The Inspection of Rolling Bearing Operation Test

Aug 03, 2021

After the bearing is installed, in order to check whether the installation is correct, it is necessary to perform a running check. Small machines can be rotated by hand to confirm whether they rotate smoothly. The inspection items include poor operation due to foreign objects, scars, and indentations, unstable torque due to poor installation and poor processing of the mounting seat, excessive torque due to too small clearance, installation error, and seal friction, etc. If there is no abnormality, power operation can be started.

Large machinery cannot be rotated manually, so immediately cut off the power after the no-load start, and the machinery runs idly. Check for vibration, noise, and contact with rotating parts. After confirming that there is no abnormality, power operation can be started.

The power operation starts at a low speed with no load and slowly increases to the rated operation under the specified conditions. The items to be checked during the test run are whether there are abnormal sounds, changes in bearing temperature, leakage or discoloration of lubricants, etc. If an abnormality is found, the operation should be stopped immediately, the machine should be inspected, and the bearing should be removed for inspection if necessary.

Rolling bearing temperature can generally be estimated based on the external temperature of the bearing seat. However, it is more accurate to use the oil hole to directly measure the temperature of the outer ring of the bearing. The bearing temperature gradually rises from the start of the operation, and usually stabilizes after 1 to 2 hours. If the bearing is installed improperly, the temperature will rise sharply, resulting in abnormally high temperatures. The reasons include too much lubricant, too small bearing clearance, poor installation, and too much friction in the sealing device. In the case of high-speed rotation, the wrong choice of bearing structure and lubrication method is also the reason.

The rotating sound of the bearing is checked with a stethoscope, etc. Strong metal noise, abnormal sound, irregular sound, etc. indicate abnormalities. The reasons include poor lubrication, poor shaft or bearing seat accuracy, bearing damage, and foreign matter intrusion.

For medium and large cylindrical roller bearing or taper roller bearings, if grease lubrication is added, especially in winter, low temperature and other environmental conditions, there will be a problem of rolling noise. Generally, even if rolling noise occurs, the temperature of the bearing will not rise, and the fatigue life will not be affected. The life of the grease can be used normally.

If you have any questions during the bearing use, please contact us.