Abstract: A multi-stage pump includes a pump head having at least two compression stages disposed in series With espect to the direction of flow of fluid through the pump, and a reverse fluid bypass circuit including a fluid passageway through which fluid flowing between upstream and downstream ones of the compression stages can he circulated back upstream of the upstream compression stage. The reverse fluid bypass circuit may restrict or stop the flow of fluid through the fluid passageway as long as the pressure differential across the fluid passage is below a. predetermined value. To this end, the reverse fluid bypass circuit may be configured to restrict the flow of fluid while the fluid is in its transitional or molecular flow regime, and allow the flow of fluid while the fluid is in its viscous flow regime.

Abstract: An orbiting plate scroll of a scroll pump includes an orbiting plate having a first side and a second side, an orbiting scroll blade projecting in an axial direction from the first side of the orbiting plate, and a flexure whose compliance is in the axial direction. The flexure is coupled to the orbiting plate at the second side of the orbiting plate, and couples the orbiting plate and orbiting scroll blade to bearings that allow for free rotation of the orbiting plate scroll about a longitudinal axis, while constraining motion of the orbiting plate scroll in the remaining degrees of freedom.

Abstract: The speed of a cooling fan of a scroll pump is controlled such that fan-generated noise can be kept low. The scroll pump includes a pump head, a pump motor, the fan, a controller and one or more sensors. The pump head includes a plate scroll set in which a tip seal is provided to create a seal between the blade and the opposing plates of the plate scrolls of the set. The speed of the fan is cycled by the controller, and the power draw on the pump motor as a result is checked. These results are used to infer the state of the pump, i.e., to discriminate several different states of the pump from one another, including a state in which a new tip seal is being worn in, and to control the speed of the fan accordingly.

Abstract: The main sources of heat in a scroll pump are cooled efficiently by a single cooling fan so that noise and, in particular, fan-generated noise, can be kept low. The scroll pump includes a pump head assembly, a pump motor, a cooling fan that produces a cooling air flow in the pump, a cowling in which the pump head assembly, pump motor and cooling fan are housed and juxtaposed with one another in an axial direction of the pump, and a shroud disposed within the cowling and extending around the pump motor to define a tunnel with the motor and through which the air flow of the cooling fan is directed.

Abstract: A scroll pump has a metallic bellows that angularly synchronizes the stationary and orbiting scroll blades of the pump, and a hack-up system for the bellows. The back-up system consists of pins integral with and fixed relative to one of the stationary and orbital parts of the scroll pump, and a guide part that is integral with and fixed relative to the other of the stationary and orbital parts. The back-up system may be a non-contacting hack-up system in which there is no contact between the pins and guide part during normal operation of the pump. Therefore, no particles are created by a wearing away of such parts which would otherwise have the potential to contaminate the fluid being worked by the pump and reduce the useful life of the pump.

Abstract: A scroll pump isolates vibrations of a pump head/motor assembly of the pump from the exterior of the pump and thus, suppresses the production of airborne noise. The pump includes a sound-muffling enclosure surrounding the pump head/motor assembly, feet supporting the enclosure, and elastic vibration isolators. The pump head/motor assembly is fixed to the tops of the vibration isolators, and the sound-muffling enclosure is fixed to the vibration isolators at the bottoms of the isolators. The scroll pump also has a locking system by which motion of the pump head/motor assembly relative to the sound-muffling enclosure can be limited or prevented, and by which the sound-muffling enclosure can be hard-mounted to a support surface independently of the feet.

Abstract: An apparatus (10) for the controlled heating of fluid comprises a general elongated electrically heating core (16) with an exterior surface (36) formed of a material having a high thermal conductivity and frustoconically shaped to slidingly receive an assembly (14) so that the assembly envelops the surface along at least a portion of the length of the core. The assembly (14) forms a sealed passageway (46) for generally unidirectional sheet-like flow upward along the core (16). A control system (20) selectively operates the heating core (16) so that the fluid, under varying flow rates, is warmed to a desired temperature without overheating, before the fluid flows from the passageway (46).

Abstract: A compact scroll fluid device includes a pair of wrap support elements with one of the wrap support elements having an inner axial surface formed with an involute spiral recess and the other of the wrap support elements having an involute spiral wrap member projecting from an inner axial surface thereof. The spiral wrap member is received within the spiral recess while being relatively movable about an orbital path therein. A synchronizer assembly is provided axially between the wrap support elements, radially inwardly of both inlet and outlet zones associated with the scroll fluid device and radially outwardly of an orbit center of the device. The entire scroll fluid device is preferably made of plastic. With this arrangement, an extremely compact and inexpensive device is provided.

