Gunner wrote:
On Fri, 10 Oct 2008 23:52:01 +0000, Christopher Tidy
wrote:


REMOVE Tom wrote:

On Fri, 10 Oct 2008 01:55:12 +0000, Christopher Tidy
wrote:



REMOVE Tom wrote:



Over lubrication is the primary cause of premature bearing failure.
Check out lube recommendations on the bearing or grease manufacturers
web site. Depending on the capacity of your grease gun usually a
couple of shots periodically will suffice.

Is that true? What damage does it do to the bearings? The worst I've
seen is for the excess grease to squirt out and make a mess.

Best wishes,

Chris


Grease is a great insulator - the rollers will push it out of their
path forming a wall which prevents it from dissipating the heat.

Surely this is only going to be a problem in bearings which run at tens
of thousands of rpm?

Best wishes,

Chris


Over greased bearings start heating up at 1500 rpm

I've sometimes seen two maximum speeds quoted on bearing data sheets: a
lower speed for grease lubrication and a higher speed for oil
lubrication. I guess the advantage of oil is that it can circulate and
carry the heat away, so it doesn't have to rely heavily on thermal
conduction.

Best wishes,

Chris