Abstract: The annular piston of a rolling piston compressor coacts with a groove in valving action such that the groove serves as a supplemental discharge flow area but gas therein is prevented from constituting part of the suction flow. The groove may be in the motor end bearing and/or pump end bearing and permits flow from the compression chamber to the interior of the piston which is in fluid communication with the interior of the shell while the compression chamber is undergoing discharge.

Abstract: There is disclosed an apparatus for pumping multiphase fluids in oil field production, particularly a twin-screw pump for providing a large pressure boost to high gas-fraction inlet streams. The pump includes a housing having an internal rotor enclosure, the enclosure having an inlet and an outlet and a plurality of rotors operably contained in the enclosure. Each rotor has a shaft and a plurality of outwardly extending threads affixed thereon, the rotors being shaped to provide a non-uniform volumetric delivery rate along the length of each rotor. The pump also has means for rotating the rotors, whereby a fluid stream entering from the inlet is subjected to a pumping action to transport the fluid stream to exit the rotor enclosure through the outlet. In one embodiment, the rotors have a plurality of threaded pumping stages separated by unthreaded non-pumping chambers.

Abstract: A rotary sliding-vane compressor is described which contains a single rotor with compressor and expander sections, together with a reduced number of parts and efficiency improvements compared to conventional compressors.

Abstract: An oil pump apparatus incorporates, an oil pump housing, and a rotor located in the oil pump housing, wherein the rotor forms a first set of pockets having a capacity increasing toward the rotating direction of the rotor and a second set of pockets having a capacity decreasing toward the rotating direction of the rotor. The apparatus further includes a plurality of suction ports connected with the first set of pockets, each of the suction ports being isolated from other adjacent suction ports, a discharge port connected with the second set of the pockets, and a control valve.

Abstract: It is sought to provide an oil-free scroll vacuum pump, which can discharge condensed fluid in it to the outside. An oil-free scroll vacuum pump body 1 for withdrawing fluid from a vessel to be evacuated, compressing the fluid and discharging the compressed fluid to the outside, comprises a stationary scroll constituted by a housing half 4 and a wrap 7, another stationary scroll constituted by a housing half 5 and a wrap 6, and a revolving scroll 3. The housing half 4 has a gas ballast gas inlet duct 10 and an inlet port 4a, and the revolving scroll 3 has a communication hole 3e. Gas is introduced through the inlet port 4e into a sealed space defined by wraps of the individual scrolls engaged with one another. The introduced gas is compressed together with compression fluid in the sealed space, and the resultant fluid is discharged through a discharge port 4c to the outside.

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: The invention relates to a vacuum pump (1) with an oil separator (42) connected downstream of its outlet (33) and with a duct (45, 46) through which the oil separated in the oil separator (42) is returned to the vacuum pump (1); to feed back the oil in a simple manner, the oil feed duct (45, 46) opens into a duct (47) that supplies gas ballast to the pump (1).

Abstract: An adjustable one-way rotary liquid pumping device including a housing, a cover fixedly engaged with the housing, a first bearing a first bearing fitted in the housing, a second bearing fitted in the cover, an axle extending through the housing and the cover and supported by the two bearings, a rotor fixedly mounted on the axle and having a plurality of pawls, a collar enclosing the rotor, a seat having two protuberances supporting the collar thereby locating the collar at an eccentric position with respect to the axle, a plurality of rollers each fitted between every two of the pawls of the rotor, a plurality of springs urging respective rollers against an inner wall of the housing and an inclined side of the pawls, and an adjustable valve fitted through the housing, the collar, and the seat, whereby the liquid can be pumped in one direction only and the speed of the axle can be adjusted as required.

Abstract: A scroll-type refrigerant compressor having a movable scroll unit and a stationary scroll unit which has a fixed stationary end plate in which a plurality of bypass ports and a discharge port are formed through which the refrigerant compressed in the pockets formed between the movable and stationary scroll units is discharged via check valves covering the bypass ports and the discharge port and preventing a reverse flow of the discharged refrigerant into the pockets. The compressor further having a suction port fluidly connected to an evaporator of an air-conditioning system, a delivery port fluidly connected to a condenser of the air-conditioning system, and a fluid channel for providing a fluid communication between the suction and delivery ports via a solenoid-operated valve for blocking and unblocking the fluid channel. The compressor can be switched from the ordinary 100% capacity to 0% capacity and vice versa.

