NKE began by developing a module of twelve different sizes for fixed and non-locating bearing positions. One requirement was to ensure easy mounting and dismounting of the bearing unit on the shaft and the pump casing without the need of special mounting instruments. The bearing unit should also be protected against splash water and ensure a maintenance-free period of three years without additional lubrication. NKE succeeded in developing a bearing arrangement composed of six components which met all the customer’s requirements. For the whole pump family consisting of 48 different models, only 21 different types of angular contact ball bearings and deep groove ball bearings were used. The bearing unit was also made suitable for high performance pump models. On the locating bearing position, pairs of angular contact ball bearings were applied in order to resist high loads and to guarantee a long service life. Instead of individual installation, the bearing pairs are mounted into the pumps as entire units.
The unit also offers easy mounting and simple handling, due to the deployment of one component instead of several single parts. This also simplifies the spare part service.