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Lubrication Training - Basics of Lubrication

Lubrication Training - Basics of Lubrication. Types of Lubrication. Hydrodynamic Boundary Mixed. Hydrodynamic Lubrication. Occurs when machine parts are completely separated by a full and continuous film of lubricant Contact between the parts does not occur.

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Lubrication Training - Basics of Lubrication

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  1. Lubrication Training - Basics of Lubrication

  2. Types of Lubrication • Hydrodynamic • Boundary • Mixed

  3. Hydrodynamic Lubrication • Occurs when machine parts are completely separated by a full and continuous film of lubricant • Contact between the parts does not occur. • Full-fluid-film lubrication is hydrodynamic lubrication, the oil adheres to the moving part and is drawn into the area between the rotating surfaces, where it forms a pressure, or hydrodynamic, wedge. • A less common form of full-fluid-lubrication is hydrostatic lubrication, where the oil is supplied to the bearing area under pressure to separate the sliding surfaces.

  4. Hydrodynamic Lubrication

  5. Boundary Lubrication • Under certain conditions such as shock loading, heavy loads, high temperature, slow speed and critically low viscosity, the lubricant is no longer hydrodynamic • Frequent contact between the surfaces, resulting in a significant rise in temperature and subsequent destruction of the contacting surfaces. • Under these circumstances, the fluid film is no longer capable of adequately protecting the surfaces. • EP capabilities in the lubricant are essential • Solid additives are mixed into the grease

  6. Mixed Lubrication • Although not a true “mode” of lubrication in the sense of hydrodynamic or boundary, mixed lubrication occurs more frequently then is realized. • Mixed lubrication is a transitional mode of lubrication between hydrodynamic and boundary • Mixed lubrication is characterized by the likelihood of intermittent surface contact • EP and anti-wear are essential properties in the lubricant

  7. Select a base fluid: MINERAL OIL or SYNTHETIC FLUID? How is a lubricant made?

  8. Selecting a base fluid: MINERAL OIL Paraffinic or Naphthenic Readily available Comparatively low cost Limited performance.

  9. Selecting a base fluid: SYNTHETIC FLUIDS PAO, PAG, Ester Synthetically manufactured Comparatively high cost Improved performance Longevity Temperature Viscosity Index

  10. Selecting a base fluid: OTHER SYNTHETIC FLUIDS Silicones Fluorinated Ultra Performance Ultra Temperature Long Life Lube for Life

  11. Base fluid selected: Mineral or Synthetic NOW SELECT THE REQUIRED VISCOSITY.

  12. Selecting the required viscosity: Generally thinner fluids are used for: Lighter loads Faster speeds.

  13. Selecting the required viscosity: Generally thicker fluids are used for: Heavier loads Slower speeds So how do we measure viscosity?.

  14. 400C & 1000C mm2 per second =centistokes (cSt) High Viscosity (Thick) Low Viscosity (Thin)

  15. What are the units of viscosity? mm2s = centistokes (cSt) = ISO VG (at 400C) 32 cSt - typical low viscosity (thin) 680 cSt - typical high viscosity (thick) ISO VG 15-22-32-46-68-100-150-220-320-460-680-1000 etc

  16. SOLID LUBRICANTS Graphite Molybdenum disulphide (MoS2) PTFE (Teflon) CHEMICAL SOLUTIONS Chlorine Sulphur Phosphorous Product enhancements: Extreme Pressure (EP) Additives

  17. Product enhancements OXIDATION INHIBITORS Longer wet life CORROSION INHIBITORS Improves corrosion protection. TACKY ADDITIVES Improves adhesion

  18. Thickener Systems – turn fluids into greases Improved Performance -Temperature -Mechanical stability Lithium complex Calcium complex Aluminium complex Soap Thickeners Lithium soap Calcium soap Aluminium soap General Purpose

  19. Thickener Properties • Lithium • Good multi-purpose, good mechanical stability, limited other properties • Lithium Complex • Excellent high temp & mechanical stability capability • Calcium Complex • Excellent load carrying and water resistance • Aluminium Complex • Excellent temperature capability & water resistance

  20. Other grease thickeners: Bentonite clay Silica PTFE. Other Thickener Systems

  21. How is the grease thickness checked ? NLGI PENETRATION TEST NATIONAL LUBRICATING GREASE INSTITUE of America.

  22. NLGI Numbers - WHAT DO THEY MEAN? SEMI FLUID/ FLUID GREASE Generally applied by Automatic Lubricator

  23. HOW IS GREASE THICKNESS MEASURED? Premium EP 2 Premium EP 1 Premium EP 000 NLGI 6 NLGI 5 NLGI4 NLGI 3 NLGI 2 NLGI 1 NLGI 0 NLGI 00 NLGI 000

  24. Summary Base fluid • Mineral or synthetic • Viscosity EP additives • Chemical and/or solids Corrosion inhibitors Oxidation inhibitors Thickeners for greases.

  25. Shaft TO SUPPORT A ROTATING SHAFT BASIC FUNCTION OF A PRECISION BEARING Outer Race Balls or Rollers Inner Race Lubricant

  26. Shaft TO SUPPORT A ROTATING SHAFT BASIC FUNCTION OF A PLAIN BEARING Plain Bush Lubricant

  27. BASIC FUNCTION OF A SLIDE TO SUPPORT A SLIDING LOAD

  28. ALL BEARINGS/SLIDES HAVE ONE SURFACE MOVING AGAINST ANOTHER FRICTIONAL HEAT WHY LUBRICATE?

  29. FRICTIONAL HEAT FRICTIONAL WEAR WHY LUBRICATE?

  30. Introduction of a lubricant film REDUCES FRICTIONAL HEAT & WEAR BASIC FUNCTION OF A LUBRICANT.

  31. Reasons for bearing failure

  32. Breakdown of “improper lubrication” section

  33. Potential failures due to over lubrication Standard grease gun can develop 3,000 psi • High pressure grease guns can develop >6,000 psi Potentially resulting in excessive drag causing: • Increased power demand • Ball/roller skid • Increased friction • Excessive heat • Excessive race wear • Degradation of the lubricant.

  34. Correct Application of a lubricant LITTLE & OFTEN! Precision Bearings: • Typically fill 1/3 to 1/2 of vacant area in bearing • High speed bearings require approx. 1/3 fill Plain Bearings • Typically fill until clean grease shows.

  35. Thank YouAny Questions?

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