Abstract: A fluid flow control system includes a disposable cartridge which is receivable in a shifting carrier body portion of a control module. The disposable cartridge houses a disposable pump and a pressure transducer element which are fluidly interconnected by an internal fluid flow circuit formed in part by an elastomeric separating sheet within the cartridge. Following loading of the cartridge, shifting of the carrier body portion automatically results in a drive connection to the pump, the positioning of various flow control valves within the cartridge and the seating of the pressure transducer element to the control module. External flow lines are readily placed in fluid communication with the internal fluid flow circuit through exterior connection ports provided on the cartridge.

Abstract: An aerodynamic drag reduction arrangement for use in a mechanical device that incorporates a high speed rotating element includes a boundary layer control member that defines a control surface. The control member is positioned adjacent the rotating element so as to optimize the clearance therebetween in order to effectively block axial flow and prevent radial pumping in order to minimize power consumption. The aerodynamic drag reduction arrangement is particularly adapted for use in electric rotors and scroll fluid devices.

Abstract: A windage loss reduction system for a co-rotating scroll fluid device includes clearance reducing or optimizing elements mounted between rotating and fixed members of the scroll fluid device and which may be used individually or collectively to reduce centrifugal and axial fluid flow of ambient gases caused the rotating elements to improve the efficiency of the scroll fluid device. The windage loss reducing elements are located between fixed housing elements and the rotor, drive shaft, and scroll elements of the device.

Abstract: A scroll fluid device includes a synchronizer having a plurality of first synchronizer elements, fixedly secured to or integrally formed along a flank portion of one of a pair of meshed wraps, which are interdigited with a plurality of second synchronizer elements carried by a wrap support plate of the other meshed wrap. According to a preferred embodiment of the invention, the synchronizer elements carried by the wrap flank comprise teeth which extend into grooves formed in the support plate of the other wrap. In addition, the synchronizer elements on each of the wraps extend about a predetermined angular portion, preferably 180.degree., of each of the scroll elements. In this manner, it is possible to form each wrap with both tooth and groove portion,s, each portion extending about complimentary 180.degree. portions of the wrap, which are interdigited with corresponding tooth and groove portions on the other wrap.

Abstract: A scroll type fluid machinery which is provided with: a first scroll and a second scroll which moves with respect to the first scroll, where the base of the first scroll is provided with suction bores perforating through the base from the rear surface thereof to the front surface, and open at the outer peripheral portion of the front surface of the base, so that fluid released into an internal space of the body casing passes through the suction bores, and into the suction sides of compression volumes formed between spiral members of the scrolls, whereby suction pressure in the compression volumes is maximized and volumetric efficiency is improved.

Abstract: A thermal isolation arrangement for use in a co-rotating scroll refrigerant compressor includes various thermal insulation elements adapted to minimize heat transfer between hot rotating members of the scroll fluid device and the return refrigerant to be compressed, and between hot lubricant in the compressor and the return refrigerant. The thermal isolation elements of the present invention may be used individually or collectively to minimize the preheating of the inlet refrigerant so as to maintain the density of the return refrigerant being compressed to thereby increase the total efficiency of the scroll fluid device.

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: A scroll fluid device includes meshing, involute scroll elements mounted for co-rotation in a support housing. One of the scroll elements is supported by a shaft extending through a bearing sleeve mounted so as to be pivotable about a pivot center located transversely of the center line of the shaft. Radial compliance movement of the shaft and bearing sleeve is also enabled about the pivot center. This enables the scroll element to pivot slightly about three independent axes to follow the movement of the opposed cooperating scroll element while at the same time providing radial compliance enabling the scroll flanks to open slightly in the event of an over pressurization between the scroll wraps. The pivot center is provided by a circular ball pivot element located between the bearing sleeve and adjacent fixed support structure.

Abstract: Centrifugal blowers which maintain a substantially constant (usually .+-.5%) static pressure field around the circumference of the blower's impeller, notwithstanding at least one abrupt radial or axial discontinuity in the volute of the blower, e.g., due to one or more external axial and/or radial constraints in an irregularly shaped package. The blower accommodates such constraints by including discontinuities in the volute; therefore the blower takes advantage of relatively unconstrained segments of the package to have an overall large size. Notwithstanding the volute discontinuities, a substantially constant pressure field around the impeller is achieved by maintaining a specific relationship between G(.THETA.) and H(.THETA.), G(.THETA.) being radial extent of the volute as a function of the angular displacement .THETA. around the impeller's circumference and H(.THETA.) being the axial extent of the volute as a function of .THETA., angular displacement around the volute.