Apparatus for automatically tensioning a drive belt.

摘要

An apparatus for tensioning a belt consisting of a tensioner arm (46) having an idler pulley (52) for engagement with a surface of a drive belt, structure for mounting the tensioner (46) arm to a support (44) for pivoting movement about a pivot axis (48) in first and second opposite directions, and structure (100) for biasing the tensioner arm (46) in one of the first and second directions. The mounting structure includes first and second members (122, 124) with first and second relatively movable cooperating friction generating surfaces (136, 138) for damping rotation of the tensioner arm (46). At least a portion of one of the friction generating surfaces (136, 138) is concave opening towards the tensioner with at least one of the friction generating surfaces (136, 138) having at least a portion defined by other than a radius centered on the pivot axis (48) of the tensioner arm (46) to thereby produce a greater resistance to rotation of the tensioner arm (46) in the other of the first and second directions than in the one of the first and second tensioner arm (46) pivoting directions.