Abstract: A pump comprises a driving rotor and a driven rotor that are positioned in a housing such that, as the driving rotor and the driven rotor rotate, the teeth of the driving rotor and the teeth of the driven rotor mesh to form a positive displacement seal. The teeth of the driving rotor and the driven rotor are configured such that seals between the inlet side and the discharge side of the pump are formed between only the leading surfaces of the teeth of the driving rotor and the trailing surfaces of the teeth of the driven rotor.

Abstract: An object of this invention is to prevent drop of life of a bearing by an axial force when using a pump as a compressor. In a vacuum pump 1 compressing and discharging gas in a direction of a rotor axis by rotation of screw rotors 3, 4 engaged together which are supported rotatably in a casing 2, balance pistons 13, 14 are disposed on shafts 6, 7 of said screw rotors at inlet side of said casing. The balance pistons separate a receiving section 17 at area of the screw rotor and a pressurizing section 16 at area of the balance piston, and a thrust force of the screw rotors at a pressurizing condition is canceled by acting the discharge pressure in the pressurizing section. The pump is used as a compressor when the discharge pressure is acted on the balance pistons 13, 14. When the pump is used as a vacuum pump, air at discharge side is sucked as cool air through a cooler toward a place near to the discharge side of the receiving section 17 at area of the screw rotor.

Abstract: External gear pump, comprising: a casing (3a, 3b) with a gear chamber (4), comprising an inlet (5) for a fluid on a low pressure side and an outlet (6) on a high pressure side and comprising axial and radial sealing stays (7, 8); toothed wheels (1, 2) being in toothed mesh, wherein the external toothings of the wheels (1, 2) form delivery cells (10) for the fluid which are axially sealed off by the axial sealing stays (7) and radially sealed off by the radial sealing stays (8); and at least one pressure fluid supply (15, 16) through which pressure fluid may be supplied to the low pressure side, wherein the at least one pressure fluid supply (15, 16) opens on the low pressure side into a delivery cell (10) which is radially opposed by one of the radial sealing stays (8).

Abstract: A variable capacity rotary compressor includes a housing defining a cylindrical compression chamber therein and having an inlet port and an outlet port communicating with the compression chamber. A rotating shaft is provided with an eccentric part to rotate in the compression chamber. A ring piston is rotatably fitted over the eccentric part such that an outer surface of the ring piston is in contact with an inner surface of the compression chamber. A vane is installed in the housing so as to be in contact with the outer surface of the ring piston and radially reciprocates, and partitions the compression chamber into an intake part and a discharging part. A re-expansion space communicates with the compression chamber, and receives refrigerant therein. A control unit opens or closes an inlet of the re-expansion space to vary a capacity of the rotary compressor.

Abstract: The present invention is directed to an apparatus for determining vane wear in rotary sliding vane pumps that operate using slideable vanes, while the pump is in operation. The invention includes a structure that allows a predetermined amount of leakage from a pumping chamber after a predetermined amount of vane length is worn away. The leakage produces a decrease in pump efficiency that is indicated by an indicating device. The indicating device serves to warn that an amount of vane wear has occurred that indicates pump inspection is warranted. The invention also includes a view port formed in the pump housing to allow inspection of the vanes without having to disassemble the pump.

Abstract: The invention relates to a pump with a pump chamber with a rotary-driven pump element mounted, at least one suction and at least one pressure connection opening into the pump chamber and with circulating pumping cells whose volume can be changed, which are connected with the suction or pressure connection depending on the rotary position of the pump element. A hydraulic intermediate capacity is provided that can be stressed with the pumping medium pressure present at the pressure connection by way of its first connection and that, by way of its second connection, can be stressed with the pumping medium pressure present at the pressure connection depending on the rotary position of the pump element or it can be connected with a pumping cell that has no direct connection to the pressure connection.