Abstract: The invention relates to a gear pump with two delivery gears meshing with one another, said gears cooperating in the rotation direction in front of or behind a plane containing the gear axes with a pressure and/or suction line. According to the invention, excess delivered pumping medium is introduced through a separate line behind the connection of the suction line in the circumferential direction of the gears, into the tooth spaces of the delivery gears in order to prevent any cavitation that might occur.

Abstract: A sea water pump (130) for a marine propulsion system includes a housing (130) having a generally cylindrical pumping chamber (134) defined by a generally cylindrical sidewall (136) extending axially between opposite end walls (138 and 140). A multi-vaned rotary impeller (44) in the chamber is driven by an impeller shaft (28) extending axially into the chamber through one of the endwalls (40). An intake port (146) at the other endwall (140) has a first branch (148) providing radial flow (170, 172) into the chamber, and a second branch (154) providing axial flow (178) into the chamber. A discharge port (158) has a first branch (160) receiving radial flow (174, 176) out of the chamber, and a second branch (166) receiving axial flow (180) out of the chamber.

Abstract: A method of operating a claw-type vacuum pump with two or more stages, each of which has a suction chamber with a pair of claw rotors and end-located suction and discharge ports. To avoid the possibility of liquids affecting operation of the pump, the invention proposes that the pump is operated without internal compression and that the gases emerging from at least one stage are cooled.

Abstract: A vacuum pump of the scroll type having first and second scroll components each having a scroll structure defined thereon. The scroll components are arranged in the pump such that the respective scroll structures inter-engage with the first scroll component being held stationary and the second scroll component orbiting the first scroll component to trap a volume of gas and urge the volume from one end of the respective scroll structures to the other end. The first and second scroll components define inter-engaging scroll structures having an initial multi-start portion including at least two pump inlets and a subsequent single-start portion including a pump outlet.

Abstract: A non-contact vane-type fluid-displacement machine includes a stator housing having an annular interior surface defining an interior bore and a rotor supported in an eccentric position in the interior bore of the stator housing relative to the annular interior surface thereof to undergo rotation relative to the stator housing about a central rotational axis. The rotor has at least one slot radially defined therein relative to the rotational axis. The machine also has at least one vane disposed in radial slot of the rotor. The vane is mounted to the rotor to undergo reciprocable movement in a radial direction relative to the rotational axis of the rotor such that an outer tip portion of the vane is maintained in a non-contacting substantially sealed relationship with the interior surface of the stator housing. Improved features of the machine relate to an arrangement of multiple discharge valves in the stator housing of the machine.

Abstract: A fuel feed assembly with a feed pump of the roller-cell pump type, of which the pump rotor rotates eccentrically in a pumping chamber has a plurality of rollers which are guided in radial grooves of the disk-shaped pump rotor and are distributed uniformly over the circumference. When the pump rotor is rotating, the rollers run, as a result of the centrifugal force, on a bore wall of an intermediate ring radially delimiting the pumping chamber. The bore wall forms a running track. At the same time, the rollers delimit individual sickle-shaped pump rotor and the bore wall and the volume decreases from a suction port towards a delivery port as a result of the eccentricity of the pump rotor. At the same time, there is provided between the delivery port and suction port in the direction of rotation of the pump rotor a narrow-gap region which, according to the invention, is made so large that the pump working spaces passing through this region are closed completely.

Abstract: A scroll machine has a multi-functional device which is attached to either or both of the scroll members that serves the purpose of optimizing or altering the discharge port geometry to a specific compression ratio or for modulation of compression ratios for performance optimization.

Abstract: An eccentric pump with lock valve and with bidirectional rotational operation, mainly for lubricant circulation of drives comprises a stationary outer casing having two parallel side walls and a cylindrical inner surface between the side walls, and further having inlet and outlet openings being sealingly separated and terminating in the cylindrical inner surface, a middle shaft arranged within the casing concentrically to the cylindrical inner surface and having a cylindrical surface being eccentric to the middle shaft as well as to the cylindrical inner surface of the casing, a circular sealing ring being sealingly displaceable in respect of the eccentric surface of the shaft as well as to inner wall portions of the casing, and further having a radial slot sealingly engaging a stationary pin with its both limiting surfaces.

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 scroll compressor for compressing a gaseous refrigerant including a lubricant in a mist state, having a stationary scroll member and a movable scroll member, which define pump chambers at an outer wall side of the movable scroll member and an inner wall side of the movable scroll member, which chambers are initially opened to an inlet port via a main intake passageway for introducing a gaseous refrigerant into the chambers when they are radially outwardly located. A sub-intake passageway, in which a shaft seal unit is provided, is diverted from the main intake passageway and is opened to the outer wall sided chamber before the chamber is sealingly closed so that a flow of gas, from the inlet port, is introduced into the chamber, the gas is positively fed to the shaft seal unit, and the shaft seal unit is lubricated.

