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).

A vehicle-mounted electric oil-free air compressor, including a motor, a box body, a piston, and a flywheel shaft. The motor is fixed on the box body, a cylinder cover is at the top of the box body, a main shaft of the motor includes a coupling driving end, the flywheel shaft is driven by an elastic body to rotate. The piston includes a primary intake valve piece and a primary exhaust valve piece, the box body is provided with a secondary cavity, a secondary exhaust valve piece is provided at a vent hole on one side of the cavity, and the primary exhaust valve piece is also a secondary intake valve piece of the compressor, increasing the exhaust pressure. When the piston reciprocates, the stress is balanced and the vibration is small, and with the assistance of a high-efficiency flywheel, the operation of the air compressor is stable.

A pneumatic micropump is provided. The pneumatic micropump includes a fluidic channel layer, an upper substrate, a lower substrate, an upper membrane and a lower membrane. The fluidic channel includes a fluid inlet a reservoir, and a fluid outlet, wherein the fluid passes through the fluid inlet, the reservoir and the fluid outlet, successively. The upper substrate includes an upper pneumatic chamber facing the reservoir. The lower substrate includes a lower pneumatic chamber facing the reservoir. The upper membrane is disposed between the upper pneumatic chamber and the reservoir, and the lower membrane is disposed between the lower pneumatic chamber and the reservoir.

First and second pistons are mounted to a common shaft which reciprocates during compression and suction strokes. During each of the strokes, fluid is pumped out at an outlet, via a one-way valve on the second piston. The one-way valve is opened or closed depending on whether the first and second pistons are in the compression or suction stroke. Additionally, pressure from the outlet assists in traversing the first and second pistons in the compression stroke. During the suction stroke, the fluid pressure applies a force on the first piston to counteract the fluid pressure on the second piston so that a smaller spring may be used. The size requirements of the solenoid and spring are reduced. Additionally, the fluid pump provides lower pressure spikes, since fluid is pumped out during both the compression and suction strokes and also provides a more even flow of fluid.

First and second pistons are mounted to a common shaft which reciprocates during compression and suction strokes. During each of the strokes, fluid is pumped out at an outlet, via a one-way valve on the second piston. The one-way valve is opened or closed depending on whether the first and second pistons are in the compression or suction stroke. Additionally, pressure from the outlet assists in traversing the first and second pistons in the compression stroke. During the suction stroke, the fluid pressure applies a force on the first piston to counteract the fluid pressure on the second piston so that a smaller spring may be used. The size requirements of the solenoid and spring are reduced. Additionally, the fluid pump provides lower pressure spikes, since fluid is pumped out during both the compression and suction strokes and also provides a more even flow of fluid.

A linear compressor is provided that may include a shell provided with a refrigerant inlet; a cylinder provided inside of the shell to form a compression space; a piston that reciprocates inside of the cylinder to compress a refrigerant in the compression space; and a motor assembly that provides a drive force to the piston and provided with a permanent magnet. The piston may include a piston body having a cylindrical outer circumferential surface and a surface-treated area, which may be processed with a material having a predetermined hardness value, and a valve support provided at an end of the piston body and having a suctioning hole be in communication with the compression space. The valve support may form a first non-surface-treated area, which is not surface-treated.

A mechanically actuated traveling valve for use in fluid pumping equipment is provided. More particularly, a mechanically actuated traveling plug valve having a valve seat and a valve plug is provided for use in any positive displacement pump with a reciprocating element (either the plunger or the cylinder) capable of pumping fluids of any viscosity, with any gas to liquid ratio, operating at any inclination angle.

A foam pump has dual, coaxial air and liquid cylinders, each having a respective air and liquid piston which move together during a dispensing operation. One or more air passageways between the air cylinder and a liquid-air mixing chamber are configured to impart rotation to an airstream passing from the air cylinder to the mixing chamber to increase turbulent mixing of the air and liquid in the mixing chamber. The liquid cylinder is axially aligned with the air cylinder to provide a low profile pump which does not require a dip tube or sleeve to communicate with the bottom of the liquid source when used in an inverted application wherein the foam pump is positioned below the source of liquid. A resilient valve member in the liquid outlet is biased to close on its own to prevent leaking in the event the air and liquid pistons do not fully return to the home position.

A cylinder piston for an air compressor, in particular for a two-stage air compressor, has at least two channel openings integrated in the piston surface of the cylinder piston, which are designed as an inlet valve and/or as an outlet valve for air in a compression chamber of the cylinder. A coherent, one-piece and flexible bending sealing element is provided inside or covering the channel openings. The sealing element for the at least two or a plurality of channel openings enables an inflow into a channel opening or outflow from a channel opening, wherein the at least two channel openings through the flexible bending sealing element can be designed independently of one another as an inlet valve or as an outlet valve. Also provided is a cylinder with at least one cylinder piston and an air compressor with such a cylinder.

A valvular conduit, preferably a Tesla valvular conduit, in which a plug member is coaxially received within a bore in a sleeve member and in which passageways are defined between the plug member and the sleeve member within interior walls configured to permit mixing of fluid flowing through the passageways in at least one direction, preferably, the relatively free passage of fluid through the passageways upstream but increased the resistance to downstream flow of the fluid through each passageway.