Abstract: The present application provides a screw compressor that comprises a first male rotor and a second male rotor, each of the first male rotor and the second male rotor having convex-helical teeth, the first male rotor and the second male rotor being rigidly connected together; a first female rotor and a second female rotor, each of the first female rotor and the second female rotor having concave-helical teeth, the first female rotor being arranged separately from and opposite to each other; wherein the convex-helical teeth of the first male rotor are engaged with the concave-helical teeth of the first female rotor, and the convex-helical teeth of the second male rotor are engaged with the concave-helical teeth of the second female rotor. The male rotors in the screw compressor are symmetrically so that the axial force exerted on the first male rotor counteract with the axial force exerted on the second male rotor.

Abstract: A fluid transfer pump that has a housing, a body portion movable within the housing between a first position and a second position, a gear coupled to the housing, a body cavity defined partially between the body portion and the housing, and an aperture defined in the housing that selectively provides a fluid to the body cavity. When the fluid is applied to the body cavity at or above a pilot pressure, the body portion is in the first position adjacent to the gear and when the fluid is applied to the body cavity at a fluid pressure lower than the pilot pressure, the body portion is in the second position and spaced from the gear.

Abstract: A gerotor pump having an inner rotor and an outer rotor, which is also the rotor of an electric drive, having a housing and a flange which closes the housing with the motor compartment, the rotor being arranged on a shaft and sealing against the flange at a gap, wherein, in addition to the gap, there is at least one device with which at least a partial pressure compensation takes place between the suction region of the gerotor pump and the motor compartment of the gerotor pump.

Abstract: Rotary systems are described, which can include at least one of compressors and vacuum pumps. Each rotary system includes a corresponding piston that rotates in an orbital motion around a respective eccentric of a shaft in order to either compress fluid or function as a vacuum pump. Multiple rotary systems can be executed on parallel on a single shaft such that these rotary systems are powered by a single motor. Various components of the rotary systems are coated with an abradable coating, which minimizes friction when these components come in contact with each other. The minimized friction minimizes the wear and tear of these components. Each rotary system can be lubricated by only the fluid being processed (for example, compressed or vacuumed) by that rotary system. The use of the fluid being processed for lubrication and the abradable coatings eliminate a need for another lubricant for lubricating the rotary system.

Abstract: An aspect of the present disclosure involves a rotary compressor that is primarily optimized for use without the need for liquid lubricants, such as in the flow path of the fluid being compressed, and is efficient and quiet to use. The compressors described herein are efficient, run quietly, use less power, and last longer than those previously known in the art. The compressors are useful for medical applications and other clean gas applications, for instance, where lubricants could contaminate the fluid being compressed and/or increased noise and/or vibration may be problematic.

Abstract: A spindle rotor pair of a spindle compressor has a two-toothed spindle rotor and a three-toothed spindle rotor meshing the other without contact. The wrap angle related to the two-toothed spindle rotor is at least 800 angular degrees. A range of at least 30 m/sec is achieved as the mean circumferential speed of the rotor head. In the transverse section, both spindle rotors have arc sectors and cycloid profile contour flanks. In the case of the two-toothed spindle rotor, they are primarily above its gear-tooth pitch circle and of convex design, however, in the case of the three-toothed spindle rotor, they are below its ear-tooth pitch circle and of concave, i.e., hollow, design. Preferably, the transverse sections of each spindle rotor are symmetrical in a way that in each transverse section, the centre of gravity of the profile surfaces comes to lie on the respective rotor pivot point.

Abstract: A shaft assembly includes a gear with a gear bore having a splined bore section adjacent to an oil dam. A shaft includes a first splined end section and a second splined end section, the first splined end section engageable with the splined inner diameter, the shaft having a bore with a bore diameter greater than a diameter of the oil dam, a first set of radial apertures axially inboard of the first splined end section in communication with the shaft inner bore and a second set of radial apertures axially inboard of the second splined end section in communication with the shaft inner bore that altogether provide lubrication of the splined end sections.

