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.

A fluid end for use with a power end. The fluid end comprises a plurality of fluid end sections positioned adjacent one another. Each section includes a single horizontally positioned bore. A plunger is installed within the bore and includes a fluid passageway. Low-pressure fluid enters the bore through the plunger and high-pressure fluid exits the fluid end through an outlet valve installed within the bore. The intake of low-pressure fluid within the fluid end section is regulated by an inlet valve installed within the plunger. Low-pressure fluid enters the plunger through an inlet component attached to both the plunger and an inlet manifold.

A packing case for a plunger or a piston rod of a reciprocating machine comprises packing cups, each packing cup comprising a body with a hole for the passage of the plunger or rod and a sealing ring seat for housing a sealing ring which slidably bear against the plunger or rod. Packing cups are aligned with each other in series. The packing case comprises lube oil ducts for supplying lube oil from an end of the packing case to the sealing ring seat. Each packing cup comprises sectors, each sector comprising at least lube oil duct portions. The packing cups are positionable to bring, one sector at a time in an activation position where some of the lube oil duct portions of the sector are connected with the lube oil duct portions of an adjacent packing cup to form lube oil ducts. The packing cups are lockable.

Various assemblies that can be used in a mud pump with a plunger-style piston to reduce seal failures, to offer control in variability of the circumference of the piston to thereby control fluid pressure, and to provide visibility into seal condition during operation. In one embodiment, a sleeve that can vary the overall effective circumference of the piston enables fluid pressure control. In some embodiments, seal failure within a pump can be monitored via a drain port that would receive drilling fluid leaking past a seal during operation of the pump. A discharge valve can be provided between an inlet and an outlet of the mud pump to reduce the load on pump components during start-up. Additional systems, devices, and methods are also disclosed.

A self-aligning mud pump apparatus is provided. In one embodiment, the mud pump includes a rotatable crankshaft, a crosshead, a crosshead guide, and a hub disposed in a housing. The hub is disposed on the crankshaft and is operable to convert rotating motion of the crankshaft to reciprocating motion of the crosshead within the crosshead guide. The hub is coupled to the crosshead via a connecting rod, which is connected the crosshead such that the connecting rod has five degrees of freedom with respect to the crosshead guide. The mud pump may also or instead include a piston coupled to the crosshead with five degrees of freedom between the piston and the crosshead. Additional systems, devices, and methods are also disclosed.

A compressor and method for compressing a working medium, including moving a drive piston which is driven by way of a driving medium within a first cylinder between a first end position and a second end position; moving a high pressure piston which compresses the working medium within a second cylinder between a first end position and a second end position; arranging a high pressure seal for sealing the high pressure piston; arranging a magazine having a receptacle for the high pressure seal and at least one replacement high pressure seal in a first operating position, in which the high pressure piston is sealed by way of the high pressure seal; and transferring the magazine from the first operating position to a second operating position, in which the high pressure piston is sealed by way of the replacement high pressure seal.

A high-pressure fuel pump includes a pump housing which defines a pumping chamber, a fuel inlet which allows low-pressure fuel into the pumping chamber, a fuel outlet which allows high-pressure fuel out of the pumping chamber, and a plunger bore which extends along an axis and opens into the pumping chamber. The high-pressure fuel pump also includes a pumping plunger which reciprocates within the plunger bore along the axis such that reciprocation of the pumping plunger within the plunger bore increase and decreases a volume of the pumping chamber. The pumping plunger includes a sealing ring groove which is concentric with the plunger bore, the sealing ring groove including a sealing ring therein which engages the plunger bore in an interference fit. A diametric clearance greater than 12 microns is provided between the pumping plunger and the plunger bore.

The invention relates to an axial piston machine in which pistons carry out a stroke movement in cylinders and in which the pistons have a seal ring receptacle for a seal ring. In order to improve robustness, wear resistance, friction and stick-slip behavior, according to the invention, the seal ring is spherical, wherein the curvature radius of the seal ring, which is spherical in regions, substantially corresponds to half the diameter of the cylinder inner wall.

A rod connector for coupling with a rod of a pump includes a cylinder including a bore, an actuator rotatably disposed in the bore of the cylinder, wherein the actuator is configured to actuate the rod connector between locked and unlocked positions, and a first coupler disposed in the bore of the cylinder and configured to releasably couple with a first rod of the pump, wherein the actuator includes an outer surface including a first pair of opposing engagement surfaces and a second pair of opposing engagement surfaces, and wherein a diameter extending between the first pair of engagement surfaces is less than a diameter extending between the second pair of surfaces.

A valve for a reciprocating pump includes a housing, a first chamber, a second chamber, a first valve element, and a second valve element. The housing includes an inlet and an outlet. The first and second chambers are within the housing. The first chamber includes a first valve seat and is fluidly connected to the inlet. The second chamber includes a second valve seat and is fluidly connected to the outlet. The first valve element is disposed in the first chamber and includes a spring-loaded check valve element. The second valve element is disposed in the second chamber and includes a buoyant material.