Aerospace Lithium Grease


Published on

Rocol Defence and Aerospace Lubricants

  • Be the first to comment

Aerospace Lithium Grease

  1. 1. ROCOL UK A Division of ITW LTD Di i i f Defence & Aerospace Lubricants
  2. 2. ITW Rocol Defence & Aerospace Products • Manufacture in Leeds, England • 130 employees • Manufacturing capability: • Aerosols • Fluids/oils • Greases • Paints • Anti-Slip • 1878: Founded as Ragosine Oil Co Ltd • 1953: ROCOL name established • 1968: Joined Morgan Crucible Plc • 1999: Acquired by ITW Inc
  3. 3. Grease Manufacturing & Packing Manufacturing & Packaging on site Approximately 750 tonnes p a p.a. Batch size range from 50 kg to 1800 kg MOD G Greases and Lubricants dL b i t • Specialised manufacturer (flexible) • Auto, Semi Auto and Hand Package • Packing for Defence customers • Container size colour and material specific • Labelling as Required, NATO Codes, Batch information, Contract Details etc.
  4. 4. Rocol MOD Specialist Lubricants Supply Core UK MOD Aerospace Greases G-354 / G-1353 XG-287 Aerospec 200, General Purpose Airframe Complex Lithium Lubricant New AMS-SAE 3052 and Airbus AIM 09-06-002 approved G-382 / G-421 XG-291 Aerospec 300 Long Life High Load Grease 300, Life, G-1352 XG-294 Aerospec 400, Developed to replace XG-293 as wheel bearing lubricant XG-293 (basically MIL-PRF-81322), Aeroshell 22, Mobil 28 (Aerospec 400 XG 294 meets SAE AMS 3058 wheel bearing grease spec 400, XG-294 Other Main MOD Lubricants include:- Def Stan 91 8 D fS 91-85 XG-273 XG 2 3 Aircraft grade GP graphite grease Ai f d hi G-353 XG-276 Aircraft low temp Moly Grease G-355 XG-285 High Load Grease Def Stan 91-64 XG-305 High Load Moly Grease g y G-460 XG-286 Sea Water Resistant Grease G-394 XG-315 Low Temp Silicone Grease O-157 & Def Stan91/103 OX24 & PX36 Weapons Lubricants
  5. 5. Aerospace Approved Lubricants Rocol Lubricants Rocol Lubricants Airbus Specified Products Include Rolls Royce Specified Products Include Sapphire Endure High Performance PFPE, Aerospec 100 Semi Fluid Lubricant Extreme Pressure Grease Aerospec 200 General Airframe MHT Grease High Temp Moly Grease, Heavy loaded slow bearings Aerospec 3052 General Airframe (AMS 3052) MTLM (ZX38) General Purpose Anti Seize Aerospec 400 (XG-294) Wheel Bearing (AMS 3058) Sapphire Precision High Temp Non chlorinated Performance PFPE Spray Aerospec Protect Corrosion Protective Lubricant Spray, (undercarriage) Anti Seize 797 Nickel / Graphite anti Seize Anti Seize Spray Anti Seize for SS and Nimonic Alloys Dry Moly Paste Moly Disulphide dry lubricant Oxylube Resin bonded Moly Dry Lubricant
  6. 6. Benefits of Lithium vs Cl B fit f Lithi Clay based lubricants
  7. 7. Benefits of Lithium Complex vs Clay based lubricants 1 Cost Savings! 2 Performance Improvements • Reduced corrosion • Improved wear and EP Protection • Provide wider range of operating temperatures • Extended life, lower oxidation 3 Increased Availability & Compatibility All major commercial aircraft manufacturers have already transitioned to Lithium complex general airframe greases greases, based on SAE AMS 3052 specification starting mid 1990’s (BMS 3-33, AIM 09-06-002)
  8. 8. SAE Commercial Aerospace “Core” Lithium Grease Standards General Airframe (-73 °C to +121°C) Wheel Bearings (-54 °C to +177°C) Now majority of GA grease sold, capable of 90% plus of all New specification intended to replace MIL 81322 clay applications, operators seeing noticeable benefits pp p g g greases, improve current “ad hoc” products p p in corrosion and wear providing single industry standard, compatibility SAE AMS 3052 SAE AMS 3058 Airbus AIM 09-06-002 09 06 002 Airbus AIM 09-06-003 09 06 003 Boeing BMS 3-33 Boeing TBC Products Include Products Include Rocol Aerospec 3052 p Rocol Aerospec 400 p
  9. 9. Comparison of Clay and C i f Cl d Lithium Technology
