The rotary piston pump is constructed with watertight fittings for the rotor, the piston and the block. When operating, the piston slides back and forth along the rotor groove, pulling fluid in on one end of the pump, simultaneously discharging fluid at the opposite end. Likewise he block slides back and forth along the piston groove, pulling in fluid through an opening in the rotor, and discharging fluid through another opening on the other side of the rotor. The rotor acts like a rotary valve, channeling fluid away from the pump’s inlet towards the outlet.
The rotary piston pump follows the same pumping principles as a direct action piston pump. There are two direct action ‘pistons’ (the piston and the block) pumping through two cylinders, with the rotor acting as an alternating valve.
The movement of the piston is provided by the central bearing of the block with turns on a rod eccentric to the motor axle. The rotor is concentric to the to this axle, and it’s spinning produces the alternating action of the piston and block within their respective grooves. Four overlapping strokes of the piston and block occur for each complete spin of the rotor. This creates a uniform constant discharge with minimum pulsation. A high volumetric efficiency is obtained by the piston action and the watertight fittings of each moving part.
The rotary piston pump handles high viscosity liquids with exceptionally high volumetric efficiency. More dilute or volatile liquids are handled with small losses through the pumping elements. Liquids susceptible to harm when agitated are transported by means of piston action, without being subjected to centrifuging or gear agitation.