Browsing by Author "Bychkova, D. M."

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    Comparative Mathematical Analysis of Transmission and Axial Disc Brakes
    (Український державний університет науки і технологій, Дніпро, 2024) Monia, Andrii G.; Bychkova, D. M.
    ENG: Purpose. A comparative study of axial and transmission disc-pad brakes. The task of the work is the theoretical determination of the braking torque and the force of pressing the pads against the disk in different braking modes, as well as the determination of the area of optimal operating modes of the indicated brakes. The methods. Comparative mathematical analysis. Findings. With equal dimensions of the two types of disc brakes and an even distribution of the braking torque between the wheel pairs, the transmission creates a greater braking torque on each of the four wheels of the traction section due to the gear ratio of the axial gearbox. Installing a disc brake on the axle of a wheel pair with a central location of the drive gear wheel allows you to change the masses of the half-axles, which means to eliminate self-oscillations that destroy the drive axle under the action of resonant torsional vibrations. The heavier the rolling stock of the train being transported, or the greater the slope of the track on the descent, the smaller the braking torque can be applied to the wheel pair, to exclude its blocking and clutch failure. The obtained results show that the smaller the moments of inertia and stiffness of the wheels, half-axles and transmission elements (gear wheels, shafts, etc.), the smaller the braking torque required to stop the locomotive on the same braking path. But the higher the speed of the train before braking, the greater the braking torque should be. Originality. The obtained results show that the smaller the moments of inertia and stiffness of the wheels, half-axles and transmission elements (gear wheels, shafts, etc.), the smaller the braking torque required to stop the locomotive on the same braking path. But the higher the speed of the train before braking, the greater the braking torque should be. Practical value. Taking into account the above-mentioned features of disc brakes, multilevel backup of brake systems of heavy mining locomotives operating on track slopes of up to 50 ‰ should be considered justified and necessary. Such locomotives should have both disc transmission brakes, as more efficient, and disc axle brakes as safer.
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    Mathematical Modeling of Rational Parameters of the Mine Locomotive Disc Brake in Computer Systems
    (Український державний університет науки і технологій, Дніпро, Україна, 2023) Monia, Andrii G.; Bychkova, D. M.
    ENG: Purpose. Determination of braking torque parameters that provide high braking performance of a mine locomotive by mathematical modeling of the braking of a mine locomotive by a disc brake that creates a pulsating braking torque. Methodology. Forced vibrations of the elements of the wheel-motor unit (WMU) of a mine locomotive in the process of braking with a disc brake are studied by the methods of differential calculus and mathematical modeling. Integration of the system of differential equations is performed by the Runge-Kutt method. Findings. A comparative analysis of a mine locomotive braking by a disc brake, which creates a constant and pulsating sinusoidal braking torque with a different number of sinusoid periods per revolution of the wheel pair, is carried out. It has been proved that the pulsating sinusoidal braking moment generated on the axle of the wheel pair equal to the sum of the constant component and the amplitude of the oscillations of the variable component multiplied by the sine of the product of the number of sinusoid periods per revolution of the wheel pair by its angular coordinate provides higher braking characteristics than the constant braking moment. It is shown that pulsating braking torque reduces the braking time and braking distance of the mine locomotive. The values of the amplitude of oscillations, which depend on the average value of the braking torque, and the number of periods of the sinusoid per one revolution of the wheelset, at which the greatest effect is achieved, are determined. Originality. For the first time, a mathematical model has been developed for braking a mine locomotive by a disc brake, which creates a pulsating braking torque on the axle of the wheel pair, depending on its angular coordinate, taking into account the nonlinear dependence of the adhesion coefficient on relative slip, on the basis of which the efficiency of a disc brake with a multi-sector disc is shown in comparison with a disc brake with a homogeneous disk under various conditions of the rail track. Practical value. The research results make it possible to determine the parameters of a disc brake with a multi-sector disc located on the wheelset axle and on the engine shaft, which provide the highest braking efficiency.