A printing method forms a continuous strand of building material for 3D printing of a structural part via a printing system. The printing system has a printing apparatus that dispenses building material out of the printing apparatus and shapes building material to form a strand of building material, and a discontinuous building material pump that discontinuously conveys building material for discontinuously dispensing conveyed building material out of the printing apparatus. The printing method includes the steps of: a) discontinuously conveying building material via the discontinuous building material pump and discontinuously dispensing conveyed building material out of the printing apparatus and shaping conveyed building material via the printing apparatus, and b) discontinuously moving the printing apparatus during the discontinuous conveying and the discontinuous dispensing such that the dispensed and shaped building material forms a continuous strand of building material.

A reciprocating plunger pump fluid end having increased material thicknesses in typical high stress concentration areas includes locating valves in spherically segmented shaped suction and discharge bores adjacent to chamfered transition areas to provide for reduced stress concentrations, resistance to fatigue failure and erosion and ease of access for maintenance. Among other features the housing includes a valve retainer assembly integrally mounted inside the housing which includes a profile to reduce stresses in the bores and facilitate access for replacement of internal components.

The present disclosure provides a two-dimensional motor combination piston pump by combining two independent two-dimensional piston pumps into one structure to achieve parallel outputting. The combination piston pump includes a two-dimensional motor and a two-dimensional piston pump. The outer rotator serves as the piston and the flow distribution mechanism of the two-dimensional piston pump. While operating, outer rotator rotates and moves axially. By combining two independent two-dimensional piston pumps into one structure to achieve parallel outputting, the combined piston pump has a greater work-to-weight ratio. The two-dimensional motor and the two-dimensional piston pump may share some structures in common, allowing the structure of the combination piston pump to be compact.

A liquid delivery device includes at least one liquid delivery pump that delivers liquid, at least one main channel communicating with an outlet of the liquid delivery pump, at least one branch channel branched from the main channel, and a switching valve that has, as a port for connecting channels, at least a port to which the main channel is connected, a port to which the branch channel is connected, at least one output port for outputting liquid delivered by the liquid delivery pump through the main channel, and at least one drain port leading to a drain, and is configured to be selectively switched to a first state, in which the main channel is connected to the output port while the branch channel is not connected to any channel, and a second state in which the branch channel is connected to the drain port while the main channel is not connected to any channel.

An electric-to-hydraulic conversion machine includes an axial flux electric motor and a hydraulic pump. The motor includes a spindle, at least one rotor configured to rotate about the spindle, and at least one stator configured to drive rotation of the at least one rotor about the spindle. The hydraulic pump includes a piston block having a plurality of cylinders, a plurality of pistons each supported in one of the cylinders of the piston block, and a cam ring. The piston block is attached to the at least one rotor and is configured to rotate about the spindle with rotation of the at least one rotor. The cam ring is configured to radially drive the pistons during rotation of the piston block about the spindle, which drives a fluid flow.

Apparatus and methods for pressurizing well operations fluids via a pressure exchanger having a housing with a bore extending between first and second ends of the housing and a rotor rotatably disposed within the bore of the housing. A chamber extends through the rotor between first and second ends of the rotor. The chamber has a larger chamber diameter section and a smaller chamber diameter section. A piston assembly is slidably disposed within the chamber. The piston assembly has a larger piston diameter section slidably disposed within the larger chamber diameter section and a smaller piston diameter section slidably disposed within the smaller chamber diameter section.

A liquid delivery device includes at least one liquid delivery pump that delivers liquid, at least one main channel communicating with an outlet of the liquid delivery pump, at least one branch channel branched from the main channel, and a switching valve that has, as a port for connecting channels, at least a port to which the main channel is connected, a port to which the branch channel is connected, at least one output port for outputting liquid delivered by the liquid delivery pump through the main channel, and at least one drain port leading to a drain, and is configured to be selectively switched to a first state, in which the main channel is connected to the output port while the branch channel is not connected to any channel, and a second state in which the branch channel is connected to the drain port while the main channel is not connected to any channel.

A two-dimensional motor combination piston pump by combining two independent two-dimensional piston pumps into one structure is provided. The combination piston pump includes a two-dimensional motor and a two-dimensional piston pump. The outer rotator serves as the piston and the flow distribution mechanism of the two-dimensional piston pump. While operating, outer rotator rotates and moves axially.

A three-stage variable color paste pump, comprising: a differential pump, which includes: a rodless cavity, a rod containing cavity, and a piston rod; configuring a control valve, which comprises a valve body and a valve core, wherein the valve body is provided with a rod containing cavity opening which is in communication with the rod containing cavity; configuring a rodless cavity opening as in communication with the rodless cavity, configuring a color paste tank opening as in communication with a color paste tank, and configuring an injection outlet; configuring a channel on the valve core, moving the valve core to different positions may form three communication structures. The pump uses one differential pump to achieve three-stage injection output, thus ensuring the accuracy of the injection output of the color paste pump. The pump has a simple structure, takes up a small surface area, and is easy to use.

Apparatus and methods for pressurizing well operations fluids via a pressure exchanger having a housing with a bore extending between first and second ends of the housing and a rotor rotatably disposed within the bore of the housing. A chamber extends through the rotor between first and second ends of the rotor. The chamber has a larger chamber diameter section and a smaller chamber diameter section. A piston assembly is slidably disposed within the chamber. The piston assembly has a larger piston diameter section slidably disposed within the larger chamber diameter section and a smaller piston diameter section slidably disposed within the smaller chamber diameter section.