Abstract: A rotor adjusting apparatus for adjusting flank clearance between the lands of meshing first and second rotors in a positive displacement screw machine is disclosed which includes a base configured to mount proximate an end of the meshing first and second rotors in the screw machine. A locking mechanism is supported by the base and operatively configured for locking the first rotor shaft in a fixed position relative to the base. An adjusting bar is configured to attach to the second rotor shaft for rotational adjustment thereof in relation to the first rotor to establish clearance between the land flanks of the meshing first and second rotors. A measuring tool is adjustably mounted to the base permitting measurement of rotational adjustment of the adjusting bar. A second locking mechanism is supported by the base and operatively configured for locking the adjustment bar in a fixed position in relation to the base and, thereby, the second rotor in relation to the first rotor.

Abstract: A scroll-type compressor has a scroll plate that is prevented from moving radially or rotating but may be axially displaced. The configuration includes a key and key way configuration and springs to axially bias one scroll plate away from the other scroll plate. The major components of the compressor assembly can be axially assembled.

Abstract: A variable pump or motor is providing including a housing with inlet and outlet ports and a vaned rotor, the vanes being extensible against a shape controlled freely rotatable flexible band within the housing.

Abstract: The position of a screw compressor slide valve in a refrigeration system is controlled using compressor discharge gas sourced from a location where the gas is relatively oil-free and has undergone little or no pressure drop subsequent to its discharge from the compressor's working chamber.

Abstract: Rotary compressor including at least one rotor (2), which is rotatably mounted in a compression chamber (1) by liquid lubricated bearings (4), a device (13-15-16) for injecting water into the compression chamber, and a supply device for supplying (1) a liquid based on polyalkylene glycol miscible with water as the bearing lubricant.

Abstract: A method of adjusting the engaged clearance between rotors of a screw compressor which has a male rotor and a female rotor inside a casing, both of the rotors being rotated while maintaining a required very small clearance using timing gears fixed individually to the rotors through shrink fitting, wherein the very small clearance between the rotors is set to a required value by loosening the shrink fitting between one of the timing gears and the rotor on which the one of the timing gears is mounted, while movement of the other of the timing gears is being restricted; and intermittently applying torques to the rotor on which the one of the timing gears is mounted using a servo motor. In this way, it is possible to obtain a screw compressor in which a very small clearance between the rotors can be set to a required value in a short time, and in which high reliability in the symmetrizing adjustment and a high compressing performance can be obtained.

Abstract: A pump for pumping a liquid containing solids comprises a housing having a first end and second end and an interior pump chamber. An inlet pipe leads to the pump chamber through the first end, and an outlet pipe leads from the pump chamber at the second end. A core having a vane extending therefrom rotates within the chamber. The core has hollow portions permitting material to move from the inlet pipe to the pump chamber and from the pump chamber to the outlet pipe. The vane extends from the core outwardly, seals against the housing, and works in cooperation with a pair of moving blades to draw material from the inlet pipe and expel the material through the outlet pipe. The blades, which are arcuate in shape and have curved ends, are operated by pneumatic cylinders and move from a retracted position in which they are positioned out of the pump chamber to a deployed position in which the curved end sealably engages the core.

Abstract: An improved scroll compressor has an orbiting scroll wrap that is designed to always be at most equal in height to the fixed scroll wrap. The orbiting scroll wrap is preferably designed shorter than the fixed scroll wrap by a distance equal to the manufacturing tolerances on the height of the two scroll wraps added together. In this way, the present invention insures that in no acceptable parts will the height of the orbiting scroll wrap exceed the height of the fixed scroll wrap. In a situation where the height of the orbiting scroll wrap does exceed the height of the fixed scroll wrap, there is a tendency to limit the stable operational envelope of the system. By insuring that the orbiting scroll wrap height is always at most equal to the fixed scroll wrap height, the present invention avoids this limitation on the operational envelope.

Abstract: A scroll-type compressor has a scroll plate with at least first and second pressure equalizing passages formed in its end plate such that the first and second pressure equalizing passages will be in the same crescent shaped pocket during at least a portion of a crescent shaped pocket's radially inward movement. The minimum pressure in a back pressure pocket will be adequate to maintain a good seal, any pressure increases will increase in accordance with the increased pressure in the crescent shaped pockets. At no point are both of the pressure equalizing passages blocked and, therefore, the pressure in the interior space does not overwhelm the effective functioning of the back pressure pocket.

