MNIPIITI, Moscow, Russia:

A. M. Keropyan, Chief Researcher, Associate Professor, Doctor of Engineering Sciences, am_kerop@mail.ru
A. V. Kalakutsky, CEO, Associate Professor, Candidate of Engineering Sciences

NUST MISIS, Moscow, Russia:

L. I. Kantovich, Professor, Doctor of Engineering Sciences

Physically, railroad movement involves interaction between rails and wheels. Parameters of this interaction govern the locomotive power, the movement safety and the main engineering-andeconomic performance of trains and rails. The theoretical and experimental research proved the need of the continuous control over geometry of the cross profile of two interacting cylindrical bodies having mutually perpendicular axes, which is a wheel-and-rail system of locomotives in open pit mines. It is found that the rail profile geometry in open pits has a direct influence on the true value of the wheeland-rail contact area which, at the strength of the friction factor, ensures the required pulling force of rail transport. The rail transport in open pit mining differs from the general use rail transport by using electric locomotives and multi-purpose traction assemblies which have static axial load up to 300 kN. Moreover, subject to production necessity, open pit mines use motor dumpcars having axial loading up to 350 kN. Continuous control of the rail profile geometry in operating open pit mines is of the high concern currently. The increase in the true value of the wheel-and-rail contact areas reduces the contact stresses, extends the service life of the railway profile and adds up to the pulling force of a locomotive. Being selected from the proposed formulas, the combinations of the curve radii of the wheel-and-rail faces, given the running clearance in a range from 0.2 to 0.8 mm, ensure the friction factor increased by 9 % owing to the conformal contact at the increased true area of interaction between two cylindrical bodies having mutually perpendicular axes.

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