Abstract: RAPPs comprise a housing, a swash plate with an inclined surface, and a rotor assembly positioned adjacent the swash plate. The swash plate and/or the inclined surface are ceramic. The rotor assembly comprises a rotor-drum having at least one cylinder bore having a piston disposed therein, wherein the piston has a ball-shaped end. A slipper is interposed between the swash plate and the rotor-drum, and includes a socket joint for accommodating the piston ball-shaped end therein. A plastic material may be disposed within the socket joint. The slipper has a ceramic interface surface in contact with the inclined surface. A stator plate is positioned in the housing, and a rotor plate is interposed between the stator plate and the rotor-drum. The stator plate has a ceramic interface surface in contact with the rotor plate. The rotor plate has a ceramic interface surface in contact with the stator plate.

Abstract: RAPPs comprise a housing, a swash plate with an inclined surface, and a rotor assembly positioned adjacent the swash plate. The swash plate and/or the inclined surface are ceramic. The rotor assembly comprises a rotor-drum having at least one cylinder bore having a piston disposed therein, wherein the piston has a ball-shaped end. A slipper is interposed between the swash plate and the rotor-drum, and includes a socket joint for accommodating the piston ball-shaped end therein. A plastic material may be disposed within the socket joint. The slipper has a ceramic interface surface in contact with the inclined surface. A stator plate is positioned in the housing, and a rotor plate is interposed between the stator plate and the rotor-drum. The stator plate has a ceramic interface surface in contact with the rotor plate. The rotor plate has a ceramic interface surface in contact with the stator plate.

Abstract: A pumping machine, that can serve a system as the sole main pump for pressurizing a primary liquid flow, incorporates, in a single machine, a rotor-drum type AP (axial piston) pump and a PX (pressure exchanger) that recovers energy from a secondary liquid flow such as the brine discharge from an RO seawater desalination system, with benefits including fewer moving parts and small machine size along with lower capital and operating costs. A single rotor-drum containing the cylinders and pistons is located between two end blocks, one or both configured with manifold passageways, ports and sliding valves. A swash-plate at one end reciprocates the pistons axially when the rotor-drum is rotated.