The influencing factors that cross-tapered roller bearings cannot be used are very complicated, and due to the differences in the working conditions and structures of various types of bearings, the unusable forms and morphological characteristics are also different. According to its damage, it can be roughly divided into several basic modes: contact fatigue failure, friction and wear failure, fracture failure, deformation failure, corrosion failure, and clearance change failure.
Fatigue wear failure
Contact fatigue failure is one of the very common failure modes of various types of bearings. It is the failure caused by the repeated action of cyclic contact stress on the surface of the crossed tapered roller bearing. The contact fatigue spalling on the surface of a bearing part is a process from initiation and propagation of fatigue cracks to cracks. The initial contact fatigue cracks are first generated from the contact surface with large orthogonal shear stress, and then expand to the surface to form pit-like spalling or small Flaky exfoliation, the former is called pitting or pitting, and the latter is called shallow exfoliation. If the initial crack occurs in the boundary area between the hardened layer and the core, causing early peeling of the hardened layer, it is called the hardened layer peeling.
Adhesion and abrasive wear failure
It is one of the very common failure modes of various bearing surfaces. The relative sliding friction between bearing parts causes the continuous loss of surface metal, which is called sliding friction. Continuous wear will change the size and shape of the parts, increase the bearing clearance, and deteriorate the working surface, which will lose the rotation accuracy and make the crossed tapered roller bearing not work properly. The forms of sliding wear can be divided into abrasive wear, adhesive wear, corrosion wear, fretting wear, etc. The common ones are abrasive wear and adhesive wear.
The phenomenon of friction surface wear between the friction surfaces of cross roller bearing parts caused by foreign hard particles or metal grinding belongs to abrasive wear, which often causes chiseling or ploughing scratches on the bearing surface. Foreign hard particles often come from dust in the air or impurities in the lubricant. Adhesive wear is mainly due to the uneven force on the friction surface due to the contour peaks of the friction surface. The local friction heat increases the temperature of the friction surface and causes the lubricant film to rupture. In severe cases, the surface layer metal will be partially melted, and the contact points will undergo a cycle of adhesion, tearing, and re-adhesion. In severe cases, the friction surface will be welded and stuck.
