Abstract: The invention is directed to a method for the operation of a twin shaft vacuum pump (1) having two rotors (4, 5; 6, 7; 8, 9) that rotate synchronously and in non-contacting fashion in a pump chamber, each being provided with a respective projection (38) and a recess (39), the one of said rotors controlling an admission opening (32, 35) and the other controlling a discharge opening (33, 37, 42); the invention is also directed to a twin shaft vacuum pump suitable for the implementation of the method; in order to be able to admit flushing gas into a twin shaft vacuum of this species during operation as well, it is proposed that flushing gas be admitted into the respectively diminishing pump volume via an orifice (45) that is controlled such by the rotor at the discharge side that the respective pump volume is closed both toward the admission opening (35) as well as toward the discharge opening (42) at the moment the flushing gas is supplied.

Abstract: A method of scavenging air and oil from a component (3) of an aircraft for returning the oil to a reservoir (4) for recirculation to the component involves the use of a gear pump (1) for scavenging the oil and gas. The gear pump centrifugally separates oil from the air and returns only the separated oil to the reservoir through outlets located upstream of the mesh zone of the gears while the air is discarded whereby lower discharge pressure of the gear pump is attained and there is no longer a need for a separate air-oil separator.

Abstract: A multi-section Roots vacuum pump of the reverse-flow cooling type having a plurality of pump sections each having rotors fixed to two common shafts. The pump includes a housing in each of the pump sections having an inlet and an outlet for a gas to be pumped and enclosing the rotors, a peripheral gas passages arranged around the housing, and a peripheral coolant water passages arraged around the peripheral gas passages. The gas flowing through the inlet into the housing and delivered through the outlet is supplied to the peripheral gas passages to be cooled there, and at least a portion of the cooled gas is returned into the housing. The remaining portions of the gas which are not returned into the housing in the pump sections except for the last pump section are supplied to the inlet of the next pump section through the peripheral gas passage.

Abstract: A multistage Roots-type vacuum pump comprising: a rotor defining a plurality of successive compression chambers (5) which are axially separated from one another by intermediate plates (1); a rotor assembly disposed inside the stator and constituted by two parallel shafts (8, 9) supported by bearings (11, 12) in end plates (2, 3) of the stator, each shaft (8, 9) being fitted inside each chamber (5) with a compression lobe (13, 14) such that each chamber thus contains two conjugate compression lobes; a motor (15) for driving one (8) of the two shafts in rotation, with the other shaft being driven in the opposite direction by gearing (17-18) situated in a housing (6) fixed to the corresponding end plate (2) of the stator, with each of the shafts passing through the end plate via a corresponding lip seal (19, 20); wherein a sealing module (24) is interposed between the end plate (2) situated adjacent to the housing (6) and the compression chamber adjacent to the housing, the module (24) comprising a partition aro

Abstract: A twin-shaft vacuum pump includes a pump chamber, a pair of rotary pistons disposed in the pump chamber, and plates which laterally delimit the pump chamber, and a housing ring which peripherally delimits the pump chamber. In order to increase the ability of the pump to withstand thermal stresses, the housing ring and the rotary pistons are made of different materials, with the coefficient of expansion of the piston material being lower than the coefficient of expansion of the housing material. Other improvements include cooling of the lateral end plates, cooling of the rotors, and the provision of sleeves which serve to fix the position of the rotors on the shafts and which are composed of a material whose coefficient of expansion is lower than that of the rotor material.

Abstract: The rotary piston machine has two internal rotors (2, 3) fixed to a common shaft (12) and two external rotors (4, 5) rigidly interconnected by means of an annular rotor disk (9). The working spaces (16) between the engagement parts of both external rotors (4, 5) extend a maximum extension (19) radially inward past the inner boundary of rotor disk (9). For the axial sealing of the working spaces (16), also in the area of said extension (19), the rotor disk (9) encloses a partition body (15), which surrounds the shaft (12) of the internal rotors (2, 3) by means of a bearing (43). A further bearing (13) is provided between rotor disk (9) and partition body (15). Partition body (15) is prevented from concomitant rotation with one of the two rotary machine parts (9, 12) adjacent thereto as a result of the radial displacement of the shaft (12) engaging therein relative to the rotation axis of rotor disk (9).

