The invention relates to a piezoelectric fan driving device comprising: a piezoelectric fan and a driving unit, wherein the piezoelectric fan comprises a connecting piece, two piezoelectric elements and at least one one-way air flowing piece. The connecting piece has an opening and two end surfaces. The two piezoelectric elements are fixed on the two end surfaces, and the connecting piece and two piezoelectric elements surround to form a cavity, one of the two piezoelectric elements having a through hole connecting to the cavity. The one-way air flowing piece connects the through hole. The driving unit electrically connects with the two piezoelectric elements to convert a DC power to an AC power, and the two piezoelectric elements are driven by the AC power.

The present invention refers to a reciprocating compressor provided with an arrangement of suction valves and, more particularly, a reciprocating compressor which, capable of operating with at least two suction lines having different working pressures, is made up of an arrangement of valves comprising including at least two orifice valve sets. One of these sets provides a semi-commanded valve, whereas the other set provides an automatic valve. The core of the invention is related to the fact that said orifice valve sets are disposed on different components of the reciprocating compressor.

Disclosed is a check valve reliably closing a fluid path without the need of machining with high accuracy. The check valve includes a pair of members with clamping surfaces; and a valve body clamped by the clamping surfaces from both sides in a thickness direction of the valve body. The valve body is formed from an elastic body and includes an outer frame, a sealing part arranged inside the outer frame and configured to open and close a fluid path formed in one of the pair of members, and a coupling part configured to allow fluid to pass therethrough in the thickness direction and configured to couple the outer frame and the sealing part to each other. The outer frame has a thickness larger than an interplane dimension between the clamping surfaces when the pair of members are joined together.

A well pump has a standing valve seat with a standing valve mounted in a lower end of a barrel. A plunger is carried within the barrel for axial stoking movement. A travelling seat with a travelling valve are mounted in a lower end of the plunger. The travelling valve has a head that lands on the travelling valve seat while the travelling valve is in a closed position. The travelling valve has a stem extending downward from the head through a hole in the travelling seat. The stem is a permanent magnet. Another permanent magnet is carried by the barrel below the travelling magnet. The polarities of the magnets are configured to interact and cause the travelling valve to lift relative to the travelling seat to an open position as the plunger nears a bottom of a stroke.

A fluid control device includes a pump and an external structure. The pump includes an actuator, a top portion opposed to the actuator such that a gap is disposed therebetween in the thickness direction, and a side wall plate extending from the top portion in the thickness direction and supporting a vibration member. The actuator includes the plate-like vibration member and a piezoelectric element configured to cause the vibration member to vibrate in the thickness direction. The top portion includes a projection portion and a fixation portion projecting beyond the side wall plate in an outward direction perpendicular to the thickness direction. The top portion is fixed to an external structure outside the projection portion.

A valve includes a valve disc movable along an axial direction and has an arcing outer engagement surface with an axis of curvature transverse to the axial direction. A valve seat defines a central opening aligned with the axial direction. The valve seat has a toroidal radially inner engagement surface around the central opening configured to engage the engagement surface of the valve disc in a closed position. The engagement surface of the valve disc and the engagement surface of the valve seat are configured to form a line of contact between the outer engagement surface and the inner engagement surface. The engagement surfaces of the valve disc and of the valve seat may be a carbide or ceramic material having a hardness of 1000 HV or more.

A check valve which allows liquid to flow in one direction while preventing liquid from flowing in a direction reverse to said one direction, the check valve comprising: an inflow port allowing liquid to flow therein; an outflow port allowing liquid to flow out thereof; a valve seat provided between the inflow port and the outflow port, the valve seat having a valve hole through which the inflow port communicates with the outflow port; a valve chamber provided between the valve seat and the outflow port; a valve element disposed in the valve chamber, the valve element opening and closing the valve hole; a plurality of holding surfaces located radially outside the valve element, the holding surfaces extending in an axial direction; and an elastic member supported on the holding surfaces and set in the valve chamber, the elastic member applying an elastic force directed toward the valve hole to the valve element.

When a condition for reducing a noise caused in the high-pressure pump is satisfied, a reduction control unit implements a noise reduction control to supply a smaller power to reduce a moving speed of a movable portion in a close acting direction to put a valve body into a closed state for a predetermined time after an energization start timing of a solenoid in a plunger rising period. A closing control unit causes a closing current, which is a constant current for surely putting the valve body into the closed state, to flow the closing current in the solenoid when the noise reduction control is completed in the plunger rising period. The predetermined time is shorter than an energization period in which a current flows in the solenoid.

A bicycle pump includes a pump body assembly, a handle assembly, a flexible hose assembly, and/or a magnet. The pump body assembly may include an outer tube, which defines an air chamber, and a head assembly with an air outlet opening. The handle assembly may slidably be associated with the body assembly, and include an inner tube and a piston, slidable inside the outer tube. The flexible hose assembly may be suitable to be stored inside the inner tube when the pump is not in use, and suitable to be connected to the air outlet opening during pumping. The magnet may connect the flexible hose assembly to the air outlet opening of the head assembly in a removable manner.

A cleaner reciprocating structure comprises a reciprocating mechanism, a water pump assembly, and a second guide assembly. During use, a reciprocating shaft is connected to a driving assembly, and the driving assembly is operated to drive the reciprocating shaft to rotate. Since a first guiding assembly is in guiding fit with a guiding portion on the reciprocating shaft, and a sleeve is connected to the first guiding assembly, the sleeve performs reciprocating movement in the length direction of the reciprocating shaft under the rotation of the reciprocating shaft. Since a plunger is connected to the sleeve, the plunger performs piston reciprocating movement in a reciprocating cavity to suck water from a first channel and discharge the water from a second channel.