Abstract: A vacuum pump of a vehicle for reducing operation noise may include a rotor rotating in a space defined by a housing formed in a pump body at an eccentric position relative to a center of the space, a vane installed to the rotor to rotate eccentrically in the space, and an oil outlet passing through the pump body and formed at a predetermined height above a lower limit of the space such that, when lubricant in the space is discharged in a pressurized state by the vane, the lubricant is not reintroduced back into the space by gravity.

Abstract: A compressor is provided having an accumulator that forms an accumulating chamber in an internal space of a shell of the compressor, reducing a size and simplifying an assembly process. A stationary shaft having a refrigerant suction passage may be directly connected to the accumulator to prevent leakage of refrigerant. A center of gravity of the accumulator may correspond to a center of gravity of the compressor to reduce vibration caused by the accumulator. An eccentric portion may be provided at the stationary shaft to secure a spacious compression space. Both ends of the stationary shaft may be supported by a frame to reduce vibration. A rotor and a cylinder may be coupled with a bearing to reduce cylinder deformation. An installation area of the compressor may be minimized to enhance design flexibility of an outdoor device employing the compressor and minimize interference with other components.

Abstract: A rotary vacuum pump, for instance a vane pump, has at least one circumferential groove (6) between facing side surfaces of the rotor (2) and of the rotor guide (3) for receiving a lubricating and sealing fluid. The circumferential groove (6) is a partial annular groove, which has an angular extension of less than 360° and has at least one interruption enabling creating a hydrodynamic fluid bearing in a region opposite a discharge region of the pump (1; 101; 121; 201), over the whole axial extension of the facing surfaces. A method of lubricating a rotary vacuum pump is also provided.

Abstract: The present invention relates to an automotive vacuum pump 10. The vacuum pump 10 has a casing 12 defining a cavity having an inlet 14 and an outlet 16, wherein the cavity contains a rotor 18 and a vane slidably mounted to the rotor 18. The rotor 18 extends through a side 21 of the casing 12 to the exterior thereof and is provided with a coupling arrangement 26 to couple the rotor 18 to a drive member. The vacuum pump 10 is provided with a lubrication conduit 50, 56, 66, 68, 70, 72, 74 for the supply of lubricating fluid to the coupling arrangement 26, the conduit 50, 56, 66, 68, 70, 72, 74 including a portion 70, 72, 74 which extends through the rotor 18 and the coupling arrangement 26.

Abstract: In aspects, the disclosure provides a drilling motor that includes a lubricating unit that selectively supplies a lubricant to the drilling fluid before the drilling fluid passes through the drilling motor so as to lubricate the stator and/or the rotor to reduce friction between the stator and the rotor and to reduce wear of the motor.

Abstract: The invention relates to a vacuum pump comprising a cup-shaped housing, a rotor eccentrically mounted for rotation in the housing, and a housing cover closing the cup-shaped housing, wherein the rotor has a rotor shaft that passes through the cup-shaped housing and by which the rotor is driven, wherein the rotor shaft is provided with a bore for delivering a lubricant, and a connection nipple is seated in the free end section of the bore.

Abstract: A gas pump including a delivery chamber with an inlet and an outlet for a gas; a first housing part with a first sealing surface which at least partially surrounds the delivery chamber; a second housing part with a second sealing surface which at least partially surrounds the delivery chamber, wherein the second housing part together with the first housing part at least partially encloses the delivery chamber; a delivery device which can be moved within the delivery chamber, for delivering the gas; and a pressing device which presses one of the housing parts against the other with a pressing force, such that the sealing surfaces abut each other and together form a sealing join which at least partially surrounds the delivery chamber, in order to seal off the delivery chamber, wherein the second housing part can be moved relative to the first housing part, against the pressing force, in order to be able to widen the sealing join to form a relieving gap through which liquid situated in the delivery chamber can e

Abstract: A screw compressor includes a screw rotor, a gate rotor and an injection mechanism. The screw rotor is provided with multiple helical grooves. The gate rotor is provided with multiple gates meshing with the helical grooves to form at least one compression chamber between at least one of the helical grooves and at least one of the gates. The compression chamber is configured and arranged such that refrigerant taken-in from a starting-end side of the helical groove is compressed and discharged from a dead-end side of the helical groove. The injection mechanism is configured and arranged to inject oil or refrigerant from a discharge hole of the injection mechanism into the compression chamber such that rotational torque is imparted in a direction in which the screw rotor is rotated at a time of compression.