Abstract: A sliding-blade water jet propulsion apparatus has an oval-shaped chamber and a water channel extending generally tangential to the chamber with a cylindrical rotor rotatably mounted eccentrically in the chamber. The rotor has at least two rectangular blades slidably mounted in slots extending through the cylindrical rotor in mutually perpendicular relation and each blade is independently movable relative to the other in a radial direction. Each blade has a guide element extending from opposed sides and through the opposed end walls of the rotor which are slidably received in guide grooves in the chamber end walls. The guide elements traveling in the guide grooves cause the blades to extend and retract radially with their outer ends following the inner periphery of the chamber side wall and a portion of the water channel with a constant clearance.

Abstract: A scroll type compressor comprises a fixed scroll having an end plate and a spiral element. The spiral element of the fixed scroll is integrally coupled to the inner wall of a housing. A movable scroll has an end plate and a spiral element, and faces the fixed scroll, with a plurality of fluid pockets formed between the movable scroll and the fixed scroll. When the movable scroll makes an orbital movement around the axis of the rotary shaft, refrigerant gas is led into the fluid pockets from outside the movable scroll. As the fluid pockets move toward the center of the movable scroll the fluid pockets decrease in volume, thereby compressing the refrigerant gas. A suction chamber which receives the refrigerant gas from outside the housing is formed between the movable scroll and the inner wall of the housing. A passage is formed in at least one of the inner wall of the housing, the connecting section and the end plate of the movable scroll.

Abstract: A non-contact rotary vane gas expanding apparatus functions to convert controlled expansion of gas under pressure to rotary motive power.

Abstract: A rotary compressor having a housing with a pump cavity, an orbiting ring piston in the cavity, a cylindrical post carried by the housing within the orbiting ring, at least one pair of vanes engaging the orbiting ring to define pumping chambers in the cavity, a pair of primary fluid inlet passages communicating with the working pressure chamber during expansion of the pressure chamber, a pair of fluid outlet ports communicating with the working chambers as the volume of the working chambers contracts upon rotation of the orbiting ring piston, and a pair of secondary fluid inlet ports in parallel disposition with respect to the primary ports formed in a valve plate adjacent the orbiting ring piston whereby the orbiting ring piston registers with the ports and opens and closes the ports in synchronism with the opening end and closing of the main ports whereby the effective inlet flow capacity for the fluid into the expanding working chamber is increased.

Abstract: The invention concerns a suction-controlled vane-cell pump whose pumped flow does not increase further above a determined speed but remains practically constant. Radially movable vanes (4), arranged in a rotor (2), form working chambers (12). Between the vanes (4) the rotor (2) has control slots (21) which cooperate with several outlets (22 or 22A) of a front plate (5) located in a pressure zone. The control slots (21) and the outlets (22 or 22A) are dimensioned so that a reflux of oil under pressure can be avoided from a higher-pressure working chamber (12) into a lower-pressure working chamber. The outlets (22 and 22A) are closed by a valve (24) with movable tongues (25, 25A). During the opening stroke, the tongues (25, 25A) rest on a supporting body (26). Suction openings (13 and 13A) communicate with a suction chamber (14) through throttle bores (31, 31A) in order to limit the suction current. Wear due to cavitation can be avoided by the invention.

Abstract: A scroll compressor includes a fixed scroll member and an orbiting scroll. The orbiting scroll member is operatively connected to a motor to be driven in an orbiting motion by the motor. The scroll members each include a plate having an inboard surface and an outboard surface. A spiral involute or wrap is formed on the inboard surface of each scroll member plate. The involutes mate to define suction zones at outer ends of the involutes and fluid pockets. The fixed scroll member defines a fluid outlet at the center of the involutes and two inlets positioned proximate the suction zones. At least two idler crank assemblies are provided to maintain the phase relationship and running clearance between the scroll members. The idler crank assemblies each include two operatively connected cranks, one being in the fixed scroll and one being in the orbiting scroll. The fixed scroll crank is externally accessible so that its rotational motion may be harnessed to drive a fan or another compressor stage, for example.

