idler pulley

idle pulley

also idler pulleyn. A pulley on a shaft that rests on or presses against a drive belt to guide it or take up slack. Also called idle wheel.

Thesaurus

Noun

1.

idler pulley - a pulley on a shaft that presses against a guide belt to guide or tighten itidle pulley, idle wheelpulley, pulley block, pulley-block, block - a simple machine consisting of a wheel with a groove in which a rope can run to change the direction or point of application of a force applied to the rope