Abstract: The position of a slide valve in a screw compressor in a refrigeration system is controlled using a gaseous medium sourced from two or more sources of such fluid, both of which are in open flow communication with the slide valve actuating piston when the slide valve load solenoid is open. Preferred gas sources are a closed compression pocket in the working chamber of the compressor and the discharge passage downstream of the compressor's working chamber. Gas at sufficiently high pressure is available whenever the compressor is operating to ensure that the compressor will load under all conditions within the compressor's operating envelope.

Abstract: The transverse tooth profile of a screw rotor which meshes with a companion screw rotor is defined by a tooth root circular arc, an outer circumferential circular arc, and two curves interconnecting the tooth root circular arc and the outer circumferential circular arc. One of the curves is defined by a trochoid curve generated by a point on an outer circumferential surface of the companion screw rotor. Alternatively, the curve may comprise two curve segments, and one of the two curve segments comprising a tooth tip arc which is defined as an arc having a radius of curvature equal to or smaller than the difference between a radius of curvature of the outer circumferential circular arc and a radius of a pitch circle of the tooth profile, and the other of the two curve segments comprising a curve connected to the tooth root circular arc and determined by a curve generated by the tooth tip arc of the companion screw rotor.

Abstract: In a rotary compressor unit an inner and an outer rotor turn in an intermeshed rotation, a compression space and a suction space being formed alternately on radially offset sides of the inner rotor. A piston moves axially back and forth within a hollow space of the inner rotor. The inner rotor has a hollow space which has front and rear control channels which are alternately connected to the compression and suction spaces to drive the piston back and forth. The piston is used to actuate a percussion tool.

Abstract: A fluid reaction device (10) is provided having a rotor (90) with vanes (92) pivotably connected thereto. The device (10) includes an entrance (30) for elevated pressure fluid and an outlet (40) for discharge of the fluid after contacting the rotor (90). The elevated pressure fluid passes from the entrance (30) into a high pressure area. The high pressure area is in contact with inlet ports (74) accessing a cylinder (70) within the device (10). The cylinder (70) supports the rotor (90) with a rotational axis (M) of the rotor (90) off center with respect to a central axis (N) of the cylinder (72). The elevated pressure fluid causes the rotor (90) and an attached output shaft (97) to rotate. The rotor (90) includes a trunk (24) with a plurality of posts (93) extending therefrom and with vanes (92) connected to the posts (93) through hinges (94). The vanes (92) can pivot from a first position collapsed against the trunk (24) to a second position spaced away from the trunk (24).

Abstract: A rotary screw compressor having a balancing piston device for balancing an axial gas force exerted on a pair of rotors during operation of the rotary screw compressor. The balancing piston device is exposed in one axial direction to a high pressure source on at least one first pressure surface, and in an opposite axial direction to one of a low pressure source and an intermediate pressure source on at least one second pressure surface. A valve is provided for selecting the low or the intermediate pressure source connection with respect to the at least one second pressure surface, whereby the thrust balancing force can be adapted to different working conditions such as starting up and full load operation in order to avoid underbalancing or overbalancing of the axial gas force.

Abstract: A gear pump is disclosed having an integrated gear cavity and bearing receptacle that includes a fluid path for lubricating the bearings. The preferred embodiment includes a helical gear pump having a manifold with inlet and outlet ports. The integrated gear cavity and bearing receptacle are located in a one piece molded end cap. The bearing receptacle receives a coupled bearing assembly. Together, the coupled bearing assembly and the bearing receptacle define a supply path outside the bearings along the bearing receptacle and a return path through the bearings so that fluid can pass by, and lubricate, the bearing-axle interface.

Abstract: The transverse tooth profile of a screw rotor which meshes with a companion screw rotor is defined by a tooth root circular arc, an outer circumferential circular arc, and two curves interconnecting the tooth root circular arc and the outer circumferential circular arc. One of the curves is defined by a trochoid curve generated by a point on an outer circumferential surface of the companion screw rotor. Alternatively, the curve may comprise two curve segments, and one of the two curve segments comprising a tooth tip arc which is defined as an arc having a radius of curvature equal to or smaller than the difference between a radius of curvature of the outer circumferential circular arc and a radius of a pitch circle of the tooth profile, and the other of the two curve segments comprising a curve connected to the tooth root circular arc and determined by a curve generated by the tooth tip arc of the companion screw rotor.

