The present disclosure relates to a pumping assembly, a piston pump and an oral irrigator. The pumping assembly includes: a cylinder, cavities providing therein with at least two cavities with different inner diameters; a piston mechanism successively extending through the at least two cavities, the piston mechanism being in slidable cooperation with walls of the cavities, and a gap being formed between a sidewall of part of the piston mechanism and the walls of the cavities; and a drive mechanism connected to the piston mechanism, the drive mechanism being configured to drive the piston mechanism to move.

The present invention relates to a pump unit applied to a high-pressure cleaning machine, including: a water inlet chamber, a water outlet chamber, and a central chamber connected to the water inlet chamber and the water outlet chamber. The pump unit further includes a plunger disposed in the central chamber and an eccentric mechanism connected to the plunger. The eccentric mechanism drives the plunger to perform reciprocating motion in the central chamber.

The present application relates to a high-pressure cleaning machine, comprising: a housing, a motor, a transmission mechanism, a pump, a handle, a detachable rechargeable battery pack and a nozzle, wherein the pump comprises a central chamber, a water inlet, a water outlet and a single plunger, a water inlet chamber connected to the water inlet, and a water outlet chamber connected to the water outlet, and wherein the plunger is disposed in the central chamber and is driven by the motor to perform reciprocating motion in the central chamber; wherein the motor, the transmission mechanism and the pump are located at one end of the handle, and the battery pack is located at the other end of the handle.

A clamp comprising a first contact surface perpendicular to a central axis of the clamp and a second contact surface tapered relative to a central axis of the clamp, whereby the clamp allows for concentric or non-concentric mating between a first component and a second component such that, when rigidly held together by the clamp such that the first contact surface of the clamp contacts a portion of the first component and the second contact surface of the clamp contacts a portion of the second component, a central axis of the first component is parallel to or coincident with a central axis of the second component.

Systems and methods are described for a reciprocating mechanism. The system includes at least one axially translating y-axis component configured to reciprocate substantially along a y-axis with a reciprocating motion of a piston assembly relative to a base. The system also includes at least one x-axis component slidingly coupled via at least one bearing assembly to and translating with the at least one y-axis component along the y-axis. The at least one x-axis component is configured to reciprocate substantially perpendicularly to the y-axis relative to the at least one y-axis component, and includes an orbital output component and an orbital linking component disposed substantially concentric with the orbital output component. The system also includes a stationary output component rotatably attached to the base in a direction that is substantially perpendicular to both the x-axis and y-axis, and a stationary linking component rotatably attached to the base in a direction that is substantially concentric with the stationary output component.

Systems to drive a downhole pump include an enclosure body with a magnetically transparent wall. A magnetic driver or a stationary member with coil windings in slots is disposed outside the enclosure body. A magnetic follower or a movable member with one or more permanent magnets is disposed inside the enclosure body such that the magnetic follower or movable member is exposed to a different environment compared to the magnetic driver or stationary member. The magnetic driver and magnetic follower, or the stationary member and movable member, are separated by a gap containing at least a portion of the magnetically transparent wall. A prime mover is operatively coupled to the magnetic driver. A rod couples the magnetic follower or the movable member to the downhole pump. Movement of the rod with the magnetic follower or the movable member operates the pump.

A pump for pumping a cryogenic liquid includes a pump housing having a cylinder with a piston slidably positioned therein. An intermediate fluid chamber that receives an intermediate fluid is defined within the cylinder adjacent to a first end of the piston and a fluid pumping chamber is defined within the cylinder adjacent to a second end of the piston. An intermediate fluid seal is attached to the piston and engages the cylinder. A pumped fluid seal attached to the piston and configured to engage the cylinder, said pumped fluid seal spaced from the intermediate fluid seal so that a differential pressure space is defined within the cylinder between the intermediate fluid and pumped fluid seals. A differential pressure vent valve is in fluid communication with the differential pressure space. A differential pressure switch senses a pressure within the differential pressure space and opens the differential pressure vent valve when the pressure within the differential pressure space reaches a predetermined pressure level.

Pumps are provided, more particularly piston type pumps having increased energy efficiency, systems incorporating such piston type pumps, and methods of operating piston type pumps. The pumps are suitable for pumping of oil from an oil well or for pumping other liquids such as ground water, subterranean liquids, brackish water, sea water, waste water, cooling water, gas, coolants, and the like.

Methods and kits for assembling a flow cage assembly are provided. The flow cage assembly may be used in a traveling valve or a standing valve of a downhole pump. In some embodiments, the kit comprises a tubular body having an axial bore, a tubular insert, and a retaining element. The kit may be assembled such that the retaining element forms an interference fit with the tubular body and thereby retains the tubular insert within the axial bore. In some embodiments, the interference fit between the retaining element and the tubular body may reduce or eliminate a possible failure point within the flow cage assembly.

A pump rod has a head extending from a neck, and the head is received within a drive slot of a drive link. The head includes a projection, and has an area smaller than an area of the head. The projection contacts an inner surface of the drive slot. The drive link may include a projection aligned with a centerline of the drive link. The drive link projection contacts a head of the pump rod. The projections provide a reduced contact area between the pump rod and the drive link, thereby reducing any side-loading on the pump rod and increasing a lifespan of the wear parts.