A mathematical model of the motion of a single particle on the working surface of the disk (working body) of a centrifugal mill is presented. The model takes into account the influence of the...

The paper presents the study of the process of lengthwise rolling. This process is characterized by elastic-plastic deformation, slipping friction, seizing friction, rest friction arising in the contact area between rolls and strip. The rolling process during the contact between rolls and strip is described, as well as rolling forces causing elastic deformation of metal products. The work of elastic-plastic deformation and friction is the cause of contact heat forming during lengthwise metal rolling. The contact temperature can vary depending on its value from room level (at low energy values and small deformation rates) to high temperature (at high energy values and large deformation rates). Friction during plastic deformation is described by complicated relationship, and it varies from classic friction with its dependence on l/h during rolling and upsetting. If l/h relationship is less than 0.5, seizing area spreads along whole length of curve seizing and tangential friction forces don’t reach the maximal values. If l/h relationship is 0.5–2.0, seizing areas spreads along whole length, while tangential forces reach maximal values in the entrance and exit of a roll area. It is necessary to differ average contact temperature, volumetric and temperature burst owing to discreteness of a contact area. The formulas for temperature calculation in friction conditions, depending on technical conditions, thermal, physical and mechanical properties of materials and contact geometry for parabolic case of variation of friction intensity by time, are concluded in the paper based on solution of Fourier parabolic equation of heat conductivity. The formula for calculation of the contact temperature between a roll and rolled strip is concluded. Recommendations for use of the formulas are given. If we know the optimal and experimentally found rolling temperature (it is individual for each metal), we can solve the backward task, i.e. determine the rolling procedures via presented formulas.

This article deals with the problems of unloading the axes of wheel sets of locomotives of industrial railway transport by the example of exploitation in conditions of open chasing works. Studies have established that the displacement of the center of mass of an open-pit locomotive depends primarily on the height of the center of gravity, the height of the location of the hook of the locomotive coupling over the rails and the slope of the track. Therefore, to increase the coefficient of utilization of the adhesive weight and to ensure rational operating conditions, it is necessary to provide an adjustable displacement of the locomotive's center of mass taking into account the actual operating conditions, including when driving on rectilinear and curvilinear sections of the track. Analysis of calculation results showed that for the traction unit OPE1 when driving in traction mode in close to the extreme operating conditions, it is necessary to provide a constructive solution for displacement of the center of mass of the locomotive up to 0.5 m in the course of movement of the locomotive's center of mass.

The results of theoretical and experimental investigations of the interaction between the working surfaces of wheel treads of open-pit locomotives with rails are presented. The actual values...

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