Abstract: A pump rotor for a screw pump includes a shaft, a first set of threads disposed on a portion of an outer surface of the shaft, at least one thread of the first set of threads including a groove disposed on an end portion thereof, and a ring seal disposed on the groove such that the ring seal is configured to protrude outwardly from the groove and to rest against an inner surface of a liner of the screw pump, and the groove is sized so as to allow the ring seal to move radially with respect to the plurality of threads as the rotor is deflected.

Abstract: A method of supplying lubrication oil to a two-stage screw compressor is disclosed in which a low-pressure stage screw compressor and a high-pressure stage screw compressor are integrally constructed. A compression space is formed by a male rotor and a female rotor, and operation gas is fed for compression to the compression space. The method prevents degradation of volumetric efficiency caused by return of lubrication oil, coming from a bearing and a shaft sealing device, to the low-pressure stage screw compressor, and as a result, refrigeration capacity is improved and the amount of the lubrication oil is reduced.

Abstract: The present invention relates to a control system for protection against breakage of the lubricating-oil film in the bearings of hermetic compressors, as well as to a control method that has the objective of guaranteeing that a variable-capacity compressor should be maintained above a minimum rotation in order to prevent the oil film close to the respective bearing from breaking. One of the forms of achieving the objectives of the present invention is by means of a control system for protection against break of the lubricating-oil film in bearings of hermetic compressors, a microprocessor (10) actuating a set of switches (SW2M) selectively, so as to generate a rotation at the motor-compressor assembly (20, 21), the compressor (21) having a minimum rotation (RPMmin) of the compressor (21) so that the oil film will not be broken.

Abstract: A screw compressor (20) has compressor lubrication network having a lubricant outlet port (242) along a low pressure cusp (244). An unloading slide valve element (102) may be along a high pressure cusp (105).

Abstract: Stator for an eccentric single-rotor screw pump has a casing made of steel or the like and a helical elastomer lining. Stator and a method for its production are described which can also be made with larger lengths at low production costs. Stator is composed of at least two stator segments that are axially arranged in a line, whereby the stator segments are connected to one another at their abutment so as to be pressure-tight by a tube of a polymer material that is pulled onto the casing and overlaps the abutments and by a metal ring radially pressed onto it.

Abstract: A screw pump includes a pair of screw rotors (2a, 2b) having teeth which are held in mesh with each other for drawing and discharging a fluid by rotating the screw rotors (2a, 2b) synchronously in opposite directions. The teeth of the screw rotors (2a, 2b) have the same shape as each other and are coiled helically in opposite directions. The teeth of the screw rotors (2a, 2b) have an axial tooth profile which allows a pair of facing teeth surfaces T of the screw rotors (2a, 2b) to be brought into contact with each other only at a pitch line P when the pair of facing teeth surfaces T are brought into contact with each other.

Abstract: A screw-type vacuum pump (1) is tempered such that characteristics of the pump are not substantially altered when the pump is subjected to thermal stress. In order to achieve said aim, cooling is adjusted according to an operating state of the screw-type vacuum pump (1), preferably to maintain a substantially constant pump gap (4).

Abstract: A rotary fluid machine, such as a pump or motor, is provided with a fluid flow control mechanism that allows the flow of fluid to be easily and precisely controlled. The device has a housing with a spherical interior in which primary and secondary vanes rotate, with the secondary vane reciprocating between open and closed positions. The primary and secondary vanes define fluid chambers within the housing that communicate with inlet and outlet ports of the device. An adjustable fixed shaft, about which the secondary vane rotates, allows the degree of communication to be varied between the inlet and outlet ports and the chambers formed by the primary and secondary vanes. In this way, the flow rate or fluid capacity of the device, and even the direction of fluid flow, can be changed.

Abstract: Disclosed are a scroll compressor having a frame fixing structure and a frame fixing method of the scroll compressor. The scroll compressor comprises an upper frame installed at an inner upper portion of a hermetic container; a fixed scroll fixed to an upper portion of the upper frame; and an orbiting scroll orbitably installed between the fixed scroll and the upper frame, wherein a joining groove is formed at a lateral surface of the upper frame, a curved portion having a penetration hole is formed at a lateral surface of the hermetic container corresponding to the joining groove, and a welding portion fixes the hermetic container and the upper frame through the penetration hole.