Abstract: A two-shaft rotary machine for use in a vacuum pump system includes rotors having a specific profile whereby any vibration and noise generated by the machine is minimized and its efficiency is increased. The number of lobes of each rotor is three or more. The tip and root portions of each rotor are defined by circular arcs, respectively, which are made smoothly continuous with each other through an involute curve. The ratio of the diameter of the tip circle to the diameter of the root circle is selected to fall within a range which is given by a specific expression.

Abstract: A multistage vacuum pump with a case with at least two pump chambers in the case, and with at least one passage connecting the pump chambers together. To detect fouling in the especially sensitive connecting passages in a simple manner, it is proposed to configure the passages as part of bores leading to the outside, which can be closed with a plug.

Abstract: A vacuum pump system comprising a first vacuum pump having at least one pumping chamber with port means for communication with an enclosure to be evacuated and having mechanical pumping means mounted on at least one shaft whose bearings and/or gears are contained in a housing and a second vacuum pump having a first pumping chamber with means for communication with the chamber of the first pump and at least one further pumping chamber wherein means are provided for communication between the housing of the first pump and a further pumping chamber of the second pump.

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 metering fuel pump adapted for feeding fuel containing vapor or air to an engine that includes a housing assembly. The metering fuel pump further includes a motor section encased inside the housing assembly for providing the required rotary motion to a two-stage pump section. The speed of the motor section is controlled by a motor controller section that provides a voltage regulated flow of fuel. The two-stage pump section imparts pressure to the fuel and encloses a cyclonic vapor separator section.

Abstract: A two-stage pumping apparatus is disclosed which is particularly suited for moving highly viscous materials, and other materials which do not readily lend themselves to pumping. The apparatus includes a generally vertically oriented housing with an infeed opening defined generally at the upper end thereof for gravity infeed of material into the apparatus. A pair of cooperating, counter-rotating screw augers are provided within the housing for rotation together about respective parallel axes. By this arrangement, material moves axially of the augers generally downwardly through the pump housing to a discharge opening defined by the housing. Notably, each of the screw augers includes helical flights intermeshed with the flights of the other auger, with the flights configured to provide a two-stage pumping action, including a first, upstream non-positive displacement pumping, and a second, downstream positive displacement pumping.

Abstract: A multi-section Roots vacuum pump of the reverse flow cooling type with internal flow division arrangement includes a sequence of pump sections, casings for the pump sections including housings for accommodating pairs of rotor therein, inlet passages and outlet passages connected to the casing for pump sections, upper peripheral gas passages connected to the inlet passage formed around an upper portion of the housing, lower peripheral gas passages connected to a supply inlet of reverse flow cooling gas formed around a lower portion of the housing, partition walls between the upper and lower peripheral gas passages, and inter-section walls for separating adjacent pump sections.

Abstract: A two-stage vacuum pump apparatus has a first stage of vacuum pump constituted by a screw-type vacuum pump and a second stage vacuum pump constituted by an oil-sealed rotary vacuum pump operative to maintain the back pressure of the first stage vacuum pump at a level ranging from 1 to 100 Torr., whereby a high level of vacuum can be attained in a system to be evacuated without any risk of contamination of the evacuated system by oil. Also disclosed is a method of operating the two-stage vacuum pump apparatus.

Abstract: A two-stage gear pump with two gear sets each having a pinion telescoped onto a slotted drive shaft with a press fit and also positively keyed to the shaft. One key in the slot of the shaft includes radial ears establishing a positive coupling between the shaft and one of the pinions and also includes cantilevered spring fingers which enhance the press fit between the shaft and the other pinion.

Abstract: A hot melt foam adhesive system including a gear pump wherein gas is mixed under pressure into the molten adhesive and is driven into solution with the adhesive. The gas is supplied to the pump via a one-way check valve operative to prevent the back flow of molten adhesive to a gas flow control valve, regulator, and gauge. The check valve is positioned above the level of the pump so that molten adhesive cannot flow by gravity into the check valve. The check valve is so constructed that it is biased into a closed position by a spring on the gas side of the valve so that adhesive cannot collect around and foul the spring of the valve.

