Purpose. To determine the parameters of elastic-dissipative connections in the running gear of the mine vehicle ensuring its safety motion through vertical and horizontal irregularities of the rail track under given angular kinematic movability of its output elements. Methodology. We have formulated a differential equation system using Lagrange equations of the 2nd order, which have been solved in Wolfram Mathematica software after differentiation. The calculated data have been used in order toidentify the values of dynamic loadings affecting the output elements of the mine vehicle and for further evaluation ofelastic-dissipative connection parameters. Findings. The mathematical simulation and analysis of dynamic processes of mechanical system "mine vehicle - railroad" has been carried out. The values of dynamic load of output elements of the running gear (on the example ofmine cart ВГ-3.3-900 with movable and resilient mounting of wheel) have been determined. The received data became initial data for calculation of the elastic-dissipative connection "wheel centre - tread". We have determined that the additional kinematic wheel movability provided by the elastic-dissipative properties is one of the main factors that influence the safety factor at curvatures.

Визначено раціональні параметри транспортних засобів, що модернізуються та тільки створюються. За допомогою комп'ютерного моделювання досліджено динамічні процеси механічних систем. Складено системи диференціальних рівнянь Лагранжа другого роду та розв'язано у WolframMathematica. Підготовлено початкові умови та масово-інерційні характеристики за допомогою Компас 3D. Перевірено достовірність одержаних результатів за допомогою "UniversalMechanism". Для аналізу динаміки механічних систем шахтного рейкового транспорту запропоновано метод комп'ютерного моделювання, що надає змогу використовувати параметризацію комп'ютерної моделі для варіювання значень характеристик моделі на стадії проектування з оцінкою динамічних показників і механічних напружень елементів конструкції, довговічності та ресурсу виробу з урахуванням умов експлуатації. Вирішення цих задач реалізується у відповідних математичних моделях, що описують технічні рішення, або у розроблених 3D моделях CAD/CAM програм, що описують інерційні, геометричні та кінематичні параметри, силову взаємодію. Підхід полягає в розробці структурної схеми дослідження, складанні 3D моделі та розрахункової схеми для рівнянь руху, одержанні динамічних показників системи та верифікації результатів. Достовірність теоретичних та експериментальних досліджень досягається завдяки використанню сучасних підходів у моделюванні динамічних процесів. Підготовка та застосування в математичних моделях вихідних даних різноманітних CAD/CAM програм надає можливості проводити числові дослідження з різноманітними параметрами системи.

Індекс рубрикатора НБУВ: З251.3 + О162.13

Рубрики:

Електричні акумулятори

Електричні акумулятори

Шифр НБУВ: Ж16377 Пошук видання у каталогах НБУВ 

Purpose. Research on surface roughness in turning of traction motor shaft of electric vehicles, depending on the measure of the main cutting edge angle and rounded-off radius of the cutter. Analysis of the impact of vitrified aluminum oxide disk characteristics on the surface profile after wheel dressing. Methodology. The research was based on existing empirical dependencies that describe the profile of the workpiece surface being machined during turning and grinding. In this case, probability-theoretical methods and methods of straight-line strip chart recording before and after grinding were used. Findings. The irregularity of the surface roughness that occurs after turning of the traction motor shaft of electric vehicles has a significant impact on the choice of geometric parameters of the cutting tool. Most often, roughness is considered as a deterministic set of irregularities of the same size and shape. There are dependencies built from the analysis of the kinematics of the treatment process and the shape of the tool cutting part. It is advisable to consider the profile of the roughness of treated surface of the part as the sum of all random deviations superimposed on an ideal geometrically calculated profile. In this case, the roughness profile will have a probabilistic character, which was formed as a result of complex stochastic processes that occur during machining. Depending on the physical phenomena that accompany the treatment process of the material, the levels of the random component should be adjusted depending on the cutting speed. Originality. For the first time, a composite model of surface roughness is considered taking into account the influence of a random component on the geometric parameters of the cutting tool. Impact analysis of the vitrified aluminum oxide disk's characteristics parameters on the surface profile after dressing the cutting wheel face was conducted. Practical value. The assignments of cutting conditions, taking into account the rational parameters of the main cutting edge angle and apex spherical radius of a cutter will ensure the necessary surface quality after machining motor shaft of electric vehicles and their collector-and-brush assembly units, which will significantly affect the overall efficiency of the electro-mechanical system of the vehicle. Regularities of forming and describing the relief of a cutting wheel face will make it possible to clarify the number of active gains in the wheel-workpiece contact, the thickness of the cut by individual grains and the components of the cutting force during grinding, which will lead to an increase in the quality of processing the traction motor shaft of an electric vehicle.

