Dryer idley pulley. The idler pulley puts tension on the drive belt. If the idler pulley fails to put the proper amount of tension on the belt, the dryer will not spin.
Motor pulley, plastic
Washing machine transmission pulley (or drive pulley). Includes pulley. thrust washer, and bearing kit. If the washer's bearing is worn out, the washer may spin slowly or may not spin at all.
Idler arm & shaft assembly
Idler pulley wheel
Belt idler rod and wheel assembly
Transmission drive pulley