Power transmission system

摘要

A power transmission system having: a power transmission belt with a tensile strength such that a force of at least 17 kgf per 1 mm width is required to effect a 1% elongation of the belt; a plurality of pulleys with which the power transmission belt is operatively engaged; and an auto-tensioner having an element to engage the power transmission belt. The auto-tensioner has a damping ratio that is not greater than 20%, where the damping ratio is defined by the following formula: Damping ratio=2[(A-B)/(A+B)]x100, where A is the force exerted by the auto-tensioner element during up-stroking of the auto-tensioner element and B is the force exerted by the auto-tensioner element during down-stroking of the idler pulley. More preferably, the damping ratio is 10-20%.