Abstract: Scroll compressors (100, 110) may include a movable scroll (20) that is disposed opposite to a fixed scroll (2). At least one compression chamber (32) is defined between the fixed scroll and the movable scroll. A motor (49) drives the movable scroll, so that the movable scroll revolves (orbits) relative to the fixed scroll. The movable scroll includes a front portion (20b) that slidably contacts the fixed scroll. The front portion receives the pressure of the pressurized refrigerant that is disposed within the compression chamber. The movable scroll also includes a rear portion (20a) that slidably contacts a portion (4a) of a compressor housing. The motor is disposed within a motor chamber (45) defined within the compressor housing. A first conduct route (94) communicates discharged refrigerant from a discharge-side region (85) to the motor chamber.

Abstract: At a boundary area between a high-pressure portion in which a discharge port of a fuel pump is disposed and a low-pressure portion in which an intake port is disposed, a pressure relief groove extending along the boundary area is formed so as to be communicated with the outside of the pump by pressure relief hole. Alternatively, a slit is formed communicated with the outside. Accordingly, a fuel at a high-pressure area portion can be drained with reliability. Further, by communicating the above pressure relief groove with a positioning pin insertion port, a single hole can serve both as a positioning pin insertion hole and a pressure relief hole.

Abstract: An axial slide valve is provided with an axially extending fluid chamber at each end with one chamber receiving a spring and being acted on by suction pressure and the other chamber coacting with a fixed piston and being acted upon by discharge pressure or the like whereby the slide valve is positioned so as to balance the spring and fluid pressures and thereby the compressor capacity.

Abstract: The invention relates to a pump with a pump chamber with a rotary-driven pump element mounted, at least one suction and at least one pressure connection opening into the pump chamber and with circulating pumping cells whose volume can be changed, which are connected with the suction or pressure connection depending on the rotary position of the pump element. A hydraulic intermediate capacity is provided that can be stressed with the pumping medium pressure present at the pressure connection by way of its first connection and that, by way of its second connection, can be stressed with the pumping medium pressure present at the pressure connection depending on the rotary position of the pump element or it can be connected with a pumping cell that has no direct connection to the pressure connection.

Abstract: An improved method and apparatus for reducing pressure pulsation when pumping fluids having highly entrained gas therein. The pump has a drive screw and a pair of idler screws. The screws are placed in a screw channel between a suction end and a discharge end. At least one of the clearances between the surfaces of the drive screw, side screw and screw channel is larger in area, from the discharge end to the suction end, than the remaining clearances. The area of the clearance is configured so that sufficient slip flow occurs between the discharge and suction ends to compress the entrained gas in a uniform and controlled fashion so that linear compression occurs throughout the flow path in the pump. Preferably, the clearance is achieved by reducing the outer diameter of the drive screw.

Abstract: The invention relates to the design of backflow orifices for a rotary compressor serving as a compressor for an engine. One example of such a rotary compressor is a roots blower. The fluid conveyed by two oppositely rotating rotors from an inlet to an outlet of the compressor flows back partially via the backflow orifices. The edges of the backflow orifices are at a varying height from an inner surface contour of the pump casing. The height variation contributes to a reduction in the noise generated by the compressor.

Abstract: At a boundary area between a high-pressure portion in which a discharge port of a fuel pump is disposed and a low-pressure portion in which an intake port is disposed, a pressure relief groove extending along the boundary area is formed so as to be communicated with the outside of the pump by means of pressure relief hole. Alternatively, a slit is formed communicated with the outside. Accordingly, a fuel at a high-pressure area portion can be drained with reliability. Further, by communicating the above pressure relief groove with a positioning pin insertion port, a single hole can serve both as a positioning pin insertion hole and a pressure relief hole.

Abstract: A geared pump, having a housing (18), two gear wheels (14, 16) that are disposed in the housing and mesh with one another, and at least one groove (22) that is embodied in the housing on the pressure side of the geared pump, cavitation damage at high rpm is to be avoided. To that end, it is provided that the groove has a first portion (24), which extends from the pressure side, and in which the bottom of the groove (22) has a slight spacing from the tips of the teeth (20) of the gear wheel, and a second portion (26), which adjoins the first portion and in which the bottom of the groove (22) has a maximum spacing from the tooth tips that is greater than the spacing in the first portion, and the first portion extends over a smaller angular range (&agr;) than the second portion, and the groove extends over a total angular range (&agr;, &bgr;) that is somewhat greater than angular spacing between two teeth (20).

