single sealed vs shield ball bearings

[rota1]

Hello everyone,
This may seem as too basic a question but nevertheless, I am having a problem in understanding what is the difference if any, between a SEAL as opposed to a SHIELD bearing.

 

[electricpete]

Seal involves rubbing, usually made out of rubber or some other soft material.

Shield has no rubbing, just a close tolerance to minimize but not eliminate contamination (or keep the grease in, depending on what you think the function is). Shield is made out of steel.


=====================================
Eng-tips forums: The best place on the web for engineering discussions.

 

[rota1]

Thanks a lot Electricpete, and what about if its either a single or double seal or shield?
I was thinking that it was the number of points of sealing that determined if it was a single or double.

 

[electricpete]

For a deep groove ball bearing (conrad bearing), there are two sides. If you have shields on one side that's single-shielded. If you have shields on both sides that's double-shielded.

=====================================
Eng-tips forums: The best place on the web for engineering discussions.

 

[Tmoose]

Just to make (keep) it confusing the large German bearing manufacturer FAG refers to the enclosures on their precision spindle bearings as having "non-contact seals".

http://www.bardenbearings.com/PDF CD/MACHINET.PDF

That's an exception, not the rule.