Tips for bearing operation quality inspection

After the bearing is installed, it shall be checked to ensure that the bearing is installed in place, rotates flexibly and has no clamping stagnation. If the bearing is installed improperly, the bearing temperature will rise rapidly and be damaged, and even major accidents such as bearing seizure and fracture will occur.
First, the rotating sound of the bearing is checked with a stethoscope, and strong metal noise, abnormal sound and irregular sound indicate abnormalities. The reasons include poor lubrication, poor accuracy of shaft or bearing seat, bearing damage, foreign matter intrusion, etc.
Second, the bearing temperature can generally be inferred from the external temperature of the bearing seat. However, it is more accurate to directly measure the temperature of the bearing outer ring by using the oil hole. The bearing temperature rises gradually from the beginning of operation, and the temperature is usually stable after 1 ~ 2 hours. If the bearing is not installed properly, the temperature will rise sharply, resulting in abnormal high temperature. The reasons are too much lubricant, too small bearing clearance, poor installation, excessive friction of sealing device, etc. In the case of high-speed rotation, the wrong selection of bearing structure and lubrication mode is also the reason.
Third, small machinery can be rotated by hand to confirm whether it rotates smoothly. The inspection items include poor operation caused by foreign matters, scars and indentation, unstable torque caused by poor installation and poor processing of mounting base, excessive torque caused by too small clearance, installation error and sealing friction, etc. If there is no abnormality, power operation can be started.
Fourth, large machinery cannot be rotated manually, so the power shall be cut off immediately after no-load start, the machinery idles, check whether there is vibration, noise, contact of rotating parts, etc., and enter the power operation after confirming that there is no abnormality.