A uniaxial eccentric screw pump includes: a casing; a stator having one end portion thereof connected to the casing and having an inner peripheral surface which is formed into a female threaded shaped; a rotor configured to be insertable into the stator and formed of a shaft body having a male threaded shape; and an end stud connected to the other end portion of the stator. The stator is configured to be expandable and shrinkable in a radial direction.

A rotary pump is presented for use in a medicament delivery device, where the pump has a back plate having an inner surface and a rotor housing is positioned adjacent to the back plate having a peripheral wall. A front plate support is connected to the back plate and a flexible front plate is positioned between the front plate support and the rotor housing. The pump is rotated using a planetary gear transmission, where an eccentric shaft is operatively connected to the planetary gear mechanism. A rotor is rotationally fixed to the eccentric shaft and movably positioned within rotor housing. The rotor has three lobes, where each lobe has two peripheral curved surfaces sharing a common apex, where a first portion of each peripheral surface adjacent to the apex defines a non-smooth curve.

A rotary pump (10) comprises a housing (20) having a first (21) and second fluid port (22) and an interior surface defining a cavity (24) in which a rotor (30; 230) is located, wherein the rotor comprises at least a surface recess (231a-231d) forming at least a fluid-conveying chamber (232a-232d) with the interior surface of the housing. The pump further comprises at least a resiliently deformable diaphragm (50): 226) providing part of the interior surface of the housing and being urged into contact with the surface of the rotor by the action of pressurising means acting on the rear surface of the resiliently deformable diaphragm. The pump further comprises one or a pair of flow channels (41a, 41b; 241a, 241b) associated with the resiliently deformable diaphragm extending longitudinally from opposite ends of the rotor. In embodiments where the pump comprises one flow channel (575), the flow channel is in fluid communication with the first fluid port and an aperture (595) opens from the interior surface of the housing to place the second fluid port in direct fluid flow communication with the fluid-conveying chamber. In embodiments where the pump comprises a pair of flow channels (241a, 241b), the pair of flow channels comprise a first flow channel in fluid communication with the first fluid port and closed to the second fluid port and a second flow channel closed to the first fluid port and in fluid communication with the second fluid port, with each flow channel being located at opposite sides of the diaphragm. Embodiments of the invention exhibit continuous fluid flow when in use.

A pumping assembly to feed fuel, preferably diesel fuel, to an internal combustion engine is provided with an electric gear pump (7) having two gears (33, 37) mounted one inside the other, and of which one is an annular rotor (33) mounted rotatably on the inside of a stator (29) through the interposition of a support bearing (42), which is delimited by a substantially cylindrical side wall (43) having at least one strip (47) of elastically deformable material which is substantially parallel to a rotation axis (30) of said rotor (33).

The invention relates to a rotary piston pump comprising a housing with a housing interior, an inlet opening, and an outlet opening; a first rotary piston which is mounted within the housing interior in a rotational manner about a first rotational axis; and a second rotary piston which is mounted within the housing interior in a rotational manner about a second rotational axis. The first rotary piston and the second rotary piston engage into each other in a region between the first and the second axis and displace liquid. The first rotary piston has a frame assembly which comprises multiple mutually spaced plates and is at least partly filled and enveloped with a polymer material.

A progressive cavity positive displacement motor having a solid metal stator and a rotor having an elastomeric seal layer on its outer surface, as well as a method of manufacturing the motor. The elastomeric seal layer on the rotor can be formed by extruding the uncured elastomer, applying the extrusion to the metal rotor core and machining the cured elastomer to produce a uniform thickness seal layer. The elastomer can be made from a high molecular weight elastomer compound. Graphene additives can further enhance the performance characteristics of the elastomer.

In a gear pump device for rubber extrusion, prolongation of the maintenance intervals is intended by preventing rubber scorch occurring at the gear support-shaft portion. It has a bushing ring 5 inserted in a gear-housing bore 3 of a housing 4. The bushing ring 5 rotatably supports a support-shaft portion 7 of a gear 2 accommodated in the gear-housing bore 3. The bushing ring 5 has a bearing 15 and a sealing means 16 built-in. The sealing means 16 includes a seal ring 22 of which cross section is ]-shaped and which has a first lip portion 22i contacting with the outer peripheral surface of the support-shaft portion 7, a second lip portion 22o disposed outside thereof in the radial direction, and a side wall portion 22m connecting between outer ends in the axial direction, of the first and second lip portions 22i, 22o.

A liquid pump includes a pump assembly attached to a motor. The pump assembly includes an inlet chamber and pump chamber. The pump chamber accommodates a drive gear driven by an output shaft of the motor and driven gear meshed with the drive gear. An inner cover is disposed within the pump chamber. An outer cover overlies the inner cover with an elastic member disposed there between. The outer cover exerts a force to the inner cover through the elastic member and holds the inner cover in sliding contact with an axial end of the drive and driven gears. An outlet chamber formed between the inner cover and the outer cover is in fluid communication with and the pump chamber.

A vane assembly for use in a rotary vane actuator, the vane assembly comprising: a rotatable vane having a first side and a second side; a vane axle connected to the rotatable vane for converting pressure exerted on the rotatable vane into rotational motion; a vane seal on the first side of the rotatable vane, the vane seal being for sealing the rotatable vane; and a side-plate on the first side of the rotatable vane, the side-plate clamping the vane seal in position; wherein the side-plate comprises: an outer part providing an outer surface of the side-plate, the outer part defining an internal volume; and an inner part filling or substantially filling the internal volume defined by the outer part, the inner part being distinct from the outer part.

A pump is formed by a housing (10) having a fluid inlet (11) and a fluid outlet (12) and containing a rotor (15) forming with the housing (10) chambers (17a, 17b) that, on rotation of the rotor (15) by a drive, convey fluid from the inlet (11) to the outlet (12) to pump the fluid. A seal assembly (14) is arranged between the outlet (12) and the inlet (11). The seal assembly (14) includes a membrane (21) that contacts the rotor (15) and a flexible resilient spring member (22, 28, 35, 37, 40) that provides a force urging the membrane (21) against the rotor (15). The spring member (22, 28, 35, 37, 40) thus, on rotation of the rotor (15), moves radially relative to the axis of rotation of the rotor (15) and is arranged to provide a force on the rotor (15) via the membrane (21) that is constant and a minimum to maintain a seal between the rotor (15) and the seal (14) for a given outlet pressure of the pumped fluid.