spur wheel vs gear wheel

spur wheel and gear wheel both are nouns.

Word	Noun	Adjective	Verb	Adverb
spur wheel	Yes	No	No	No
gear wheel	Yes	No	No	No

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

spur wheel: gear wheels that mesh in the same plane
gear wheel: a toothed wheel that engages another toothed mechanism in order to change the speed or direction of transmitted motion

Other hypernyms of spur wheel include cogwheel, gear, geared wheel.

spur wheel (noun)	gear wheel (noun)
gear wheels that mesh in the same plane	a toothed wheel that engages another toothed mechanism in order to change the speed or direction of transmitted motion