| abstract |
A variable displacement hydraulic system contains a housing, a cylinder block provided with a plurality of pistons movable in reciprocation, and a swash plate for controlling reciprocation of each of the pistons so that the swash plate is slantwise rotatable along a slidable contact surface of arcuate shape. A thrust metal is mounted to an arcuate contact surface of the housing. Arcuate plates having smooth surfaces of high sliding efficiency are fixed onto outwardly curved portions formed at the rear surface of the swash plate, which is in contact with the thrust metal. Alternatively, a smooth surface layer having a high sliding efficiency is formed on the swash plate by applying chemical processes, thereby reducing the sliding resistance of the swash plate and improving the ease with which the swash plate is restored to the neutral position. |