Schaeffler WEC Solutions

Innovative Solutions for Preventing White Etching Cracks
Bearing supports used in wind turbines and other industrial applications such as electric motors, paper machines, or drives in marine applications are subject to higher forces and torque, which subject the components to ever increasing loads. A phenomenon that has a negative influence on the reliability of bearings are so-called white etching cracks (WEC). These structural changes in the material form below the surface of the bearing. These changes result in the formation of cracks, which extend to the surface during stress conditions under different external loads. As a result, that causes the affected bearing to prematurely fail. Schaeffler’s innovative solutions help to increase the resistance of bearings to white etching cracks and prevent premature bearing failure.

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TRACKING WHITE ETCHING CRACKS
It is still not completely clear what causes white etching cracks to occur. According to current knowledge, however, additional stresses in the form of dynamics, mixed friction, and the effects of electrical systems create the conditions needed for WEC to form. The WEC risk can be limited by the design of the bearing and the selection of lubricants and materials. An optimum design can reduce the stresses placed on the bearing, which can, in turn, be subjected to higher loads by matching the lubrication and preservation concepts and selecting the optimum material.

COATINGS MAKE BEARING SUPPORTS MORE RESISTANT
Schaeffler offers different solutions for making bearing supports more resistant to white etching cracks and protecting them against premature failure. The technology that Schaeffler recommends and has statistically verified for efficiently and cost-effectively reducing WEC damage is the through hardening of the bearings in combination with black oxide coating on the inner and outer rings and the rolling elements.

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