Lubrication

Why Lubrication ?

• Separate the bearing surfaces
  • Eliminate wear
  • Reduce friction
• Protect the bearing
  • from corrosion
  • from external

Considerations for Oil Viscosity

• Low viscosity
  • Low friction
  • Thin oil film
• High viscosity
  • Thick oil film
  • High friction
• Find the right balance

What is Grease ?

• Grease is 90% oil held in a thickener (10%)
• Think of the thickener as a sponge holding the oil
• It is not:
  • a thick oil
  • a solid oil (wax)

What is a Grease made of ?

Grease Additives

• Anti-oxidants
  for longer grease life

• Extreme pressure (EP) additives
  protection against cold welding

• Anti-corrosion additives
  for bearing protection

• Solid additives (graphite, MoS 2 )
  for when oil film is inadequate

Important Properties of Grease

• Operating temperature range
• Viscosity of the base oil
• Consistency of the grease