Abstract: An first rotor and an second rotor rotate about a longitudinal axis in a housing. The second rotor moves longitudinally relative to the first rotor. Rotor vanes extend outward from the rotors and are longitudinally split into longitudinally extending second vanes and longitudinally extending first vanes that slide longitudinally relative to one another. The second vanes travel longitudinally with the second rotor relative to the first rotor, and the second vanes slide relative to the first vanes that remain with the first rotor. The second rotor and the second vanes move longitudinally toward and away from a recess defined by the first rotor such that the active surface area of the rotor vanes is varied. When the second vanes slide away from the first vanes, surfaces of the first vanes are exposed that reciprocate into and out of specially defined chambers in a pump-like fashion. A movable element is connected to and extends from the second rotor.

Abstract: A pair of conveyor screws for rotating positive-displacement pumps, the conveyor screws including a rotor and a contra-rotor, wherein the conveyor screws comprise a screw spindle pump and rotate with zero contact in a bore and in flanks and rotate at the same speed, the conveyor screws form loss gaps and have the same thread depth, the same number of threads and flank profiles which are symmetrical. The conveyor screws include a tooth base positioned below a flank profile reversing point and a tooth head positioned above the flank profile reversing point, wherein a profile-produced loss gap height in an axial section on a pitch circle is kept constant for a specific rotor diameter by shifting the flank profile reversing point as a function of a rotor pitch.

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 hydraulic machine is disclosed, with an annular gear with internal teeth and, eccentrically mounted in the annular gear, a gearwheel with external teeth which engage with the internal teeth, the internal teeth comprising one more tooth than the external teeth and the contour of the external teeth being formed by an envelope of a system of generating circles, the midpoints of which lie on a trochoid which, as a rolling circle rolls without slipping on a base circle, can be generated by the movement of a point lying on a radial ray of the rolling circle co-rotating with the rolling circle. A method of producing the contour of a rear wheel of such a machine is also disclosed. In such a machine it is desirable to realize a satisfactory inner seal and low Hertzian stresses. To that end, the spacing of the point from the midpoint of the rolling circle is larger than the radius of the rolling circle.

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 swinging type blade which allows compressor reliability to be improved by preventing a blade from being fracture-damaged at its joint portion while reducing the compressors ineffective volume. A rotary compressor that adopts a swinging type blade including a swelling portion formed at the joint portion of the blade with a roller. Further, a recessed portion for receiving the swelling portion is provided in a swing bushing. Further, the swelling portion may be symmetrical relative to the blade or asymmetrical with an associated notch provided on the opposite side of the blade with respect to the asymmetrical swelling portion.

Abstract: A gear pump comprises rotors disposed in roller bearings. For the delivery of very viscous polymer meltings, bearings surfaces of at least one of inner races, outer races of the bearings and bearing surfaces of roller elements are made of a steel with a high-temperature stability. Bearing takes place on material pairings consisting of one of S6-5-2 high-speed steel and silicon nitride Si.sub.3 N.sub.4. The roller bearings are either unlubricated or lubricated by a lubricant remaining in the bearing, preferably a solid-substance lubrication. A distance of supported shafts, from a gearwheel face to a supporting area of the shafts, determined by the outer contact point in the roller bearing, is smaller than twice the median diameter of the shafts therealong.

Abstract: To reduce squeeze pressure peaks on meshing rotors of a gear pump, recesses are molded into the product duct wall in the meshing area, on the delivery side and the suction side. The recesses are formed with spherical segments or other continuously curved surfaces.

Abstract: Close tolerance, oil free scroll type vacuum pumps, when run at RPM speeds in excess of 1800 RPM, prevent pump exhaust outlet to pump vacuum inlet back diffusion (backwards migration) of light atmospheric gases from a process vacuum is useful in a number of vacuum applications. The light gas isolation capability of the invention scroll type vacuum pumps is due to the close tolerance pumping mechanism that these pumps employ, the RPM speed that the mechanism is operated at, and the absence of light gas absorbing materials inside the pump such as oil.

Abstract: A membrane pump has a housing which includes a pump head provided with an internal recess. The pump head is further provided with an inlet opening and an outlet opening which communicate with the recess and are disposed next to one another near an edge of the housing. A membrane extends across the recess and is clamped at its edges by the housing. The membrane and recess together define a pumping chamber. A segment of the membrane is held stationary against the pump head by a clamping finger and forms a seal with the pump head. The seal extends radially between the inlet and outlet openings from the periphery of the pumping chamber to its center. A drive successively urges circumferrentially successive segments of the unconfined part of the membrane into sealing engagement with the pump head to thus direct fluid from the inlet opening to the outlet opening.

