Overheated
Bearings
The
most common reason for an overheated pillow block bearing is over-packing
it with grease. The churning lubricant produces heat. As speed
increases, so does the heat. Adding more grease only worsens the
problem, and, you run the risk of blowing out a seal. Excess grease
will usually purge through the seals and the bearing will run
cooler.
In nasty environments (gravel pits,
fertilizer operations and construction sites) bearing life can
be significantly increased by using bearings that have flushing
chambers. These units have three (3) grease fittings. A flushing
chamber with an outboard labyrinth seal is on either side of the
central bearing chamber, which is protected by lip seals. Each
flushing chamber is periodically flushed with grease through the
labyrinth seals to purge contaminants. Only the central grease
fitting supplies lubricant to the bearing. This technique will
extend bearing life to years when a proper maintenance program
exists.