rotor head vs rotor shaft

rotor head and rotor shaft both are nouns.

Word	Noun	Adjective	Verb	Adverb
rotor head	Yes	No	No	No
rotor shaft	Yes	No	No	No

As nouns, rotor head and rotor shaft are synonyms defined as:

rotor head and rotor shaft: the axis around which the major rotor of a helicopter turns

rotor head (noun)	rotor shaft (noun)
the axis around which the major rotor of a helicopter turns	the axis around which the major rotor of a helicopter turns