Abstract: A screw compressor is equipped with a manually operated internal volume ratio adjusting slide valve and capacity adjusting slide valve. The compressor is simple in construction, can be produced with low cost, can accommodate decrease in suction pressure, for example, in an aged gas well, and can be operated without an electric power source for controlling the operation thereof. Also a combined screw compressor unit consisting of a plurality of screw compressors for producing high discharge pressure is provided which can accommodate high suction pressure in order not to overload the higher pressure compressor or compressors with the efficiency of the unit kept as high as possible by including at least a screw compressor according to the present invention in the unit.

Abstract: A multi-chamber installation (1) treats objects under vacuum. An evacuation system (5) is connected to a plurality of chambers (2, 3, 4). To reduce the complexity of the evacuation process, a forepump (5) has several stages (11, 12, 13). Each of said stages is connected to one of the chambers (2, 3, 4).

Abstract: A rotary pump includes a stator housing and a rotor. The stator housing preferably has an oblong inner surface. The rotor, which is disposed in the stator housing, preferably has a substantially circular outer surface within which a plurality of vane slots are defined. A first chamber is defined between a first half of the oblong inner surface and the outer surface of the rotor. Similarly, a second chamber is defined between a second half of the oblong inner surface, diametrically opposite the first half, and the outer surface of the rotor. Resting within each of the plurality of vane slots is a corresponding sliding vane. A first inlet port and a first outlet port each provide access to the first chamber. Similarly, a second inlet port and a second outlet port each provide access to the second chamber. At least one of the vanes separates each of the first inlet port, the first outlet port, the second inlet port and the second outlet port from one another.

Abstract: Vane pump (10) mechanical losses are reduced by removing vane friction losses and replacing them with lower magnitude journal bearing fluid film viscous drag losses. A freely rotating cam ring (70) is supported by a journal bearing (80). A relatively low sliding velocity is imposed between the cam ring and the vanes (26). This permits the use of less expensive and less brittle materials in the pump by allowing the pump to operate at much higher speeds without concern for exceeding vane tip velocity limits.

Abstract: A compressor assembly having a housing in which a compressor mechanism and discharge chamber are located. A first port communicates compressed gas and oil from the compressor mechanism to the discharge chamber. A one-way valve allows the compressed gas and oil to enter the discharge chamber through the first port. A second port in the discharge chamber defines an outlet in the housing through which compressed gas and oil are discharged from the compressor assembly. The second port is disposed vertically below the first port in the lower half of the discharge chamber to thereby limit the quantity of oil which may collect in the discharge chamber. The second port may be defined by a discharge tube which passes through the housing at a flat portion of the housing which thereby facilitates the welding of the tube to the housing.

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

Abstract: Scroll compressors include a tap for communicating a compressed refrigerant to a back pressure chamber to resist a separating force. A restriction is placed within this tap to slow build-up of the back pressure chamber at start-up. Further, the restriction smoothes out any fluctuations in the back pressure force as the pressure in the compression chamber from which the refrigerant is tapped may fluctuate.

Abstract: A scroll compressor is provided with a generally spiral wrap having an abradable or conformable coating on radially inner portions of its tip. The coating is not applied to radially outer portions. During operation of the scroll compressor, the coating will eliminate tip gap leakage adjacent radially inner, higher discharge pressure portions of the compression process. The outer, non-coated portions will bear the axial load, and ensure the coating will not wear away to an undue amount.

Abstract: A positive displacement device that incorporates two rotors that are offset from collinear and each comprising a first and second set of vanes where the engagement surfaces of the first set of vanes are adapted to only engage when the rotors are in the top dead center location and the second set of lobes of each rotor only engage one another at the bottom dead center position of rotataion.

Abstract: The invention concerns a Moineau type gear pump stator (1), comprising a stator cavity with global axial extension inside an elongated body, characterised in that the stator cavity is defined by a rigid-walled metal tubular element (3) having internall the shape and dimensions of the stator cavity such that, when it is assembled with a rotor, a positive clearance with the rotor is obtained.

