Oil Debris Monitoring in Aerospace Engines and Helicopter Gearboxes

E t A GEaton Aerospace Group

Presented at the Mid Atlantic Symposium onPresented at the Mid‐Atlantic Symposium on Aerospace, Unmanned Systems and Rotorcraft

April 10, 2014Villanova University Conference Center

Oil Debris Monitoring (ODM) Basics: Debris TTypes

Debris particles contain lots of information:information:• Quantity, rate of production, shape, size, material, color, size distribution etcdistribution, etc.• Different failure modes produce different types of particles:• Rolling contact fatigue chunks• Rolling-contact-fatigue – chunks• Adhesive wear – fine grit• Bearing and gear wear – ferrous

Bron e cage ear non ferro s• Bronze cage wear – non-ferrousEtc.

Debris MonitoringDebris Monitoring• Chip Collectors ‐ Collect Ferro Magnetic debris for visual 

inspection– Inexpensive solution that is proven effective in failure 

detection: – Key Features include:

R bl M i Pl• Removable Magnetic Plug • Typically Includes a Self Closing Valve (SCV) Feature to minimize oil loss during removal and installation of Plug.

• Various Mounting ConfigurationsVarious Mounting Configurations– Threaded– Quick Disconnect – Bayonet, Helilok®– Flange Mount

• Optimized Magnetic Capture Area – Magnetic Selection, Capture Area, and Valve design

Debris MonitoringDebris Monitoring• Electric Chip Detectors – Provides remote indication of Ferro Magnetic 

debris; Also provides Visual Indication• FAA (FARS, 14 CFR), Section 27.1337 requires all helicopter gearboxes to 

be equipped with electric chip detectorsbe equipped with electric chip detectors

– Key Features include:• Removable Magnetic Plug with Axial or Radial Chip Gap – As 

particles bridge the gap, electrical continuity is achieved, d d f lproviding indication of particles

• Chip Gap size and configuration can be varied to indicate target particle sizes

• Typically Includes a Self Closing Valve (SCV) Feature to minimize oil loss during removal and installation of Plugoil loss during removal and installation of Plug.

• Various Mounting Configurations– Threaded– Quick Disconnect – Bayonet, Helilok®– Flange Mount

Chip Gapg

• Optimized Magnetic Chip Gap Area – Magnetic Selection, Capture Area, Gap size/ geometry, target particle size(s), and Valve design

Debris MonitoringDebris Monitoring

A i l Chi GAxial Chip Gap

Radial Chip Gap

Debris MonitoringCHIP GAPS - Axial or Radial

Debris Monitoring

•Axial Gap Magnetic Chip Detector

•Contains two pole pieces which have a gap between them in an axial direction relative tobetween them in an axial direction relative to the magnetic chip detector.

•Typically used for engine applications where increased sensitivity is required.

• Radial Gap Magnetic Chip Detector –

•Contains two pole pieces which have a gap between them in a radial direction relative to th ti hi d t tthe magnetic chip detector.

•Typically used for applications where lower sensitivity due to higher debris generation rates, such as transmissions and gearboxes.rates, such as transmissions and gearboxes.

Debris MonitoringMagnet

H li

SpringIsolated GroundChip DetectorAxial GapDebris MonitoringHelixAxial Gap

Valve CupValve

Axial GapPole Pieces

Valve

Helix PinPlug

Debris Monitoring• Zapper® ‐ Capacitive discharge method to remove nuisance fuzz 

accumulated on electric chip detector

Debris Monitoring

– Controlled amount of Energy– May have Integral Temperature Switch ‐may inhibit zap– Automatic or Manual operationp– Various form factors used:

• Attached pod• Self contained in handle• Self contained in handle• Separate Power Module for multiple CDs

– Zapping depends on power voltage

Debris Monitoring• Smart Zapper® 

– Can handle many channels by sharing capacitors

Debris Monitoring

– Incorporates Built in Test (BIT) Functions to verify wiring and system integrity

– Allows more sophisticated reporting, e.g. ARINC 429 Busp p g, g– Zapping independent of voltage– Can provide multiple zapping attempts, report and record attempts

Software developed to meet DO-178B requirements

S92 Smart Zapper® System

requirements

Debris Monitoring for EnginesA schematic of a typical gas turbine engine lubrication system

Debris Monitoring for EnginesSystem shown: GE90 (B i 777)

QDM® (Quantitative Debris Monitor) with “Lubriclone®”

Debris Monitoring for Engines

GE90 (Boeing 777)

L b i lLubriclonethree-phase vortexseparator for debris and air

Signal conditioner

debris and air separation from oil (installed in combined-

QDM® inductive debris sensor (installed incombined

scavenge line) sensor (installed in separator) counts, collects and retains ferrous debris

Debris MonitoringDebris Monitoring• Lubriclone® ‐ Provides phase cyclonic separation 

– Principle of OperationPrinciple of Operation

• Fluid rotational motion is created through tangential injection of fluid into a cylindrical vessel

• Phase separation results from differences in densities• Air exits via a vortex finder containing an orifice• Debris is removed through a small passageway on the downstream end of the cylinder through use of QDM 

Chi D t tor Chip Detector

Debris Monitoring

Very high efficiency (data for

Operating Principle – Three-Phase Vortex SeparatorDebris Monitoring

Very high efficiency (data for GP7200):

• Air separation > 95%p• Oil separation > 99.8%• Debris separation > 88%• Pressure drop< 9 psid at 41 gpm oil, 8scfm air