Purpose. To formulate the requirements for the basic properties of lubricants suitable for use in the systems of on-board lubricators of rail vehicles. To develop a generalized algorithm for controlling the devices of the lubrication system of rail vehicles and to propose a method for controlling the lubrication system of the wheel flanges of a rail vehicle, which makes it possible to turn on the system in advance in order to prevent an increase in the interaction forces of the wheel flanges and rails during the entry to the curved section of the rail track, as well as on the turnouts. Methodology. Research methods include statistical analysis of the results of experimental tests of the properties of existing and proposed lubricants on the STs-2 friction machine and in the conditions of real operation of the rolling stock of JSC "Ukrzaliznytsia". Findings. Based on the results of operational tests, it was found that Relsol-M lubricant, which is regenerated, homogenized and modified with solid lubricating impurities, even with an expired shelf life, retains and demonstrates the "transfer effect" on all wheels of the VL11m/6 locomotive, and also slows down the wear rate of the combs of the wheel rims which were not chiseled during the tests by 3,57 times and the combs of the bandages which were chiseled during the tests by 4,25 times. "Mariol NT" demonstrated the effect of reducing the intensity of wear processes of the ridges of locomotive tires in the mode of freight traffic in relatively light track conditions by 2,5 times, and in more difficult road conditions - by 5 times. Originality. Requirements for the basic properties of lubricants, which are suitable for use in on-board lubricator systems of rail vehicles, have been formulated. Practical value. A generalized algorithm for controlling the lubrication system of railway rolling stock is developed and a method for controlling the lubrication system of the flanges of the rail rolling stock is proposed, which makes it possible to turn on the lubrication system in advance when a rail vehicle enters a curved section of the track, as well as a turnout.

Purpose. Mathematical representation of the geometry of the overhauled valve seat surfaces in the shape-forming process in the auto repair industry. Methodology. The research methods were based on: the theory of cutting and metalworking scientific positions, theoretical foundations of the technology of mechanical engineering and overhaul repairs; the basics of technical operation and vehicle structure; provisions of standardization, technical measurements; means of mathematical modelling, statistics and programming. Findings. The geometric 3D-model of the processing surfaces of valve seats has been presented, which is used in the overhaul process of these parts, which is basic in the general model of the shape-forming system, which allows controlling the shaping parameters with the required precision due to the structure of the model itself and introducing the results of processing particular models: interpolation (to assess the worn surfaces state) and optimization (for determining the volume of cut material and setting cutting conditions). Originality. For the first time a particular mathematical 3D-model of the general shape-forming system has been developed, consisting of other particular mathematical models (interpolation and optimization), which gives a geometric representation of the processed valve seat surfaces within their overhaul in the auto repair industry. Practical value. The proposed mathematical 3D-model allows: implementing the shape-forming process adequately within the simultaneous boring of three inner conical surfaces by copying with a profile cutting plate, which provides the required parameters of precision and quality of processing during the valve seats overhaul; implementing the results of the flaw detection process of worn surfaces of valve seats with a complex-variable topography due to usage of the of roundness- and profile-diagrams and method based on an interpolation geometric 3D-model; introducing an optimization model to determine the optimal volumes of cut material and the rational cutting modes select. The MathCAD software package has been developed, which allows having a graphical performance of the formed surface based on the interpolation model.

Шифр НБУВ: Ж16377 Пошук видання у каталогах НБУВ