Patent ID: 7384355
Filing Date: 2008-06-10
Classification: F16H,Y10T

Abstract:
1. An autotensioner comprising: a base that has a bottomed tubular shape; a rocking arm that has a tubular part rotatably supported at the inside of said base; a pulley that is attached to one end of said rocking arm, and abuts against a belt; a torsion coil spring that is housed in said base, and biases rotation of said rocking arm in a direction tensioning said belt with respect to said base; said torsion coil spring being attached eccentrically to the axial center of said base, and said rocking arm being supported to be able to be displaced relative to said base, whereby the first damping force acting on said rocking arm when said belt is tensioned becomes relatively larger than the second damping force acting on said rocking arm when said belt is slack; a friction member that is interposed between an outer circumferential surface of said tubular part and an inner circumferential surface of said base, and provided across a range of at least 180 degrees around the axial center of said base, a part of said tubular part being biased to be pushed against said friction member by said torsion coil spring; and a damping member separate from said friction member, said damping member engaging with said rocking arm movably in the radial direction and frictionally sliding with said base.