Three factors of failure of tapered Roller bearings

Contact fatigue failure.

Contact fatigue failure refers to the failure of the bearing working surface due to the effect of alternating stress. Contact fatigue falls on the working surface of sliding bearings, which is often accompanied by fatigue cracks, mainly from the maximum alternating shear stress below the contact surface, and then extends to the surface to form different falling shapes, such as pitting or pitting falling. Peeling is called shallow falling. Due to the gradual expansion of the falling surface, it often expands to the deep, forming a deep fall. Deep fall is the fatigue source of contact fatigue failure.

Clearance modification invalidation.

In the operation of the bearing, due to the influence of external or internal factors, the original cooperation clearance is changed, the precision is reduced, and even the "bite" is called clearance change failure. External factors such as excessive interference, inadequate equipment, expansion caused by temperature rise, instantaneous overload, and internal factors such as residual austenite and unstable residual stress are the primary causes of clearance modification failure.

Wear failure.

Wear failure refers to the failure caused by the relative sliding friction between the surfaces resulting in the continuous wear and tear of the metal on the working surface. The continued wear will cause the bearing parts to be damaged gradually, and eventually lead to the loss of dimensional accuracy of sliding bearings and other related problems. Wear may affect the shape change, the increase of cooperation gap and the change of working surface morphology, or affect the lubricant or make it contaminated to a certain extent, resulting in the complete failure of lubrication function, so that the bearing wear rotation accuracy and even can not operate normally. Wear failure is one of the common failure modes of all kinds of bearings, which can be divided into common abrasive wear and adhesive wear according to the wear form.

First of all, if the structural design is reasonable and advanced, there will be a longer bearing life. The manufacture of bearings generally goes through many processes, such as casting, heat treatment, turning, grinding and equipment. The rationality, advancement and stability of each processing technology will also affect the life of the bearing. The heat treatment and grinding processes that affect the quality of the finished bearing are often more directly related to the failure of the bearing. In recent years, the research on the surface metamorphosis layer of bearing operation shows that the grinding process is closely related to the surface quality of bearing.

The metallurgical quality of bearing materials used to be 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 bearing failure analysis has decreased obviously, but it is still one of the main influencing factors of bearing failure.