A pump (2) comprising a stator (4) and a rotor (6) axially and rotatably movable relative to the stator, the stator comprising a rotor shaft receiving cavity (18), an inlet (14) and an outlet (16) fluidly connected to the rotor shaft receiving cavity (18), the rotor comprising a shaft (24) received in the rotor shaft receiving cavity (18). The rotor shaft (24) comprises a cavity (39) receiving a piston portion (12) of the stator therein to form a piston chamber (42), a seal (44) mounted between the piston portion (12) and inner sidewall of the cavity (39) to sealingly close an end of the piston chamber (42). The rotor further comprises a port (38) fluidly connecting the piston chamber (42) to an outer surface (60) of the rotor shaft (24), the port (38) arranged to overlap at least partially the inlet (14) over a rotational angle α of the rotor corresponding to a pump intake phase, and arranged to overlap at least partially the outlet (14) over a rotational angle β of the rotor corresponding to a pump expel phase.

A valve module comprising: a cylindrical canister containing a valve assembly for a high pressure pump, wherein the valve assembly comprises a valve body and a valve seat, wherein the valve module provides a fluid flow path from an inlet to an outlet of the valve module from one side of the valve seat along a central axis of the valve module to the other side of the valve seat along the central axis and between the valve body and the valve seat when the valve assembly is in an open configuration, and does not provide the fluid flow path when the valve assembly is in a closed configuration.

A valve module comprising: a cylindrical canister containing a valve assembly for a high pressure pump, wherein the valve assembly comprises a valve body and a valve seat, wherein the valve module provides a fluid flow path from an inlet to an outlet of the valve module from one side of the valve seat along a central axis of the valve module to the other side of the valve seat along the central axis and between the valve body and the valve seat when the valve assembly is in an open configuration, and does not provide the fluid flow path when the valve assembly is in a closed configuration.

A pump draws fluid from a reservoir and drives the fluid downstream to a spray tip where the fluid is applied to a surface. The pump includes a polymer pump body and a metallic piston configured to reciprocate relative to and within the polymer pump body. The metallic piston interfaces with an inner cylinder formed within the polymer pump body and pumps fluid through the polymer pump body to a spray nozzle downstream of the inner cylinder.

A pump draws fluid from a reservoir and drives the fluid downstream to a spray tip where the fluid is applied to a surface. The pump includes a polymer pump body and a metallic piston configured to reciprocate relative to and within the polymer pump body. The metallic piston interfaces with an inner cylinder formed within the polymer pump body and pumps fluid through the polymer pump body to a spray nozzle downstream of the inner cylinder.

An apparatus for pumping a fluid from a fluid inlet to a fluid outlet is disclosed. The apparatus comprises: a spool axially movable within a cavity, wherein a first chamber is located at a first axial end of the cavity and a second chamber is located at a second axial end of the cavity, wherein the volume of the first chamber and the second chamber varies depending upon the axial position of the spool within the cavity; a valve movable between a first position and a second position, wherein in the first position the valve is configured to convey fluid from the fluid inlet to the first chamber and from the second chamber to the fluid outlet, and in the second position the valve is configured to convey fluid from the fluid inlet to the second chamber and from the first chamber to the fluid outlet.

An apparatus for pumping a fluid from a fluid inlet to a fluid outlet is disclosed. The apparatus comprises: a spool axially movable within a cavity, wherein a first chamber is located at a first axial end of the cavity and a second chamber is located at a second axial end of the cavity, wherein the volume of the first chamber and the second chamber varies depending upon the axial position of the spool within the cavity; a valve movable between a first position and a second position, wherein in the first position the valve is configured to convey fluid from the fluid inlet to the first chamber and from the second chamber to the fluid outlet, and in the second position the valve is configured to convey fluid from the fluid inlet to the second chamber and from the first chamber to the fluid outlet.

A self-energizing valve includes a valve body defining an inner chamber having an inlet and an outlet. A valve head within the inner chamber is moveable between a first position and a second position. A valve seal in fluid communication with the inlet has a sealing surface with a sealing member between the valve head and the valve seal. The sealing member is movable between a closed position where the sealing member engages with the sealing surface and an open position where the sealing member disengages from the sealing surface to allow flow through the inlet into the inner chamber. A cam is coupled to the valve head. Rotation of the cam causes movement of the valve head between the first position and the second position to move the valve head to the first position to hold the sealing member in the closed position.

A valve module comprising: a cylindrical canister containing a valve assembly for a high pressure pump, wherein the valve assembly comprises a valve body and a valve seat, wherein the valve module provides a fluid flow path from an inlet to an outlet of the valve module from one side of the valve seat along a central axis of the valve module to the other side of the valve seat along the central axis and between the valve body and the valve seat when the valve assembly is in an open configuration, and does not provide the fluid flow path when the valve assembly is in a closed configuration.

A valve module comprising: a cylindrical canister containing a valve assembly for a high pressure pump, wherein the valve assembly comprises a valve body and a valve seat, wherein the valve module provides a fluid flow path from an inlet to an outlet of the valve module from one side of the valve seat along a central axis of the valve module to the other side of the valve seat along the central axis and between the valve body and the valve seat when the valve assembly is in an open configuration, and does not provide the fluid flow path when the valve assembly is in a closed configuration.