Abstract: A two-shaft vacuum pump which draws gas in at an inlet and compresses it at a first outlet for discharge, thereby producing a vacuum at the inlet, has a second, pressure-responsive outlet from the area where the gas is compressed for discharge from the first outlet. The second outlet thereby relieves excess, compression gas pressure which could overload the pump motor, for example, at the start of operation when high-density gas is drawn in for compression.

Abstract: A two stage mixing gear pump for dispersing a gas into a liquid wherein a metered quantity of liquid from the first stage of the pump is supplied to gas filled intertooth spaces of the second stage pump. The gas is introduced into the intertooth spaces of the second stage of the pump through a gas inlet which is adjacent the low pressure side of the gear teeth meshing zone of the second stage of the pump and the liquid enters the gas containing intertooth spaces downstream of the gas inlet.

Abstract: A unique gerotor-type pump is disclosed for pumping gases. The pump has an inner gear-type rotor mounted within and rotating off-center with respect to an outer gear-type rotor ring, about a parallel axis. Surfaces of the teeth of the inner rotor are in continuous contact with the outer rotor to define at least one pumping chamber which alternately expands and contracts as the inner and outer rotors turn. An elongated inlet port is positioned to communicate with the pumping chamber during a substantial portion of the cycle when the pumping chamber is expanding, (the intake cycle) and an outlet port is positioned to communicate with the pumping chamber only just prior to and at the end of the contraction or exhaust cycle. Oil for sealing and lubricating between moving parts of the pump is provided by employing differential pressure created by the pump's own operation to draw oil through passageways which communicate between an oil reservoir and the pumping chamber.

Abstract: A mechanical pump includes a pumping chamber through which extends a pair of parallel shafts 3. Each shaft 3 carries in tandem rotors 4, 5 and 6 at least two of which are the intermeshing "claw" type. The rotors are arranged in complementary pairs and each pair occupies a separate location in the pumping chamber. Each "claw" type rotor 6 of a complementary pair in one location is mounted on its shaft 3 in reverse orientation to the "claw" type rotors 5 of the complementary pairs in the adjacent location.

Abstract: A positive displacement rotary compound chamber motor comprises a piston rotor and a barrier rotor rotating cooperatively in a ported housing. The piston rotor has a compound piston which during rotation sweeps out a compound working chamber. The barrier rotor has a small piston which sweeps out a high pressure (HP) chamber. A flange on the piston rotor is the barrier for the HP chamber. All pistons mesh with recesses in the rotor assemblies. During operation, the HP chamber is filled with HP gas, which then expands in the compound chamber. A compound piston larger than the small piston achieves a high expansion ratio. A leakage path from the HP chamber to exhaust is blocked by the addition of an intermediate piston and its meshing intermediate recess.

Abstract: This invention relates to a method and a device for intermediate cooling in an oil-injected multi-stage screw compressor. Between the outlet (14) in one stage (10) and the inlet (16) in a subsequent stage (11) a connecting passageway (15) is located, through which the gas compressed in the firstmentioned stage (10) is supplied to the subsequent stage (11). For cooling the gas flowing out from the firstmentioned stage (10), in the connecting passageway (15) at least one nozzle (19) is located for the supply of a large cooling oil amount.

Abstract: An oil-free rotary compressor having mating impellers rotatably mounted in working chambers; each impeller has at least two profiles; each profile having only one lobe and one well of substantially 180 degrees in arcuate extent. An inlet port communicating directly with all of the profiles and an outlet port in a side plate at the axial extremity of the working chambers. The angular displacement between adjacent profiles is at least 130 degrees and the pitch velocities of each impeller is at least 200 feet per second.

Abstract: A fluid system, especially for a transmission having a hydrodynamic torque converter and a mechanical change speed gear box downstream therefrom. For supplying pressurized fluid to the working chamber of the torque converter, the clutches and brakes of the torque converter and the servomotors which control the gear steps of the downstream mechanical change speed gear box, there is provided a pressure system having first and second low pressure pumps and preferably an auxiliary high pressure pump. The first low pressure pump delivers fluid continuously for delivery to the working chamber of the torque converter and to the servomotors. The second low pressure pump can deliver pressurized fluid through a one way valve to the discharge side of the first low pressure pump or alternatively its output can be bypassed directly to the input of the second low pressure pump.

