Some
Observations of the Detection of Rolling
Element Bearing Outer
Race Fault
Lin Liu,
ZhuangLi
SpectraQuest Inc., 8201 Hermitage Road, Richmond, VA 23228
Published: Sep, 2006
Abstract
The
rolling element bearing is used widely in industry. It is one of the
most
vulnerable components in a machine because it is most often under
high load and high speed running conditions. Prompt diagnostics of
rolling element bearing faults is critical not only for the safe
operation of machines, but also for the reduction of maintenance
cost. Among the three main components in a rolling element bearing,
the outer race, the inner race and the ball, this work studies the
diagnostics of faults on bearing outer race. There is an argument
that a rolling element will excite the natural frequencies of
bearing component when it passes the fault on the outer race.
Therefore, the bearing outer race natural frequencies have been
identified by numerical simulation and hammer test. Vibration data
were collected on a Machinery Fault SimulatorTM (MFS)
with good as well as faulted bearings. The data were analyzed using
the VibraQuestTM software and efforts were made to
identify the bearing fault characteristic frequency and its
harmonics.
Full Text (PDF)
Introduction
The natural frequencies and mode shapes of the
bearing outer race are simulated A tri-axial accelerometer is bolted
on a bearing outer race and a hammer test is carried on a bearing
outer race. The accelerometer has a frequency range up to 10 kHz.
The data were collected using the VibraQuest TM software/hardware
system. First, the baseline vibration data for good bearings were
collected in different running speed conditions. Next, the inboard
good bearing was replaced by a bearing with faulted outer race. The
location of the fault on the outer race is in line of the load path.
Again, data were collected in different speed conditions. Second, A
bearing, whose outer race has a hole, was installed on the inboard
bearing housing and the vibration data were collected in different
speed conditions. During the running tests, the load on the bearings
was kept constant
Fig: Vibration Spectrum for a Bearing Outer Race
with a Hole (1840RPM)
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