Let's first briefly introduce the rolling sound of bearings. The size and sound quality of the rolling sound should be checked using a sound detector for the stamping outer ring needle roller bearings in operation. Advanced tools can accurately identify the problem. Even if the bearing has slight peeling or other damage, it will emit abnormal and irregular sounds, which can be distinguished by a sound detector.  

Continuing with the vibration inspection of the stamped outer ring needle roller bearing, it is very sensitive to the damage of the bearing, such as peeling, indentation, rust, cracks, wear, etc., which will be reflected in the bearing vibration measurement. Therefore, by using a special bearing vibration measuring device (frequency analyzer, etc.), the magnitude of the vibration can be measured, and the specific situation of the abnormality cannot be inferred through frequency differentiation. However, the values measured by each machine may vary due to the usage conditions of the bearings or the installation position of the sensors, so it is necessary to analyze and compare the measured values of each machine in advance to determine the judgment criteria.  

1. Measurement of shaft vibration

The measurement of axial vibration of stamped outer ring needle roller bearings can be carried out using contact measurement. A black gold contact surface is used, which is directly pressed onto the surface of the shaft neck by a spring. The black gold is rigidly connected to an extended metal rod and passes through the bearing shell, with the black gold surface tightly attached to the rotor surface. So, the vibration of the Wujin surface directly reflects the axial vibration, and the vibration of the extension rod rigidly connected to the Wujin surface also reflects the axial vibration. Using eddy current sensors to measure the vibration of metal extension rods avoids the interference caused by the excitation current passing through the coil output line on the measurement of bearing vibration.

2. The treatment of axial vibration of rear bearings often involves raising the elevation of stamped outer ring needle roller bearings or excitation machine bearings on site to ensure the shaft system's lift, resulting in severe edge contact of the rear bearings and causing significant vibration. The rear bearing is pre-set to be inclined, which ensures better contact between the bearing and the shaft neck, ensuring both the contact of the bearing and the lift of the shaft system, achieving good results. At the same time, it is necessary to ensure that the spherical surface of the shaft is well ground, and the self positioning function of the bearing shell is well utilized. In addition, the tightening force of the bearing shell should be adjusted appropriately, and the foot screws should not be loose. In this way, the problem of large axial vibration of the rear bearing can be basically handled properly.

3. Handling of large rotor disturbance force

When there is no measurement error in axial vibration and no problem of large axial vibration caused by rear axle tile edge contact, after analysis and judgment, it is true that the axial vibration exceeds the standard and the vibration is at the power frequency. The vibration can be improved by on-site high-speed dynamic balancing. As long as the method is appropriate, basically one balancing can be successful, at most two times.