Which sealing variants are available for ball bearings?

Marco Thull | 20. December 2019

Many metallic rolling bearings are available as a sealed version The sealing is usually absolutely necessary for metallic ball bearings as otherwise dirt can get into the ball running surfaces, mix with the lubricant and thus block the rolling of the bearing.

Metallic bearings must be protected

Metallic ball bearings are also available in an open design, but they are rarely used due to the problems mentioned above. A dusty environment alone is sufficient to negatively influence the running properties over a longer period of time.

Ball bearings made of plastic or ceramic are usually only offered as open type

Because these bearings do not have to be lubricated!
The open design has a great advantage with these materials: any contamination that occurs can also be easily removed, if needed rinsed or blown out with compressed air. There is no dirt adhesion due to lubricants.

The sealing of metallic ball bearings is based on the principle of the shaft seal. The following manufacturer-specific seal designations are possible:

• Z = one-sided sheet metal cover disc with gap seal
• ZZ/2Z = as above, from both sides
• RS = one-sided, grinding rubber seal
• LB = as above
• 2RS = as above, from both sides
• LLU = as above, non-contact rubber seal, from both sides
• EE = as above, touching from both sides, grinding
• RZ = one-sided, non-contact rubber seal
• LB = as above
• 2RZ = as above, from both sides
• LLB = as above

The seal designations are valid worldwide and, depending on the manufacturer, usually appear as a suffix after the respective DIN installation size.

igus® ball bearing with cover plate

In the product range of the igus ball bearings, the customers also have the choice between different cover variants. Not all are available for every bearing installation size, but a one-sided cover plate is always available for selection.

Do you have any further questions and/or wishes? Then just send an email to me: okreutz@igus.net