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: A sliding vane pump having an inside liner with a constant radius pump arc and a constant radius stop arc, connected together by cycloidal arcs. The liner has inlet slots arranged extending around a perimeter of a liner extending into the pump arc for maximum filling of the pumping volume. A herringbone-shaped slot arrangement is provided on a outlet side which increases vane life, increases sealing around the vanes on the outlet side, and decreases liner wear. A relief/fill porting arrangement is provided to pressurize the fluid in the pump chamber, or alternately to relieve pressure from the pump chamber. An improved thrust absorber is described particularly useful for truck mounting of the pump. An asymmetrical inside profile for the liner assists in pump operation by providing a fluid mathematical profile which approaches zero acceleration forces at the point of tangency.

Abstract: A rotary air motor has a liner disposed within a tool housing and having a cylindrical bore therethrough. A rotor having radially slidable vanes is eccentrically rotatably mounted in the bore by bearings in the plates of the liner, the vanes cooperating with the rotor and the liner to define a plurality of rotating variable volume fluid compartments. A fluid inlet port in one end plate communicates sequentially with the fluid compartments. First and second exhaust ports respectively formed in the end plates also communicate sequentially with the fluid compartments, but the two exhaust ports are angularly offset from each other so that the fluid compartments communicate first with the exhaust port remote from the entry end plate and then with the exhaust port at the entry end plate. The exhaust passage from the remote exhaust port passes along the outside of the liner back to the entry end plate, thereby ensuring cooling of both ends of the motor.

Abstract: A vane compressor capable of obtaining a two stage compression. The compressor has a front and rear rotor 6a and 6b for defining, together with a cylinder bores 43 and 44, first and second operating chambers 39 and 40, respectively. A refrigerant from a first inlet opening 28 is sucked into the first operating chamber 39 by a rotation of the front rotor 6a for obtaining a first stage compression at the first chamber 39. The refrigerant is then introduced, via an intermediate pressure chamber 36, to the second operating chamber 40 for obtaining a second stage compression at the second chamber 40, which is discharged outwardly.

Abstract: An aggregate for feeding fuel from a supply tank to an internal combustion engine of a motor vehicle has a feeding pump having two end walls forming a pump chamber with a suction opening and a pressure opening and a feed element rotatable in the pump chamber so as to supply fuel from the suction opening to the pressure opening. At least one of the end walls is provided with a groove-shaped unloading passage in a region between an end surface of the feeding element and a sealing surface of the one end wall and communicating through a further opening the pump chamber with a low pressure region. The suction opening has an end facing in a rotary direction of the feeding element. The unloading passage is located near the end of the suction opening.

Abstract: The invention relates to a system for supplying inert gas to a multi-stage, dry-running vacuum pump (1) with systems for distributing the inert gas to the pump stages. To be able to monitor the flow of the inert gas and/or influence the rate of flow, a modularly constructed apparatus (36) with inert gas inlet, inert gas outlets and inert gas conduits is proposed, which is equipped with monitoring components.

Abstract: An aggregate for feeding fuel from a supply tank to the internal combustion engine of a motor vehicle, has a pump chamber with a suction opening for receiving fuel and a pressure opening for supplying a fuel and a feeding element rotating in the pump chamber and feeding fuel from the suction opening to the pressure opening. At least one of the chamber end walls in a region of a sealing surface formed between an end surface of the feeding element and one of the chamber walls has an opening which leads to an unloading space, and the opening as considered in a rotary direction of the feeding element is located near one edge which limits the suction opening, and has a radial extension which is at least equal to a radial extension of the suction opening.

Abstract: In a suction port for a vane-type compressor in which suction holes 15a and 15 a along the inner peripheral edge 1a of the cylinder 1 are disposed in the read side block 4 and notch portions 15b and 15b opposing to the suction holes 15a are disposed at the opening edge on he suction side of cylinder 1, the suction holes 15a and 15a are arranged outside the vane sliding zone of the rotor-side end face 4a of the rear side block 4. If a vane juts out of a vane groove, the tip of vane does not enter the suction holes 15a and 15a even if the tip of a vane is inclined, so that the vane does not heavily rub the end portion of the suction hole on the rotor-side end face 4a.

Abstract: Improvements in screw pumps, and especially positive displacement pumps, are disclosed. The clearance between the screw flight and the bore is increased over an increased period. The screw is balanced at preferred locations on the flight. Wear hard material such as tungsten carbide is emplaced on a portion of the outer surface of the screw flight. A wear measurement port extends from the outside surface of the pump to the inner surface of the bore. Pressure regulating ports and controls provide an active pressure feedback control system to control the feeding of pressure from the outlet end of the screw back toward the inlet end of the screw. Pump wear, and pressure pulsations in the operation of the pump are thus reduced. The wear measurement port enables a method of monitoring wear on the pump screw during operation without disassembling the pump, namely by manipulating a wear measurement device through the port. The wear measurement device can be a proximity sensor which can be connected to a monitor.

