planetary gear vs geared wheel

planetary gear and geared wheel both are nouns.

Word	Noun	Adjective	Verb	Adverb
planetary gear	Yes	No	No	No
geared wheel	Yes	No	No	No

As nouns, geared wheel is a hypernym of planetary gear; that is, geared wheel is a word with a broader meaning than planetary gear:

planetary gear: an outer gear that revolves about a central sun gear of an epicyclic train
geared wheel: a toothed wheel that engages another toothed mechanism in order to change the speed or direction of transmitted motion

Other hypernyms of planetary gear include cogwheel, gear, gear wheel.

planetary gear (noun)	geared wheel (noun)
an outer gear that revolves about a central sun gear of an epicyclic train	a toothed wheel that engages another toothed mechanism in order to change the speed or direction of transmitted motion