Abstract: A seal assembly configured for use with a high pressure single screw compressor includes a seal body and at least one attachment structure. The at least one attachment structure fixedly attaches the seal body to the rotor of the compressor, such that the seal body is rotatable along with the rotor. The seal body has a textured outer surface which creates a labyrinthine path between the compressor housing and the seal body.

Abstract: A screw compressor element may have a housing; a cylinder bearing including an inner ring, an outer ring, a raceway, and a cylindrical rolling element that contacts the inner ring and the outer ring at a location of the raceway thereof; and a ball bearing including an inner ring, an outer ring, a raceway, and a ball shaped rolling element that contacts the inner ring and the outer ring at a location of the raceway thereof, wherein a rotor is rotatably arranged by way of the cylinder bearing and the ball bearing.

Abstract: The invention relates to a dual-spindle helical spindle pump with a single-entry design, comprising a pump housing (11) which has a pump portion (12), a bearing portion (13) and a gear portion (14) with a gear chamber, wherein the bearing portion (13) and the pump portion (12) are designed separately from one another, comprising a feed housing part (50) as a component of the pump portion (12) in which two feed screws (17, 18) are provided, said feed screws having flanks (46) and being arranged on shafts (15, 16) in a feed space (51), wherein the shafts (15, 16) are mounted in the bearing portion (13) (external bearing system) and extend into the gear portion (14), and wherein the feed housing part (50) has at least one feed portion (52) with an inner wall (58) which faces the outer face (59) of the feed screws (17, 18).

Abstract: A screw spindle pump for delivering a cooling liquid for cooling a battery and/or power electronics or a cleaning or supply liquid of a motor vehicle, including a housing in which a working spindle, which is coupled to a drive assembly, and at least one running spindle, which meshes with the latter, are accommodated, and including a feather key-like support element, which is fixed by the housing and against which the working spindle and the running spindle are axially supported. In the housing, there is provided at least one aperture through which it is possible to insert the support element, which, in the assembled position, is received with one end in the aperture and with the other end in a receiving part situated diametrically opposite the aperture, wherein the support element is secured via at least one securing element which closes the aperture at the outside.

Abstract: A screw-spindle pump stage having a drive spindle and a running spindle which runs opposite the drive spindle and a pump housing for receiving the two screw spindles. The pump housing 16 has an offset interface with centering action, for a statically determined coupling to an electric motor. The pump housing has an offset section functioning as an abutment, which is able to be abutted against the electric motor for the application of an axial preload. At least one pressure region of the abutment section, which is close to the interface and, during a rolling, is encapsulated, and at the same time sealingly enclosed, by a sheet-metal casing, forms a rolling region of the pump, the screw spindles, together with the associated pump housing section, at least partially project from the rolling region of the pump on the suction side.

Abstract: A refrigerator utilizes an ice dispensing system incorporating first and second ice movers and a controller that operates the first ice mover to move ice toward the first end of a storage bin and out of a dispenser outlet during an ice dispensing operation, and operates the second ice mover concurrently with operating the first ice mover to circulate ice in the storage bin during an ice circulation operation.

Abstract: A blower may include a blower housing that may include a plurality of rotor chambers and a plurality of rotors. The plurality of rotors may be substantially identical and each may include a twist angle and a helix angle. The rotors and the blower housing may be configured to create internal fluid compression when the rotors are rotating at a first rotational speed and not to create internal fluid compression when the rotors are rotating at a second rotational speed. The rotors and the blower housing may be configured to create the internal fluid compression without backflow slots in the blower housing. The twist angle may include the angular displacement of lobes of the plurality of rotors between axial ends of the plurality of rotors. The helix angle may be a function of the twist angle and a pitch diameter of the plurality of rotors.

Abstract: A high suction pressure thrust load balance assembly configured for use with a single screw compressor includes comprises a sealing baffle that is keyed to, so as to be rotatable along with, a main rotor drive shaft of the single screw compressor. The sealing baffle is configured to create a force or load to counteract the axial force of the main rotor drive shaft created during rotation of the main rotor drive shaft using the pressurized oil used to lubricate the mechanical shaft seal of the compressor.

Abstract: Volumetric compressor (1) for collection and/or treatment equipment of material in liquid, solid, dusty or muddy form. The compressor (1) comprises an operative chamber (50), defining a suction section and an exhaust section of a first fluid, a first header (61) and a second header (62), which delimit said chamber (50) on opposite parts along a longitudinal axis (101). The compressor further comprises at least two rotors (80?, 80?) with lobes (81?, 81?) housed in the chamber (50), each rotor (80?, 80?) rotating about a rotation axis (108?, 108?) substantially parallel to said longitudinal axis (101). The lobes of each rotor develop according to a helical profile. Furthermore, each of the headers (61,62) defines at least one injection opening (71?, 71?,72?,72?) communicating with a feeding device (150) of a second fluid.

