Lubrication

Floating on a film of oil

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Viscous shear force $F = \mu A v / h$.
• Thin films raise the force; lubrication replaces scraping with shearing.
• Rotating shafts float on self-pressurising oil wedges.

Steps

1. Shearing a thin layer
2. Slide the plate
3. Thinner film
4. Self-pumping bearings
5. Running faster
6. Power lost