lubricants and their properties
TRANSCRIPT
WHY LUBRICATE?
• Minimize Wear• Separate moving surfaces
• through a suitable lubricant film• mainly during start-up
• Avoid metal to metal contact• Minimize Friction• Sealing
• Filling the gaps between • pistons and liners • piston rings and piston grooves• vanes and pump case
N7
WHY LUBRICATE?
• Cooling• Good thermal conductivity• Provide for high oil flow rate
• Keep the machine clean• Hold contaminants in
suspension• Prevents corrosion and rust
N7
BASE OILS
BASE OIL GROUPS• GROUP I (Solvent Refined)
• >90% Saturates• >0.03% Sulfur• VI 80-120
• GROUP II (Hydrogenation-Hydrogen Gas)• >90% Saturates• <0.03% Sulfur• VI 80-120• Better Anti-oxidation Properties
N7
BASE OILS
• GROUP III (Hydro-cracked higher pressure/temp)• >90% Saturates• <0.03% Sulfur• VI >120• Very pure base oil
• GROUP IV (SYNTHETIC)• Polyalphaolefin (PAO)• Polyolefin (POE)
• GROUP V• Base oil and synthetic combinations, Polyalkylene
Gylcol (PAG), Diester, Phosphate Esters
N7
HOW A LUBRICANT WORKS
• Petroleum-based products are ideal choices as lubricants due to their ability to wet metal surfaces
• Lubricant is able to get in between two metal surfaces and form a barrier
• Viscosity is key measure of lubricant effectiveness
N7
WHAT IS VISCOSITY?
• The measurement of a fluid’s resistance to flow
• Viscosity is dependent on temperature and pressure
N7
HOW A LUBRICANT WORKS
• High viscosity good for:• High temperatures• High loads• Low speed rotation
• Low viscosity better for:• Low temperatures• High speed rotation
• The less viscosity variation with temperature, the greater the Viscosity Index (VI)
• High VI - little variation good• Low VI - lots of variation bad
N7
VISCOSITY INDEX IMPROVERS
• Polymers are added to lubes to increase VI• At low temperature they form balls allowing
improved flow• At higher temperatures they inter-twine and
decrease flow• Polymer chains can be broken in areas of
high shear, e.g. in bearings which results in drop of VI and viscosity
N7
LUBRICATION REGIMES
• There are four major lubrication modes, or regimes:
• Boundary• Mixed• Hydrodynamic• Elasto-hydrodynamic (EHL)
• Increasing film thickness
N7
LUBRICATION REGIMES- BOUNDRY/MIX
• Boundary lubrication occurs due to:• Viscosity is too low• Speed is too low• Contact area is too small
SOLID FRICTION
STATIONARY
SLIDING
WELDING (WEAR)
BOUNDARY LUBRICATION
SLIDING
EXTREME PRESSURE
STATIONARY
ADDITIVE
N7
LUBRICATION REGIMES- HYDRODYNAMIC
• Hydrodynamic pressure is generated by:• Sliding of layers• Equipment design• Adequate oil supply• Oil viscosity
• Hydrodynamic is the desired regime
HYDRODYNAMIC PRESSURE
FLUIDPRESSURE BUILD UP
N7
LUBRICATION REGIMES- EHL• EHL is characterised by
• Elastic deformation of surfaces• Large increase in pressure and viscosity
• Typically found in anti-friction bearings (ball, roller bearings)
