Fitting deep groove ball bearings onto its power harrow machine was getting to be an expensive and time-consuming hassle for German agricultural machinery maker Lemken. Its Zirkon 10 power harrow was previously designed with a standard deep groove ball bearing. A radial oil seal running on the inner race of a needle roller bearing and a felt seal in a metal housing were arranged next to the deep groove ball bearing. Each of these four components had to be handled and fitted separately.

To eliminate all these extra components and tasks, Lemken turned to bearing manufacturer NKE Austria, Steyr, Austria and Clifton Park, N.Y., to create a special bearing unit for the cutter tine rotor of the power harrow. The new bearing unit replaces four separate components to reduce spare stock, simplify purchasing, storage, and installation, and cut total production costs.

NKE proposed a unit in which the external seals were already integrated in the bearing. Based on a standard deep groove ball bearing 6212, the resulting bearing features an RS synthetic rubber seal on one side, a radial oil seal between the outer and inner races, as well as a felt seal with a metal cap on the other. The design changes required from Lemken were minimal: Only one snap ring groove had to be relocated. Thanks to the new design, only a single part has to be purchased and fitted now instead of the four components previously required.

The special bearing was developed by NKE in cooperation with Lemken's design engineers. Before its use in serial production, a sample batch was field tested for about a year. NKE's bearing solutions for Lemken withstand the adverse conditions — mud, rain, dust, impact loads, and corrosion — to which these machines are routinely subjected.

Visit www.nke.at for more information.