Debris MonitoringDebris Monitoring– Common Lubriclone® Terminology

• Air separation efficiency ‐ the amount of air (at standard conditions) by volume that exits the air exit port, vs. the amount of air that enters the air/oil inlet port (at standard conditions) 

• Oil separation efficiency ‐ the amount of oil by volume that exits the oil outlet port, vs. the amount of oil by volume that enters the separator air/oil inlet portAi d Oil ti ffi i i b ti i d f ifi• Air and Oil separation efficiencies can be optimized for specific application requirements by varying air/oil inlet and air outlet orifice sizes

• Dwell time (residence time) ‐ The amount of time it takes fluid toDwell time (residence time)  The amount of time it takes fluid to pass through the Lubriclone

Debris Monitoring (GP7200 Lubriclone®) Air O tletLubriclone®) Air Outlet

SSensor Port(Debris Capture)

Air/Oil/DebrisInlet

Oil Outlet (Enters Tank)

Debris MonitoringDebris Monitoring• Lubriclone® with QDM – Typical Design Challenges

– Lubriclone® Sizing• Optimizing Air & Oil Separation efficiencies for a 

variety of flow conditions• Minimizing Pressure Drop • Structural Weight• Structural, Weight

– Sensor Capture Capabilities• Defining particle threshold above which indications 

shall be provided• Understanding material, shape, and mass of failure 

debris• Capture Efficiency

C l i h Fi P f R i (2000 °F f– Comply with Fire Proof Requirements (2000 °F for 15 minutes.) 

Debris Monitors for EnginesDebris Monitors for Engines

GEnx Trent XWBGEnx Trent XWB

Operating Principle ‐ QDMOperating Principle  QDMMagnetic field

Sense coilBIT coil

Magnetic pole pieceMagnet

Magnetic pole pieceOutput pulses for a “small” and a “large” particle

QDM sensor is a passive, magnetic, inductive sensor that collects, retains d i di t t f i di id l f ti ti land indicates capture of individual ferromagnetic particles

Operating Principle ‐ QDMOperating Principle  QDMSample Output Signal – 0.798 mg particle

QDM Operating Principle – System ExampleQDM Operating Principle  System Example

QDM signal conditionerPre set mass threshold

Chip pulses to Engine

QDM sensor

conditionerQDM counts discrete particles

Pre‐set mass threshold Engine Monitoring System, FADEC or HUMS

sensor output

BIT input to sensorNotes: 1 Th h i i hi h h ld j i i d d f l

Bit input from EMS, FADEC or HUMS

1. The system has a minimum, pre-set chip mass threshold to reject noise-induced false counts.

2. Chip count algorithms for alerting flight and/or maintenance crew are included in EMS, FADEC or HUMS software.

3. Limited chip mass classification (“binning”) is possible, but this requires more complex signal conditioning and chip alert algorithms.

ODM Basics: Rolling-Contact Fatigue (RCF) Debris From Engine Shaft BearingDebris From Engine Shaft Bearing

Bearing debris particles produced by Rolling Contact Fatigue (RCF) vary

id l i h dwidely in shape and mass

Extruded RCF spall flake, ca. 300 µm diameter

Bearing RCF particle, approx. 110 µgg p , pp µg

Oil Debris Monitoring (ODM) Basics: Comparison between Actual and Test Debrisbetween Actual and Test Debris

Debris MonitoringDebris Monitoring• Quantitative Debris Monitor (QDM)

– Counts ferromagnetic chips arriving at the sensorCounts ferromagnetic chips arriving at the sensor.– Collects and retains all chips for alert verification by means of chip inspection and analysis.C ll hi i h b i i i– Counts all chips with a mass above a preset sensitivity threshold, which is set so that environmental noise (EMI, vibration) does not cause false counts.

– Chip alerts are generated by FADEC, EMS or HUMS‐based alert algorithms. Examples are: number of chips per flight or number of chips per elapsed time interval. There can be in‐p p pflight alerts or maintenance alerts, or both. 

Future Challenges for Debris Monitoring

• Rotary Wing Air‐framers are clamoring to design “hybrid y g g g ybearings” into their products

• Hybrid Bearings Use standard inner and outer race material, typically M50 type steels; however, the rolling elements are made of silicon nitride – a ceramic material – a non‐metal

• Hybrid Bearings have many advantages over all steel bearing designs.  These special features provide greatly improved engine and mechanical efficiencies

Future Challenges for Debris Monitoring

• Hybrid Bearing Advantages Include:Hybrid Bearing Advantages Include:– Higher Operating TemperaturesLower Centrifugal Forces Higher DN speeds– Lower Centrifugal Forces – Higher DN speeds

– Less Dependent on LubricationL W i ht h 40% d ti– Lower Weight – as much as 40% reduction

– High Insulation Properties to Resist Electrical ArcingArcing

Future Challenges for Debris Monitoring

• The Challenge is to develop newer moreThe Challenge is to develop newer, more sophisticated monitoring systems that can detect ferrous non‐ferrous and non‐metallicdetect ferrous, non ferrous and non metallic debris

• The leading and most likely technologies will• The leading and most likely technologies will be optically and/or acoustically based with a second inductive confirmation stagesecond inductive confirmation stage

Trent XWBSpecifications

75 000 97 000 lb th t75,000 – 97,000 lbs. thrust

Bypass Ratio 9.3:1

Overall Pressure Ratio 50:1

Fan 22 Blade 118” Dia.

Powers Airbus A350/A380Powers Airbus A350/A380

Eaton Debris Monitoring Productsg• Chip Collectors and Detectors• Zapper ®, Smart Zapper ®• QDM ® (Quantitative Debris Monitor)• Lubriclone ®