Abstract: A pump comprises a rotor arrangement and a stator arrangement. The stator arrangement comprises a first part made from a corrosive resistant material which defines a volume which in use is swept by the rotor arrangement for pumping fluid from an inlet to an outlet of the stator arrangement. A second part of the stator arrangement is made from a thermally conductive material which envelopes the first part so that heat generated in the first part can be transferred to the second part at the interface surface between the two parts. The second part has formed therein at least one duct 80 for conveying a liquid coolant through the second part so that heat can be transferred from the second part to the liquid coolant for cooling the stator arrangement.

Abstract: The invention relates to a rotary piston engine, in particular a rotary engine of trochoidal design, with a side disk (4) on the exhaust side and a rotary piston (6) with at least of one, and preferably three, through-flow openings (6) through which the mixture can flow axially, wherein the side disk (4) on the exhaust side has a side exhaust port (43) and the at least of one through-flow opening (60) has an asymmetric internal contour (600) at least on its exhaust side, so that when the rotary piston (6) passes over the side exhaust port (43) the said side exhaust port (43) is not in fluid communication with an internal area of the through-flow opening (60). The invention further relates to a rotary piston (6) for a rotary piston engine.

Abstract: The present invention relates to a scroll compressor, with an oil-separating drive shaft, that comprises a housing a fixed scroll which is installed inside the housing, a orbiting scroll which orbits around the fixed scroll, and a drive shaft which drives the orbiting scroll. In the orbiting scroll, a discharge hole is formed. A discharge path is formed along the longitudinal direction of the drive shaft so that discharged coolant from the discharge hole flows therethrough. At least, a part of the discharge path is inclined forward from the rotary axis to the exterior. A lubrication hole is formed in the drive shaft that penetrates from the discharge path to the outer surface of the drive shaft.

Abstract: A fluid machine (101) includes a first compressor (107) and a second compressor (108). The first compressor (107) has a first closed casing (111), a first compression mechanism (102a), an expansion mechanism (104), and a shaft (113). A first oil reservoir (112) is formed in the first closed casing (111). The second compressor (108) has a second closed casing (125) and a second compression mechanism (102b). A second oil reservoir (126) is formed at a bottom portion in the second closed casing (125). The first closed casing (111) and the second closed casing (125) are connected to each other by an oil passage (109) so that a lubricating oil can flow between the first oil reservoir (112) and the second oil reservoir (126). An opening (109a) of the oil passage (109) on a side of the first closed casing (111) is located above the expansion mechanism (104) with respect to the vertical direction.

Abstract: An anti-self rotation mechanism for preventing self-rotation of the eccentric shaft includes a long orbiting key formed at an end of the eccentric shaft, a ring formed of a long hole through which the orbiting key slides, ring keys that extend toward both outer sides in the direction orthogonal to the longitudinal direction of the hole, and two key grooves formed in the casing, through which the ring keys slide.

Abstract: The invention relates to a dry-compressing dual-shaft rotary displacement screw spindle pump machine for delivering and compressing gases. The spindle rotor pair therein includes multiple stages, having a primary delivery thread, a secondary delivery thread and a gas outlet collector chamber therebetween. The primary delivery thread head circle diameter decreases in the gas outlet direction, while the foot circle diameter thereof increases correspondingly for an application-specific matching inner “integral” compression ratio. The secondary delivery thread nominal delivery direction is opposite to the primary delivery thread nominal delivery direction. The secondary delivery thread is implemented such that the actual gas flow direction is opposite to the nominal delivery direction thereof, and is always directed away from the gas outlet plenum, having a gas permeation under ambient pressure just as the space in the gearbox.

