What are the basic modes of bearing failure

Roller bearings whose working principle is to roll friction instead of sliding friction, generally by two rings, a set of rolling body and a keep frame composed of a very strong generality, standardization, a high degree of series of mechanical infrastructure, due to a variety of machinery with different working conditions, the bearing in the load capacity, structure and use of performance, etc. have put forward a variety of different requirements, for this reason, the bearing needs to have a variety of structure, but the basic structure is composed of an inner ring, outer ring, rolling body and keep frame. However, the basic structure is composed of inner ring, outer ring, rolling body and cage.

1. Contact fatigue (fatigue wear) failure

Contact fatigue failure is one of the common failure modes of all types of bearings, and is a failure of the bearing surface caused by the repeated action of cyclic contact stress. Bearing parts surface contact fatigue spalling is a fatigue crack from the sprouting, expansion to cracking process. The initial contact fatigue crack first arises from the larger orthogonal tangential stress below the contact surface, and then extends to the surface to form pitting spalling or small flake spalling, the former is known as pitting or pitting spalling; the latter is known as shallow spalling. If the initial crack is produced in the junction area between the hardened layer and the core, resulting in early spalling of the hardened layer, it is called hardened layer spalling.

2. Adhesion and abrasive wear loss effect

It is one of the common failure modes of various bearing surfaces. Bearing parts between the relative sliding friction leads to its surface metal continuously loss is called sliding friction loss. Continuous wear will make the size and shape of the parts change, bearing with the gap increases, the work surface shape deterioration, thus losing rotational accuracy, so that the bearing can not work properly. Sliding wear form can be divided into abrasive wear, adhesive wear, corrosion wear, micro-motion wear, etc., which is common for abrasive wear and adhesive wear.

Bearing parts between the friction surface by foreign hard particles or metal grinding caused by the friction surface wear phenomenon belongs to the abrasive wear.

For the bearing, the inner ring usually with the shaft tight fit, and with the shaft together with the operation, the outer ring usually with the bearing seat or mechanical shell hole into the transition fit, play a supporting role. However, in some occasions, there are outer ring operation, inner ring fixed support role or inner ring, outer ring are running at the same time. For the bearing, with the shaft tight fit and together with the movement of the said shaft circle, with the bearing seat or mechanical shell hole into the transition fit and play a supporting role said seat circle. Rolling body (steel ball, roller or needle) in the bearing usually with the help of keep frame uniformly arranged between the two rings for rolling movement, its shape, size and number directly affect the bearing load capacity and use performance. In addition to keep frame will be rolling body evenly apart, but also can play a guide rolling body rotation and improve the bearing internal lubrication performance and other roles.