Investigation on the Effect of Different Parameters in Lubrication Conditions in the Roller Bearings of the Rotary Kiln of Pelletizing Plant of Butia Iranian Steel Company

Roller bearings are one of the most widely used mechanical components. The load on the bearing is supported by the pressure that is developed in fluid-film and thus the lubricant is less able to escape and a longer-lasting lubricant film is generated called elastohydrodynamics lubrication (EHL). In general, to understand the lubrication regimes, it is important to consider the thickness of the lubrication layer. Lubricant film thickness is one of the most important parameters affecting the performance of bearings. In the present study, using theoretical equations and using MATLAB programing software, the load distribution along the rotary kiln was investigated and calculated, and then the film thickness of the lubricant (base oil and grease) in the roller bearings of the rotary kiln of Butia Iranian Steel Pelletizing Complex was calculated. Finally, the effect of various parameters such as rotary kiln speed, lubricant operating temperature, fill ratio, base oil viscosity and viscosity index of base oil were deliberated. The results showed that by increasing the base oil viscosity from 150 cst to 1000 cst, the film thickness increased by 239%. Furthermore, increasing the viscosity index caused small changes in the base oil viscosity in the operating temperature and reduced the starting torque at the beginning of application.