Abstract: Cryogenic refrigeration system employs a power driven screw compressor which delivers pressurized refrigerant gas through a closed system to expand in a screw expander to produce refrigeration. The screw expander is rotatively coupled to the compressor. The screw compressor-screw expander cryogenic system includes heat exchangers and operates on the closed Brayton cycle to produce refrigeration.

Abstract: A hot melt adhesive foam pump system having a first stage pump that meters molten hot melt adhesive into a second stage pump, which in turn mixes gas under pressure into the adhesive so that the gas is driven into solution with the adhesive at an adjustably controllable ratio. The pump is insensitive to changes in adhesive viscosity and pump speed, and provides uniformity of foam density and output flow rate when the adhesive is ejected from a dispenser connected to the pump.

Abstract: A gear pump for dispersing a gas into a liquid is provided with mixing means for improving the uniformity of the dispersion. In preferred form, the mixing means comprises a series of fixed, shallow, blind cavities that open to the pumping cavity between the liquid inlet and the outlet, and which are positioned to be "wiped" by the gear teeth as the gears rotate. The alternate connection and disconnection of the intertooth spaces to these cavities as the gears rotate establishes motion or turbulence of the gas/liquid mixture within the intertooth spaces, and surprisingly improves uniformity of the dispersion.

Abstract: Screw fluid machines are for use as a compressor for generating high pressure gas, a cooling-medium-compressing compressor for use in a refrigerator or an air conditioner. The fluid machine includes a rotor casing, two side-casings, a pair of screw rotors, and accessories such as silencer, a gas cooler, an oil cooler, and an oil tank. The rotor casing includes an outer wall, an inner wall and interconnecting members or ribs which interconnect the outer wall and the inner wall, with a space being provided between the outer wall and the inner wall. This space is partitioned into two or more spaces by means of the aforesaid interconnecting members. A working chamber or space is provided inwardly of the inner wall and has an inlet port and a discharge port. Both side-casings are secured to the opposite end faces of a rotor casing through the medium of flanges and are provided with a passage adapted to bring two or more spaces thus partitioned, into communication with each other.

Abstract: In screw compressors for fluids there is normally leakage of fluid axially through the rotor-shaft bearing assemblies at the high-pressure end of the casing housing the interacting rotors. To obviate or mitigate the resulting inefficiency in the operation of the compressor, and also reduce atmosphere pollution arising from the leakage, a fluid coupling is provided between said bearing assemblies and an additional fluid inlet opening in the compressor casing, said additional opening being positioned to communicate with a land of the rotor when the rotor is at or beyond rotor cut-off, so that fluid leaking from the compression chamber is recirculated to the compression chamber.

Abstract: A single rotary fluid unit can act either as a compressor or as an expander. Each unit has a casing enclosing two rotors moved in synchronism. The rotors sealingly engage and coact with each other and the casing walls to form chambers providing the necessary intake and exhaust functions. Two units can be connected together to operate in a mirror-like or reverse fashion whereby one unit is a compressor and the other unit is an expander. The thus formed compressor-expander units or apparatus can be connected to additional apparatus to form a Stirling cycle engine or an air cycle refrigeration apparatus.

Abstract: In a two-stage liquid injected helical screw gas compressor a bypass line with a check valve is provided between compressor stages for delivering compressed gas from the first stage directly to the compressed gas receiver and liquid reservoir. Bypass of gas to the reservoir at startup assures pressurization of the reservoir and early flow of liquid to the first and second stage compression chambers. As the working pressure in the second stage discharge line increases above first stage discharge pressure, the check valve closes and all flow from the first stage is conducted through the second stage compression chamber.

Abstract: A fluid pump includes a housing in which is defined a bore. A pump assembly is mounted within the bore a pump assembly including a drive shaft extending through an aperture in an end wall serving to close one end of the bore, the other end of the bore being closed by an end closure. The pump assembly comprises three stator portions and disposed in end to end relationship with each end stator portion and the center stator portion being separated by components of two stages of the pump.

