Inspection Method of Bearings
Bearings are one of the most important components of machines. During operation, the bearing needs to bear alternating loads and cyclic shock loads to ensure correct installation and good lubrication. Therefore, it is necessary to regularly inspect the bearing, so that the bearing can be used with reliable performance for a long time.
1. Bearing inspection method
1.1 Visual inspection
Check whether the bearing lubricant has been damaged or aging, and also check whether the bearing has rust spots, scratches and other damage.
1.2 Dimension inspection
Check the inner ring, outer ring, rolling body, rolling surface and raceway of the bearing. It is necessary to measure the straightness, roundness, chamfer, clearance and other sizes in accordance with the drawings and the specified tolerances.
1.3 Performance inspection
The main performance parameters of rolling bearings are bearing rotation accuracy and bearing noise. The bearing accuracy is divided into P0, P6, P5, P4 and P2 categories, of which P0 has the highest accuracy and P2 has the lowest accuracy. Bearing noise is expressed in decibels, the general noise value is not more than 65dB.
2. Main Bearing Inspection Steps
2.1. Visual inspection
(1) Check the bearing appearance and identify the bearing model number.
(2) observe whether there are impact marks, cracks and other phenomena on the surface of the bearing, and determine whether it is suitable for use.
(3) Scrub the bearing and observe if there is any foreign matter such as dust or rust on the bearing.
(4) Observe whether the bearing has been heated and corroded, and burn it with a lighter to observe whether there is any smoke and peculiar smell.
2.2 Measure the size
Measure the dimensions of the inner and outer diameters of the bearing, the total width of the bearing, the diameter of the rollers, and the spacing of the rollers of the bearing.
2.3 Bearing clearance and preload test
(1.) A bearing preload test is conducted to check whether the bearing clearance is appropriate, and the test should conform to the specific provisions.
(2) The bearing preload test and following assembly requirements must conformed to the relevant provisions in the technical conditions.
2.4 Noise test
Vibration and ultrasonic testing of the bearing to check the noise level and bearing running noise.
2.5 Load test
Conduct a bearing load test. The bearing radial and axial load value and their relative ratio should meet the requirements of the performance and use requirements, and should not exceed the parameters corresponding to the bearing strength limit.
2.6 Quality inspection
The bearing adopts visual inspection and non-destructive testing such as metallographic inspection, hardness test, magnetic inspection and chemical composition analysis to detect the quality of the bearing.
3. Conclusion
In order to ensure the normal operation of the bearing, it is very important to regularly examine the bearing. The common test methods include visual inspection, dimension inspection, performance inspection and quality inspection. The inspection must be done in accordance with the relevant regulations, and measures should be taken to maintain the normal performance of the bearing in order to extend its service life.
