A ball bearing lets a shaft turn with very little friction while it carries load. Instead of the shaft rubbing against the housing, hardened steel balls roll between two rings.
What is inside
- Inner ring fits onto the shaft and carries the inner raceway.
- Outer ring fits into the housing and carries the outer raceway.
- Balls roll between the two raceways and carry the load.
- Cage keeps the balls evenly spaced so they do not rub against each other.
- Seals or shields keep grease in and dirt out on sealed bearings.
- Grease reduces friction and protects the steel surfaces.
Load: radial and axial
Radial load pushes across the shaft, like the weight of a pulley. Axial (thrust) load pushes along the shaft. A deep groove ball bearing takes mostly radial load with some axial. An angular contact bearing takes both together. A thrust ball bearing takes axial load only.
Where they are used
Electric motors, fans, pumps, gearboxes, conveyors, vehicles and home appliances. If a machine has a turning shaft, it almost certainly has a bearing.
When to replace one
Noise, vibration, heat or play in the shaft are the usual signs. Read the number stamped on the side of the old bearing and send it to us. That number tells us the size and type.
