TENSION ADJUSTING DEVICE FOR AUXILIARY MACHINE DRIVING BELTS

摘要

A tension adjusting device for an engine accessory driving belt is provided which can maintain high sealability in the bearing portion about which a pulley arm supporting a tension pulley pivots for a long period of time. By tightening a bolt 7 threaded into an engine block 8, a fulcrum shaft 6 is fixed. A tension pulley is rotatably supported by a pulley arm 2 pivotally supported about the fulcrum shaft 6. A regulating force of a hydraulic auto-tensioner is applied to the pulley arm 2 to press the tension pulley against the belt B. A washer 10 is disposed between a boss 3 formed on the pulley arm 2 and the head 7a of the bolt 7. The washer 10 has an outer cylindrical portion 11 covering one end of the boss 3. A slinger 12 is mounted on the end of the boss 3 to define a labyrinth 13 between the slinger 12 and the cylindrical portion 11, thereby preventing entry of muddy water and dust into the bearing portion pivotally supporting the pulley arm 2.