A fuel pump includes a plunger which reciprocates within a bore of a housing. The plunger extends from a first end proximal to a pumping chamber to a second end distal from the pumping chamber and includes a sealing ring groove between the first end and the second end. The sealing ring groove extends from an upper shoulder proximal to the first end to a lower shoulder distal from the first end and are separated by a first distance. A sealing ring is located within the sealing ring groove and engages the bore in an interference fit. A diametric clearance greater than 12 microns and less than 30 microns is provided between the plunger and the bore such that the diametric clearance extends between the sealing ring groove and the first end for a second distance which is at least four times the first distance.

A pump inlet valve includes a valve body and a plunger assembly. The valve body includes a valve body cavity. The plunger assembly is arranged within the valve body cavity and includes a plunger body, a plunger barrel formed at the plunger body so as to form a plunger barrel volume, and a plunger. The plunger is configured to move within the plunger barrel to thereby allow a fluid to flow past the plunger assembly when the plunger is in an open position and to inhibit the fluid from flowing past the plunger assembly when the plunger is in a closed position. The plunger is configured to allow continuous fluid communication between the plunger barrel volume and a supply inlet, through which fluid is supplied to the pump inlet valve.

A valve assembly (10) including first and second housing parts (22, 24). The first and second housing parts are secured to each other such that respective channels in each are aligned to define inlet and outlet fluid pathways (25, 35) through the valve assembly. A leaf valve insert (38) is arranged between the first and second housing parts, and includes a plurality of leaves (40). First and second leaves are respectively aligned with the inlet and outlet fluid pathways. The first leaf (40a) is configured to permit fluid flow in the inlet fluid pathway in a first direction while impeding fluid flow in a second direction. The second leaf (40b) is configured to permit fluid flow in the outlet fluid pathway in the second direction while impeding fluid flow in the first direction. The first direction is from the first housing part toward the second, and the second direction is from the second housing part toward the first.

A reciprocating plunger pump fluid end having increased material thicknesses in typical high stress concentration areas includes locating valves in spherically segmented shaped suction and discharge bores adjacent to chamfered transition areas to provide for reduced stress concentrations, resistance to fatigue failure and erosion and ease of access for maintenance. Among other features the housing includes a valve retainer assembly integrally mounted inside the housing which includes a profile to reduce stresses in the bores and facilitate access for replacement of internal components.

An electric pump device includes a single motor, a pump that discharges fluid from a discharge port with driving force of the motor, and a flow passage switch that includes outlets configured to be in communication with the discharge port and switches an outlet of the outlets that is in communication with the discharge port with driving force of the motor.

A pump suitable for use in a wearable medical device, such as a patch pump, comprises an axially translatable chamber with an inlet and an outlet, a piston or a diaphragm rotatably received in the chamber, a first valve between the inlet and the chamber, a second valve between the outlet and the chamber, a cam affixed to the chamber, a follower affixed to the piston and in contact with the cam for axially translating the chamber, and a biasing means acting on the chamber for applying a force on the chamber in an axial direction of the chamber to maintain such contact.

A diaphragm pump assembly can include a pump drive chamber, a first pump diaphragm chamber, and a second pump diaphragm chamber. The assembly can include a pump motor configured to rotate a motor shaft extending into the pump drive chamber. The assembly can include a cam connected to the motor shaft and configured to rotate in response to rotation of the motor shaft. The assembly can include a drive yoke having a yoke frame and a yoke pocket having a first wall and a second wall parallel and opposite the first wall. First and second pistons can connect to the drive yoke and to first and second diaphragms, respectively. The diameter of the cam can be less than and within 5% the width of yoke pocket and the yoke can be configured to move the pistons along a straight line.

A fuel pump includes a plunger which reciprocates within a bore of a housing. The plunger extends from a first end proximal to a pumping chamber to a second end distal from the pumping chamber and includes a sealing ring groove between the first end and the second end. The sealing ring groove extends from an upper shoulder proximal to the first end to a lower shoulder distal from the first end and are separated by a first distance. A sealing ring is located within the sealing ring groove and engages the bore in an interference fit. A diametric clearance greater than 12 microns and less than 30 microns is provided between the plunger and the bore such that the diametric clearance extends between the sealing ring groove and the first end for a second distance which is at least four times the first distance.

A valve assembly for regulating the flow of working fluid between a working chamber of a fluid working machine and a working fluid gallery comprises: a valve comprising a valve member and one or more cooperating valve seats; an actuator actuatable to apply a force to urge the valve member away from or towards the one or more valve seats; and a coupling between the actuator and the valve member. The coupling comprises a connector located at least partially within a tube. A connector void provided between at least a portion of the connector and the tube is in fluid communication with a working fluid gallery outlet.

A pressing tool is described for plastically deforming a workpiece. The pressing tool comprises a piston pump driven by a motor that rotates in operating rotation direction RA and a pressure release valve and a coupling arrangement, which mechanically couples the motor to the pressure relief valve, so that the motor opens the pressure relief valve when operated in a loosening rotation direction RL opposite to the operating rotation direction RA. Also described is a corresponding method of operating a pressing tool.