Bearing
A bearing is a machine element that supports a rotating or oscillating shaft, constrains its motion and reduces friction between moving parts. Rolling-element bearings use balls or cylindrical, tapered or spherical rollers running between inner and outer rings, while plain (journal) bearings rely on a lubricant film between the shaft and a bushing. Bearings are used in pumps, motors, gearboxes, fans and compressors. Selection depends on radial and axial load, speed, operating temperature, required rating life (L10 per ISO 281), lubrication method (grease or oil), sealing, internal clearance and mounting arrangement. Boundary dimensions of rolling bearings are standardised in ISO 15, which allows interchangeability between manufacturers. Condition monitoring typically uses vibration analysis and temperature measurement to detect wear before failure.
Examples
- Deep-groove ball bearings in electric motors
- Tapered roller bearings on gearbox shafts
- Spherical roller bearings in conveyor pulleys