Abstract: The invention relates to a vacuum pump comprising a cup-shaped housing, a rotor eccentrically mounted for rotation in the housing, and a housing cover closing the cup-shaped housing, wherein the rotor has a rotor shaft that passes through the cup-shaped housing and by which the rotor is driven, wherein the rotor shaft is provided with a bore for delivering a lubricant, and a connection nipple is seated in the free end section of the bore.

Abstract: A capacity varying type rotary compressor and a refrigeration system having the same are provided. The capacity varying type rotary compressor includes a casing that contains a certain amount of oil and maintains a discharge pressure state; a motor installed in the casing that generates a driving force; one or more cylinder assembly fixed in the casing, having a compression space that compresses a refrigerant by a rolling piston that performs an orbit motion and a vane that performs a linear motion by contacting the rolling piston, and having a vane pressure chamber formed at a rear side of the vane that implements a normal driving as the vane contacts the rolling piston or a saving driving as the vane is separated from the rolling piston; and a mode switching device that selectively supplies a suction pressure or a discharge pressure to the vane pressure chamber of the cylinder assembly according to a driving mode.

Abstract: An axial air cooling system for scroll-type positive fluid displacement apparatus provides needed cooling. The system includes an axial fan and centrifugal pump and internal cooling air channels inside parts integrating main housing, base housing and motor housing with their corresponding shell parts by cooling fins. The cooling air channel also includes passages inside the orbiting scroll, shaft central hole and gaps inside stator slots and winding. Heat pipes are installed inside the fixed and orbiting scrolls to conduct heat from inside of the apparatus to the peripheral condenser portion of the heat pipes to be cooled by the cooling air.

Abstract: A piston cooling system for a pivoted piston (1) for an internal combustion engine, said piston (1) having a piston body (2), a pivot shaft (3) by which the piston body (2) may be pivoted about a pivot axis (4) within a combustion chamber of the internal combustion engine, a first arcuate sealing surface spaced from the pivot axis and transcribing a circumferential path about the pivot axis, and a second arcuate sealing surface radially offset from the first arcuate sealing surface and connected to the first arcuate sealing surface by a floor (5) of the piston body (2), a portion of said floor (5) including a combustion chamber piston crown (6), characterised in that the cooling system includes a coolant path (10) formed in the piston, said coolant path having an entry point at a first end (11) of the pivot shaft (3) and an exit point at a second end (12) of the pivot shaft (3), wherein said coolant path (10) extends from the entry point, through a first portion (13) of the pivot shaft (3), into said piston b

Abstract: A pneumatic vane motor comprising a housing (10) with a cylinder (11), two end walls (13,14), and a rotor (18) journalled in the housing (10) and carrying one or more pairs of sliding vanes (31), and vane supporting pins (32) longitudinally movable in transverse bores (33) in the rotor (18) and forming spacers between two diametrically opposite vanes (31), and the rotor (18) having a coaxial bore (48) with a closed end (49) and an open end (50) closed by a removable plug (51), wherein the coaxial bore (48) intersects the transverse bores (33) and being filled with a lubricant for providing lubrication of the vane supporting pins (32).

Abstract: A vane air motor is disclosed which is configured to prevent grease in a radial bearing from leaking into a rotor chamber. The vane air motor has a motor housing (20) having a rotor chamber, a rotor (22) with vanes (24) disposed in the rotor chamber, a first end wall (16) of the motor housing equipped with a radial bearing (50) rotatably supporting a support shaft portion (28) of the rotor, and a casing contiguously joined to the motor housing to form a compressed air supply chamber (44) together with the first end wall to supply compressed air into the rotor chamber through an air supply hole (46) formed in the first end wall. The first end wall has communication means (16-5, 16-6 and 16-7) for supplying compressed air from the compressed air supply chamber to the side of the first radial bearing closer to the rotor.

