Industrial bearings are custom designed for each
application. They consist of hard, finely machined
metals that roll easily and resist wear, elastomeric
seals to prevent contamination, and lubricants to
They fail in many ways. Sometimes, they are
damaged (often with a hammer) or mis-aligned during installation. Seals get
punctured or eaten away by chemicals.
Operators run machines too fast or cut
an alloy or crush ore with different
hardnesses or chemical compositions.
Even lubricant can be an enemy if
operators use too little, too much, or
the wrong type.
Before they fail, bearings emit cries
for help. Each mode of failure has a
distinct sound. By listening to those
sounds with a vibration monitor—
while monitoring heat, torque, and rotating speed—researchers can estimate
how long a bearing has left.
This is called condition monitoring.
First, engineers calculate the frequencies
to watch from the bearing’s geometry. Then they
try to isolate those frequencies while suppressing
the noise made by other bearings and moving parts
inside a machine.
A large paper mill, for example, might have
hundreds of rotating parts. It takes a combination
of sensors and algorithms to get it right.
SKF got into the business when it purchased a
pioneer in the field, Palomar Technology, in 1989.
As van Camp noted, it now monitors millions of
bearings. Yet condition monitoring has its
“You could look at vibration and draw
conclusions about whether to stop now
or continue to operate, but you couldn’t
really say how much longer,” she said.
“To do that, we need more data
about the process. For example, if
it is an ore crusher, we needed to
know what type of rocks they were
crushing, the sizes going in and out,
“With all that process data, we can
start making accurate predictions.
We can tell a miner how long the
crusher will operate or to crush smaller
rocks to run longer. We can tell how long a
cutting machine can run before it ruins a part,"
bearings in remote
the top of wind
turbines (left). An
SKF ball bearing