| abstract |
A belt tension adjustment device is provided which, even when the slide bearing is heated to a high temperature by the heat of an automobile engine, is less likely to be worn and in which the propeller shaft does not seize. The belt tension adjusting device comprises a stationary propeller shaft, an arm rotatably supported on the propeller shaft by means of a synthetic resin slide bearing, a tension pulley mounted on the arm at one end thereof for tensioning a belt, and a damper which has a piston rod abutting the other end of the arm. The tension pulley is pressed against the belt by tilting the arm under the force of the piston rod, which adjusts the tension of the belt. The inner peripheral surface of said slide bearing, which is in sliding contact with said drive shaft, is shaped so that it has a surface roughness Ra of not more than 6.3 µm. The slide bearing is made of a resin composition comprising 65 to 85% by volume of a thermoplastic polyimide resin, an aromatic polyether ketone resin or a mixture of the resins and 15 to 35% by volume of a tetrafluoroethylene resin. |