Abstract: A geared pump, having a housing (18), two gear wheels (14, 16) that are disposed in the housing and mesh with one another, and at least one groove (22) that is embodied in the housing on the pressure side of the geared pump, cavitation damage at high rpm is to be avoided. To that end, it is provided that the groove has a first portion (24), which extends from the pressure side, and in which the bottom of the groove (22) has a slight spacing from the tips of the teeth (20) of the gear wheel, and a second portion (26), which adjoins the first portion and in which the bottom of the groove (22) has a maximum spacing from the tooth tips that is greater than the spacing in the first portion, and the first portion extends over a smaller angular range (&agr;) than the second portion, and the groove extends over a total angular range (&agr;, &bgr;) that is somewhat greater than angular spacing between two teeth (20).

Abstract: A positive displacement rotary pump including a housing having an internal chamber and inlet and discharge ports, a sealing land on the housing between a downstream end of the inlet port and an upstream end of the discharge port, and a rotating group in the internal chamber defining a plurality of pump chambers. The pump chambers traverse in succession and at regular intervals the inlet port and the sealing land and the discharge port. The housing has a stationary pre-charging passage which communicates with the discharge port and overlaps the sealing land. The rotating group includes a plurality of rotating pre-charging passages which communicate with respective ones of the pump chambers.

Abstract: A rotary compressor of the low operational noise type is disclosed. This compressor consists of a casing, a rotating shaft set within the casing, a roller eccentrically fixed to the rotating shaft and eccentrically, rotatably set within a cylinder so as to form a variable suction chamber and a variable compression chamber within the cylinder. The compressor also has a bypass passage, which is formed on the internal surface of the cylinder at a position around the refrigerant exhaust stroke initiating point, thus allowing the compression and exhaust chambers to communicate with each other through the bypass passage and allowing highly compressed refrigerant to be fed from the compression chamber back into the suction chamber at the initial stage of each exhaust stroke.

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: The required larger than normal pressure drop between the infeed and pump inlets of a positive displacement gear or lobe type pump pumping a high viscosity fluid such as pastry dough is obtained by the introduction of a vacuum inside the pump at or near the rotary nip points of the gear or lobe type pump to provide a means for the removal of any gas present in the vicinity of the nip point.

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: In a Roots displacement fluid machine (5) comprising rotors (15, 17) meshed with each other in a tooth trace (57, 59) formed in parallel to a rotating central axis, and a casing (13) having a rotor chamber (33) rotatably receiving the rotors (15, 17), a fluid inlet port for a fluid and a fluid outlet port, an inclined surface (67) forming an angle .theta. with respect to an opposing surface (65) of the rotor chamber (33) is disposed at least in a tip end of the end portion of the rotor (15), and a gap (69) is formed with respect to the opposing surface (65).

Abstract: A gas blower and method according to which the gas is introduced into the inlet of a housing where it is pressurized by rotating impellers. The pressurized gas is directed to a discharge plenum from which a first portion of the gas is discharged. The remaining portion of the gas is passed from the discharge plenum through a plurality of openings to a recirculating chamber for recirculating the gas back to the housing. The gas is passed from the recirculating chamber back to the housing through two radially-spaced sets of angularly-spaced openings formed in the housing.

