Definition
A bearing designed so that its inner and outer races can shift slightly in relation to each other, allowing the shaft it supports to remain in proper alignment even when the shaft or its housing is not perfectly straight. This is typically achieved by using a spherical outer race or two rows of balls running on a curved track.
Plain English
A bearing that can adjust itself a small amount to keep a slightly bent or misaligned shaft turning smoothly without binding.
Context Anchor
Seen in aircraft maintenance when inspecting or replacing bearings in control linkages, hinges, actuators, and other moving assemblies.
Derivation
Self-aligning' simply means the bearing aligns itself. The point of including it as a term is that ordinary bearings cannot do this -- they require precise alignment from the structure around them. This bearing solves that problem on its own.
Why Pilots Care
Allows control and engine parts to move freely despite airframe flex or thermal changes, reducing stress and preventing premature failure.
Intuition Check
Do not read bearing here as a compass direction. In this term, a bearing is a mechanical part that supports motion and load.
Example Sentence 1
The control cable pulley uses a self-aligning bearing so that slight flexing of the airframe does not cause the pulley to bind.
Example Sentence 2
Engine vibration caused the self-aligning bearing on the accessory mount to wear, requiring replacement during the inspection.