Abstract: A discharge valve is incorporated into a scroll compressor for use in a refrigerator or an air conditioner. A valve element seating surface having a concave cylindrical shape is formed in the upper surface of the stationary disk of the stationary scroll plate of the scroll compressor, a discharge port is formed through the stationary disk of the stationary scroll plate so as to open in the valve element seating surface, and a discharge valve element having a cylindrical shape conforming to the concave cylindrical shape of the valve element seating surface is seated on the valve element seating surface so as to open or close the discharge port. The valve element seating surface having a concave cylindrical shape facilitates machining the stationary scroll plate, reduces the top clearance of the scroll compressor without reducing the rigidity of the stationary disk, prevents the concentration of stress on the delivery valve, and improves the reliability of the delivery valve.

Abstract: A scroll-type compressor is disclosed having a discharge diffuser for improving the efficiency of the compressor, especially at off-design, high pressure ratio operating conditions. The diffuser allows fluid pressure recovery and consequently results in an efficient discharge process using a relatively small discharge port. It also reduces compression losses by reducing gas transport in the reverse flow direction.

Abstract: A synchronous rotating type scroll fluid machine has a first scroll member driven by a shaft of a first motor and having an end plate and a scroll wrap protruding from a surface of the scroll end plate, and a second scroll member driven by a shaft of a second motor and having a scroll end plate and a scroll wrap protruding from a surface of the scroll end plate. The machine further has a mounting structure for mounting the scroll members such that the axes of the scroll members are offset from each other and that said scroll wraps of the scroll members mesh with each other. Thrust balancing arrangements are provided for attaining a balance between the thrusting forces acting on each said scroll member, both at the mounting structure and said scroll members. The thrust balancing arrangement includes through-bores formed in the respective motor shafts and serving as passage bores for discharging a compressed gas.

Abstract: A pump comprises an outer rotor and an inner rotor. A plurality of pressure chambers are defined between the outer rotor and the inner rotor to cause fluid to be sucked from a suction port and discharged to a discharge port by the movement of these pressure chambers with changing their volumes. A pressure relief passage is opened between the discharge port and the suction port and communicated directly with a fuel tank provided outside the pump. This causes the pressure in the pressure chamber to be reduced before the pressure chamber is communicated with the suction port. In consequence, it is possible to prevent the fuel of discharge pressure in the pressure chamber from being brought in the suction port, thereby preventing the generation of vapor caused due to vacuum boiling and the reduction of discharge rate.

Abstract: A rotary engine that comprises a rotor having two side faces, a side housing disposed facing to one of the two side faces of the rotor and a center housing disposed facing to the other of the two side faces of the rotor. The side housing has an intake port formed therein. Also, the center housing has an intake port formed therein. The intake port of the center housing has an opening end which is dislocated from an opening end of the intake port formed in the side housing facing thereto to a retard side. A space is formed between the side face of the rotor and the center housing. And a relief hole is provided in the center housing in a dislocated portion of the opening end of the intake port of the center housing so as to escape a blow-bye gas pressure from the space.

Abstract: Apparatus for performing a plurality of functions including fluid pump, fluid motor, fluid transmission, air compressor and steam engine employ a circular rotor chamber with a rotor operable therein. The rotor is connected to a drive shaft, both of which are offset from the center of the chamber. The rotor employs at least one pair of opposed vanes which are slidable in relation to the center of the rotor and move with the rotor in contact with the circumferential chamber wall. Valves, vanes and related elements are arranged to effect the intended function.

Abstract: A rotary engine that comprises a rotor having two side faces, a side housing disposed facing to one of the two side faces of the rotor and a center housing disposed facing to the other of the two side faces of the rotor. The side housing has an intake port formed therein. Also, the center housing has an intake port formed therein. The intake port of the center housing has an opening end which is dislocated from an opening end of the intake port formed in the side housing facing thereto to a retard side. A space is formed between the side face of the rotor and the center housing. And a relief hole is provided in the center housing in a dislocated portion of the opening end of the intake port of the center housing so as to escape a blow-bye gas pressure from the space.