Abstract: A screw compressor is connected to a motor to be driven by the motor even during periods of low compressed air consumption. During such periods, the screw compressor is at least partially unloaded to make it easier and less costly to drive the compressor. The unloading is performed by removing air from the compressor. Preferably, that is done by communicating the air inlet of a small capacity vacuum device with the air outlet of the screw compressor. Suction from the vacuum device is transmitted to the air outlet of the screw compressor to suck air out of the screw compressor to reduce the engine horsepower needed to rotate the screw compressor. The vacuum device can also be used to boost the air volume and/or the air pressure. The system can be used in a drilling rig which drills holes in the ground. The screw compressor can be unloaded during start up of the motor by briefly driving the vacuum device by pressurized liquid from a pre-pressurized hydraulic accumulator.

Abstract: A method of controlling shifting of a multiple ratio fluid motor (10) between first and second speed ratios. The motor includes a shift valve (61) operable to achieve the second speed ratio by interconnecting recirculating volume chambers (33R). The method includes providing a pressure control valve (75) in communication with a source (73) of pressure fluid, the valve (75) being operable to communicate a pilot pressure to the shift valve in response to changes in a command signal between a first signal (113B) and a second signal (113C). When a shift to the second condition is commanded, the method changes the command signal (113) from the first to the second over a first time (T1). For a shift back to the first condition (FIG. 3), the method changes the electrical command signal (113) from the second to the first over a second time (T2), wherein T2 is greater than T1.

Abstract: A method of controlling shifting of a multiple ratio fluid motor (10) between first and second speed ratios. The motor includes a shift valve (61) operable to achieve the second speed ratio by interconnecting recirculating volume chambers (33R). The method includes providing a pressure control valve (75) in communication with a source (73) of pressure fluid, the valve (75) being operable to communicate a pilot pressure to the shift valve in response to changes in a command signal between a first signal (113B) and a second signal (113C). When a shift to the second condition is commanded, the method changes the command signal (113) from the first to the second over a first time (T1). For a shift back to the first condition (FIG. 3), the method changes the electrical command signal (113) from the second to the first over a second time (T2), wherein T2 is greater than T1.

Abstract: A multi-stage compression type rotary compressor 10 is provided with an electrical-power element 14, the first and second rotary compression elements 32, 34 driven by a rotary shaft 16 of the electrical-power element 14 in a sealed vessel 12. The refrigerant compressed by the first rotary compression element 32 is compressed by the second rotary compression element 34. The refrigerant is combustible. The refrigerant compressed by the first rotary compression element 32 is discharged to the sealed vessel 12. The discharged medium pressure refrigerant is compressed by the second rotary compression element 34. Additionally, the displacement volume ratio of the second rotary compression element 34 to the first rotary compression element 32 is set not less than 60% and not more than 90%. By using the multi-stage compression type rotary compressor, a rotary compressor using a combustible refrigerant can be carried out.

Abstract: A compressor has male and female rotors with enmeshed screw-type body portions. A housing cooperates with the rotors to define inlet and outlet chambers for pumping of fluid from/to when the male rotor in a first direction and the female rotor rotates in an opposite direction. The housing cooperates with the rotors to define inlet and outlet ports at the inlet and outlet chambers for each of a male and female compression pocket. The inlet ports and/or outlet ports of the respective male and female compression pockets are positioned to respectively close or open sequentially.

Abstract: A supercharger includes multiple back flow ports which are controlled by valves. The valves regulate the timing and area for back flow of pressurized outlet air into the rotor chambers. The back flow air tends to equalize air pressure in the chambers prior to their exhausting into the outlet and thereby reduces flow back noise. The multiple ports are opened selectively or sequentially to provide noise control with improved efficiency at varying speeds.

Abstract: A compressor has male and female rotors with enmeshed screw-type body portions. A housing cooperates with the rotors to define inlet and outlet chambers for pumping of fluid from/to when the male rotor in a first direction and the female rotor rotates in an opposite direction. The housing cooperates with the rotors to define inlet and outlet ports at the inlet and outlet chambers for each of a male and female compression pocket. The inlet ports and/or outlet ports of the respective male and female compression pockets are positioned to respectively close or open sequentially.

