Gear boxes (helicopters, vehicles) are
critical components that require costly maintenance and
upkeep. Erallo has proposed a technology to allow for monitoring
of the complex structures of a gearbox using. Multiple technologies
must be employed to develop a complete picture of what is
going on inside the gearbox: Acoustic monitoring, vibration
monitoring and strain monitoring. By comparing the vibratory
signal of damaged versus undamaged parts of the gearbox,
an initial assessment can be performed that will identify
structural damage within the rotating components (gears
and bearings) without the need to disassemble the gearbox.
A promising approach to aviation condition
monitoring is using Acoustic Emission (AE) techniques to
detect gearbox component cracks/fatigue. AE technology is
an effective monitoring technique to detect crack initiation
and propagation when coupled with real-time processing.
The type of AE signals emitted by gearboxes and rotating
machinery has advantages (over vibration signals). When
deformation, fracture or internal stress of materials and
components exceed their yield limit, an irreversible stage
of plastic deformation occurs and strain energy is released
in the form of transient elastic waves, called acoustic
emissions. The accuracy of fault diagnosis in helicopter
gearboxes and components could be improved by using AE signals
to identify fault signatures of early cracks. It is anticipated
that AE technology could produce a clearer feature frequency,
even in noisy environments, for predicting for shallow,
obscure and/or early crack propagation.
The proposed approach is to apply the
team’s prior experience to developing specialized algorithms
and cleaning/filtering techniques to isolate, detect and
analyze the signatures of early crack initiation and propagation.
The team’s previous experience – using sensors
to collect and analyze stress/strain signals on metal structures
– will be used to develop a system for identifying
early damage conditions on rotating gearbox components.