Abstract: A vane type rotary pump including a stator housing, a cam ring formed at its inner periphery with a cam surface and mounted within the stator housing, a pair of end wall structures fitted to the opposite ends of the cam ring to form a pump cavity in the cam ring, a drive shaft rotatably mounted within the stator housing and extending into the interior of the pump cavity through one of the end wall structures, a rotor contained within the cam ring and mounted on the drive shaft for rotation therewith, and a plurality of circumferentially equally spaced vanes slidably fitted into the body of the rotor to move radially outward from the rotor and cooperating with the cam surface of the cam ring to form a plurality of expandable pump chambers, wherein one of the end wall structures is formed at its inside face with a suction port at a portion where the pump chambers expand as the vanes move radially outward and is formed at its inside face with a discharge port at a portion where the pump chambers contract as the

Abstract: A bearing for a gear pump including a bearing dam which has a surface, an inlet face relief located on the bearing dam, and a discharge face relief located on the bearing dam. A bearing dam wall is located between the inlet face relief and the discharge face relief and a bleed hole arrangement. The bleed hole arrangement includes a blind passage located on the discharge face relief, and a second passage positioned perpendicular to and connected to the blind passage. The second passage extends to the surface of the bearing dam. In an alternative embodiment, the second passage is of a stepped configuration. The bleed hole arrangement reduces cavitation on the bearing and gear surfaces by pulsing fuel into an inter-tooth volume formed between the gear teeth during gear rotation.

Abstract: A method and apparatus is provided for producing a gear pump/motor in a low cost and efficient manner that can effectively operate in air entrained oil without emitting undesirable noises. This is accomplished by providing bleed slots in a housing adjacent an outlet passage at a location that allows first and second intersecting cavities to be machined with the same boring tool. The bleed slots have a length defined by the distance between two adjacent teeth of first and second intermeshing gears and a cross-sectional area at the mid-point of the arcuate length that is defined by multiplying the flow of the pump at a given RPM time a derived constant. The machining of the body of the gear pump/motor is accomplished in a low cost and efficient manner to produce a gear pump/motor that operates in air entrained oil without emitting undesirable noises.

Abstract: A suction pump (22) suitable for use in a fuel dispensing system (20) or other fluid delivery system for volatile liquids. The suction pump includes a pump casing that defines a pump chamber (52) with inlet and outlet ports. A rotor (54) with vanes (58) is seated in the pump chamber. The vanes define fluid cavities (96a, 96b, 96c, . . . 96f) that rotate between the inlet and outlet ports. During each turn of the rotor, each fluid cavity passes through a section of the pump chamber in which it is isolated from both the inlet port and outlet port. A bleed duct (102) extends from the outlet port. A bleed port (104) extends from the bleed duct to the section of the pump chamber that defines the isolated position of the fluid cavities. During operation of the pump, pressurized fluid discharged from the outlet port flows through the bleed duct and bleed port into the isolated fluid cavity.

Abstract: The present invention refers to a vane pump used for dividing a pasty and compressible substance into portions and comprising a pump housing and a rotor which is arranged eccentrically in said pump housing and which is adapted to be rotated, and further comprising vanes which are supported within said rotor such that they are radially displaceable, said vanes defining with the wall of the pump housing, the base and the cover of said housing, as well as the outer surface of the rotor, vane cells and cooperating sealingly with said components, and said pump housing having an inlet and an outlet which have arranged between them a compression sector and a dosing sector, and a pressure-relief valve being arranged at least in the area of the dosing sector.

Abstract: A variable displacement vane pump having a vaned rotor adjustably contained within a cam member for rotation between fuel inlet and fuel discharge arcs. Adjacent vanes form enclosed fuel bucket areas which are expanded and axially-supplied with fuel in the fuel inlet arc and are contracted and axially-discharge the fuel in the fuel discharge arc. Fuel circulation is improved by providing a central recess at each vane tip and/or a central groove in the cam surface to prevent trapping, stagnation and overheating of fuel at the centerpoints of the bucket areas, which overheating can result in expansion of the vane tips, scoring of the cam surface and pump failure.

Abstract: A rotary positive displacement blower for producing a flow of fluid. The blower includes a housing having a rotor chamber, an inlet port and an outlet port. The outlet port has a first end and a second end and a first edge and a second edge which extend from the first end towards the second end while becoming increasingly spaced apart from one another. A first rotor and a second rotor are located in the rotor chamber. Each rotor includes a plurality of lobes and are each rotatable about a respective axis. Each rotor includes a plurality of pockets adapted to rotate into fluid communication with the inlet port to receive fluid and to rotate into fluid communication with the outlet port to deliver fluid as the rotors rotate.