Abstract: A rotary vane pump, including a housing within which is rotatably mounted a rotor having a plurality of slots therein with a vane positioned for sliding movement within each of the slots. An access port is formed in the housing communicating with the rotor at a reference position in relation to the slots. The access port is sized to permit alignment of any one of the slots with the access port by rotating the rotor, maintaining the vane within the aligned one slot and at a datum within the slot, and permitting entry into the access port of an aligned slot of a stylus having a predetermined length in relation to the datum for determining the length of the vane. A determination of whether wear to the vane has met or exceeded a predetermined amount can be determined by reference to a portion of the stylus exterior to the access port.

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

Abstract: A scroll compressor having a hybrid wrap is defined to have its wrap origin offset from a drive center of both the orbiting and non-orbiting scroll members. The offset is selected in a direction such that it eliminates extremes in the torque curve relative to shaft rotation. In this way, torque reversal is generally eliminated.

Abstract: The invention comprises an arrangement for controlling the flow of a coolant fluid in a compressor, in particular in a rotary compressor, in which a coolant-fluid inlet for coolant fluid discharged from the compressor and a coolant-fluid outlet for returning the coolant fluid into the compressor are provided. A fluid cooler is also provided through which, when necessary, part of the coolant fluid can be directed for cooling and a system-control actuator is used to control the magnitude of the proportion of the coolant fluid that is directed through the fluid cooler on the basis of system parameters, in particular on the basis of the temperature of the coolant fluid.

Abstract: A hermetic scroll-type compressor including a housing having a motor mounted therein. A compression mechanism is also mounted in the housing and is operatively coupled to the motor. The compression mechanism is secured to a crankcase having a shield surface integrally formed thereon. A suction tube is provided having an outlet end mounted in the housing. At least a portion of the shield surface is substantially aligned with the outlet end such that an oil and refrigerant gas mixture entering the housing via the suction tube impinges upon the shield surface, whereby oil separates from the mixture.

Abstract: The present invention relates to a compressor (1) that has an associated coolant circulation system (1, 4, 6, 8, 11, 13), and also to a method of maintaining a low bacteria content in the coolant circulating system (1, 4, 6, 8, 11, 13), in which method gas and coolant are supplied to the compressor (1) during running of the system and the gas is compressed in the compressor (1) to an outlet pressure, the gas and the coolant are removed together from the compressor (1) and then separated into a respective gas and a liquid phase, whereafter the gas is passed to a recipient and the liquid is cooled before being returned to the compressor as coolant. The method is characterized by creating bacteria-killing conditions intermittently in the system by appropriating the heat-generating capacity of the compressor (1) to raise the temperature of the circulating coolant to at least 55° C. for a duration of at least 15 seconds.

Abstract: A drive rod has pins on each end of its body. Each pin has tapered threading and little or no undercut thereby enhancing its ability to transfer rotational motion through the drive rod string by increasing the surface area through which torque is transferred. The tapering of the threading on the pins allows for connectors having thicker walls. This means the connectors can withstand higher rotational stress. The drive rods and connectors are especially well suited for use with progressive pumps.

Abstract: A two-speed gerotor motor (10) including motor valve means (19,43) to communicate fluid to and from expanding (33E) and contracting (33c) fluid volume chambers. The motor includes a shift valve spool (61) to cause the motor to operate either in the normal, low-speed, high-torque (LSHT) mode (FIG. 3) or in a high-speed, low-torque (HSLT) mode (FIG. 4). When the motor operates in HSLT mode, certain of the volume chambers comprise recirculating volume chambers (33R). The motor (10) defines a supplemental fluid passage (89) through which fluid is communicated from a system charge pump (73) to each of the recirculating volume chambers (33R). A control valve (83) is operable, in a shift mode (S) to permit fluid communication from the charge pump (73) to the supplemental fluid passage (89), thus preventing cavitation during shifting of the motor (10), especially when shifting from the HSLT mode to the LSHT mode.

Abstract: A pump comprises multiple, axially stacked positive displacement fluid device sections, such as circumferential piston pumps having chambers and contra-rotating chambers. The device can be similarly employed as a fluid motor. The stacked sections are arranged within an outer retaining barrel in one or more stages. The pump is particularly suitable for installation downhole in the casing of a wellbore. Each section comprises a pair of rotors fit to shafts which are rotatably supported on hard faced bearings between the shafts and the bosses. Each pump section draws fluid from an inlet port and discharges fluid to a common and contiguous discharge manifold. The inlets of the pump sections for a suction stage communicate with a fluid source. Cross-over sections route fluid between stages. Successive pressure stages draw fluid from the cross-over fit to the preceding stage's discharge manifold.

