Zollern Z-Bearings

With 80 years' experience in the production and use of industrial bearings, Zollern has developed its own range of DIN bearings - the "Z-Bearing" This new product offers a number of improvements in comparison to competing products

Advantages of Zollern Z-Bearing

On the strength of over 80years' experience in the production, assembly and use of industrial bearings for a variety of industrial end-uses, Zollern has developed its own range of DIN slide bearings – the "Z-Bearing" The new Z-Bearing offers a number of considerable improvements in comparison to similar competing products :

Bearing Housing in Nodular Iron GGG40

This material has the advantage of greater strength and ductility and stretching. Furthermore, spheroidal graphite iron casting possesses good notched impact strength values even at sub-zero temperatures. This is of particular advantage with machines exposed to abrupt loads or spasmodic movements. Its large degree of attenuation absorbs or inhibits vibration. Spheroidal graphite iron also offers excellent fatigue strength properties and possesses a high level of corrosion-resistance to atmospheric influences, alkalis and weak acids.

Bearing metal on Sn-Basis, without Pb, Cd, As

The bearing metal is smelted in our own foundry and can thus be modified for specific purposes. The standard bearing metal (see information sheet) displays higher heat strength, i.e.: increased protection against overheating, and also higher fatigue strength with dynamic loads. Oil is not discolouring on contact with lead oxide.

Avoidance of mis-assembly

Design features such as asymmetric fitting hole separation mean that parts cannot been correctly fitted

Improved Cooling

Increased heat-emitting surface, especially with the self contained bearing and smarter cooling fin design

Compact machine side fitting

Inset cooling fins on the ZR (pedestal, finned) bearing giving the same depth as the smooth housing, give easier access to the machine side bearing elements and seals

Better Sealing

Improvement of shaft floating labyrinth seal through the choice of tough, high-temperature-resistant material (Ryton A100). Inclined oil return drillings ensure good oil return flow. To prevent the seal from being destroyed during mounting of the upper housing, the anti rotation pins are positioned within the joint

Smarter anti-rotation pins

In order to prevent the bearing shell tilting during machine operation, the anti rotation pins are arranged at the centre of the bearing. The pin cannot be forced out of the housing during assembly or operation

More durable electrical insulation

Tough insulating materials for the coating of the spherical bearing seats within insulated bearings. The coating will not obstruct heat flow through the bearing seat, thus there will be no performance difference between insulated and non-insulated bearings, as would be the situation with inserted PTFE-sheets. This new insulating material will not affected by vibration, and there is not a risk that reduction in adhesion will lead to failure of the bearing

Probe fitting

The housing is strengthened in its upper part so that 2x45 spot faces can be provided for threaded holes for can be attached for vibration or other sensors


Zollern bolt on baffles are also made from high-quality cast materials with fitted Teflon-Bronze strips. These strips do not react as strongly to changes in temperature and humidity as plastic (polyamide) would. In this way Zollern's bolt on baffle seals can be incorporated without concern for dimensional or shape stability. The baffle design is also ideally suited to the fitting of vibration or other probes

Lubrication and Cooling

Enlarged sight glasses enable better oil level control. It is also possible to mount oil outlet pipes of larger diameters onto the Zollern bearing, this offers better oil flow from the bearing and thus increased protection against oil leakage. The oil outlet screw is positioned in a recess in the housing floor into which dirt particles collect to be automatically removed during oil change. Improvement of the oil supply through optimised loose oil rings made from a durable copper alloy which is chemically resistant to all known lubricants


Seal carriers and additional chamber seals are fastened with a greater number of better positioned screws. Fixing screws have been arranged near the joint so that sealing is improved, especially when use is made of a compound (Loctite, Hylomar). Machine seals for the ZF (end-flange)bearing can be supplied on request with Teflon-Bronze strips with the aim of preventing the oil being sucked from the bearing should the machine pressure drop. Teflon-Bronze strips allow for a running gap of minimal value. The strips are light (only2mm thick), and are lifted off the shaft during running. There are minimal friction and heating effects and consequently there will be no overheating or distortion of the shaft (as for instance with the use of hemp/tallow packing or plastic rings). Machine seals on ZM (centre-flange) bearings are usually fitted with Teflon-Bronce strips due to the generally high demands placed on them. During maintenance neither extended baffle seals nor machine seals need be changed. Only the Teflon-Bronze strips need occasionally changing. This is clearly a cost advantage

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