Sheaves and blocks.
Vitruvius (De Architectura 10.2):
In trocleam induntur orbiculi duo per axiculos versationes habentes.
Two pulley wheels are inserted into the block, turning on its axles.
From what I can tell so far, classical Latin does not seem to have a word exactly corresponding to ‘pulley’; there was the sheave—the grooved wheel itself—orbiculus, and there was the block with the axles on which the sheave or array of sheaves was mounted, trochlea.  In English the word ‘pulley’ appears to refer originally to the sheave but often to the whole apparatus; in the former case the translation would be orbiculus, and in the latter trochlea is probably the better term.
[For trochlea.]
Tagged 1st century BC, orbiculus, pulleys, translation, trochlea, Vitruvius