Abstract: A scroll machine has an intermediate pressure cavity which is operable to open and close a leakage path between the discharge zone and the suction zone of the scroll machine. The leakage path is closed when intermediate pressurized fluid is supplied to the cavity and the leakage path is open when the cavity is open to the suction zone of the compressor. A valve which can be mechanical or electrical is used to open and close a passageway extending between the cavity and the suction zone of the machine. Biasing means is located within the scroll machine in order to control the rate at which the intermediate pressurized fluid is bled to the suction zone of the compressor.

Abstract: A scroll machine has an intermediate pressure cavity which is operable to open and close a leakage path between the discharge zone and the suction zone of the scroll machine. The leakage path is closed when intermediate pressurized fluid is supplied to the cavity and the leakage path is open when the cavity is open to the suction zone of the compressor. A valve which can be mechanical or electrical is used to open and close a passageway extending between the cavity and the suction zone of the machine.

Abstract: A rotary pump for volatile hydrocarbon fuels for use in a fuel system of an internal combustion engine of an automotive vehicle. A pulsation chamber allows purging of fuel vapor from the pump and dampens expansion and contraction of the fuel and vapor due to pressure pulses created during the pumping cycle thereby greatly reducing audible noise of the operating pump. The pulsation chamber has an axial passage with an outlet for returning fuel and vapor from the pulsation chamber to the fuel supply.

Abstract: A pump having a housing with an integral fluid reservoir and flexible end plates to permit the pump to be run dry for an extended period of time. A pair of reservoirs are provided, one each side of a pumping chamber. These reservoirs are in fluid communication with the pumping chamber via openings provided through the end plates of the pumping chamber and slots in the impeller hub. When the pump is run dry, fluid stored in these reservoirs is permitted to be released into the pumping chamber to provide a lubrication between the impeller and the chamber walls, thus reducing friction. The chamber end plates are thin and flexible. These end plates can bow outwardly due to the impeller expanding from increased heat when the pump is run dry, and thus reduce friction with the impeller. Accordingly, the pump can be run dry for an extended period of time without damaging or destroying the pump impeller.

Abstract: A positive displacement, recirculating Roots-type rotary gas compressor which operates on the basis of flow work compression is disclosed. The compressor includes a pair of large diameter recirculation conduits (30 and 32) which return compressed discharge gas to the compressor housing (16), where it is mixed with low pressure inlet gas, thereby minimizing adiabatic heating of the gas. The compressor includes a pair of involutely lobed impellers (12 and 14) and an associated port configuration which together result in uninterrupted flow of recirculation gas. The large diameter recirculation conduits equalize and accelerate gas flow velocities within the compressor and minimize gas flow losses. The compressor is particularly suited to applications requiring sustained operation at higher gas compression ratios than have previously been feasible with rotary pumps, for example continuous pumping of natural gas in gas transmission facilities.

Abstract: This invention relates to a porting system for a hydraulic device comprising a housing having a chamber communicating with an intake port and an exhaust port; a pair of rotary gears disposed internally of said chamber adjacent said ports and defining expanding and contracting pockets as said gears rotate over said intake and exhaust ports; said ports having a cross-sectional area in the direction perpendicular to the rotation which varies in relation to the rate of change of the expanding and contracting pockets.

Abstract: A positive displacement, recirculating Roots-type rotary gas compressor which operates on the basis of flow work compression. The compressor includes a pair of large diameter recirculation conduits (24 and 26) which return compressed discharge gas to the compressor housing (14), where it is mixed with low pressure inlet gas, thereby minimizing adiabatic heating of the gas. The compressor includes a pair of involutely lobed impellers (10 and 12) and an associated port configuration which together result in uninterrupted flow of recirculation gas. The large diameter recirculation conduits equalize gas flow velocities within the compressor and minimize gas flow losses. The compressor is particularly suited to applications requiring sustained operation at higher gas compression ratios than have previously been feasible with rotary pumps, and is particularly applicable to refrigeration or other applications requiring condensation of a vapor.

