Rotary positive displacement machines based on trochoidal geometry, that comprise a helical rotor that undergoes planetary motion within a helical stator are described. 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 structural and/or operational advantages in the rotary machine.

A device is provided for pumping fluid from a wellbore up to surface. The device includes a stator unit, a rotor unit run within the stator unit on a rod string, the rotor unit and the stator unit engaging with one another to form an annular space therebetween for passage of fluid. An upstream check valve on the rod string uphole of the rotor unit is moveable from an open position in which fluid is passable through the annular space, and a closed position in which fluid passage through the annular space is prevented. A hollow rod section extends through the rod string in fluid communication with the annular space both downstream and upstream of the upstream check valve, for entry of fluid into a downhole end of the hollow rod section, passage of fluid upstream therefrom and exit of fluids from an uphole end of the hollow rod section, back into the annular space. A method is further provided for pumping fluid from a wellbore after shutdown.

A collecting device for loosening and collecting debris in a well comprises a first and second end portions, a collecting receptacle between the first and second end portions having at least one receptacle section and at least one screen receptacle, and a motor. The device at its first end includes a feed pipe, a conveying screw in feed pipe driven by the motor and arranged to move the debris in towards the collecting receptacle, and a tool at the leading end portion of the conveying screw. A method described of loosening and collecting debris in a well by the collecting device.

A system for conveying pasty material through a conduit has an eccentric screw pump having a stator, a rotor that rotates in the stator, a housing with an intake port, and an output port connected to the conduit. A drive rotates the rotor and thereby draws the pasty material in through the intake port and expels the drawn-in material as a compressed-material strand into the conduit. A valve supplies gas pulses to the conduit at time intervals for separating the compressed-material strand into material plugs of limited length traveling through the conduit.

Rotary positive displacement machines based on trochoidal geometry, that comprise a helical rotor that undergoes planetary motion within a helical stator are described. 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 structural and/or operational advantages in the rotary machine.

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 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.

Provided herein 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 invention relates to an eccentric screw pump, comprising at least one stator (1) composed of an elastic material and a rotor (2) that can be rotated in the stator (1), the stator (1) being surrounded by a stator casing (3) at least in some regions. The stator casing (3) consists of at least two casing segments (19) as a longitudinally divided casing and forms a stator clamping device, by means of which the stator (2) can be clamped against the rotor (1) in the radial direction. The pump is characterized in that the casing segments (19) have at least one clamping flange (20) having first clamping surfaces (21) at each end of the casing segments and that one or more clamping elements (22, 23), which can be displaced in the axial direction and have second clamping surfaces (24), are placed onto the clamping flange (20), the first clamping surfaces (21) and the second clamping surfaces (24) being designed in such a way and interacting in such a way that the stator casing (3) can be clamped against the stator in the radial direction in the course of an axial displacement of the clamping elements (22, 23).

A progressive cavity pump for transporting a liquid containing solids comprises a helical rotor, a stator having an inlet and an outlet, within which the helical rotor is rotatably disposed about a longitudinal axis of the stator, and comprising a helical inner wall corresponding to the helical rotor. The helical rotor comprises a shape tapering down toward the outlet or inlet, and the helical rotor and stator are disposed relative to each other and implemented such that at least one chamber is formed for transporting the liquid, and the chamber is cut off by a constriction. The progressive cavity pump includes an adjusting device for adjusting a relative axial position of the helical rotor and stator, wherein the adjusting device is implemented for expanding the constriction between the helical rotor and stator.