1 BearingsLubrication &Cooling Roger Bortignon

2 ball thrust bearingsball thrust bearings needle thrust bearingsneedle thrust bearings

3 Why are bearing surfaces hard? chief cause of rolling friction: deformationchief cause of rolling friction: deformation  steel wheel on steel rail:.002 C of F  riding a bike with a flat tire: high C of F bearings & there are races very hard  smaller “footprint” & a lower “C of F”bearings & there are races very hard  smaller “footprint” & a lower “C of F” this is a compromise between size & strengththis is a compromise between size & strength

4 Lubrication Engine oil is designed to… Lubricate moving parts (minimize wear/reduce friction) Lubricate moving parts (minimize wear/reduce friction) Cool engine parts by absorbing heat Cool engine parts by absorbing heat Clean engine via detergents that are added to the oil Clean engine via detergents that are added to the oil Seals the area between the rings and the cylinder wall to improve combustion Seals the area between the rings and the cylinder wall to improve combustion Quiets the engine by separating moving parts Quiets the engine by separating moving parts

5 Bearings Ride On A Film Of Oil

6 Engine Oil Oil viscosity: its resistance to flow or rate of flow.Oil viscosity: its resistance to flow or rate of flow. Low viscosity oil = thinner (think baby oil)Low viscosity oil = thinner (think baby oil) High viscosity oil = thicker (think honey)High viscosity oil = thicker (think honey) Viscosity Grade: determined by…Viscosity Grade: determined by… Society of Automotive Engineers (SAE)Society of Automotive Engineers (SAE) lower numbers = thinner oillower numbers = thinner oil higher numbers = thicker oilhigher numbers = thicker oil Oil Service Classification: determined by the American Petroleum Institute (API)Oil Service Classification: determined by the American Petroleum Institute (API)

7 Synthetic (man-made) Engine Oils 1) Synthetic motor oils will withstand higher engine temperatures than petroleum based oils   600 degrees F compared to   450 degrees F for petroleum oils 2) Synthetic oils will begin lubrication at lower temperatures than petroleum oils   -58°F degrees, compared to   -35°Fdegrees for petroleum based oils 3) Synthetic oils are more “slippery” than petroleum oils   less wear and tear   cooler engine   better performance

8 Hydrodynamic Lubrication

9 Lubrication Systems 1) Splash Lubrication: used with a “dipper” (horizontal shaft)used with a “dipper” (horizontal shaft) or “oil slinger” (vertical shaft)or “oil slinger” (vertical shaft)

10 Lubrication Systems Continued 2) constant level splash: uses simple splash plus… 2) constant level splash: uses simple splash plus… a pump a pump a trough a trough and a strainer and a strainer

11 Splash Lubrication Systems Continued 3) Ejection pump 4) Barrel pump

12 Full Pressure Lubrication System uses a positive displacement oil pumpuses a positive displacement oil pump pump feeds pressurized oil to bearing surfaces, camshaft, connecting rod and valve trainpump feeds pressurized oil to bearing surfaces, camshaft, connecting rod and valve train can be used with splash systemcan be used with splash system

13 Oil Filtration 1) Bypass System

14 Oil Filtration 3) Full Flow System