An electro hydrostatic actuator (EHA) comprises a hydraulic pump and an electric motor driving the hydraulic pump. The hydraulic pump comprises an inlet and an outlet for hydraulic fluid and an active fluid flow path arranged therebetween such that, in an active mode of operation when the pump is driven by the electric motor, hydraulic fluid is actively drawn in through the inlet and exhausted out through the outlet. The hydraulic pump further comprises a bypass flow path arranged between the pump inlet and outlet, such that, in a damping mode of operation, hydraulic fluid is able to freely flow between the inlet and outlet in either direction.

A cylinder block (1) for a compressor has a central opening (3) for accommodating a drive shaft of a drive unit and defines a central axis of the cylinder block (1) with a plurality of cylinder bores (2) arranged around the central opening and each of the cylinder bores (2) adapted for accommodating a piston (14).The cylinder block (1) also has at least one stop (10) on a drive side of the cylinder block (1) with the stop (10) arranged within a triangular area which is delimited by the central opening (3) and the two adjacent cylinder bores (2).

A manifold for a pump is configured to connect to a jacket to form a reservoir and to connect to at least one pumping mechanism disposed within the reservoir. The manifold includes a first side including a first side surface configured to face the reservoir and a second side including a second side surface. The manifold also includes a bypass passage, at least one push rod guide bore extending through the first side surface and the second side surface, and a leakage passage fluidly connecting the at least one push rod guide bore to an outlet disposed outside the first side surface. The manifold further includes a discharge passage including at least one inlet disposed in the first side surface, and the at least one inlet is configured to receive fluid pumped by the at least one pumping mechanism.

A pump plunger is disclosed. The plunger may include a proximal end and a distal end opposite the proximal end. The plunger may also include a body portion extending between the proximal end and a second transition datum, and additionally include a transition section extending between a first transition datum and the second transition datum. The transition section may have a non-linear geometric profile. A first shoulder portion may be positioned adjacent to the transition section that may extend between the second transition datum and a third datum. The third datum may be positioned radially inward of the second transition datum. The plunger may also include a tip portion positioned adjacent to the first shoulder portion that may extend between the third datum and a fourth datum positioned at the distal end. The fourth datum may be positioned radially inward of the third datum.

A pump in desalination systems has four cylinders, each having a double acting piston. Each cylinder and piston defines a feed chamber and a recovery chamber. The pistons connect to a common drive. The connection to the common drive is such that the pistons reciprocate in a sequence equally spaced in time. Reciprocating valving for each piston is driven by the common drive to be 90 degrees out of phase with the respective piston. The valving connects the recovery chamber alternately to an inlet manifold for an intake stroke of the piston relative to the recovery chamber, and to an outlet manifold for a discharge stroke of the piston relative to the recovery chamber. A brief period of closure coincides with top dead centre and bottom dead centre of the piston, during which the recovery chamber is blocked off from both the inlet and outlet manifolds. The reciprocating valving is midway between its top dead centre and bottom dead centre during the period of closure.

A piston pump for a high-pressure cleaning appliance is provided, which includes a plurality of pistons that are movable back and forth and each of which enters a pump chamber and is displaceably held at a piston guiding part. The piston guiding part has a supporting wall on which a plurality of guiding elements, each of which guides a piston, are disposed. In order to be able to produce the piston pump in a more cost-effective manner, it is proposed according to the invention that the supporting wall is curved.

A barrel assembly for a pumping mechanism includes a first end, a second end opposite the first end, and a plunger bore configured to receive a plunger for sliding within the plunger bore. The barrel assembly also includes at least one inlet passage including at least one inlet extending through the first end and fluidly connected to the plunger bore to communicate fluid from the at least one inlet passage to the plunger bore. The barrel assembly further includes an outlet passage fluidly connected to the plunger bore and configured to receive fluid from the plunger bore, the plunger bore and the outlet passage forming separate openings in the second end of the barrel assembly.

A pump draws fluid from a reservoir and drives the fluid downstream to a spray tip where the fluid is applied to a surface. A piston is driven in a reciprocating manner to pump the fluid. A check valve is disposed downstream of the piston to regulate a flow of the fluid downstream from the piston. The pump is initially dry and is primed with fluid prior to operation. To facilitate priming, the piston is dimensioned to impact the ball and unseat a valve member of the check valve during a priming stroke, thereby ejecting any air from the pump through the check valve. With the air ejected from the pump, a vacuum is formed during a suction stroke of the piston, which draws fluid downstream from the reservoir to prime the pump.

A plunger pump fluid end housing assembly comprising: a fluid end housing, multiple plungers, a single in-line suction valve and seat corresponding with each said plunger, a discharge valve and seat corresponding with each said plunger; wherein axis of said suction valve and seat are parallel with said plunger, and the suction manifold is positioned to teed the fluid chamber opposite the power end of the fluid end. Plunger chamber of said fluid end housing is square or rectangular in cross section with large fillets at corners and flats between said fillets. Said flats are approximately equal in width to radii of said fillets.

An axial piston machine may include a rotor with a shaft. A plurality of cylinders may be arranged in an annular manner about the shaft. A plurality of pistons may each be positioned within each of the plurality of cylinders and may be constructed and arranged to move translationally within the plurality of cylinders. A cylinder head may include a plurality of inlet openings and may be in operative communication with the plurality of cylinders. A sealing washer having a plurality of passage openings may be disposed on the cylinder head so that the plurality of passage openings and the plurality of inlet openings may be flush with one another. A number of the plurality of inlet openings may correspond to a number of the plurality of passage openings. A valve plate may be connected to the shaft in a rotationally fixed manner and may be constructed and arranged to be brought into congruence with the plurality of passage openings of the sealing washer based on a rotary angle. The sealing washer may be disposed between the plurality of inlet openings and the valve plate and may be prestressed against the cylinder head and onto the inlet openings.