Abstract: A rotary gas compressor or expansion motor with a housing having circumferentially spaced inlet and outlet ports. An outer cage or sleeve rotor has alternate slots and teeth. An inner lobe rotor has lobes which mesh with the slots of the cage rotor as the two rotate. The space between the two rotors is filled with a crescent-shaped housing member. The slots, teeth and lobes of the rotors are helical.

Abstract: Two stage screw compressor having two working spaces provided side by side with parallel axes within a common barrel member and extending in the same direction from a common plane surface of an end plate member in which one rotor of each stage are interconnected by a gear transmission including an input power shaft.

Abstract: A rotary compressor having a pair of rotatable impellers in mating engagement in working chambers, each impeller having a plurality of constant cross-sectional profiles, each profile having a plurality of lobes and wells, the trailing well region of each profile communicating with the leading well region of an adjacent profile, an inlet communicating with the working chambers and an outlet located out of the plane of at least one of the profiles on each impeller.

Abstract: A screw compressor has at least two pairs of compressor rotors arranged in series, the outside diameter of the rotors of the two pairs being substantially the same, and the ratio of the outside diameter to the diameter at the base of the rotor teeth or vanes of the second pair being such that the capacity of the rotors corresponds to the intake volume of fluid to be compressed flowing from the first to the second pair of rotors.

Abstract: The unloading means comprise unloading ports, and valving therefor, for step-control unloading of a gas compressor. In a first embodiment, the unloading means are provided in side walls of a rotary, positive displacement, gas compressor, and in an alternate embodiment the unloading means are disposed within end walls (of a rotary, positive displacement, gas compressor), and comprehends means for step-control of a plural-stage machine.

Abstract: A rotary compressor having a pair of rotatable impellers in mating engagement in working chambers, each impeller having a plurality of constant cross-sectional profiles, each profile having a plurality of lobes and wells, the trailing well region of each profile communicating with the working chambers and an outlet located out of the plane of at least one of the profiles on each impeller.

Abstract: The disclosure is that of an invention directed to a rotary energy converter so constructed that it may be used either as in internal or external combustion engine, a fluid pump or as a gas or air compressor. The basic configuration consists of a stationary housing within which is rotatably mounted a disc-like primary circular rotor having a parallel-sided chamber symmetrically disposed with respect to its axis of rotation and a secondary circular rotor rotatable within the parallel sides of the chamber of the primary rotor and eccentrically affixed to a shaft that is mounted within the housing for rotation about an axis that is disposed in parallel offset relation to that of the primary rotor.

Abstract: A rotary compressor having a pair of rotatable impellers in mating engagement in working chambers, each impeller having a plurality of constant cross-sectional profiles, each profile having a plurality of lobes and wells, the trailing well region of each profile communicating with the leading well region of an adjacent profile, an inlet communicating with the working chambers and an outlet located out of the plane of at least one of the profiles on each impeller.

Abstract: A method and a device for injecting liquid into a screw compressor is disclosed which allow the injected cooling liquid to move through the compressor in a pure axial movement. Through this a more even distribution of the liquid in the compression chambers is achieved resulting in improved cooling of the working medium.

Abstract: A screw rotor machine is disclosed which comprises a screw cam rotor provided with gudgeons and a screw thread rotor enclosing the screw cam rotor. The screw cam rotor is made as single-thread-screw which is generated in relation to an inner base cylinder. The profile of the single-thread-screw is such that it in each cross section encloses both the inner base cylinder and the cylindrical extensions of the gudgeons. Furthermore the single-thread-screw comprises two parts having different lead angles.

Abstract: A rotary compressor having mating rotary impellers defined by lobes and well spaces therebetween, a discharge port sealed by the peripheral surface of one of the lobes and passages for communicating one impeller well space with a well space of the other impeller as the discharge port is sealed by the one impeller peripheral surface. According to one form, the passages are defined by conduits in the compressor housing; whereas according to a second form the passages are defined by a recess in one impeller and the interior of the compressor housing.