Track rollers and cam followers are often exposed to aggressive ambient media. That is why reliable rust protection is a decisive factor with respect to their service life.
Like the state of the art, the requirements for which components are used are constantly evolving. Reliable corrosion protection plays an important role in many applications because the components of industrial systems are usually of a metallic nature. In 2011 Findling Wälzlager GmbH began offering track rollers with two different coating variants.
Standard bearings quickly reach their limits under corrosive operating conditions. While stainless steel roller bearings provide excellent corrosion protection, their load ratings and service life are reduced by their low hardenability. However, this is particularly important for track rollers and cam followers. Longer services lives make products with surface coatings possible. They are often also the more economical solution compared to corrosion-resistant steels. Findling now also offers surface treatments for track rollers. The self-retaining, single or double-row ball bearings with particularly thick outer rings can handle axial forces in both directions in addition to radial forces. The lateral surface of the outer rings is cylindrical or crowned. The latter is suitable for cases in which skewing occurs relative to the raceway and edge stresses are to be avoided. So far, solutions based on track rollers from the LR-200, LR-3000 and LR-5200 series have been realized and combined with DD sealing technology that offers particularly effective sealing against the penetration of contamination and moisture. The KR and KRV cam followers and NATV and NATR yoke type track rollers are also suitable for this corrosion protection treatment.
Findling currently offers two coating variants: a zinc-iron alloy and a zinc-nickel alloy. The zinc-iron variant (3-6 µm layer thickness) with subsequent thick film passivation is more cost-effective cathodic corrosion protection that can be used for all bearing types. The salt spray resistance according to DIN EN ISO 9227 is between 48 and 360 hours of protection against red rust formation. The zinc-nickel version (3-6 µm layer thickness) with subsequent thick film passivation provides even better protection. It is very high-quality cathodic corrosion protection. In this case, the salt spray resistance according to DIN EN ISO 9227 is between 360 and 720 hours of protection against red rust formation. This coating is primarily used in the automotive industry and other outdoor applications involving severe weather conditions. Neither of the alloys contain harmful chromium(VI) compounds. The thick film passivation produces passivation with a chromium(VI)-free solution. The passivation layer that is applied is ten times thicker than in the case of trivalent blue passivation and thus an ideal replacement for hexavalent yellow chromating.
As a full-range supplier, Findling Wälzlager offers products and equipment components such as lubricants, seals or surface coatings for more and more applications. Our comprehensive, multi-manufacturer expertise is especially useful when designing bearings for specific applications.