand and gravel to dumps through pipelines. With this method of laying the finished product, the jet pump creates a static pressure of the hydraulic mixture, sufficient for its transport to the dump. However, another way of laying the finished product in dumps is also possible – through the air with a slurry stream. In this case, the jet pump performs the function of a hydrometer – a device for creating a high-speed slurry jet. A review of the literatureshowed that this mode of operation of the jet pump was not investigated. The effective operation of the jet pump-hydrometer depends on the ratio of the areas of the outlet section of the nozzle and the normal section of the mixing chamber, the relative density of the slurry in the input hopper. For each value of the relative density of the slurry, there is an optimal ratio of the areas of the nozzle and the chamber at which the specific energy consumption of the active stream will be minimal. The aim of this work is to determine and analyze the characteristics of an ejection hydrometer and to identify the most effective modes of its operation.