lathe vs wheel lathe

lathe and wheel lathe both are nouns.

Word	Noun	Adjective	Verb	Adverb
lathe	Yes	No	No	No
wheel lathe	Yes	No	No	No

As nouns, wheel lathe is a hyponym of lathe; that is, wheel lathe is a word with a more specific, narrower meaning than lathe:

lathe: machine tool for shaping metal or wood; the workpiece turns about a horizontal axis against a fixed tool
wheel lathe: a lathe for turning railway-car and locomotive wheels.

Other hyponyms of lathe include bench lathe, turning and boring mill, metal spinning lathe.

lathe (noun)	wheel lathe (noun)
machine tool for shaping metal or wood; the workpiece turns about a horizontal axis against a fixed tool	a lathe for turning railway-car and locomotive wheels.