PULLEY UNIT

摘要

A rotation adjusting mechanism is provided in a power transmission path from an alternator pulley to an alternator shaft and includes mainly a coil spring as an elastic member and a clutch mechanism having a function to switch between transmission and interruption of power. The power of the alternator pulley is transmitted from the coil spring to the alternator shaft via the clutch mechanism in a power transmission state. The coil spring reduces a minute change in rotation generated in at least one of the alternator pulley and the alternator shaft by its elastic deformation. The clutch mechanism is provided in an intermediate position of the power transmission path from the coil spring to the alternator shaft and interrupts the power transmission from the alternator pulley to the alternator shaft when a rotation speed of the alternator pulley lowers below a rotation speed of the alternator shaft by a predetermined value or greater.