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.

Rotor and/or stator designs and methods thereof to improve progressive cavity motor or pump durability. In one or more implementations, the rotor may have a variable outer diameter or variable stiffness along an axial length thereof. The stator may similarly have a variable inner diameter or variable stiffness, which may compliment or diverge from the variable outer diameter or variable stiffness of the rotor.

An intelligent oil extraction system using an all-metal screw pump includes: the all-metal screw pump, an oil collecting unit (43), and a steam generating unit (45); wherein an internal threaded curve surface and an external threaded curve surface of the all-metal screw pump are both tapered spiral structures with equal tapers; the oil extraction system comprises a lifting mechanism and monitoring and control mechanism; the monitoring and control mechanism comprises: a controller (34), a torque sensor (35), a flow sensor (36), a pressure sensor (39), a liquid level detector (38), and a backup power source (37); the controller (34) is electrically connected to the torque sensor (35), the flow sensor (36), the pressure sensor (39), the liquid level detector (38), the backup power source (37), a drive motor (48), a servo motor (33), a first valve and a second valve.

A method of manufacturing a metallic rotor of an eccentric screw pump, comprising clamping a workpiece extending along a central longitudinal axis in a workpiece clamping device and removing material from the workpiece by cutting with a cutting tool. The invention further comprises not producing the surface of the rotor in a three-axis whirling process, using the cutting tool to produce the outer surface geometry of the rotor, advancing the cutting tool along an axis of advance that is parallel to the longitudinal axis of the rotor, and rotating the cutting tool about an axis of tool rotation that is parallel to the longitudinal axis of the rotor.

A pump comprises a housing, with an interior defining a rotor path, an inlet formed in the housing at a first position on said rotor path, an outlet formed in the housing at a second position on said rotor path spaced from said first position. A rotor is rotatable in the housing with a first surface that seals against the housing. A second surface is formed on said rotor circumferentially spaced from said first surface and forms a chamber that travels around said rotor path to convey fluid from the inlet to the outlet. A resilient seal formed with the housing is located on the rotor path to prevent fluid flow from said outlet to said inlet past the seal. A passage may be provided to supply fluid to an under surface of the seal at a pressure that acts to urge the seal against the rotor.

A rotary piston and cylinder device (1) comprising: a rotor (2), comprising a rotor surface (2a), a piston (5) which extends from the rotor surface, a stator (4), a rotatable shutter (3), the rotor surface and the stator together defining an annular chamber, and the piston arranged to rotate, through the annular chamber, wherein when the chamber is viewed in axial cross-section, substantially a single surface of the stator in part defines the chamber (100).

A positive displacement rotary motion device including in one example a pulse detonation device. Also; an indexing system for a rotor assembly where in one example the indexing system regulates the rotational location of drive rotors. In one example the rotors are configured to rotate about a shaft.

Compression of water vapour as R718 is disclosed with and without addition of additives as an aqueous solution in rotational displacement machines, i.e. refrigeration, air-conditioning and heat pump technology. To largely avoid over or under-compression, it is proposed for the easiest possible adaptation of the currently effective internal volume ratio as so-called iV value in the displacer that the compressor housing starting from the outlet side with rotor profile length L.sub.R over a length L.sub.iV comprises planar, i.e. flat iV disks (3.sub.j) with the index j for 1?j?n; n is the number of disks; n?1 with a width b.sub.j per iV disk having planar surfaces P.sub.F preferably perpendicular to the neutral axis A.sub.N. The iV disks are displaced in a targeted manner individually by movement control devices (5.sub.j) per iV disk in each case by a distance s.sub.i where 0<s.sub.i?s.sub.j.

Pressure changing devices and methods of making and using the same are disclosed. One pressure changing device includes an elliptic cylinder and a piston that has an external surface with a trochoid cross-section. Another pressure changing device includes a piston and a rotating cylinder that has an internal surface with a trochoid cross-section. Another pressure changing device includes two fixed axes, one for rotation of one component and another for orbiting or oscillation of the other component. The devices and methods include stacked pressure changing devices with one or more common shafts. The pressure changing device may be easier and less expensive to manufacture and repair than prior pressure changing devices of the same or similar functionality, and can provide efficient gap sealing in a high-pressure expansion part of a compression or expansion cycle.

A system for cryocooling an optical sensor on a satellite to a temperature below 200K with minimal vibration comprising a miniature conical rotary screw compressor comprising an inner element configured to only rotate around a first stationary axis and an outer element configured to only rotate around a second stationary axis so that both elements revolve with minimal vibration; with at least one of a) a length of at least one of the inner element and the outer element is between 10 mm and 100 mm; b) a diameter of at least one of the inner element and the outer element is between 2 mm and 45 mm; c) a compression ratio of the rotary screw compressor is between 1:2 and 1:20; and d) a shaft speed of the conical rotary screw compressor is between 1001 and 20000 revolutions per minute.