Abstract: In a vane pump, a pump housing assembly contains a cam ring having an internal cam surface. A rotor carrying plural vanes is disposed within the cam ring and rotated by a drive shaft. Both end surfaces of the cam ring contact with a pair of flat contact surfaces formed within the pump housing assembly, respectively, and the vanes define plural pump sectors between the rotor and the cam ring, together with the rotor, the cam ring and the pair of contact surfaces. The contact surfaces are formed with a pair of intake ports and a pair of exhaust ports. Furthermore, one of the contact surfaces is provided with a pair of pressure leaking grooves formed at locations between the intake ports and the exhaust ports.

Abstract: In a drive coupling unit suitable for use in an four-wheel drive unit for motor vehicles of the type wherein a torque is transmitted via a fluid pressure produced depending on a difference in rotational speed between two rotating shafts, each working fluid supply passage and a corresponding check valve disposed therein are arranged to interconnect one of two intake/discharge ports in each respective pump chamber with a tank in which a working fluid is retained. With this construction, an improved response characteristic of the check valves and a substantial reduction of the overall size of the drive coupling unit can be attained.

Abstract: A high ratio positive displacement recirculating rotary compressor is disclosed. The compressor includes an integral heat exchanger and recirculation conduits for returning cooled, high pressure discharge gas to the compressor housing to reducing heating of the compressor and enable higher pressure ratios to be sustained. The compressor features a recirculation system which results in continuous and uninterrupted flow of recirculation gas to the compressor with no direct leakage to either the discharge port or the intake port of the compressor, resulting in a capability of higher sustained pressure ratios without overheating of the compressor.

Abstract: A screw supercharger is provided having a set of male and female screw rotors rotatably supported in a casing and driven through a wrapping transmission including belts and pulleys by a prime mover, wherein a through hole is formed in the wall of the causing at a position through which the input shaft of the screw rotor or the extension of the axis of the input shaft of the screw rotor extends, in that a cylindrical bearing supporting part is formed around the through hole so as to project outside from the casing, and in that a driven pulley is supported through bearings on the bearing supporting part and is fixedly mounted on the input shaft.

Abstract: An external axial rotary piston blower for quarter-roller type of construction with transfer ports leading to the outlet in the casing runway surfacing or inner peripheral surface of the housing with length differing relative to each other and increasing cross section differing toward the outlet, the greatest length of which can be permitted to be dimensioned or measured only such that the transfer ports are first opened when the inlet is closed-off by the piston traversing the same.

Abstract: A screw pump including a screw assembly in a sleeve, the assembly comprising a drive screw having protruding threaded sides, and multiple driven screws having concave threaded sides which are closely meshed with the drive screw, thus forming a series of sealed chamber. The screw pump further includes one or more channels which are formed in the circumferential direction around the periphery of the driven screws, so that the final sealed chamber adjacent a discharge port of the pump partially communicates with the port through the channels shortly before the chamber completely opens to the port.

Abstract: A trochoidal oil pump including a housing defining an internal space; an outer rotor fitted rotatably in the internal space of the housing and having internal teeth; an inner rotor having outer teeth meshing with the internal teeth of the outer rotor to define a sealed space therebetween; and suction and discharge chambers formed in the housing and opened into the internal space of the same. The discharge member is formed to begin at an angle l formed in the direction of forward rotation from the dedendum to the beginning portion of the discharge chamber extending in the direction of forward rotation and defined by the following relationship:l.sub.1 <l.ltoreq.70.degree.,where l.sub.1, designates an angle taken in the direction of rotation from the dedendum of the inner rotor to the contact position, in which the outer rotor and the inner rotor have their addendums contacting at first, at the maximum volume of the sealed space.

