a wheel with a grooved rim around which a cord passes, which acts to change the direction of a force applied to the cord and is chiefly used (typically in combination) to raise heavy weights
滑轮,滑车。
a wheel or drum fixed on a shaft and turned by a belt, used especially to increase speed or power
皮带轮。
hoist with a pulley
用滑轮升起(或绞起)。
"Middle English: from Old French