  10. 10. What Are Greases ? 5 to 15 % Thickener either 2 t 10 % to Metal Soaps Additives Complex Metal Soaps can include Gels Gels- greases Polyureas Anti Wear Polymers / Plastics Tackifiers Corrosion Inhibitors Additive Thickener EP (Extreme Pressure) ( ) 70% to 80 % Oxidation Inhibitors Oil either Oil Mineral Oil Synthetic Oil Semi-Synthetic Oil
  11. 11. Base Oils (70- 80% of the grease) Mineral Oil Synthetic / Semi Synthetic • Cost Effective More Expensive (Life 5 to 10 times that of mineral) • Basic Oil (Distilled from Crude) Oil, Chemically Manufactured & Blended • Limited Operating Temperature Wider Operating Temperatures (-90ºC to 300ºC) Typical (-20ºC to 150ºC) Enhanced Performance (Typ. Wear) PAO, Polyalphaolefin • Wide Temp Range (-55ºC to 200ºC) Other Advantages Include Ester (di-ester) • Higher Film Strength • Extreme Low and High Temps Possible • Stronger Chemical Bond in Polymer Chain (-75ºC to 200ºC) Improved High Temperature Perfluorinated (PFPE) Improved Wear Properties • Oxygen Stability, Long Life, Good load carrying Heavier Loads • I t & Non-reactive, Radiation Stable Inert N ti R di ti St bl • Improved Compatibility with Additives • Temp Range (-90ºC to 280ºC) Silicone Oil • Long Light Duty Service Life • Wide Temp Range (-90ºC to 200ºC)
  12. 12. Additives (2 to 10% of Grease) Corrosion Inhibitors (sacrificial protective) • Sulphonates (Barium / Calcium) Anti Wear Additives • Phosphates & Dithio-Phosphates (engine oils) • Esters • PTFE EP Extreme Pressure Additives • Chemicals Sulphur Compounds (react with surface Iron Sulphide) • Boron compounds • Solids (Molybdenum Disulphide, up to 100,000 psi 450ºC) (Graphite , 15,000 to 20,000 psi up to 550ºC) Oxidation Inhibitors • Amines or Phenol Compounds
  13. 13. Thickener Systems (10-15% of Grease) Gel or CLAY “Soap”, “Metal Soaps or “Lithium” Greases Traditionally Used In Many “Synthetic” Thickening Products – Excellent Scope for Additives Greases BENTONITE CLAY LITHIUM COMPLEX LITHIUM (Latest Technology) •None Melting •Temperature range • Improved Temperature Range •High temperature capabilities (typically -20ºC to + 150ºC) (Drop Point typically >260ºC) •Good Stability with Water •Moderate Water Resistance • Good compatibility with additives •Versatile & Low Cost •Good Compatibility with Additi G dC tibilit ith Additive • Improved water washout • Improved shear stability Disadvantage • Longer service life •Limited scope for Additives !
  14. 14. Benefits of Clay vs Lithium - Summary Synthetic Lithium “Soap” Thickened greases have many potential advantages over Clay’s • Improved wear and EP / high load protection (especially high speed and temps) • Much wider range of operating temperatures • Significantly better corrosion protection • Controlled oil bleed, higher shear stability, • Lower oxidation • Improved Service Life! This is generally as a result of the wider range of additives able to be used…. However…. Mixing different types of grease does not necessarily make a better Grease… • Could Co ld be a problem with additi es (eg cla and lithi m – de gelling) ith additives clay lithium de-gelling) • Reaction between additives (eg lithium / lithium - corrosion)
  15. 15. SAE AMS 3058 Wh l B Wheel Bearing G i Grease Specification History & Compatibility
  16. 16. SAE AMS 3058 Lithium Wheel Bearing Grease Introduced - September 2008 • 3 yr development through SAE E34 Working group involving Airbus, Boeing, Shell, Mobil, Nyco, Rocol, USMC and others • SAE specification AMS 3058 intended as “core” similar to AMS 3052 core • Airbus issues AIM 09-06-003 in February 09 • Boeing - TBC AMS 3058 Specification Drivers • Enhance corrosion protection • Improved stability in presence of water • Low water washout • Reducing wear and improved EP performance • Align specification with AMS3052, General Airframe Specification SAE AMS 3058 intended as replace • MIL-PRF-81322 clay grease (currently used in wheel bearings) • Other lithium greases currently used b t not meeting MIL Ai b Oth lithi tl d but t ti MIL, Airbus, SAE and possible BMS spec d ibl
