Positive-displacement pump or positive-displacement motor for fluids

摘要

A conventional positive-displacement pump or a conventional positive-displacement motor has, even if to a limited extent, certain disadvantages due to production, above all at the corner region of the cuboid sliding spool. In operation, sealing problems can also arise in these corner regions. In order to counteract this, it is provided that instead of a cuboid sliding spool provision is made in each case of one or, possibly, two cylindrical working pistons (9b, 9d) which lie offset by 90@ relative to one another in two planes and are arranged movably in cylinder bores (12, 15) which can be produced appropriately without any problem. The at least one or two working pistons (9b, 9d) are connected in a driving manner to an axle body (4) of a shaft (17) via a coupling member (9a). The positive-displacement pump or the positive-displacement motor is particularly suitable for hydraulic fluids. <IMAGE>