One of the greatest mechanical challenges in rotary kiln maintenance today is maintaining the efficient operation of girth gear and pinion meshing. Misalignment during production creates uneven and unstable stress concentration on the teeth, resulting in component damage. An early-warning system can inform kiln operators long before the mechanical problem and any damages appear. By Paweł Kędzior, Havec Engineering Co, Poland.
Misalignment of the girth gear affects every rotary kiln at some point in its life. This is because it is directly related to the kiln shell. Sudden temperature changes on the shell circumference close to the girth gear, eg due to brick lining failure or coating collapse, cause thermal crank at the kiln shell. This crank changes the geometrical position of the girth gear, which is directly attached to the kiln shell, risking the correct operation of meshing between the girth gear and pinion.
To monitor this misalignment effectively, two basic parameters have to be continuously controlled: axial run-out and radial run-out.