  17. 17. SAE AMS 3058 Lithium Wheel Bearing Grease g
  18. 18. Rocol A R l Aerospec 400 AMS 3058 Grease Compatibility
  19. 19. Grease Compatibility Testing – Test What and Why ? No Universal Standard for Testing • SAE Commercial Specification for Airframe Grease attempts to quantify • SAE AMS 3052 considers changes t CORE properties of G id h to ti f Grease mixtures ranging 10/90 to 90/10 What Why Dropping Point At what temperature will the grease mixture thin and start to drip Copper Corrosion Will the various additives in the grease start to react together and start to cause corrosion ? (Some EP additives can corrode steel if too much) Oil Separation Will the grease mixture start to De-Gel ? Extended Work Penetration (softening of the Grease) E t d dW kP t ti ( ft i f th G ) Will the structure of the grease start to break down when the Lubricant is mechanically worked. Any potential compatibility issues should start to effect these core properties first!
  20. 20. Drop Point and Copper Corrosion • Drop point IP 396 • Copper Corrosion IP 112 • 24 hours at 100 C
  21. 21. Oil Separation • Def Stan 05-50 Part 9 • 30 hours at 177 C
  22. 22. Shear Stability Extended Worked Penetration • Def Stan 05-50 Part 63 • 100 000 strokes 100,000 t k • With and without 10% water Penetration
  23. 23. Shear Stability - Roll Stability • ASTM D 1831 • 2 Hrs • With and without 10% water Penetration
  24. 24. Grease Compatibility Additional Testing EP Weld Load EMCOR Corrosion AMS 3058 • Test Method IP 220 • 3% NaCl solution • SKF 1306K bearing Beware (If no corrosion on outside ) Water soluble corrosion inhibitor h b i hibit has been used !!! d 5 3 MIL 81322 AMS 3058 Weld Load N/S 315kg min (Typ 230kg) (Typ 355kg) 2 0 MHL 30min 50min Scar Di IP239 S Dia IP239, 1hr @40kg 70C 0.8max 0.7max
  25. 25. Why Use EMCOR “dynamic” Corrosion Tests? Example uses data for MIL PRF 23827 Type II clay (G-350) vs Lithium G-354 TEST METHOD NUMBER TEST CONDITIONS ACCEPTANCE CRITERIA 1. Dynamic Rust Prevention IP220 3% NaCl solution 0 rating Properties SKF Emcor Salt Fog Test ASTM B117 38 C, 38°C 5% NaCl Comparison 2. 2 solution TEST METHOD MIX RATIO NUMBER AEROSHELL 7 : AEROSPEC® 200 100:0 50:50 0:100 1. 1 Dynamic Rust Prevention IP220 5 2 0 Properties SKF Emcor SH 33 AS200 SH 33/SH7 AS200/SH7 SH7 50/50 mix 50/50 mix 2. Salt Fog Test ASTM B117 168h Clear Clear Clear 336h Clear Clear Clear 504h Clear C Clear C Clear C TEST METHOD MIX RATIO NUMBER AEROSHELL 7 : AEROSHELL 33 100:0 50:50 0:100 1. Dynamic Rust IP220 5 1-2 0 Prevention Properties SKF Emcor 2. Salt Fog Test ASTM B117 168h Clear Clear Clear 336h Clear Clear Clear 504h Clear Clear Clear
  26. 26. Grease Compatibility Conclusions Replacing Clay NATO G-395 / MIL PRF 81322 with Lithium NATO G-1352 • G-1352 (Aerospec 400) Lithium Grease demonstrates good compatibility when mixed with 2 most widely used NATO G-395 / MIL PRF 81322 clay based greases • Shear stability, oil separation and corrosion remain largely unaffected even with 50/50 mix • 4 Ball EP, MHL and Wear data indicate that some performance criteria of NATO G395 clay grease may be exceeded by mixtures of clay and lithium (although not recommended)
  27. 27. Conclusions • Airbus and Boeing will increasingly aim to standardise around 2 core lithium g grease specifications, AMS 3052 and AMS 3058 p , • AMS 3058 has been specifically developed within the commercial aircraft industry to meet current and future requirements for aircraft wheel bearings • AMS 3052 and 3058 lubricants have a high degree of commonality and compatibility • Rocol Aerospec 400 has demonstrated good compatibility with both existing clay and lithium wheel bearing lubricants already in service AMS 3058 lubricants have the potential to further enhance performance and reduce costs