Bearing Lubrication and Sealing

Why Lubricate

• Reduce friction and wear
• Prevent corrosion
• Dissipate heat
• Dispel contaminants and moisture

Main Consideration for Design of Sealing

• Lubrication retention
• Contaminant retention
• Rotational speed
• Pressure differential

Lubrication

• Grease lubrication usually used for lifetime lubrication (w/ bearing seals)
• Oil lubrication is usually for high speeds or continuous runs

Oil Lubrication for Drive Trains

• Oil bath: The simplest for gear boxes, the bearing just dips into the oil back and rotates to lubricate
• Circulating oil
  • With a reservoir and a filter with a pump

Bearing Sealing

• Contact seals (the shaft contacts the seal itself) include:
  • Felt seals
  • Lip seals
• Non-contact seals include:
  • Oil grooves
  • Labyrinth seals

Lip Seal

• Given a catalogue, different identification codes specify the type of lubricant the lip seal works against