Inspection items after bearing operation

After the bearing is installed, in order to check whether the installation is correct, an operation inspection must be performed. Small machinery can be rotated by hand to confirm whether it rotates smoothly. Inspection items include poor operation due to foreign matter, scratches, and indentations, unstable torque due to poor installation and poor machining of the mounting base, excessive torque due to too small clearance, installation errors, and sealing friction, etc. wait. If there is no abnormality, the power operation can be started.

Large machinery cannot be rotated manually, so the power is cut off immediately after starting without load, and the machinery is idling. Check whether there is vibration, noise, contact between rotating parts, etc. After confirming that there are no abnormalities, enter power operation.

Power operation starts from no-load low speed and slowly increases to rated operation under specified conditions. The inspection items during the trial operation include whether there are abnormal sounds, changes in bearing temperature, leakage or discoloration of lubricant, etc. If any abnormality is found, the operation should be stopped immediately, the machinery should be inspected, and the bearings should be removed for inspection if necessary.

The 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 bearing outer ring. The bearing temperature gradually increases from the beginning of operation, and usually stabilizes after 1 to 2 hours. If the bearing is poorly installed, the temperature will rise sharply and cause abnormally high temperatures. The reasons include too much lubricant, too small bearing clearance, poor installation, excessive friction of the sealing device, etc. In the case of high-speed rotation, the wrong selection of bearing structure and lubrication method is also the reason.

Use a stethoscope to check the rotating sound of the bearing. Strong metallic noise, abnormal sound, irregular sound, etc. indicate abnormality. The reasons include poor lubrication, poor accuracy of the shaft or bearing seat, bearing damage, foreign matter intrusion, etc.