Abstract: The surface of a central section of a spiral element formed on a stationary or a movable scroll unit of a scroll type compressor is determined through the steps of locating an outer wall surface changing point G in a first polar coordinate system X, Y having a first origin O, drawing a circle Cs with its center at the first origin O and with a diameter corresponding to the orbital radius e of the orbiting motion of the movable scroll unit, locating a contact point P at a desired contact angle .beta. on the circle Cs, drawing a straight line m passing through the contact point P and the first origin O, drawing a straight line I passing the outer wall surface changing point G and inclined at a predetermined angle .alpha.

Abstract: The position of a slide valve in a screw compressor in a refrigeration system is controlled using a gaseous medium sourced from the higher pressure one of two or more sources of such fluid. Preferred sources are refrigerant gas in a closed compression pocket in the working chamber of the compressor and refrigerant gas in the discharge passage downstream of the compressor's discharge port. The multiple sources of such gas are connected to a solenoid valve which, when open, permits gas to act on the piston which controls the position of the slide valve. Due to a check valve arrangement, it is always the one of the sources of gas which is at higher pressure that acts on the slide valve actuating piston. The adverse affects of refrigerant gas out-gassing and gas bubble collapse associated with use of hydraulic fluid rather than a gaseous medium to modulate compressor capacity are avoided while advantageous use is made of compressor overcompression in the control of slide valve position.

Abstract: An infinitely variable scroll-type fluid displacement apparatus comprises an orbiting scroll having a spiral element interfitted with a spiral element of a base scroll. The orbiting scroll and the base scroll are both rotatably disposed in the compressor housing and operationally connected through a rotation prevention mechanism. The orbiting scroll is continuously driven by a drive shaft, even when fluid is not displaced through the scroll-type fluid displacement apparatus. The base scroll is mounted on a carrier which has magnetic rotor elements extending in close proximity to an electromagnet. When the electromagnet is energized, an attraction force is generated between the electromagnet and the magnetic rotor elements, thereby imparting a braking force to the base scroll. Depending on the amount of braking force imparted to the base scroll, the capacity of the scroll-type fluid displacement apparatus can be infinitely varied.

Abstract: A gear pump rotor assembly is disclosed. In order to prevent that the gear toothing is cooled in an unreliable manner, radial heat flow is reduced in the toothing area of the shaft, preferably by means of an insulation air chamber or other insulated section, with respect to the heat flow in other shaft areas to be cooled.

Abstract: A scroll-type fluid displacement apparatus has two interfitting spiral-shaped scroll members which have predetermined geometric configurations. The novel design provides desired displacement and a high built-in volume ratio, while at the same time achieving the optimum number of turns. The two scroll members can be either identical or non-identical. One scroll member is non-orbital and movable along its center axis. The non-orbital scroll member is urged by forces, mechanical or hydraulic, toward the other scroll member and is stopped by a positioning mechanism such that gaps are maintained between tips of one scroll member and bases of the other scroll member. A stabilizing mechanism prevents the scroll members from tipping.

Abstract: A rotary device in which a seal is formed between the rotor and the stator end members by a sealing material having a coefficient of thermal expansion which is greater than that of the material of the end member in which said sealing material is located. When exposed to normal service temperatures, the sealing material bulges out of the parent material to fill in the gap between the end member and the rotor. The sealing material is wearable such that as it expands into engagement with the rotor, it will eventually wear until it no longer contacts the mating surface and a small gap or "minimal clearance" exists.

Abstract: A rotary compressor includes a stator (2) having an inlet (3) and an outlet (4) for gas to be compressed, a rotor (5) within the stator (2) and vanes (7) being present to define cells (C) to transport gas from the inlet (3) to the outlet (4). According to the invention a supplementary passage (11) is present in the end wall (10) to direct gas from a region of high pressure (A) towards a region of lower pressure (B) thereby allowing lubricant to reach the region of high pressure gas.

Abstract: An outlet check valve includes an output valve seat provided at an outlet port or an outlet passage for compressed air in the vicinity of an outlet port of a compression mechanism and an outlet valve body. The valve seat and valve body are biased away from each other by a gravitational force or a spring. With this arrangement, even if a compressor is rotated at a low speed during a start-up operation, it is possible to cause stagnant liquid to undergo reverse flow into an accumulator disposed on the suction side and to store the liquid temporarily, thereby removing the liquid in the compression spaces and the suction passages and facilitating the start-up operation in a normal rotational direction. A pressure difference between the pressures upstream and downstream relative to the valve body is large when the normal rotating operation is stopped. By this pressure difference, the outlet valve body is moved to close the outlet valve seat, thereby to prevent the reverse rotation of the compression mechanism.