Abstract: The pump includes a stator and a rotor which describe an upper annular chamber having a filling mouth and a delivery mouth and a lower annular chamber in which is housed an annular cam to drive the pump blades housed in a vertically sliding manner in respective radial passages of the rotor. Into the lower chamber essentially in a position diametrically opposed to the filling mouth there opens an exhaust mouth which communicates with the upper chamber through an ample passage and with the zone of the lower chamber underlying the filling mouth through a narrow passage.

Abstract: A scroll fluid apparatus including a fixed scroll member and an orbiting scroll member each having an end plate and a wrap, the two scroll members being maintained in meshing engagement with each other with the respective wraps facing inwardly to allow the orbiting scroll member to move in orbiting movement with respect to the fixed scroll member without rotating on its own axis. The fixed scroll member is formed with a discharge port at its central portion and a suction port at its outer peripheral surface to draw a gas by suction through the suction port and allow same to flow in a sealed space defined between the two scroll members and reducing its space during operation to thereby compress the gas and discharge the compressed gas through the discharge port.

Abstract: A supercharger of an internal combustion engine having a Roots-type pump comprising; a pair of rotors rotatably mounted in a pump housing so as to rotate synchronously in opposite directions to suck air from an air inlet and discharge it through an air outlet. The pump housing defines annular spaces around the rotor shafts and between the axial end faces of the rotors and bearings rotatably supporting the rotor shafts. The annular spaces are connected to the atmosphere via a control valve, so that the atmospheric air is introduced into the annular spaces during certain engine driving conditions to reduce the pressure difference existing around the bearings.

Abstract: A screw pump of the kind including a screw array consisting of a central screw (1) with convex flanks and one or more side screws (2) with concave flanks, the threads being formed such that coacting screws seal against each other with the screw array being sealingly surrounded by a screw housing (3), so that at least one closed chamber is formed by the sides and roots of the threads as well as the screw housing, the chamber migrating axially from the inlet end of the screw array to its outlet end when the screws are turned, and is in communication at least during a portion of its migration with a pressure fluid source (9) via at least one duct (14) made in the pump. To prevent the occurrence of, and to eliminate, existing air and gas bubbles in the liquid chamber without efficiency being unnecessarily deteriorated, the pump is provided with a regulating device (15) coacting with the duct for adjusting the quantity of liquid flowing to the chamber from the pressure fluid source.

Abstract: A screw compressor having a recess formed in the high-pressure end surface of the casing. This recess receives the fluid from a closed working space which has just been isolated from the discharge port and closed in the compression step. Consequently, the abnormal pressure rise in the closed working space, which is caused due to the compression of the fluid confined, is completely eliminated. The recess has a configuration involving a curve conforming with the leading flank of the female rotor at the instant at which the working space is isolated from the discharge port and closed.

Abstract: A pump device comprises a housing having an air intake port and an air discharge port, and with its inner peripheral surface being formed in a cylindrical shape; a rotor mounted in said housing and rotating eccentrically in said housing; a plurality of vanes mounted in said rotor and getting into slide-contact with the inner peripheral surface of said housing with rotation of said rotor so as to send under pressure the gas from said air intake port to said air discharge port; a communicating port defined by said vane, the inner peripheral surface of said housing, and the outer peripheral surface of said rotor, and communicatively connected with said operating chamber; and a gas storing chamber for sending and receiving the gas between it and said operating chamber through said communicating port to reduce a pressure differential in said air discharge port and said operating chamber.

Abstract: A rolling piston type compressor comprises a cylinder; a piston eccentrically rotating along the inner peripheral surface of the cylinder; a vane which is in contact with the outer peripheral surface of the piston, performs reciprocating movement therealong, and defines the cylinder interior into a low pressure chamber and a high pressure chamber; a discharge port to discharge compressed gas outside the cylinder; a discharge valve provided in the discharge port; and an escape groove formed in the inner peripheral wall of the cylinder and extending in the direction opposite to the rotational direction of the piston with respect to the discharge port.