PRESSURECURVE
FLUIDBALL BEARING
OUTER RACE
N7
LUBRICATED PARTS-BEARINGS
• Illustration
FULL OIL PRESSUREOIL SUPPLY
RUNNING
HYDRODYNAMICLUBRICATION
NO OIL PRESSURE LOW OIL PRESSURE
LOAD OIL PRESSURE
MIXEDLUBRICATION
BOUNDARYLUBRICATION
START UP
N7
DIESEL ENGINE OILS• HIGH SPEED DIESEL ENGINES
• MOBILGARD 312• MOBIL DELVAC 1300 SUPER 15W40 • MOBIL DELVAC 1 ESP 5W40 (SYNTHETIC)• MOBILGARD HSD+ 15W40
• MEDIUM SPEED DIESEL ENGINES• MOBILGARD 412• MOBIL DELVAC 1630 OR 1640• MOBILGARD ADL 40 OR ADL 30• MOBILGARD 410 OR 450 (ZINC FREE)
ExxonMobil Lubricants
DIESEL ENGINE OILS• LOW SPEED DIESEL ENGINES
• MOBILGARD 300C (TRUCK OIL)• MOBILGARD 570C (CYLINDER OIL-RESIDUE FUELS)• MOBILGARD 525 (CYLINDER OIL-DISTILLATE FUELS)
ExxonMobil Lubricants
ExxonMobil Lubricants
TURBINE OILS• MARINE TURBINE OILS
• MOBIL DTE MEDIUM (ISO-46)• MOBIL DTE HEAVY MEDIUM (ISO-68)• MOBIL DTE HEAVY (ISO-100)
• MARINE GAS TURBINE OILS• MOBIL JET OIL II (LM2500 NAVY)• MOBIL JET OIL 254 (LM-2500 COMMERCIAL)
GEARS• MAIN AND AUXILIARY GEARS (MINERAL OILS)
• MOBILGEAR 600 XP 68• MOBILGEAR 600 XP 100• MOBILGEAR 600 XP 150• MOBILGEAR 600 XP 220• MOBILGEAR 600 XP 320• MOBILGEAR 600 XP 460• MOBILGEAR 600 XP 680
ExxonMobil Lubricants
• MAIN AND AUXILIARY GEARS (SYNTHETIC OILS)• MOBILGEAR SHC MT 68* (FUTURE CONTRACT MOD)• MOBIL SHC 629• MOBIL SHC 630• MOBIL SHC 632• MOBIL SHC 634
• TRANSMISSION/GEAR OILS (AUXILIARY EQUIPMENT)• MOBIL ATF DM• MOBIL ATF 220• MOBILFLUID 424• MOBILUBE HD PLUS 80W90• MOBILUBE HD PLUS 85W140
ExxonMobil LubricantsGEARS
• HYDRAULIC FLUIDS• MOBIL DTE 10 EXCEL 15• MOBIL DTE 10 EXCEL 32• MOBIL DTE 10 EXCEL 46• MOBIL DTE 10 EXCEL 68• MOBIL DTE 10 EXCEL 100• MOBIL DTE 10 EXCEL 46 (ZINC FREE)• MOBIL DTE 10 EXCEL 68 (ZINC FREE)
ExxonMobil Lubricants
HYDRAULICS
• REFRIGERATION COMPRESSOR OILS (POE)• MOBIL EAL ARCTIC 32• MOBIL EAL ARCTIC 46• MOBIL EAL ARCTIC 68• MOBIL EAL ARCTIC 100 * (FUTURE CONTRACT MOD)• MOBIL EAL ARCTIC 220 * (FUTURE CONTRACT MOD)
REFRIGERATION
ExxonMobil Lubricants
• COMPRESSOR OILS• MOBIL RARUS 427 (MINERAL-RECIPROCATING)• MOBIL RARUS 429 (MINERAL-SCBA)• MOBIL RARUS SHC 827 (SYNTHETIC-RECIPROCATING)• MOBIL RARUS SHC 1025 (SYNTHETIC-ROTARY)• MOBIL RARUS SHC 1026 (SAME SHC RARUS 68) AAB-TURBO• MOBIL SHC RARUS 68 (SYNTHETIC-ROTARY SCREW AND VANE)
ExxonMobil Lubricants
COMPRESSED AIR
• GREASES• MOBILGREASE 28 (SYNTHETIC-CLAY)• MOBILGREASE XHP 220 (EP0-LITHIUM COMPLEX)• MOBILGREASE XHP 221 (EP1-LITHIUM COMPLEX)• MOBILGREASE XHP 222 (EP2-LITHIUM COMPLEX)• MOBIL UNIREX N2 (MULTI-PURPOSE BEARING- LITHIUM)• MOBILITH SHC 100/220/460 (SYNTHETIC-LITHIUM)• MOBILTAC 375 NC (NON-CHLORINATED) CALCIUM• MOBILGREASE XTC (NGLI-1 LITHIUM) COUPLING GREASE• MOBILARMA 798 ( CALCIUM-WIRE ROPE GREASE )• MOBIL POLYREX EM (POLYUREA- MOTOR BEARING)
ExxonMobil LubricantsOTHER LUBRICATION REQUIREMENTS