BELT TENSIONER WITH RELEASABLE BELT LOAD DAMPING

摘要

38 BELT TENSIONER WITH RELEASABLE BELT LEAD DAMPING A belt tensioner having a sleeve bearing pivotally mounting a pivoted structure on a fixed structure for spring pressed movement between first and second positions. The sleeve bearing is larger than and surrounds a ball bearing assembly rotatably mounting a pulley on the pivoted structure. The pulley has a cantilevered rim which axially overlaps and annularly surrounds the sleeve bearing. One of the structures and the sleeve bearing have slidably interengaging surfaces which are compressed together by the belt load force in the pivoted structure and the reactionary force acting in the fixed structure so as to provide a damping torque resistance to the pivotal movement of the pivoted structure which prevents movements resulting from dynamic changes in the belt load force within a range. The arrangement is such that independent vibrational forces instantaneously release the damping torque resistance to permit instantaneous movements otherwise prevented.