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 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 device for controlled supply of high-pressure fluid includes a pressure generator with an electric linear motor having a stator and a forcer to drive the high-pressure plunger in the high-pressure cylinder, and the electric linear motor(s) is (are) connected to a control unit. Associated methods for supplying high-pressure fluid to an apparatus are also disclosed.

A device for controlled supply of high-pressure fluid includes a pressure generator with an electric linear motor having a stator and a forcer to drive the high-pressure plunger in the high-pressure cylinder, and the electric linear motor(s) is (are) connected to a control unit. Associated methods for supplying high-pressure fluid to an apparatus are also disclosed.

A well pump assembly has a barrel, a standing valve at an upper end of a standing valve chamber, and a plunger. A travelling valve admits well fluid into the barrel during a fill stroke. The travelling valve closes during a power stroke so that the plunger pushes well fluid from the barrel into the standing valve chamber. A gas release port extends from the standing valve chamber to the exterior of the pump assembly. A check valve in the gas release port has an outward flow blocking position for blocking liquid well fluid in the standing valve chamber from exiting through the gas release port while the plunger is in the power stroke. The cheek valve has a gas release position that enables gas present in the standing valve chamber to flow out the gas release port while the plunger is in the power stroke.

A well pump assembly has a barrel, a standing valve at an upper end of a standing valve chamber, and a plunger. A travelling valve admits well fluid into the barrel during a fill stroke. The travelling valve closes during a power stroke so that the plunger pushes well fluid from the barrel into the standing valve chamber. A gas release port extends from the standing valve chamber to the exterior of the pump assembly. A check valve in the gas release port has an outward flow blocking position for blocking liquid well fluid in the standing valve chamber from exiting through the gas release port while the plunger is in the power stroke. The cheek valve has a gas release position that enables gas present in the standing valve chamber to flow out the gas release port while the plunger is in the power stroke.

A pump unit (la) comprising a cavity (6a) defined by an immobile part (17), a reciprocating part (16), and a top element (18) sealing the cavity to define a chamber. The top element is fixedly attached to a scrolling piston wall (5a), slidably disposed within the cavity to move perpendicularly relative the chamber, dividing it in two sealed subchambers, the chamber following the reciprocating parts component of the piston wall, along the immobile part. Each subchamber has inlets and outlets on the immobile part, that are alternately exposed and covered as the reciprocating part and the piston wall moves.

The invention relates to a device for generating a pulsating hydraulic fluid pressure in a working chamber (1) filled with hydraulic fluid, comprising a driveable working piston (4) movably guided in a hollow working cylinder, wherein a working chamber (1) that is in fluid communication with the working piston (4) is provided, such that, by means of the movement of the working piston (4) within the hollow working cylinder, a pulsating hydraulic fluid pressure can be generated in the working chamber (1). In order to provide a device for generating a pulsating hydraulic fluid pressure and in particular a diaphragm metering pump comprising such a device, which has small dimensions and in addition a rapid passage through the phase between closing the suction valve and opening the pressure valve, according to the invention, an auxiliary piston (20) is movably guided in a hollow auxiliary cylinder and is in fluid communication with an additional chamber (18, 21), wherein a closeable auxiliary channel (22), which connects the additional chamber (18, 21) and the working chamber (1), is provided, wherein the auxiliary piston (20) and the hollow auxiliary cylinder are formed and arranged in such a way that, by moving the auxiliary piston (20) within the hollow auxiliary cylinder, a hydraulic fluid arranged in the additional chamber (18, 21) can at least partly be forced out of the additional chamber (18, 21) into the auxiliary channel (22) and from the auxiliary channel (22) into the working chamber (1).

A piston pump is configured to convey pressure medium in a pressure medium circuit, in particular in a braking circuit of a motor vehicle braking system that may be electronically controlled to counteract slip. The pump piston delimits an operating chamber and is received in a displaceable manner in a pump cylinder and may be driven to produce a stroke movement that goes back and forth between two reversing positions. The operating chamber may be connected in a controllable manner to a pump inlet or outlet. A pressure medium connection is provided from the pump outlet to the operating chamber, said pressure medium connection is controllable in dependence upon a relative position of the pump piston with respect to the first reversing position. Pressure pulsations of the piston pump are prevented and the operating noise is reduced.

The present disclosure relates to a liquid crystal (LC) display field and discloses an LC pump. The LC pump may include a case; a second linear container arranged within the case; and a nozzle arranged at the bottom of the case. The second linear container may include an LC delivery channel and at least two LC inlets. And LC may flow through the LC inlets and the LC delivery channel sequentially and then may be ejected from the nozzle.