Patent ID: 7273432

Claim:
A belt tensioner comprising: a cup shaped base section having a hollow bearing pin; a retainer pivotally mounted on said bearing pin for rotation about a first axis, said retainer having a radial plain bearing frictionally engaging said bearing pin, said retainer being movable in an axial direction along said bearing pin, and said retainer having an idler pulley mounted for rotation about a second axis, said second axis being offset from and parallel to said first axis; a coil spring extending between said base section and said retainer, said coil spring urging said retainer to rotate about said first axis and bias said idler pulley into engagement with a belt; a spring bush and a coil bush supporting said coil spring on said retainer and said base section, respectively; a locking piece forming a locking joint on a free end of said bearing pin, presenting a hollow passageway through said tensioner enabling said tensioner to be mounted on an engine part; and a Belleville spring mounted about said bearing pin, said Belleville spring axially urging said retainer against said locking piece.