Pump (motor) with several pistons (as rule 7 to 11) that are arranged parallel to the drive shaft. The pistons are actuated by a swash plate or a drive flange (inclined axis).
These two designs differ fundamentally in the resolution of the piston forces and the consideration of the change in torque over time.
With the swash plate (MZ system (Figure A 30 a)) the resultant piston force generates a torque at the cylinder drum that is fed to the drive shaft.
On the inclined axis design (MH system, b) there are no tilting forces on the pistons that together with the cylinder drum remain free of torque.
Along with these two designs the swash plate pump is also an axial piston machine. However, it is used comparatively infrequently.
Axial piston machines have a smaller output volume than radial piston pumps and also have simpler sliding-contact and sealing conditions at the control disc (automatically adjusting gap!) compared to the pintle valve on the radial piston pump. Today they therefore cover roughly 80 % of the demand for high-pressure piston pumps.
Figure A 30: Axial piston pump: MZ (a) and MH system (b)