Abstract: An oil-free lubrication centrifugal refrigerant compressor for compressing low-pressure refrigerant into high-pressure refrigerant, includes: a housing; a refrigerant pathway; a compression module; a radial bearing; a first conducting member, collecting troughs and a first exhaust member.

Abstract: A rotor assembly for a supercharger assembly is provided. The rotor assembly includes at least one lobe defining at least one cavity. The at least one cavity is configured to contain a fluid operable to cool the at least one lobe. A supercharger incorporating the rotor assembly is also disclosed.

Abstract: An oil supply groove 12 in communication with a pump room 2A is formed above a bearing 2B of a housing 2, and an open air groove 14 in communication with an atmospheric air is formed at a position rotated around the bearing 2B by 90° from the oil supply groove. In a shank 3B of a rotor 3, a branch passage 11a branching from an oil passage 11 formed in its axial direction to the diametrical direction of the shank and an open air passage 13 formed in the direction perpendicular to the branch passage are formed. The branch passage and the oil supply groove communicate with each other while the open air passage and the open air groove are arranged to also communicate with each other. When the oil passage and the oil supply groove communicate with each other as the rotor stops, atmospheric air flowing in from the open air passage eliminates a negative pressure in the pump room to prevent the lubricating oil from flowing into the pump room in large quantities.

Abstract: Provided is an oil-cooled type screw compressor having a compressor body for compressing a suction gas and discharging the compressed gas.

Abstract: A fluid machine (10) includes: a closed casing (11) having an oil reservoir (16) in its bottom portion; a main compression mechanism (3) supplied with oil contained in an upper portion (16a) of the oil reservoir; a rotation motor (8); a main compression mechanism side shaft (38) for coupling the main compression mechanism (3) and the rotation motor (8); a mechanical power recovery mechanism (5) disposed below the upper portion (16a) and recovering mechanical power from a working fluid; a sub-compression mechanism (2) disposed below the upper portion (16a); a mechanical power recovery shaft (16) for coupling the mechanical power recovery mechanism (5) and the sub-compression mechanism (2); and a heat-insulating structure (80) located between the upper portion (16a) and the mechanical power recovery mechanism (5) and restricting flow of oil between the upper portion (16a) of the oil reservoir (16) and a lower portion (16b) of the oil reservoir in which the mechanical power recovery mechanism (5) is provided.

Abstract: A baffle member for use in scroll compressors. In one exemplary embodiment, the baffle member is attached to a portion of the crankcase and, in use, deflects lubricant that may be thrown from the thrust surface of the crankcase during operation of the compressor away from the flow of working fluid, and also aids in directing the flow of working fluid away from the thrust surface of the crankcase and toward a suction inlet in the compression mechanism.

Abstract: A rotary combustion engine with at least one working unit, which has essentially a peripheral engine housing, a side housing plate on one side, a side housing plate on the power takeoff side, a triangular piston, and an eccentric shaft. The piston is configured of several parts, which are connected to each other. The connection is accomplished by electron-beam welding under vacuum, which yields excellent results as long as certain conditions are met. The one sidewall and the power takeoff sidewall of the piston are preferably welded to a piston housing, as a result of which the casting molds can be of simpler design and simpler contours can be used, which leads to welds of higher quality and to a decrease in the costs of casting.

Abstract: The invention relates to a scroll-type refrigerant compressor The inventive compressor comprises: a sealed chamber which is defined by a ferrule (2) and which contains a suction volume and a compression volume; and an electric motor which is disposed on the suction side and which comprises a stator (7) and a rotor (8), the latter being solidly connected to a drive shaft (26). The stator (7) is surrounded by an intermediate casing (6) which defines (i) an annular volume (13) with the moving ferrule (2) of the compressor and (ii) a chamber (11) containing the coil end of the motor and facing the compression volume side. The end of the intermediate casing that faces the side opposite the compression volume is disposed at the end of the stator facing the side opposite the compression volume or set back from same. In addition, means (14) are provided in order to convey at least part of the gas arriving at the gas inlet in the ferrule into the chamber (11) containing the coil end.

