bevel gear vs gear wheel

bevel gear and gear wheel both are nouns.

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

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

bevel gear: gears that mesh at an angle
gear wheel: a toothed wheel that engages another toothed mechanism in order to change the speed or direction of transmitted motion

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

bevel gear (noun)	gear wheel (noun)
gears that mesh at an angle	a toothed wheel that engages another toothed mechanism in order to change the speed or direction of transmitted motion