Tribology & Mechanical Components Branch Overview

Dr. Robert F. Handschuh NASA Glenn Research Center Cleveland, Ohio, U.S.A.

Abstract:

An overview of NASA Glenn Research Center's Tribology & Mechanical Components Branch is provided. Work in space mechanisms, seals, oil-free turbomachinery, and mechanical components is presented. An overview of current research for these technology areas is contained in this overview. Tribology &Mechanical Components Branch Overview

Dr. Robert F. Handschuh NASA Glenn Research Center Cleveland, Ohio, U.S.A. Topics

• View from 30,000 feet • Structures and Materials Division • Tribology &Mechanical Components Branch • Branch teams • Oil-free bearing research activities • Tribology activities • Seals Team activities • Drive system activities • Summary NASA Glenn Research Center Materials and Structures Division Capabiliti Materia ls and Structures Division

Propulsion and Power System Components Aeroshells Surface mobility systems TPS; Cooled strs. Nozzles Cryogenic tanks In-space & on-surface modules Nacelles Rotor discs and systems Combustors Turbine vanes Engine fan system Energy absorbing systems Mechanisms Mechanical drive systems Oil-Free engines Human health systems Injectors Thrusters High-power motors Bearings and flywheels Space lubricants Solid oxide fuel cells, batteries Protective Coatings High temp. and cryogenic seals Sensors Porous membranes Thermoelectrics BN nanotubes

ore R&T Capabilities Probabilistic methods Matl. and strl. Concepts Design technology Mechanical power transfer Health prognostics Experimental methods Impact dynamics Blast mechanics Measurement technology Structural mechanics Structural dynamics Aeroelasticity Material modeling Joining technology Durability and life Material characterization Failure and damage growth Fatigue and fracture Functional materials Processing technologies High temp. and cryo seals Metallic alloys Shape memory alloys Ceramic materials Computational materials Protective coatings Multifunctional Materials Surface science Extreme environment effects Lubricant chemistry Materials science High temperature chemistry Friction and wear Tribology & Mechanical Components Branch r

“NASA ʼs one-stop-shop for all its mechanisms & lubrication needs”

Branch Organization:

â Oil-Free Turbomachinery – Dr. Chris DellaCorte â Space Mechanisms & Lubrication – Dr. Phil Abel â Aerospace Seals – Dr. Bruce Steinetz â Aero Drive Systems – Dr. Robert Handschuh • Tribology & Mechanical Components Branch

Oil-Free Turbomachinery Space Mechanisms & Lubrication

From basic research to app lication

• Aero / Space application • Accelerated space lubricant life testing under vacuum • World-leading bearing experts • New mechanism concepts for planetary environment • Advanced modeling methods • New space lubricant development • Foil bearing predictive design • Terramechanics modeling & testing for efficient wheels Aerospace Seals Research Aero Drive Systems

Heat Shield • Gear fatigue research Interface Seal • High speed gear lubrication • Drive system diagnostics • Fatigue crack modeling • Dynamic mechanical components • Rotorcraft transmission systems Docking Seal • Advanced rolling element and • Space habitat seals for extreme environments wave bearing technologies • Structural / thermal protection seals • Non-contacting turbine seals Oil-Free Turbomachinery

CAD Foil air bearings

TGIR Award for Level I Milestone: “Core Hot Bearing Tests” (OFTET)

Oil-Free enabling technologies ? r

PM304 bushings for industrial furnaces and valves " P10 , Oil-Free Key Facilities & Capabilities

ambient pressure test rig

Coating deposition research facility

MicroTurbine proof-of-concept & environmental durability test facility Hot high-speed Shaft rotordynamic thrust foil bearing rig simulator test facility Space Tribology & Materials

BEARING RIG Full Scale Bearing Tests

Other Facilities: SPIRAL ORBIT TRIBOMETER *Vapor Pressure of Fluids Accelerated Lubricant Life VACUUM 4-BALL *Radiation Damage of Testing Under Realistic Accelerated Bulk Property Polymers Conditions Testing of Lubricants . Nano-Structured Lubricants for Tribology

Carbon nanostructure transformation by industrially scalable GRC developed process

Heating soot to high temperatures in an inert atmosphere graphitizes the carbon to form nano-onions.

Addition of a small amount of nano-onions to oil improved the lifetime by a factor of 8x while decreasing the friction by a factor of 2.6

Spiral Orbit Tribometer (SOT) SOT Nano-grease Friction Traces

Rotating plate 1000 moo 3000 moo (tilted up for clarity) - I Rotation u 3

Spiral orbit Ball orbit -^ '^ ® Nano-onions mixed with oil (I^'ytox : ^ 143AB) form a nano-grease. When tested in the SOT, which mimics the motion of a ball bearing, significant friction and lifetime improvements o. in air are realized.

of

Orbits Surface Science Tools

Raman

Dft„ema.ek-91- --p-d to aiff—t c Chermam b—fi w .m.s.e rwtn mir.na my ccz aaw RedNbnP^MYn.gWan: CF3 V.G. . w^.C.F^ 0 FT-IR

0 1 2 3 ,um Depth (,,Metres) AFM Auger NASA GRC Seal Team

NASA GRC Seal Team contributions have influenced several flight projects: - Shuttle main landing gear door environmental seals - Thermal barrier (braided carbon fiber rope) for nozzle joints of Shuttle and Atlas V SRM’s

Thermal barrier for Shuttle and Atlas V SRM nozzle joints NASA GRC Seal Team Overview

• NASA GRC Seal Team contributions have influenced several flight projects: – X-38 rudder/fin seals – X-37 flaperon seals

