Ball bearing closures fulfil two tasks at the same time: firstly they prevent contamination and secondly then contain lubricants.

Non-contact closures

Because of the proximity with the inner ring land the ball bearing closure forms an effective gap seal. It neither increases the torque nor influences the maximum speed compared with open ball bearings as the shields do not touch the inner ring. This is sufficient for most applications.

Metal shields
The shields are stamped from stainless steel on the majority of ball bearings. They are fastened to the outer ring with a circlip and can thus be removed. Ball bearings can also be fitted with pressed-in shields made from deep drawing steel sheet.

Rubber closures
The RZ closure is made of molded tuber with metal stiffener and can be used at temperatures from -30^oC to 120^oC. This closure is fastened in the outer ring by the rubber border. 

Seal with inner ring contact

This ball bearing seal touches the inner ring land. This causes an increase in torque.

Teflon seal
The TS seal is made from glass-fibre reinforced Teflon which is fastened in the outer ring by a circlip. 

Teflon seals can be used at working temperatures of -240oC to 300oC. They prevent contamination. However an hermetic sealing cannot be achieved. The torque is lower than for rubber seals due to the favourable low friction combination (PTFE/Steel) and the low contact force of the sealing lip.

TS seals are universally resistant to chemicals. The ball bearings are normally made from stainless steel, chrome steel can also be provided in appropriately large quantities.

Rubber seal
The RS seal is made of molded rubber with metal stiffener and can be used at temperatures of -30oC to 120oC.

The VS seal is made of molded Viton with metal stiffener and is suitable for temperatures of -20oC to 230oC.

Both seals are fastened in the outer ring by the rubber border.

We would like to remind you that certain lubricants cannot be used with rubber. Please contact us about difficult operating conditions.

Special closures

In addition to the standard closures GRW also manufacture special closures and combinations of different closers. Please contact us for further information.