The influence of spray lubrication of an open gear transmission on the tooth wear and transmission efficiency

W artykule przedstawiono wpływ rodzaju smarowania na tribologiczne zużywanie i niezawodność eksploatacyjną otwartych przekładni zębatych w układach napędowych młynów kulowych i pieców obrotowych. Przeanalizowano wpływ rodzaju smarowania na zużycie energii elektrycznej przy tego typu układach napędowych. Badania i analizy obejmowały wielkogabarytowe przekładnie zębate, wykorzystywane w układach napędowych wymienionych urządzeń, pracujące między innymi w przemyśle: cementowym, chemicznym, górniczym, energetycznym czy celulozowym.The article covers the issues of the influence of the type of lubrication on the tribological wear and operational reliability of open gears in the propulsion system of ball mills and rotary kilns. The influence of the type of lubrication on electricity consumption for these types of drive systems was analysed. The research and analysis included the large-size gear transmissions used in the drive systems of these devices, working among others in the following industries: cement, chemical, mining, energy, or cellulose. It has been found that the plastic grease spray lubrication with addition of graphite is more effective compared to the dip lubrication of gear transmissions. Spray lubrication reduces the friction coefficient of rolling-sliding between mating teeth, which leads to a reduction in electricity consumption in the range of 1–3%, and it also extends troublefree transmission operation. The depositions of the grease in the micro-irregularities on the surface of the tooth and the filling of the pores on the surfaces by the grease with graphite were beneficial. Due to the very heavy operating conditions of the transmissions, the high concentrated pressures occurred on the surface of the tooth. This can lead to the penetration of carbon particles into the surface layer of the steel from which the gear wheels are made, and this leads to changes in the structure of the steel and in the hardness of working with each tooth surface