The Floating Cup principle has been built with double faced pistons to create a mirrored design. An important advantage of this construction is the complete balancing of hydraulic forces in axial direction. This enables the use of small, simple bearings.
When built completely symmetrical, the displacement generated on each side of a piston pair is completely in phase and the whole unit will behave as a 12-piston machine. However, in order to reduce flow pulsations, pressure pulsations and noise, it is more attractive to have 24 displacement volumes. This is realized by simply changing the orientation of the two port plates around the central shaft of the unit. Although this slightly affects the complete balancing of the hydraulic forces in axial direction, the torque on the shaft is still very small compared with conventional axial displacement units.