Abstract: A hermetic scroll-type compressor including a housing, fixed and orbiting scroll members, a frame member having a thrust surface adjacent the orbiting scroll member back surface, and a crankshaft coupled to the orbiting scroll member. A seal between the thrust surface and the back surface of the orbiting scroll member seals between a radially inner portion of the back surface exposed to discharge pressure and a radially outer portion exposed to suction pressure. The frame member defines an annular oil chamber having a side surface and a bottom surface above which the radially outer portion of the back surface orbits in spaced relationship. The oil chamber contains a sufficient depth of oil to extend the oil level above an upper peripheral edge of the orbiting scroll member, whereby oil from the oil chamber is sucked between the intermeshed scroll members. Radial compliance of the orbiting scroll meters the oil flow between the scroll members.

Abstract: Co-orbiting scroll members are maintained in a fixed angular relationship. An anti-rotation structure limits one of the scroll members to orbiting motion with respect to the separator plate. In a first embodiment the scroll members coact with a common anti-rotation structure while in a second embodiment the other scroll coacts with an anti-rotation structure which coacts with the crankcase. The scroll members orbit in orbits of different radii.

Abstract: An apparatus includes a rotary compressor having an inlet end, a discharge end, and a predetermined built-in volume ratio. The compressor has at least one rotor which is encased by a housing which is defined by at least a first portion and a second portion. The second housing portion has formed therein a first discharge port dimensioned as a function of the predetermined built-in volume ratio. A removable plate has formed therein a second discharge port dimensioned as a function of the predetermined built-in volume ratio. The removable plate mounts on the housing intermediate the first and second housing portions. When the plate is mounted on the housing the first and second ports cooperatively, fluidly communicate with the discharge end of the compressor.

Abstract: A mechanism for providing motive power consisting of a plurality of rotary-type pistons fitted into chambers uniformly situated about the axis of the engine in a housing for improving the effective displacement and compression of such engines. Motive forces generated by the pressure exerted on the piston are transferred from the cylinders through operative pins projecting axially from each of the pistons. The operative pins engage tracks in a guide plates. Due to the shape of the operative pins and tracks in the guide plate, the resultant forces generated between the operative pins and the guide plate cause the housing to rotate relative to the guide plate, generating torque. Thrust layers are provided which have involutes to introduce fuel and other fluids into the piston chambers and to remove exhaust fluids from the chambers. Cover plates are also provided to prevent the introduction and removal of fluids from the chambers from interfering with the transfer of power to the guide plates.

Abstract: A bearing and lubrication system for a sealed, integrated motor driven co-rotating scroll refrigerant compressor includes hydrostatic bearings and an independent motor driven lubricant supply pump for supplying lubricant to the hydrostatic bearings mounting in the housing. The housing is divided into a high-pressure section that receives compressed refrigerant and a low pressure section containing the involute scroll compressor wraps. Individual lubricant supply sumps are provided in the high and lower pressure housing sections for supplying lubricant to the compressor bearings. The lubricant pump is capable of drawing lubricant from one or both of the lubricant supply sumps. A lubricant level sensor associated with one of the low or high pressure housing sumps is provided to maintain a desired level of lubricant therein. The lubricant supply pump is controlled so that pressure is supplied to the hydrostatic bearings during compressor operation.

Abstract: Method and apparatus for on-site cleaning of a gear pump by coupling the gear pump outlet to the gear pump inlet and to the inlet end of the passage and which bypasses the bearing and is preferably controlled by a valve element which can block off the bypass in normal operation and be opened for a cleaning operation to increase the pressure on the side of the bearing connected to the inlet and thereby increase the velocity of the flushing stream.

Abstract: An adjustable eccentric mechanism for an orbiting rotary compressor comprising an eccentric, disposed within an orbiting roller, pivotally engaging a crankshaft and locking means for locking the eccentric to the crankshaft in a manner permitting adjustment of the eccentricity of the roller. A method of setting the eccentricity of an orbiting roller by swinging the roller around within the cylinder chamber into contact or a specified clearance with the sidewall, then locking the roller eccentric into place.

