| 摘要 |
PROBLEM TO BE SOLVED: To provide a fulcrum bearing device of a pulley arm capable of preventing plastic deformation of a seal member and, thereby, securing preferable sealing property over a long time.SOLUTION: A shaft insertion hole 5 is formed on a boss part 4 of a pulley arm which supports a tension pulley for pressing a belt by means of a hydraulic auto tensioner, a sleeve 7 is inserted into the shaft insertion hole, washers 8 are fitted onto respective outer circumferences of small diameter tube parts 7a formed on both edge parts of the sleeve, the sleeve is fixed to an engine block 10 by fastening a bolt 9 inserted into the sleeve and, thereby, the pulley arm is swingably supported. Large diameter seal storage recessed parts 12 are disposed on both edge parts of the shaft insertion hole, a seal member 13 stored in the seal storage recessed part is supported by the sleeve and is closely adhered to an inner surface of the washers, and a gap 15 larger than an aperture 11 in the axial direction formed between the washers and opposite surface of the boss part is disposed between the inner surface of the seal member and the lateral surface of the seal storage recessed part to prevent pressurization to the seal member at the boss part. |
