Generally speaking, the correct use of imported bearings can achieve fatigue life. However, in case of accidental early damage, it can no longer be used. Unlike fatigue life, this early damage is called a failure or accident.
Most of them are caused by poor consideration of installation, use and lubrication, foreign matters invading from the outside or insufficient research on shaft and bearing seat.Causes and Countermeasures of bearing oil damage ina
Causes and Countermeasures of bearing oil damage ina
The damage state of INA Bearing, such as the scratch of the ring retaining edge of roller bearing, may be caused by insufficient lubricant, improper brand, defective oil supply and drainage structure, intrusion of foreign matters, installation error of oil-free bearing or excessive deflection of shaft, or a combination of the above reasons.Causes and Countermeasures of bearing oil damage ina
Therefore, only investigating the bearing damage, it is difficult to know the real cause of the damage. However, if we fully understand the machine, working condition and peripheral structure of the bearing, understand the situation before and after the fault, and then analyze the damage of the bearing and various related reasons, we can prevent the recurrence of similar faults. Representative causes and Countermeasures of bearing damage.Causes and Countermeasures of bearing oil damage ina
Even if the advanced manufacturing technology is adopted to process INA Bearing parts. Observe the change of reading with preload. Preloading method has its disadvantages, which are well known. The working surface will always keep the dial indicator against the appropriate part of the bearing end face or shaft.
In severe cases, metal peeling and large-area random scratches occur on the contact surface; In general, mechanical damage of oil-free bearing refers to different levels of groove marks on the alloy surface of bearing bush.
Contact surface damage and ablation exist at the same time. The main reason for bearing mechanical damage is that the surface of ina bearing is difficult to form oil film or the oil film is seriously damaged.Causes and Countermeasures of bearing oil damage ina
Plastic deformation and cold work hardening occur on the outer surface layer, and ina bearing is under the repeated action of cylinder pressure (impact load). The deformation capacity is lost locally, and the grain is gradually formed and continuously expanded. Then, with the falling off of wear debris, the loaded outer layer forms a hole.
Generally, when the bearing bush is pitted, the pit first appears, and then the pit gradually expands and causes the cracking of the alloy layer interface. The crack extends along the parallel direction of the interface until it peels off.
The main reason for cavitation of oil-free bearing is that the sudden change of the cross section of structural elements such as oil groove and oil hole causes strong disorder of oil flow, and bubbles are formed in the vacuum area with disorder of oil flow, and then cavitation occurs due to the collapse of bubbles due to the increase of pressure.
Cavitation usually occurs in the high load area of the bearing, such as the lower bearing bush of the crankshaft main bearing.
First of all, the reasonable design and advanced nature of the structure will lead to longer bearing life. The manufacturing of bearings generally goes through multiple processing processes such as forging, heat treatment, turning, grinding and assembly. The rationality, advanced nature and stability of all the processing technologies will also affect the life of bearings.
Among them, the heat treatment and grinding processes that affect the quality of finished bearings are often more directly related to the failure of bearings. In recent years, the research on the metamorphic layer on the working surface of bearing shows that the grinding process is closely related to the surface quality of bearing.Causes and Countermeasures of bearing oil damage ina
The metallurgical quality of imported bearing materials was once the main factor affecting the early failure of rolling bearings. With the progress of Metallurgical Technology (such as vacuum degassing of bearing steel), the quality of raw materials has been improved.
The proportion of raw material quality factor in ina bearing failure analysis has decreased significantly, but it is still one of the main influencing factors of oil-free bearing failure. The proper selection of bearing material must still be considered.Causes and Countermeasures of bearing oil damage ina
The main task of imported bearing failure analysis is to find out the main factors causing bearing failure according to a large number of background materials, analysis data and failure forms, so as to put forward targeted improvement measures, prolong the service life of INA Bearing and avoid sudden early failure of oil-free bearing.Causes and Countermeasures of bearing oil damage ina