，题目是 Check and Fault Treatment of Bearings in Operation 检查与轴承运转中故障处理
Check and Fault Treatment of Bearings in Operation
Bearings are important components in mechanical transmission, which ensure the relative movement between the stationary and rotating parts of the machine. Therefore, bearing faults are related to the safety, economic efficiency and normal operation of the machine. Therefore, it is very necessary to detect bearing faults in time and carry out corresponding treatment.
1 Check before use
(1) Cleaning and inspection of bearings. When selecting bearings, the appearance quality should be inspected in the factory to check whether there is any damage or other phenomenon. After the bearing is obtained, it should be installed according to the assembly principle, cleaned before assembly (especially anti-rust oil must be removed completely), and then carefully inspected before assembly. When inspecting, rollers, cages, and raceways should be handled lightly.
(2) Measure bearing clearance. The size of radial clearance between the inner and outer rings of the bearing is an important factor that affects the service life and performance of the bearing. Excessive clearance will cause the bearing to heat, vibrate and make noise. Severely overloaded bearings will also cause instantaneous seizure or forging wear. The measurement of the bearing radial clearance can be measured with a feeler gauge or with the help of a small unit bearing (oil pressure).
(3) Measure the outer diameter. Bearings should be measured and marked before assembly. After installation and before operation, check whether the roller rotation is normal and whether there is axial displacement of the bearing ring, which can be checked with a gauge. When the bearing is installed in a high-precision machine with a housing assembly, it is also necessary to measure the generated outer diameter after assembly to ensure that the clearance of the bearing is normal.
(4) Measure bearing vibration. If the bearing vibration is normal during idling, it is judged that the bearing is basically qualified, if the bearing has vibration (strong vibration, weak vibration and pulsating vibration) and rumbling noise, it can be further judged that the quality of bearing is unqualified.
2 Fault diagnosis and treatment
(1)Burning failure. It is mostly caused by overheating due to too much loading or bearing fatigue life exceeding the rated service life. The overloaded line may be on the outer ring, inner ring or both sides of the rolling element. When it is found, stop the machine and check the reason.
(2)Peeling failure of the rolling body surface. This type of damage is caused by poor lubrication, improper installation clearance and bearing selection of insufficient size. When such damage is found, it must be stopped and the reason should be found out.
(3) Peeling of raceway surface. It is usually caused by poor lubrication, improper selection of bearing size and too much loading. When found, stop the machine and check the condition of bearing.
(4) Fatigue pits. The causes of surface fatigue pits include improper bearing size, inner and outer ring raceway surface roughness, improper bearing clearance, etc. When found, the bearing should be stopped immediately, the reason should be investigated, and the bearing should be wiped clean to check the surface fatigue pits. If the number is small, the fatigue pits can be filled with thin grease for repair.
(5) Noise failures. It is usually caused by improper bearing selection, installation clearance too large or too small, or incorrect installation posture.
Therefore, in the operation of bearings, it is necessary to do a good job in bearing check, lubrication and fault diagnosis and treatment to ensure the normal operation of bearings.
