Статті КЕкІ (ДМетІ)

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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.
Mathematical Model of Pressure and Temperature Distribution in Working Area of Mine Locomotive Disc Brake
(Dnipro University of Technology, Dnipro, 2024) Monia, Andrii G.
ENG: Purpose. Calculate the coordinates of the maximum temperature and the greatest pressure on the working surface for the rational parameters of the main elements of the disc brake of the mine locomotive with a multi-sector brake disc selected by mathematical modeling. The methods. To find the coordinates of the maximum temperature and the greatest pressure on the working surface of a disc brake with a multi-sector brake disc with selected rational parameters, mathematical modeling of temperature and pressure on the friction surface was carried out. Findings. On the basis of mathematical modeling, the maximum temperature and its coordinates and the greatest pressure on the working surface of a disc brake with a multi-sector brake disc were found. It is shown that the maximum temperature on the friction surface of the main elements of the disc brake with the selected parameters in specific mine conditions under the most unfavorable operating conditions will not exceed the permissible value. The originality. A mathematical model of braking of a mine locomotive with a disc brake was developed, which creates a pulsating braking moment on the axle of the wheel pair, which depends on its angular coordinate, taking into account the non-linear dependence of the coupling coefficient on the relative slip, on the basis of which the parameters of the braking moment are established, which allow to improve the braking characteristics. Practical implementation. A scientifically based engineering methodology for choosing rational parameters of the disc brake of a mine locomotive and determining the dynamic and kinematic characteristics of the drive of a mine locomotive when braking with a disc brake with a multi-sector disc has been developed. An analytical solution to the non-stationary thermal conductivity problem of finding the temperature field that occurs in the brake disc and friction linings of the disc brake of a mine locomotive when the linings are made in the form of a ring sector was obtained, on the basis of which the dependence of the relative temperature on the friction surface of the brake was found of the disk over time during cyclic braking.