Abstract: According to the present invention, an oil supply passage is formed in a suction space of a fixed scroll part, and an oil collision part is provided in the suction space. The oil collision part is provided in the suction space, an amount of oil to be supplied is controlled, refrigerant and lubricant oil are sufficiently mixed with each other. Tangents of ends of the oil collision part are made acute angle to smoothen the flow of the refrigerant.

Abstract: The invention relates to the rotor housing (1) of a helical screw compressor which is surrounded by a cooling housing (21, 23, 25) which forms a cooling chamber (27) which surrounds the rotor housing (1) in an annular-shaped manner, said cooling chamber being intercepted on a point by a separating wall (29) which connects the rotor housing (1) to the cooling housing (21). The coolant, which is guided to an inlet (31), is oriented counter to the lower side of the separating wall (29) through a perpendicular inlet channel (35) which flows in an upward direction, is deviated there and flows about the rotor housing (1) until the upper side of the separating wall (29), where it is deviated again and is discharged to the outlet opening (33) through a perpendicular outlet channel (37) which extends in an upward manner.

Abstract: A compressor and an oil supplying structure therefor are provided. When a compressor is operated at a high speed or low speed, a predetermined amount of oil is supplied to compression pockets formed between a wrap of an orbiting scroll and a wrap of a fixed scroll. Pressure leakage between the wraps may be prevented, thereby enhancing a performance of the compressor. Further, since friction between the orbiting scroll and the fixed scroll may be prevented, abrasion of the components may be minimized.

Abstract: A hermetic rotary compressor operates two cylinders simultaneously in the regular operation; however it halts operating one of the cylinders when it selects an operation with a half capacity. A vane room of the halted cylinder is air-tightly sealed with respect to lubricant atmosphere in a hermetic case. An oil-supplying groove is provided to a vane groove of the halted cylinder, and lubricant is supplied to the oil-supplying groove in order to lubricate the vane.

Abstract: In a compression/expansion unit (30) serving as a fluid machine, both a compression mechanism (50) and an expansion mechanism (60) are housed in a single casing (31). An oil supply passageway (90) is formed in a shaft (40) by which the compression mechanism (50) and the expansion mechanism (60) are coupled together. Refrigeration oil accumulated in the bottom of the casing (31) is drawn up into the oil supply passageway (90) end is supplied to the compression mechanism (50) and to the expansion mechanism (60). Surplus refrigeration oil, which is supplied to neither of the compression and expansion mechanisms (50) and (60), is discharged out of the terminating end of the oil supply passageway (90) which opens at the upper end of the shaft (40). Thereafter, the surplus refrigeration oil flows into an oil return pipe (102) from a lead-out hole (101) and is returned back towards a second space (39).

Abstract: A groove is provided in the periphery of a pressure receiving area of a pressure receiving surface opposing to the load of axis weight within a bearing surface supporting an axis, and a liquid supply route communicating with the groove is provided so that liquid is supplied to the groove through the liquid supply route. In such a configuration, a bearing having a simple structure and a high compact load capacity and a liquid cooling type screw compressor using the above bearing are provided.

Abstract: A scroll compressor is provided with a passage for providing both an unloader function and an economizer injection function. This common passage communicates with separate ports. The ports that are exclusively used for by-pass unloading operation are open only during by-pass unloading operation, but blocked off by a check valve during vapor injection operation. The other, normally smaller vapor injection ports are open for both vapor injection and by-pass unloading operation. By utilizing these two sets of ports, a smaller total port area is provided for vapor injection operation and a much larger total open port area for by-pass operation. The different open port areas for by-pass unloading operation and vapor injection operation allows optimization of compressor operation at both of those regimes of operation.