Abstract: A pump assembly includes commonly driven coaxially positioned helical rotors, rotatably engageable within corresponding stators. Each combination of rotor and stator defines a pump having a different volumetric flow rate, each pump discharging to a common discharge port, thereby providing an accurately proportioned mixed fluid of two separate fluids. The rotors are integrally molded from a thermoplastic material and include an integral drive shaft suitable for interconnection to an electric motor. The two rotors are simultaneously driven by a common drive shaft and therefore produce a constant mixed ratio irrespective of rotational speed.

Abstract: A vane pump for conveying pasty masses, in particular sausage meat, comprising a pump housing and a rotor, which is eccentrically arranged within the pump housing and which is caused to rotate. Radially continuous vanes are supported on the rotor in a radially displaceable manner that define angular conveying cells with the wall of the pump housing and cooperate with the wall to produce a sealing effect. An adjustable pressure piece is mounted in a radial recess in the wall of the pump housing, the pressure piece replacing the contour of the wall of the pump housing with its surface which faces the vanes. Adjustment of the pressure piece adjusts the pressure applied to the vanes in a radial direction in the pressure area of the pump prior to its outlet.

Abstract: A scroll-type fluid machine has a pair of interfitting scrolls. Each scroll has a discharge port at its center which communicates with a discharge chamber via a discharge passage formed in the scroll. A check valve is disposed in each discharge port.

Abstract: An oil pump assembly having an adjustable gear hub assembly enclosed within a housing, which assembly includes a spur gear for driving two independent gear pumps, a gear hub and an adjusting sleeve for adjusting the position of and securing the spur gear, elastically deformable oil seal rings fitting on either side of the gear hub for ensuring a tight fit of the components within the assembly and washers fitting outwardly of the oil seal rings each equipped with a "dog" for engaging the revolving spur gear. The oil pump assembly may also be provided with coverplates, one or both of which contain improved bypass channels that serve to meter the oil in the assembly so as to prevent oil leakage, while also maintaining a supply of oil in the pump assembly so as to prevent friction build up upon starting of the sewing machine.

Abstract: A suction controlled gear ring pump effects a continuous decrease of the vacuum occurring in the feed cells of the pump at higher rotational speeds due to the long movement path of the feed cells from the end of the suction region to the beginning of the discharge opening and the thereby occurring diminution of the feed cells. In order to prevent squeeze oil when working at a lower rotating speed, the feed cells positioned successively in the feed direction are connected between the teeth respectively with the neighboring feed cells by overflow channels extending through the gear teeth, check valves in said overflow channels preventing a flow against the feed direction.

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: A heat transfer system employing a two-stage compressor and a heat recovery system including a flash vapor receiver which pools warm refrigerant from a system condenser, delivering receiver refrigerant vapor to the compressor at its second stage inlet and delivering receiver liquid refrigerant to a system evaporator. The system also employs evaporation, compression and condensation of an oilless refrigerant, or an azeotrope mixture of oilless refrigerants, to reduce compression and resulting power requirements. The system evaporator or evaporators are flooded with refrigerant, with vaporous refrigerant separated and routed to the compressor and liquid refrigerant separated and returned to the evaporators.

Abstract: A gas removable pump for liquid comprising a housing having an inlet for introducing the liquid thereinto and an outlet for feeding the liquid therefrom, a drive shaft extending into the housing and having formed therein an axial bore, a rotary pump disposed within the housing, and a discharging chamber defined within the housing and separated from the rotary pump in a liquid-tight manner. The rotary pump includes a rotor secured to the drive shaft for co-rotation therewith and a plurality of cells for feeding the liquid, each cell constituting a separator for gas-rich liquid upon rotation of the rotor. A stationary shaft extends in the axial bore between the rotary pump and the discharging chamber. A connecting arrangement is provided in the drive shaft and stationary shaft for selectively connecting each cell with the discharging chamber. Also provided is an injector for ejecting into the discharging chamber the gas-rich liquid separated in the cells through the connecting arrangement.

Abstract: In the screw compressing apparatus, by rotating paired male and female rotors as meshing with each other, a gas is suctioned from a suction chamber into a working space, and compressed in the working space. The compressed high pressure gas is exhausted from a exhaust chamber, and then cooled by an aftercooler, thereby producing a low temperature, high pressure gas. In the compression process, the temperature of the gas in the working space becomes high at the exhaust chamber side. When this exhaust gas temperature reaches a predetermined value, a part of the gas cooled by an aftercooler is injected into the working space for lowering the temperture in the working space.