DUAL FRICTION SURFACE ASYMMETRICALLY DAMPED TENSIONER

摘要

A belt tensioner for a power transmission belt is provided that utilizes asymmetrical motion control and is operable in a first condition and a second condition. The belt tensioner (14) has an arm (18) with a belt engaging section (22) and a drum section (26), a support member (16) for securing the tensioner (14) relative to the belt (12), and a spring (20) that urges the arm (18) to pivot about the support member (16) in a first direction and urges the belt engaging section (22) against the belt (12) with a force to tension the belt. The tensioner (14) also has a stator (28) coupled to the support member (16) to form arcuate spaces (35) circumferentially spaced around the stator (28) between the stator and the drum section (26) and arcuate shaped wedges (32) in the arcuate spaces (35). The tensioner (14) further has a Belleville spring (33, 133) coupled to the arm (18) for pivoting therewith and a friction device (30, 130) in sliding contact with the wedges (32) and Belleville spring (33, 133).