A pump unit for feeding fuel, preferably diesel fuel, to an internal combustion engine; the pump unit (1) comprising: a head (4) inside which a cylinder (12) extending along an axis (A1) is formed; a pumping piston (5) extending along the axis (A1) and slidingly coupled with the cylinder (12); a through-hole (13) which extends from the cylinder (12) towards the outside of the pump unit (1); an intake chamber (8) communicating with the cylinder (12) via the hole (13); an intake valve (7) which controls the flow of fuel from the intake chamber (8) to the hole (13); a cap (23; 123; 223) which is connected to the head (4), is arranged on the opposite side to the pumping piston (5) and can be selectively fixed along an outer surface (25) of the head (4) so as to close the intake chamber (8) on one side.

A lubrication system for an internal combustion engine includes a fluid flow control device at the outlet side of the pump that regulates pressure conditions at the outlet side of the pump upstream of the lubrication circuit in the engine. The fluid flow control device includes a chamber that is opened in response a fluid pressure exceeding a threshold to allow the fluid to pass from the outlet side of the pump back to the inlet side of the pump. The fluid flow control device also includes at least one elongated aperture in communication with the chamber for receiving fluid fed from the chamber and allowing the fluid in the chamber to flow to the inlet side of the pump.

A pump arrangement for pumping a liquid, in particular a liquid contaminated with dirt particles, the pump arrangement having at least one working chamber (1, 2, 11, 12) and at least one delivery piston (3, 4, 13), and at least one inlet valve (7) and at least one outlet valve (8), and the delivery piston (3, 4, 13) being movable in order to suck liquid into the working chamber (1, 2, 11, 12) through the inlet valve (7) and to eject liquid out of the working chamber (1, 2, 11, 12) through the outlet valve (8), and the pump arrangement having a wear-monitoring device (40) for monitoring the wear on the inlet valve (7) and/or outlet valve (8) with at least one pressure sensor (41) and one pressure evaluation unit (42) for processing pressure measurement values output from the pressure sensor (41), wherein the pump arrangement, for the purpose of moving the delivery piston (3, 4, 13), has a drive fluid system (20) that can be operated with a drive fluid, and the pressure sensor (41) of the wear-monitoring device (40) is arranged to detect the pressure of the drive fluid in the drive fluid system (20).

A hose for a reciprocating pump, the hose comprising: a first end and a second end separated by a length (L) along a centerline of the hose, wherein the first end reciprocates with a reciprocating element of the reciprocating pump during operation of the reciprocating pump; an inner surface and an outer surface separated by a thickness; and a variable bend radius wherein a bend radius of a first section of the hose is different from a bend radius of at least one second section of the hose, such that, during operation of the reciprocating pump, a stress on the first end of the hose, the second end of the hose, or both the first end of the hose and the second end of the hose is reduced relative to that of a hose that does not contain the variable bend radius.

A pump for spraying liquid according to one aspect of the invention can include a housing having an interior space for holding a content; a guide that moves up and down within the interior space and has an inlet hole connecting with the interior space; a piston that moves with the guide while maintaining contact with the housing and the guide and is capable of closing the inlet hole; a valve coupled to and connecting with the guide and protruding to the exterior of the housing; a shoulder coupled to an upper portion of the housing; and an elastic member having one end contacting the shoulder and the other end contacting the valve to provide an elastic force pushing the valve upward, where the elastic member can include a center portion and deformation portions formed as an integrated body such that the elastic member is capable of elastic deformation.

An example pressure-driven metered mixing dispensing pump includes a housing, a fluid inlet, a piston disposed in the housing at least partially defining first, second and third chambers, the first and second chambers each in fluid communication with the third chamber, the piston to, in response to first fluid entering the first chamber via the fluid inlet, move in a first direction to decrease the volume of the second chamber thereby ejecting second fluid from the second chamber into the third chamber, a spring to move the piston in a second direction to decrease the volume of the first chamber thereby ejecting at least some of the first fluid from the first chamber into the third chamber thereby mixing the at least some of the first fluid and the second fluid to form a mixture, and an outlet to discharge the mixture from the third chamber.

An example pressure-driven metered mixing dispensing pump includes a housing, a fluid inlet, a piston disposed in the housing at least partially defining first, second and third chambers, the first and second chambers each in fluid communication with the third chamber, the piston to, in response to first fluid entering the first chamber via the fluid inlet, move in a first direction to decrease the volume of the second chamber thereby ejecting second fluid from the second chamber into the third chamber, a spring to move the piston in a second direction to decrease the volume of the first chamber thereby ejecting at least some of the first fluid from the first chamber into the third chamber thereby mixing the at least some of the first fluid and the second fluid to form a mixture, and an outlet to discharge the mixture from the third chamber.

An air driven reciprocating piston hydraulic pump having a main changeover valve with a main valve body having an annular valve body portion which includes first and second annular valve faces that approach closely or contact first and second annular valve seats on valve cases which are formed on the upper and the lower ends of the annular valve body portion. An air intake chamber is defined by a piston reception hole and a drive piston portion, and an auxiliary changeover valve changes over the main changeover valve between its air supply position and its air discharge position by supplying compressed air to the air intake chamber or discharging air therefrom via a first and second valve members and a small diameter portion of a valve rod. A center side portion of the main valve body is made as a separate auxiliary valve body for facilitating up and down motion thereof.

The present disclosure provides an oil scavenge pump, which includes a cap member, a piston member and a resilient member. The cap member and the piston member are connected to each other and with the resilient member therebetween. The cap member includes a cap head, a valve connected to the cap head, a resilient unit disposed between the cap head and the valve, and a first sphere disposed between the resilient unit and the valve. The piston member includes a valve stopper, a main portion, a second sphere, a rod portion, a first-seal ring and a second-seal ring. The main portion has two ends respectively connected to the valve stopper and the rod portion. The second sphere is disposed between the valve stopper and the main portion. The first-seal ring and the second-seal ring respectively surround the main portion and the rod portion.

The invention relates to a delivery device (1) for delivering a fluid medium, having a delivery drive (2), a pump device (3) and a scoop device (4). The delivery drive (2) is arranged at a first end (6) of a pipe (5), wherein the pump device (3) and the scoop device (4) are arranged inside the pipe (5). The scoop device (4) includes a foot valve (8), which is arranged at a second end (7) of the pipe (5) and which foot valve (8) serves to control an inlet (9) for an inflow of medium into a piston chamber (10). A piston (11), which sub-divides the piston chamber (10) into an inflow area (12) and a discharge area (13), is arranged in the piston chamber (10), wherein the inflow area (12) and the discharge area (13) are or can be connected via the piston (11), wherein the piston (11), via a piston rod (14), is movable between a retracted position and an extended position inside the piston chamber (10) by the delivery drive (2) (FIG. 1).