Аннотация
This article examines the pressing scientific and practical challenge of improving the operational reliability and wear resistance of friction units in lever-hinge mechanisms (LHM) of mine hoist braking systems. The authors provide a detailed analysis of the kinematics and operating characteristics of pin-sleeve friction units using equipment operated at the Kamyshinskaya and Artemyevskaya mines as an example. It is demonstrated that severe operating conditions - high radial loads (80 ÷ 150 kN), alternating pulses, constant vibration, and the presence of abrasive dust - lead to the degradation of protective oxide films, fretting corrosion, and an avalanche-like increase in radial clearances in the hinges. Bushing wear triggers dangerous edge pressures, fatigue stresses in the pin body, and a sharp drop in the mechanical efficiency of the drive. To address this issue, comprehensive comparative tribological tests of various antifriction materials were conducted using a ball-on-disk design on a Microtest automated tribometer under strictly controlled laboratory conditions. The experiments provided a detailed study of the patterns of change in the mass of mating bodies, the dynamics of the friction coefficient over a distance of 100 m, and the geometric parameters of the resulting wear craters for SCh-15 gray cast iron, traditional bronze, grade 45 steel with a MoS2 solid lubricant coating, and ZhGr3M porous iron-graphite with molybdenum. The quantitative data obtained and the resulting graphical dependencies allow for a scientifically substantiated choice of material for upgrading friction units and transitioning to maintenance-free hinges.