Novel bearing design eliminates pump maintenance

In collaboration with a large pump maker, bearing manufacturer NKE has developed a new modular system of bearings to rationalise a whole generation of pumps. NKE will present the bearing unit in its application at the Motion, Drive and Automation show in Hanover this year. The original objective was the rationalisation of a complete pump family, and involved the development of a module in 12 different sizes for fixed and nonlocating bearing positions. A key criterion was to ensure easy mounting and dismounting of the bearing unit on the shaft and the pump casing without the need for special tools. The bearing unit also had to be protected against water splashes and provide a maintenance-free period of three years without additional lubrication. NKE succeeded in developing a bearing arrangement comprising six components which met all the customer's requirements. For the whole pump family of 48 different models, only 21 different types of angular contact ball bearings and deep groove ball bearings were used. A particular challenge was the development of the bearing unit for the higher 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, NKE found a solution to mount the bearing pairs into the pumps as entire units. The advantages of this new bearing unit include easy mounting and simple handling, thanks to the deployment of a single assembly instead of multiple components. This also simplifies spare parts and servicing, and thanks to lifetime lubrication maintenance costs are almost eliminated. The rationalisation of the bearing arrangements also reduces production costs. This system has been so well received by the pumps? end users that NKE's partner is planning to covert all its pumps to this new modular system.