Abstract: A positive displacement, recirculating Root's type rotary compressor which operates on a constant volume, near isothermal cycle is disclosed. The compressor includes a pair of involutely lobed impellers and a discharge pressure reflux flow loop. The flow loop includes a discharge port, a flow distributor, an output port, and one or two pair of low impedance rectangular conduits terminating in linear nozzles that serve as reflux ports. Reflux flow through the nozzles is directed with impeller rotation. It isentropically expands into the constant volume displacement cavities so that the contained pressure approaches discharge level. The final pressure increase into discharge is gained through adiabatic compression at a low pressure ratio. The resulting process is inherently non-contaminating, as there are no valves and no contacting or rubbing parts in the flow stream. It can be applied wherever gases or vapors must be compressed.

Abstract: A gear pump includes a pair of gears accommodated in a gear chamber. When the inside pressure of a trap region which is changed with the rotation of the gears becomes substantially equal to the inside pressure of an inlet chamber, the communication state is switched from a state in which communication between the trap region and the first and second relief channels is blocked to a state in which the trap region communicates with the second relief channel. With the inside pressure of the trap region being substantially equal to the inside pressure of the inlet chamber, the trap region is opened to the inlet chamber.

Abstract: A gear pump for delivering liquid media has a pump housing with at least two bores, in which at least two meshing gears with tooth tips are contained. The gears are radially mounted by bearing surfaces which on one side consist of areas of the tooth tips and on the other side, of areas of the interior of the bores. This arrangement requires no slide bearings in the conventional sense, which results in a smaller number of pump parts and hence to reduced manufacturing costs.

Abstract: Rotary pump apparatus includes a pump housing having a drive gear and a driven gear positioned in the interior of the housing. A fluid-flow passageway provides fluid to a volumetrically changing space located between meshing gear teeth to prevent the pressure in the space from dropping below the vapor pressure of the fluid.

Abstract: A gear pump exhibiting improved efficiency over a broader range of fluid viscosity and pump speed includes a compression zone defined between each of a pair of pump gears and internal walls of a gear chamber, wherein the compression zones have a non-uniform thickness along a longitudinal direction of the gears. The geometry of the compression zones provides a mechanism whereby the drag of the viscous fluid which is induced by the rotation of the pump gears carries the viscous fluid through a progressively narrower gap in the direction of rotation ending in a final smooth pinch-off at the start of the seal zone. The geometry of the compression zone maximizes the drag and pressurization of the viscous fluid being pumped into the teeth of the gears, thereby assisting in the complete filling of the teeth. The result is improved fill efficiency over a broader range of pump speeds and over a broader range of fluid viscosity.

Abstract: A fluid machine comprises a rotor (7, 9) meshed with each other in concave and convex portions (23, 26) and (25, 24), and a casing (3) enveloping these elements within cylindrical portions (43, 45) of a rotor chamber (5) and having a flow inlet port (31) and a flow outlet port (33). The cylindrical portions (43, 45) are moved to moved centers (47, 49) from standard centers (35, 37) at a predetermined distance L toward the flow inlet port (31), so that the rotor chambers (5) is expanded to cylindrical portions (55, 57) from the cylindrical portions (43, 45).

Abstract: A fluid flow device and method are provided according to which one or more impellers are mounted for rotation in a chamber formed in a casing. Fluid to be processed is introduced into an inlet formed in the casing and at least one impeller is mounted for rotation in the chamber to flow the fluid through the casing and through an outlet in the casing. The impeller also draws atmospheric air into the chamber through an air inlet formed in the casing, and any backflow of the fluid from the fluid outlet into the air inlet is prevented.

Abstract: The invention is embodied in a hydraulic gear machine, such as for example a pump or motor, with at least one multistage pressure building slot in an axial plate of the housing. The slot is designed to facilitate a gradual rise of fluid pressure between the mating teeth of the gears and to reduce the noise being generated by the machine as a result of advancement of fluid from a suction inlet to an outlet for pressurized fluid.

Abstract: Volumetric blower comprising an internally hollow body (11) for defining a compartment (12) which is placed in communication with an intake manifold (30) and a delivery manifold (31) and which has, arranged inside it, two rotors (20) which are parallel to a longitudinal axis (X—X) of the blower, counter-rotating and shaped in the manner of lobes (21) having a correlated profile and which are designed to produce, together with the internal wall (11a) of said compartment, the periodic formation of a chamber (40) containing the fluid to be conveyed to the delivery manifold (31), the opposite openings in the longitudinal direction of said compartment (20) being closed by an associated cover (50), wherein the internal surface (51) of said covers (50) has, formed in it, at least one duct (52;152) arranged, with respect to the longitudinal axis (X—X), on the side corresponding to the delivery manifold (30) so as to allow connection of said chamber (40) to the delivery manifold itself and designed to be c

Abstract: A metering pump includes a set of externally-toothed gears, with a first of the gears, the drive gear, having a central opening to receive a drive shaft. The gears are supported within a housing defined between first and second housing plates. The first and second housing plates each have central openings aligned with the central opening in the drive gear, and inner wall surfaces adjacent opposite side surfaces of the gears. The first and second gears are rotatably supported within the housing such that the rotational axis of the gears are parallel to one another, and certain of the gear teeth intermesh together when the gears rotate. A first port in the housing provides an inlet fluid flow to an inlet side of the meshing gear teeth, while a second port provides an outlet fluid flow from an outlet side of the meshing teeth. An annular resilient, face-type lip seal is disposed against each side surface of the drive gear, surrounding the central opening in the gear.