Technical Information


Double-row ball bearings have the advantage that they are very light and adjustable.

The difference between the ball bearings and the spherical roller bearings in the Extreme Bearing is that the ball bearings are sealed by 2-rs bearing seals whereas the spherical roller bearings are not. These seals will give extra protection in case the housing’s seals become broken or breached.

Spherical roller bearings have the advantage that they provide a much larger load capacity than ball bearings and can accommodate axial force.


Clever fitting using an adapter sleeve does away with the need for an eccentric clamping ring or allen key, both of which have been known to cause additional problems. The choice of materials used contributes to a longer service life and, ultimately, better results and lower costs.


Standard Extreme Bearing housings feature centrifugal seals specially developed to repel dirt and contaminants using centrifugal force generated by the shaft.

The gaps between the lips of the centrifugal seal and the stator must be sealed to keep out dust and water. To improve bearing life for centrifugal shaft seals, use an automatic lubricator.

Many sealing options are possible. Each possesses different properties depending on the application. We would be pleased to advise you on the best choice of seal.


  1. Double lip centrifugal seal
  2. Grease-filled housing
  3. 2-RS bearing seal



Standard Extreme Bearing housings are made of 316 stainless steel. Specially developed centrifugal seals are also used.

The rubber of the rotor ring clamps around the shaft and is turning with the shaft vertically against the stator ring. Because the lips are positioned vertically against the stator ring, the dirt will be repelled by the centrifugal force from the sealing lips. The rotor ring can be moved eccentrically in relation to the stator ring. In this way, the centrifugal seal is able to absorb any misalignment of the shaft without creating wear on the rubber lips.

The grease passes the retaining edge through the lubrication channels under the stator ring and between the two sealing lips and stator ring. The grease ensures that any dirt is flushed away.

The clamping of the rubber rotor ring around the shaft means that the bearing can be assembled even on a shaft which has suffered light surface damage such as a groove.


Berulub FG-H-2-SL is highly recommended as the grease for lubricating Extreme Bearings. It is a high performance and food-safe lubricant.

Due to the low viscosity of the base oil, this grease is very suitable for use in the centrifugal seal. This smooth but tacky grease will make sure that all dirt is kept out of the seal. The high-load capability (four ball weld load >4000N acc. DIN 51 350 P4) makes this grease ideal for all types of Extreme Bearings. We supply the bearings but we do not supply lubricants. For more information about lubricating Extreme Bearings, you are welcome to write to a Dutch distributor of lubricants at the following email address: FenS.


Suitable for expansion and contraction of the shaft


The seats are machined to a tolerance to provide a loose fit.

The bearing seats in the housings are sufficiently wide to allow axial displacement of the bearing and to accommodate for thermal expansion of the shaft due to high temperatures, such as on a baking conveyor belt.

The Extreme Bearing blocks can absorb expansion of the shaft because there is an adjustment or locating ring in the bearing housing. The locating ring can be removed from a bearing block of a pair placed opposite each other so that axial displacement is possible.

More technical information

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