Sealing in rotary positive displacement machines based on trochoidal geometry that comprise a helical rotor that undergoes planetary motion within a helical stator is described. Seals can be mounted on the rotor, the stator, or both. The rotor can have a hypotrochoidal cross-section, with the corresponding stator cavity profile being the outer envelope of the rotor as it undergoes planetary motion, or the stator cavity can have an epitrochoidal cross-section with the corresponding rotor profile being the inner envelope of the trochoid as it undergoes planetary motion. In some embodiments, the geometry is offset in a manner that provides advantages with respect to sealing in the rotary machine. In multi-stage embodiments, the rotor-stator geometry remains substantially constant or varies along the axis of the rotary machine.

A progressive cavity pump includes at least one of a jacketed stator casing and a jacketed inlet body. The jacketed stator casing includes a stator heating chamber, a stator assembly, and a rotor rotatably disposed within the stator assembly. The stator heating chamber forms a first space around the stator assembly and receives heating fluid therein. The stator assembly includes a cylindrical wall and a stator segment that forms a helically-convoluted chamber within the cylindrical wall. The jacketed inlet body includes an inlet heating chamber and a working fluid chamber in fluid communication with the helically-convoluted chamber. The inlet heating chamber forms a second space around the working fluid chamber and receives heating fluid therein. The stator heating chamber and the inlet heating chamber are isolated from each other, the helically-convoluted chamber, and the working fluid chamber.

An apparatus and method for pressure testing a tubing string of a fluid production well, the tubing string being provided with a progressing cavity pump at a downhole end, which apparatus and method can be used to help determine whether the tubing string has failed or the pump has failed. The apparatus comprises a plug member connected to the rod string assembly that includes the pump rotor, such that the rod string assembly can be lowered to seat the plug member in a seat member within the tubing string above the pump, thus sealing off and isolating the pump from the rest of the tubing string, allowing pressure testing of the tubing string above the pump.

A cartridge system for an eccentric screw pump, comprising a cartridge for receiving a medium to be dosed, a stator being provided on the cartridge, which cooperates with a rotor unit of the eccentric screw pump for dosing the medium, and a plug being movably supported in the cartridge for a fluid-tight closure of the cartridge, wherein the plug comprises a rotor breakthrough through which the rotor unit can be passed.

An eccentric screw pump for delivering solid-laden liquids includes a rotor and a stator within which the rotor is rotatably arranged. The rotor and stator are arranged and designed with respect to one another in such a way that at least one chamber is formed, which serves to transport the liquid. The eccentric screw pump has a drive motor for rotating the rotor, a control device for controlling the drive motor at least in a working state, in which the rotor is rotated, and an idle state, in which the rotor does not rotate, and an engagement unit, which is designed to set an engagement between the rotor and stator to an idle engagement in the idle state and to a working engagement in the working state. The idle engagement is less than the working engagement. A method for operating the eccentric screw pump is also disclosed.

Disclosed are a transmission method and a device for coaxially outputting autorotation and revolution. The axis of a power output shaft (17) and the axis of a crank of a power input shaft (1) are coincided with each other. The power output shaft (17) revolves around the axis of a main shaft of the power input shaft (1), and the revolution speed equals to the rotation speed of the power input shaft (1). After the superposition of a transition gear train (A) and a K-H-V few-tooth-difference planetary gear train (B), a driving force of the power input shaft (1) enables the power output shaft (17) to generate the autorotation which has the same speed as that of the power input shaft (1) but in the opposite direction, and at the same time, a thrust bearing (19) coaxial with the power output shaft (17) is connected to a thrust bearing (18) coaxial with the main shaft of the power input shaft (1) in series to bear axial loads. The transmission device for coaxially outputting autorotation and revolution is mainly formed by the power input shaft (1), the transition gear train (A), the K-H-V few-tooth-difference planetary gear train (B), the thrust bearings (18, 19) connected in series, and the power output shaft (17), etc. The device can be combined with a plasticizing delivery device using an eccentric rotor and having pulsed volume deformation to form an extruder.

The disclosure of this application is directed to a downhole tool comprising a central element/member and a sleeve that is rotatably and orbitally disposed around the central element/member. The sleeve rotates and orbits around the central element/member responsive to fluid flowing through the downhole too. The disclosure is also related to a method of advancing the downhole tool in a well by flowing fluid through the tool.

The disclosure of this application is directed to a downhole tool comprising a central element/member and a sleeve that is rotatably and orbitally disposed around the central element/member. The sleeve rotates and orbits around the central element/member responsive to fluid flowing through the downhole too. The disclosure is also related to a method of advancing the downhole tool in a well by flowing fluid through the tool.

The present disclosure relates to a method and system for manufacturing a multi-lobed helical rotor. The method for manufacturing a multi-lobed helical rotor may comprise mixing one or more powdered metals, compacting a mixture of one or more powdered metals to form a solid metal piece, sintering the solid metal piece, and polishing the solid metal piece. The system may comprise a positive displacement pump, which may comprise a casing, a multi-lobed helical rotor disposed in the casing, wherein the multi-lobed helical rotor comprise sintered powdered metals, an inlet to the casing, and an outlet leading from the casing.

This invention relates to a collecting device and method for loosening and collecting debris in a well, the collecting device includes a first end portion and a second end portion; a collecting receptacle between the first and second end portions, the collecting receptacle including at least one receptacle section and at least one screen receptacle section and at least one screen receptacle; a motor; and the collecting device, at its first end portion, including a feel pipe; a conveying screw in the feed pipe driven by the motor, the conveying screw being arranged to move the debris in towards the collecting receptacle and a tool at the leading end portion of the conveying screw.