While taking bearing temperatures and walking the rotary kiln, check the rotary kiln to see the direction of thrust. On standard rotary kilns with thrust rollers both uphill and downhill of the thrust Tyre, it is important to note that the rotary kilns are on a daily basis. If it is one direction, is it riding on the thrust roller continuously or does it come off of the thrust roller for a percentage of the kiln rotation? This is important to know because excessive thrusting of the kiln will cause wear of the thrust roller and contact between the gears and pinion can be reduced as a result. Furthermore, excessive thrusting of a kiln will increase the amps on the drive motor, which will essentially draw more power to operate the kiln. On kiln rotary that has hydraulic thrust rollers only on the downhill side, it is equally important to monitor the pressure gauges on a daily basis and record the pressure. Monitoring the conditions mentioned above will be beneficial in determining if support roller adjustments are needed to control the axial thrust of the kiln. When monitoring axial thrust, make sure to check the feed rates and rpm of the kiln to determine if operating conditions are in normal parameters.

While checking the temperatures of the bearing housings and roller shafts, record the direction of thrust of each individual support roller. For example, it is the roller shaft in the downhill direction and thrusting the kiln uphill, or is it in the uphill direction and thrusting the kiln downhill? The direction of the rollers shaft can be determined by sounding end cap on some kilns, while other rotary kilns will require opening a view port to see the direction of the shaft. The maintenance staff can demonstrate how to find the direction of thrust. The reason why checking the direction of the support roller shafts is important to aid the maintenance staff in knowing which roller needs to be moved if there is excessive axial thrust of the kiln. Also, if there are signs of hot bearings on a support roller it is important to know the direction of thrust of the rollers shaft.