The main task of the support and tension rollers in a conveyor belt is to shape the belt, act as a support element for the material to be conveyed and reduce the resistance to movement. If the material is conveyed with low friction, this reduces both the overall energy requirement for transportation and the operating costs. In mining, the conveyor belt rollers are exposed to difficult operating influences and

Environmental conditions: high loads and possible impact loads, additional loads due to shaft deflection and vibrations, high speeds, heavy external contamination and demanding weather conditions such as high humidity, rain, snow and extreme temperature fluctuations.

Rolling bearings are among the most important components of the support and tension rollers in conveyor belts. Even if the bearings used in the conveyor belt rollers are properly designed, sealed and permanently lubricated, they are significantly affected by the factors mentioned above. In particular, the extremely dirty mining environment favors the penetration of impurities into the bearing position, which can lead to premature bearing failure. This not only shortens the bearing service life, but also affects the performance and reliability of the other components of the conveyor system.

NKE has developed single-row deep groove ball bearings specifically for conveyor belt rollers that are used under harsh operating conditions. The new design has resulted in improvements that optimize performance and product life compared to standard bearings. The special bearings have a special cage design made of low-friction plastic, an improved raceway geometry, adapted radial clearance, special extremely low-friction seals and a selected lubricant for use in a wide operating temperature range.

Conveyor belt rollers of a conveyor belt system © NKE

The new design from NKE can withstand the tough operating requirements of conveyor rollers even where conventional bearings fail. Previously used standard bearings lead to an uncontrolled, sudden rise in temperature when impurities enter the bearing interior. This rise in temperature impairs the positive lubricant properties, destroys the cages and ultimately leads to the bearing blocking. This is referred to as "hot running" of the bearing - a catastrophic, sudden bearing failure. The blocking of the bearings in turn blocks the rollers, the conveyor belt is damaged and the risk of fire increases enormously.

Despite a comparatively high degree of contamination, NKE roller bearings for conveyor belt rollers retain their function even under high loads and without increased frictional torque.

NKE's new bearing concept, specially adapted to the requirements of conveyor belt rollers, offers a number of advantages: it reduces the risk of fire, offers optimized bearing life under the most difficult conditions, reduces energy consumption, increases the reliability of the conveyor system and reduces overall operating costs.

"The development, which is very complex in terms of design, is a response to the desire of many customers to improve the functionality of conveyor belts," says Michael Rößl, application engineer at NKE in Steyr. "Our new roller bearing system will contribute to a significant reduction in downtime during material transport." The bearing concept ensures a low-friction rolling process. This helps to reduce the friction of the entire system to a minimum and enables the transport system to be operated more cost-efficiently and reliably. "In order to achieve an optimum result, it is important to ensure that the ingress of contamination particles to the bearing and into the bearing interior is prevented as far as possible by the system developer or system operator using external sealing systems," adds the application engineer. as