epicyclic train vs power train

epicyclic train and power train both are nouns.

Word	Noun	Adjective	Verb	Adverb
epicyclic train	Yes	No	No	No
power train	Yes	No	No	No

As nouns, power train is a hypernym of epicyclic train; that is, power train is a word with a broader meaning than epicyclic train:

epicyclic train: a system of epicyclic gears in which at least one wheel axis itself revolves about another fixed axis
power train: wheelwork consisting of a connected set of rotating gears by which force is transmitted or motion or torque is changed

Other hypernyms of epicyclic train include gear, gearing, geartrain, train.

epicyclic train (noun)	power train (noun)
a system of epicyclic gears in which at least one wheel axis itself revolves about another fixed axis	wheelwork consisting of a connected set of rotating gears by which force is transmitted or motion or torque is changed