Shel Mechanical seal attac Shelf/sealing surface: AETB-8 ,tile ;on'alumin structure Low Impact Docking System (LIDS)

• LIDS is a system under development by NASA JSC designed to: – Provide gender-neutral (androgynous) interface permitting docking and berthing between any two space vehicles – Reduce impact loads between two mating space craft – Become new Agency standard for docking/berthing systems Seal Test Facilities

alignment Drive System Test Facilities

Spur Gear Fatigue Test Rigs Spiral Bevel / Face Gear Test Facilities Gear Noise / Dynamics Test Facility

Split Torque Test Facility OH-58 Transmission Test Facility High Speed Helical Gear Train Facility Drive System Analytical Capabilities

Finite Element Based Structural - Thermal Planetary Gear Dynamics High Speed Gearing Results NASA - ARL/VTD - Bell Helicopter

100 - _ ___ = -'" Bearing Losses 80

Total ` _...._.._..... Gear Meshing Losses Losses 60 (hp) 40 WIndage Losses 20

0 8000 10000 12000 14000 16000 18000 20000 Input Torque (in*lb) ' 2.85 4.7 0.15 P Windage = C3 C N D v

99 70 ------f Dawson Model 1% Lube 60 ------—v— Dawson Model 0.75% Lube ------• _-_-_-_-_-_-_---f-_-_-_ - Daswson Model Lube •:------_-- •• -••• 98 - • %% Dawson Model 0.25% Lube 50 • • • --- ,------• —^ Dawson Model - No Lube '------• .- "'""

97 Windage ...... ::-- --,...... _...... ::::::::::: ...... 40-.. EfÞciency Power - ---, ...... :... ' ...... - , ------(%) Loss - --- ...... _ ...... ,- - ,.. (hp) 30 96 ------tom:...... ------

20 / 0 Experimental Results 12500 RPM 95 d —,0— Experimental Results 15000 RPM • •^^• Analytical Prediction 12500 RPM 10 ...... _ .. ^.....- k - -—------• • y* • Analytical Prediction 15000 RPM

94 0 1000 2000 3000 4000 5000 6000 8000 10000 12000 14000 Gearbox Power (hp) Input Shaft Speed (RPM) Condition Based Maintenance

Objectives: Increase reliability and decrease false alarms for mechanical component diagnostics. Demonstrate integration of oil debris and vibration based damage detection techniques results in improved capability.

Approach: Instrument and monitor all GRC gear fatigue test facilities and work with other govt. agencies, university, and industry

Condition Based Maintenance

Vibration Techniques

151 ^^15 (FM4,NA4) and Oil ,j Debris

^q 10 7 f J^ 11 S 10^ f i, r +r r °

RW

r.-- n • ^ ^ n ^ ^ 500 100D 1500 2000 2500 3000 3.50 1 Reading Number 1 - r 0.9 Damage CLa 0.8 0.7 0.6 7@- 0.5 Inspect 0.4 Output of 0.3 0.2 Fuzzy Logic Model 0. 1-, Normal 0 0 500 1000 1500 2000 2500 3000 3500 Reading Number Wave Bearing Technology

Bearing Concept Test Facility

• Improved stability and cooling • Ability to tailor stiffness and damping • Use of hard sleeves Advanced Gear Material

Surface Fatigue Results Fracture Toughness Gear Number Number of Median life Material of tests (million failures completed cycles) AMS 15 21 134 6308B [Ref. 10] AISI 25 33 200 9310 [Ref. 13] Ferrium 5 10 361 ® C69 [present study] Ferrium C69 AISI 9310

b, e^07 o4y1' r r,' • Excellent Contact Fatigue • Poor Fracture Toughness Space Mechanism Wear

Dither Damage Assessment Low Cycle Bending Fatigue

650

600

550

500 Bending 450 Stress 400 Index (ksi) 350

300

250

200 1e+0 1e+1 1e+2 1e+3 1e+4 1e+5

Cycles Civil Tiltrotor Drive System Configuration r

To Mid-Wing Gearbox Variable /Multi-Speed n Gearbox

Tilt Axis Combiner Gearbox Gearbox Reduction Gearbox

Hover Ratio 131.4: 1 Forward Flight Ratio 243.6 : 1 Penn State Univ. - NASA NRA R&D

Rotorcraft Configuration —^ Assemble Model

Flight r—— ——^ . Condition I I Pilot Flight Control System Inputs System Model . I I I I Powertrain • Control Law I I

System Dynamics Gear Performance

Subsonic Rotary Wing: High Fidelity Design Tools Windage Test Facility, NASA-GRC

Drive Motor

Speed Increasing '- Gearbox -

Dr. Robert F. Handschuh, Army Research Lab, NASA - Glenn Mark A. Stevens, NASA Glenn Research Center In-Line Two Speed Advanced RC Drive System r

J Wet / Dry Clutch

Input Output

Over-Running Clutch

High Speed Operation (hover): Wet/ Dry Clutch engaged, Over-Running Clutch over-running Low Speed Operation (cruise): Wet/ Dry Clutch disengaged, Over-Running Clutch driving Dr. Robert F. Handschuh (October 2007) Variable / Multi-Speed Drive Facility Concept

Flywheel Flywheel

Torsional Drive Load Motor

Transmission Concept Summary

• Four main focus areas in the drive system area: * Oil-Free Turbomachinery * Tribology –Surface Science * Seals –Static and Dynamic * Drive System Technologies • Currently conduct /manage research within our center as well as at contractor and university locations • Involved in analytical and experimental developments • Work closely with the space &aerospace industry, other government agencies / NASA centers, NESCÉ.