Abstract: An axial piston pump has a structure in which an opening of one of the piston chambers starts overlapping with an opening portion when a pressure of another piston chamber reaches a pressure of a discharge port, and an opening of one of the piston chambers starts overlapping with an opening when a pressure of another piston chamber reaches a pressure of a suction port.

Abstract: A tandem, swash plate-type hydraulic pump in which a drive force transmission system for extending one or more hydraulic pumps and a structure relating to the system can be made simple and light, and one or more hydraulic pumps even when extended can be compactly arranged without increasing the axial length of the pump unit. A drive force take-out mechanism for taking outward part of a driving force out of a spline sleeve member of a spline coupling which is an intermediate coupling of a tandem, swash plate-type hydraulic pump. A first gear is connected with a spline sleeve member and a gear box. The gear box is composed of an intermediate gear, a driven gear, a spline sleeve member, and a gear case for rotatably housing these components. The gear box is removably fixed to an intermediate block and provided on both surfaces of the gear case are pump mounting portions for mounting hydraulic pumps which may be added as appropriate.

Abstract: A swash-plate type piston pump motor has a housing assembly comprising: an end plate for rotatably supporting a cylinder rotor against thrust loads in its axial direction and also rotatably supporting the upper end of an output shaft; a cylinder side peripheral wall encompassing the cylinder rotor; an inner peripheral wall which is joined contiguously to the cylinder side peripheral wall and extends downward toward the lower end of the output shaft. The inner peripheral wall encloses and supports a swash plate in an inclined state. A downwardly extending outer peripheral wall is also joined contiguously to the cylinder side peripheral wall and is flared outward toward the lower end of the output shaft, an annular space being formed between the inner and outer peripheral walls. The maximum flare angle of the outer peripheral wall relative to the axial direction of the output shaft is 30 degrees. The outer peripheral wall has at its open flare extremity a motor mounting flange.