A valve assembly is adjustable in three independent ways allowing it to provide a variable input volume. The valve assembly has a base and an entrance plate. An outer guide, an inner guide and a shaft, each with a passage, are held together and the shaft is rotatable between the guides. The valve is open when the passages of the inner guide plate and shaft are aligned and closed when the passages are not aligned. The shaft RPM determines how many times per minute the valve opens. The open/closed ratio of the valve assembly determines how long the valve is open during each half revolution. The location of the shaft up or down in relationship to the inner guide determines what percentage of possible flow passes through the valve during each half revolution. The valve assembly can be used with either a gas or liquid medium.

A hydrostatic axial piston machine is disclosed, in the housing of which a drive shaft is rotatably mounted about an axis of rotation. The housing comprises a pot-like housing part having a first abutment and a cover-like housing part having a second abutment. The two abutments are clamped against one another in a sealing manner. A first fitting pin is inserted precisely into a first fitting recess of the first abutment on the one hand and into a second fitting recess of the second abutment on the other hand. A second fitting pin is provided on a side opposite the axis of rotation, which is inserted precisely into a third fitting recess of the first abutment on the one hand and into a fourth fitting recess of the second abutment on the other hand. The second fitting recess has a radial widening relative to the axis of rotation, whereby the second fitting recess is a slotted hole and/or a fitting groove.

A fluid pressure rotary machine includes a cylinder block that is fixed to a rotary shaft and includes a plurality of cylinder bores, a piston disposed to be free to slide in each cylinder bore such that a volume chamber is defined thereby, a swash plate that causes the piston to reciprocate such that the volume chamber expands and contracts, and a valve plate that slides against the cylinder block and includes an intake port and a discharge port communicating with the volume chamber. The valve plate includes a sliding surface formed to project in a spherical shape against the cylinder block. The cylinder block includes a sliding surface formed as an indentation corresponding to the shape of the sliding surface of the valve plate. A minute gap is formed between the sliding surface of the valve plate and the sliding surface of the cylinder block in an outer edge position.

A hydrostatic axial piston machine is disclosed, in the housing of which a drive shaft is rotatably mounted about an axis of rotation. The housing comprises a pot-like housing part having a first abutment and a cover-like housing part having a second abutment. The two abutments are clamped against one another in a sealing manner. A first fitting pin is inserted precisely into a first fitting recess of the first abutment on the one hand and into a second fitting recess of the second abutment on the other hand. A second fitting pin is provided on a side opposite the axis of rotation, which is inserted precisely into a third fitting recess of the first abutment on the one hand and into a fourth fitting recess of the second abutment on the other hand. The second fitting recess has a radial widening relative to the axis of rotation, whereby the second fitting recess is a slotted hole and/or a fitting groove.