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.

According to an aspect, an active valve for an implantable device includes a base plate defining an opening, a piezo element, a diaphragm actuator coupled to the piezo element, and a protrusion coupled to the diaphragm actuator. The diaphragm actuator, in response to the piezo element being activated, is configured to move the protrusion into the opening in a first direction until the protrusion contacts a portion of the base plate.

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 liquid sending device includes a plunger pump, which performs an intake operation of liquid to and a discharge operation of liquid from a pump chamber and in which pressure in the pump chamber in a case where the intake operation is performed is lower compared to a case where the discharge operation is performed, a check valve that is provided at an inlet port, has a spherical valve element and a valve seat, and passively operates according to the pressure in the pump chamber in such a direction that the valve element is seated on or detached, a pressure sensor that detects the pressure, and an attachment detector that compares the pressure with a preset threshold value and detect attachment of the valve element to the valve seat in a case where the pressure in the pump chamber is equal to or lower than the threshold value.

A prime mover and hydraulic actuators, a hydraulic machine having a rotatable shaft engaged with the prime mover and having a plurality of working chambers, a hydraulic circuit extending between a group of working chambers of the hydraulic machine and the hydraulic actuators, each working chamber of the hydraulic machine having a low-pressure and a high-pressure valve regulating the flow of hydraulic fluid between the working chamber and a corresponding low-pressure manifold and a high-pressure manifold. The hydraulic machine controlling the low-pressure valves of the group of working chambers to select the net displacement of hydraulic fluid by each working chamber on each cycle of working chamber volume, and thereby the net displacement of hydraulic fluid by the group of working chambers, responsive to a demand signal, the apparatus further having a controller calculating the demand signal responsive to a measured property of the hydraulic circuit or an actuator.

Systems and methods for a compressor system are provided for selectively operating the compressor system with reduced power consumption. An output demand level of the compressor system can be monitored over time to identify a demand profile. A pressure setpoint for the compressor system can be selectively adjusted based on the demand profile, including to selectively transition between an operational pressure setpoint for an active demand profile and a reduced pressure setpoint for an inactive demand profile.

A pressure gradient wound therapy apparatus (50) including a pump assembly (10). The pump assembly (10) includes a diaphragm (12) comprising a magnetic material (16), an electromagnetic actuator (18) switchable between two or more operational states and a valve arrangement (24) including an inlet valve (26) and an outlet valve (28) for the introduction and/or removal of fluid into a fluid chamber (30) of the pump assembly (10). The actuator (18) is configured to move the diaphragm (12) with respect to the actuator (18) between a first position corresponding to a first operational state of the actuator (18) and a second position corresponding to the second operational state of the actuator (18).

A high-pressure pump includes a pressurizing chamber forming portion including a cylindrical inner peripheral wall that defines a pressurizing chamber, a plunger, a housing including a housing outer peripheral wall, a valve member, an electromagnetic driving unit, a discharge passage portion, and a fixed portion that is connected to the housing. The fixed portion has multiple bolt holes. The multiple bolt holes are arranged radially outward of the housing outer peripheral wall in a circumferential direction when viewed along a direction of an axis of the cylindrical inner peripheral wall. The high-pressure pump is virtually divided into a first region and a second region by a virtual surface on which axes of adjacent ones of the multiple bolt holes and an axis of the cylindrical inner peripheral wall extend. Both the electromagnetic driving unit and the discharge passage portion are located in the first region or the second region.