Abstract: A rotary combustion engine with one or more working units, which include a peripheral housing, a front housing plate, a rear housing plate on the output side, an eccentric shaft, and a piston, where the eccentric shaft includes an eccentric, and front and rear sealing parts. Lubricating oil is conveyed by an oil pump from an oil tank through the eccentric shaft to first and second main bearings, and to an eccentric bearing, from which a bevel on the front sealing part conveys it to a piston space, from which it is conveyed by way of a bevel on the piston and a rear bevel back to the oil tank to close the oil circuit. The bevels direct the oil circulation from the front of the working unit to the rear, reduce splash losses, and increase the cooling action on the internal surfaces of the piston.

Abstract: A scroll-type compressor is provided in an inclined or inverted position with an oil sump disposed adjacent to a gas inlet of the scroll wraps to allow droplets of oil to be entrained in the gas being compressed so that the oil droplets in the gas can cool the scroll wraps. An oil injection fitting also extends through the compressor shell and communicates lubricating oil to a lubrication passage in the crankshaft for providing lubricant to the bearings of the crankshaft of the compressor and other components. The oil injection fitting is supplied with lubricant from an externally disposed source.

Abstract: According to one embodiment of the invention, a gerotor apparatus includes an outer gerotor having an outer gerotor chamber, an inner gerotor, at least a portion of which is disposed within the outer gerotor chamber, and a synchronizing apparatus operable to control the rotation of the inner gerotor relative to the outer gerotor. The inner gerotor includes one or more entrance passages operable to communicate a lubricant into the outer gerotor chamber.

Abstract: A scroll-type fluid machine such as a scroll compressor or a scroll vacuum pump generates compression heat during compressing operation. A scroll body comprises a stationary scroll and an orbiting scroll that is revolved with respect to the stationary scroll eccentrically. The stationary scroll has a stationary wrap and the orbiting scroll has an orbiting wrap engaged with the stationary wrap to form a compression chamber therebetween. In the scroll-type fluid machine, a cooler is provided to cool high-temperature compressed air discharged from a discharge bore at the center of the stationary scroll.

Abstract: A screw vacuum pump (1) has shafts (7, 8) and rotors (3, 4) secured to the shafts. Each rotor has a central hollow chamber (31) which receives the shaft or contains in built-in components rotating along with the rotor to define a relatively thin annular slot segment (32) for cross-flow circulation of coolant. The annular slot segment is disposed between the built-in components and an inner wall of the rotor's hollow chamber and between a suction side and a delivery side of the rotor. Separate feed and discharge lines (41, 55, 63, 77, 78, 81, 89, 99, 101, 103) circulate the coolant through the annular slot segment in such a way that the coolant remains cavitation-free and bubble-free.

Abstract: An oil storage area (45a) is defined on the bottom of a motor chamber (45) of a scroll compressor (1). An oil transfer route (4a) is defined in the portion of a center housing (4) that corresponds to the storage area (45a). Lubricating oil L is separated from the discharged, compressed refrigerant by an oil separator (80) and the lubricating oil L is supplied to the backside of a movable scroll (20) due to a pressure differential within the compress (1). After lubricating a bearing (10), the lubricating oil L is temporarily stored in the storage area (45a) and then is transferred due to a pressure differential to the suction-side of a compression mechanism (21) via the oil transfer route (4a). The lubricating oil L is then transferred to the oil separator (80) together with the compressed refrigerant that is discharged from a compression chamber (32) of the compression mechanism (21).

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 fluid machinery comprises a helical mechanism provided with a cylinder, a roller eccentrically disposed inside the cylinder and formed with a helical groove and a blade member fitted in the helical groove, an electric motor unit connected to the helical mechanism through a rotational shaft, the roller, which eccentrically rotates, having an engagement portion engaged with a crank portion of the rotational shaft, and a pair of bearings disposed to both axial end portions of the cylinder so as to support the rotational shaft. The engagement portion of the roller and the bearings are formed with through holes for ventilation, respectively.