Definition
The structural housing of a generator or motor that supports the field poles and provides the magnetic path between them. The field frame holds the field coils (or permanent magnets) in position around the rotating armature and completes the magnetic circuit that allows the machine to produce or use electrical power.
Plain English
The outer iron shell of a generator or motor. It holds the magnets in place and gives the magnetism a solid path to travel through.
Context Anchor
Seen in aircraft electrical system and maintenance discussions, especially when describing starters, generators, or starter-generators.
Derivation
‘Field’ refers to the magnetic field inside the machine. ‘Frame’ is the supporting structure. Together: the structure that supports and shapes the magnetic field.
Why Pilots Care
A pilot usually does not handle a field frame directly, but understanding the term helps when reading maintenance write-ups or discussing starter or generator problems with a mechanic.
Intuition Check
Do not read “field” as an open area of land here. In this term, “field” means the magnetic area inside an electrical machine.
Example Sentence 1
The field coils are bolted to the inside of the field frame, surrounding the armature.
Example Sentence 2
Rust inside the field frame can weaken generator output.