Abstract: A pump comprises multiple, axially stacked positive displacement fluid device sections, such as circumferential piston pumps having chambers and contra-rotating chambers. The device can be similarly employed as a fluid motor. The stacked sections are arranged within an outer retaining barrel in one or more stages. The pump is particularly suitable for installation downhole in the casing of a wellbore. Each section comprises a pair of rotors fit to shafts which are rotatably supported on hard faced bearings between the shafts and the bosses. Each pump section draws fluid from an inlet port and discharges fluid to a common and contiguous discharge manifold. The inlets of the pump sections for a suction stage communicate with a fluid source. Cross-over sections route fluid between stages. Successive pressure stages draw fluid from the cross-over fit to the preceding stage's discharge manifold.

Abstract: The invention relates to a method for compressing a compressible medium, in which at least two displacement elements, each having at least one limiting face extending helically in the cross section, are orbited in relation to each other under formation of at least one chamber, the volume of the chamber being changed by the orbiting movement, performing a cycle with a suction phase, a compression phase and a discharge phase, the chamber being opened and forming a suction chamber during the suction phase. It is endeavoured to improve the thermodynamic conditions during compression of a compressible medium. For this purpose, for the duration of the suction phase, the suction chamber is reduced by a volume limiting element in such a way that at the end of the suction phase the chamber has a volume of at least 90% of a maximum volume appearing during the suction phase.

Abstract: An improved rotary engine and method for determining the contours of the sealing surfaces thereof. The improved engine provides for maintaining a predetermined, optimal gap between the sealing surfaces during rotation. The gap may be parallel or angled, and may be positive or negative so as to form an interference engagement. The rotors of the engine may be provided with mirror-image sealing surfaces so as to prevent development of excessive back-lash and clearance, and also to permit efficient reverse operation. The sealing surfaces may also be provided with recesses for interrupting the seal at predetermined points in the rotational cycle, for enhanced wear characteristics and/or to accommodate abrasive or shear-sensitive fluids.

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

Abstract: A method and apparatus for compressing process fluids in a working chamber having a male and a female rotor, each supported by shafts in a first and a second bearing chamber maintained at low and high pressures at least equal to 90% of the low and high pressures in the working chamber, respectively. The compressor has a first pressurized lubrication reservoir connected to the first bearing chamber and a second pressurized lubrication reservoir connected to the second bearing chamber. The fluids in the working chamber, which may be corrosive, are kept out of the fluids in the bearing and gear chambers by labyrinth seals on the rotor shafts, the seals having grooves in communication with a pressurized buffer gas system. Leakage of buffer gas from the seals enters the bearing chambers and reservoirs, and is released from them at flow rates to control the bearing chamber pressures.

Abstract: A scroll compressor includes a stationary scroll and a moveable scroll. The stationary scroll has a top surface, a bottom surface, and side edges extending between the top surface and the bottom surface. The moveable scroll moves in a path between the side edges of the stationary scroll. The moveable scroll has a top surface, a bottom surface, and side surfaces having side edges extending between the top surface and the bottom surface. At least one of the top surface and the bottom surface of the moveable scroll includes at least one inner ridge and an outer ridge, and a valley is located between each of the at least one inner ridge and the outer ridge.

Abstract: A scroll-type compressor having a stationary scroll and a movable scroll is provided. A compression chamber is defined between a stationary scroll and a movable scroll. A refrigerant introducing passage formed in the movable scroll for introducing a refrigerant from the compression chamber to a driving mechanism. The compressed refrigerant including a lubricant introduced through the passage is affective to lubricate the driving mechanism. The compressor may also include a sump to collect the lubricant leaving the driving mechanism. Collected lubricant is reintroduced into the compression region via a suction region of the compressor.

Abstract: A rotary vane pump, including a housing within which is rotatably mounted a rotor having a plurality of slots therein with a vane positioned for sliding movement within each of the slots. An access port is formed in the housing communicating with the rotor at a reference position in relation to the slots. The access port is sized to permit alignment of any one of the slots with the access port by rotating the rotor, maintaining the vane within the aligned one slot and at a datum within the slot, and permitting entry into the access port of an aligned slot of a stylus having a predetermined length in relation to the datum for determining the length of the vane. A determination of whether wear to the vane has met or exceeded a predetermined amount can be determined by reference to a portion of the stylus exterior to the access port.