Abstract: An unloading arrangement for a rotary screw compressor includes discrete and different unloading apparatus associated with the male and female rotors respectively. The unloading apparatus associated with the male rotor is an axial piston continuous unloader movably disposed in a bore which is remote from but in flow communication, through a series of ports, with the compressor's working chamber. The unloading apparatus associated with the female rotor is a step unloader which, when opened, unloads the compressor in a single, relatively large capacity step. The compressor is therefore capable of being unloaded both over a continuous operating range and in a discontinuous, stepwise fashion. By duplexing compressors of this type, continuous capacity modulation of a multiple compressor system is made available over a large operating range without the employment of compressors unloaded by slide valve mechanisms.

Abstract: A rotary compressor is provided that has a housing including a bore, bearings, a low pressure end having a low pressure inlet and a high pressure end having a high pressure outlet. A rotor is rotatably mounted by the bearings in the bore and has an end face subject to a variable axial thrust force; and a plurality of compression chambers having a low pressure, a high pressure and intermediate pressures. A piston is provided for exerting a counterbalancing force on the rotor in opposition to the axial thrust force at the high pressure end of the compressor. An intermediate pressure port is provided in communication with the intermediate pressure chamber. A conduit is connected between the piston and the intermediate pressure port which varies according to suction pressure to cause the piston to apply a variable counterbalance force on the rotor through the output range of the compressor.

Abstract: A screw compressor employs a piston unloader which is disposed in a bore remote from the compressor's working chamber. Flow communication between the bore and working chamber is through a series of non-overlapping unloader ports. The unloader piston has a notched end face which effectively causes the unloader ports to overlap in operation. Precise and continuous capacity control of the compressor over a predetermined portion of its operating range is thereby achieved while internal high to low side gas leakage within the compressor and the clearance volume of the unloader ports is minimized. Compressor efficiency is thereby increased.

Abstract: The present invention relates to an internally constrained vane rotary compressor employing a floating carrier ring, containing a plurality of non-continuous cam surfaces to guide a corresponding plurality of vanes about the interior of a stator, resulting in improved compressor performance. The invention features a triple roller assembly operating in conjunction with the carrier ring to both guide and constrain each vane. In addition, the invention describes a method for increasing the operating efficiency in rotary vane compressors.

Abstract: A constrained rotary vane compressor having a rotor-vane assembly within a stator often exhibits unwanted noise and vibration effects. The present invention offers a design and method to decrease noise and vibration effects of such compressors by the incorporation of an oil skive formed in the interior wall of the stator. The oil skive rids the vane tips of any excess liquid which may have collected on the rotating vanes, which otherwise may impact certain interior regions of the stator resulting in unwanted noise and vibration of the compressor.

Abstract: A fluid displacement machine of the vane type which can be operated as a compressor or motor utilizes a cylindrical rotor equipped with one or more tethered sliding vanes wherein the rotor and vane set is rotatably located eccentrically inside an internal conforming casing profile between opposing endplates to define enclosed variable volume compartments. [Each vane is fitted on opposite sides eith tethers which are pivotally-mounted remotely from the vane tips. The tethers engage, through anti-friction means, circular annuli located within the endplates which are eccentric with the hollow casing profile.] Anti-friction tether-to-annuli means are used, one in the form of freely-rotating caged roller bearings interposed between the tethers and the respective internal annuli, and another in the form of tethers equipped with trunnioned bearings which directly engage these internal annular surfaces.

Abstract: In a co-rotational scroll apparatus having two interleaving scroll wraps secured to end plates rotating about parallel, non-aligned axes to produce a relative orbital motion, a mass secured to at least one of the scrolls for enhancing the nutational stability of the scroll member. Preferably, the nutation reducing means includes a mass affixed to an end plate of the scroll member to induce a dynamic imbalance during rotation of the scroll member, creating a balancing or moderating moment sufficient to compensate for the moment induced by the varying pressure of the fluids in the various compression chambers during the rotation of the scroll member.

Abstract: Co-orbiting scroll members are maintained in a fixed angular relationship. Each of the scroll members coacts with a common anti-rotation structure which controls orbiting motion between the scroll member. A second anti-rotation structure limits one of the scroll members to orbiting motion with respect to the crankcase. The scroll members orbit in orbits of different radii.

Abstract: In a gas pumping system including a first stage rotary lobe pump for pumping gas to a second stage liquid ring pump, cooling liquid is injected into the compression zone of the rotary lobe pump so that the liquid mixes intimately with the gas being compressed in that zone and reduces the temperature rise of the gas in that zone in order to reduce heat transfer from that gas to the lobes of the rotary lobe pump.