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 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 cam liner for use in an integrated drive generator has a cam liner body extending between a first end spaced from the second end by a first distance. The body is generally cylindrical. An outer diameter of the cam liner defines a second distance. A ratio of the first distance to the second distance is between 0.90 and 1.00. An integrated drive generator and a method are also disclosed.

A progressing cavity pump or a positive displacement motor includes an external member having three or more lobes and an internal member extending through the external member and having one less lobe than the external member. One of the internal member and the external member rotates with respect to the other. The curvature of a profile of each of the internal member and external member is finite at all points. A ratio of a lobe volume of the external member to a valley volume of the external member enclosed between a minor external member diameter and a major external member diameter is between 0.9 and 1.2. A lobe height of the external member is related to a ratio of a minor internal member diameter to one less than the number of internal member lobes.

A rotary device for use with a fluid includes a housing, a rotor, a ring, and at least one vane. The housing includes a tubular surface defining, in part, a tubular volume. The housing is segregated into at least a pumping zone positioned between first and second working zones. The first working zone is configured to receive a fluid and the second working zone is configured to output the fluid. The rotor is mounted for rotation about a rotation axis. The rotor includes a body mounted within the tubular volume. The body includes a plurality of slots. The ring is at least indirectly coupled to the housing by way of a bearing. The at least one vane is associated with one slot of the plurality of slots. The at least one vane is connected at least indirectly to the ring and configured to rotate within the tubular volume.

An oscillating piston compressor includes two oscillating compression units, and an introduction section configured to introduce an intermediate-pressure refrigerant into a compression chamber of each of the compression units. Each compression unit has a cylinder forming a cylinder chamber, a piston housed in the cylinder chamber, and a blade integrally formed with the piston. The piston rotates in the cylinder chamber while the blade oscillates. The two compression units are configured such that phases of the pistons are opposite to each other. The piston has a non-circular outer peripheral surface, and the cylinder chamber has an inner peripheral surface with a shape determined based on an envelope of the outer peripheral surface of the piston in rotation.

An internal-combustion engine includes an engine housing having an interior space with an inner wall, which section-wise corresponds to a segment of a circular cylinder and a segment deviated from the circular cylinder, wherein a rotary disc is centrally rotatably mounted in the interior space around an axis, and an intake area, a compression area, an ignition area, a working area and an exhaust area are formed, wherein the rotary disc is a circular cylinder with two slots in the circumferential area, into each of which slots a sliding element is inserted, wherein each sliding element movable along the slot, and is moved along the slot on rotation of the rotary disc.

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 method for impregnating a stator of a progressive cavity assembly with nanoparticles. The assembly comprising a stator having an inner core formed on its inner surface, the inner core defining a groove. A primary rotor is disposed within the groove. In operation, the primary rotor is removed from the stator, and a plurality of nanoparticles are distributed throughout the groove. A work rotor is installed within the groove and rotated at a high rate so as to press the nanoparticles into the inner core. The work rotor is removed from the stator and the primary rotor is re-installed into the stator.

Liquid ring pumps are used to pump a variety of fluid types. The present invention provides a two stage liquid ring pump through which an exhaust gas comprising compounds to be destroyed is passed. The exhaust gas passes through the first stage to a gas abatement device, following which it is passed back to the second stage of the liquid ring pump for removal of the compounds formed in said abatement device. The stages of the liquid ring pump may be adjustable.