Abstract: The present invention is directed to an apparatus and method for determining vane wear in rotary vane pumps that operate using slideable vanes. A view port is formed in an end of the pump housing. The view port is dimensioned such that a width of the port represents a predetermined amount of vane length loss. The view port is positioned in relation to the slots such that an end of the vane not in engagement with the wall of the pump will appear in the port only after a predetermined amount of vane loss occurs, and relative to the slots and the vanes to allow a determination of vane length for each vane when the vane is in engagement with the wall.

Abstract: A scroll compressor including a housing having a compression mechanism and a motor disposed therein, rotatively coupled by a drive shaft. A crankcase is disposed in the housing and supports the compression mechanism. A brake element is operatively engaged with the crankcase with at least one roller located therebetween. The roller has a first position relative to the brake element and the crankcase when the compressor operated in a forward direction, in which forward motion of the orbiting scroll member is unimpeded. At the onset of reverse rotation, the roller has an assumed second position relative to one of the brake element and the crankcase, in which the roller is in binding engagement with the brake element and the crankcase to arrest reverse motion of the orbiting scroll member.

Abstract: The invention is relative to a series of gear motors for differing output volumes with at least two gear motors. Each gear motor has at least two intermeshing displacing elements, a first displacing element and a second displacing element in the form of gears. The individual gear motors of the series comprise substantially identical dimensions for the axial interval between the theoretical axes and between the theoretical axes of rotation of the two displacing elements, and a substantially identical gearing width in the form of a substantially identical axial extension of the gearing elements. The individual gear motors differ from each other at least as regards the size of the tip circle diameter of at least one of the two displacing elements.

Abstract: A scroll compressor including a housing having a compression mechanism and a motor disposed therein, rotatively coupled by a drive shaft. A crankcase is disposed in the housing and supports the compression mechanism. A brake element is operatively engaged with the crankcase with at least one roller located therebetween. The roller has a first position relative to the brake element and the crankcase when the compressor operated in a forward direction, in which forward motion of the orbiting scroll member is unimpeded. At the onset of reverse rotation, the roller has an assumed second position relative to one of the brake element and the crankcase, in which the roller is in binding engagement with the brake element and the crankcase to arrest reverse motion of the orbiting scroll member.

Abstract: A scroll compressor includes a stationary scroll and a moveable scroll. The stationary scroll has a top surface, a bottom surface, and side edges extending between the top surface and the bottom surface. The moveable scroll moves in a path between the side edges of the stationary scroll. The moveable scroll has a top surface, a bottom surface, and side surfaces having side edges extending between the top surface and the bottom surface. At least one of the top surface and the bottom surface of the moveable scroll includes at least one inner ridge and an outer ridge, and a valley is located between each of the at least one inner ridge and the outer ridge.

Abstract: The invention is related to a series gear pump for differing output volumes with at least two gear pumps, each gear pump comprises at least two intermeshing displacing elements, a first displacing element and a second displacing element in the form of gears. The individual gear pumps of the series comprise a substantially identical dimensions for the axial interval between the theoretical axes and between the theoretical axes of rotation of the two displacing elements, and a substantially identical gearing width in the form of a substantially identical axial extension of the gearing elements. The individual gear pumps differ from each other at least as regards the size of the tip circle diameter of at least one of the two displacing elements.

Abstract: A multi-lobe, or Roots, blower has two multi-lobe rotors connected for rotation to two drive gears one of which drive gears is connected for rotation to a motor by a quill drive spanning one of the rotors. In sequence, the multi-lobe rotors are preferably within a first chamber of a monolithic housing, the drive gears within a second chamber, and the motor outside the housing. In the quill drive a central shaft is affixed at one end to a shaft of the motor, and at its other end to a hollow tubular shaft containing the central shaft. The tubular shaft affixes at its exterior both one of the two drive gears and one of the two multi-lobe rotors. The quill drive thus transmits torque from the shaft of the motor along the central shaft completely through the first chamber and a multi-lobe rotor therein until, ultimately affixing the tubular shaft and the drive gear within the second chamber, the drive gears and the rotors are caused to be rotated.