Abstract: A gear pump having double-helical gears with bearing assembly seals and gear end seals which provided double seal interfaces between the pump cavity and bearing cups having disposed therein bearing assemblies for supporting pump shafts for rotation. The double seal interfaces preclude pumped fluid, particularly contaminated fluid including entrained abrasives from making contact with the bearing assemblies. An adjustable packing seal mechanism, a gear gap adjustment mechanism, a fluid pressure relief system, and pump heat exchanger features are also disclosed.

Abstract: A screw compressor includes a housing having an inlet for receiving gas to be compressed by the compressor and an outlet for discharging pressurized compressed gas. A pair of meshing threaded rotors, each rotor having an axis and being rotatably received in the housing, each rotor having a first end near the inlet and a second end near the outlet. A bearing rotatably carrying each rotor about its axis and positioned near the first end and the second end of each rotor. A conduit formed in the housing in selectable fluid communication with at least one bearing and a force generating source from a pressurized fluid source, the force generating source selectably providing a force in a radial direction relative to the axis of the at least one bearing.

Abstract: A method for converting energy from compressed air into mechanical energy, and a compressed air motor therefor. The motor includes a shaft rotor and a counterpart rotor which intermesh with each other using trochoid toothing to effect rotation of a power takeoff shaft. Compressed air is used to operate the counterpart rotor which then operates the shaft rotor thereby converting the rotation of the shaft rotor or the power takeoff rotor into mechanical rotary energy.

Abstract: A screw compressor has a balance bearing whose outer ring is movable relative to the casing. A balance piston divides a balance cylinder into a high pressure fluid chamber and a low pressure fluid chamber, and movement of the piston in the balance cylinder is transmitted to the outer ring of the balance bearing. The high pressure fluid chamber and the low pressure fluid chamber are arranged such that higher pressure fluid in the high pressure fluid chamber urges the piston to press the outer ring of the balance bearing oppositely to a spring and toward the main thrust bearing, and lower pressure fluid in the low pressure fluid chamber urges the piston to press the outer ring of the balance bearing away from the main thrust bearing.

Abstract: The invention relates to a gas flow separator dividing the flow into a primary and a secondary stream, especially for a dual rotor axial turbomachine. The separator comprises a splitter nose of the turbomachine and includes a generally wedge-shaped leading edge in the gas flow to be split. The flow separator also comprises a metal blade having a longitudinal section in the form of an “S” and located in the nose in contact with the back of the leading edge and extending from the leading edge to a rear end of the separator at some distance from the leading edge, so as to be in contact with a heat source, such as a heat exchanger, located at some distance from the leading edge.

Abstract: A system is provided for controlling the balance piston pressure in a screw compressor. The system can use the slide valve of the compressor as a valve to control the flow of fluid from a fluid source to the balance piston. When the slide valve prevents direct flow between the fluid source and the balance piston, an alternate path is used to provide fluid at a reduced pressure to the balance piston. The reduced pressure fluid is obtained by passing the fluid from the fluid source through an orifice to lower the fluid pressure.

Abstract: A gear drive assembly for a supercharger is provided. The gear drive assembly has at least one gear member rotatable about an axis of rotation and includes a cover member operable to substantially enclose the at least one gear member. A tube member extends though the cover member and is generally aligned along the axis of rotation. The tube member is operable to vent the gear drive assembly. A supercharger assembly incorporating the gear drive assembly is also disclosed.

Abstract: A positive-displacement rotary pump comprising a pair of meshing gears (13, 14) or rotors, consisting of a driving gear and a driven gear, contained in a shell (10) having an output opening and an intake opening for a fluid. The gears (13, 14) include shafts (23, 24) which are supported by bushings (15a, 15b) having two faces (17a, 17b) which are subjected, in use, to pressures which bring about an axial load on the bushing itself, wherein the resultant of the axial loads (S?, S?) on the two bushings has a predetermined direction so as to move the bushings (15a, 15b) and the gears (13, 14) as a whole into close abutment with a predetermined reference plane (VI—VI).

Abstract: A positive-displacement rotary pump comprising a pair of meshing gears (13, 14) or rotors, consisting of a driving gear and a driven gear, contained in a shell (10) having an output opening and an intake opening for a fluid. The gears (13, 14) comprise shafts (23, 24) which are supported by bushings (15a, 15b) having two faces (17a, 17b) which are subjected, in use, to pressures which bring about an axial load on the bushing itself, characterized in that the resultant of the axial loads (S′, S″) on the two bushings has a predetermined direction so as to move the bushings (15a, 15b) and the gears (13, 14) as a whole into close abutment with a predetermined reference plane (VI-VI).

Abstract: A helical screw rotor machine is provided which has at least one trunnion having an axial thrust surface located in a chamber filled with pressure medium and actuated axially by the pressure medium. A casing is closely fitted around the trunnion. The casing has an outer end which is connected to a bottom wall that includes a hole in its center, and the casing is rotatably and slidably mounted on the trunnion and is movable between a first axial position in which the bottom wall is spaced from an end wall of the chamber and a second axial position in which the bottom wall is in abutment with said end wall. A supply channel is connected to an opening in the end wall of the chamber opposite the hole in the bottom wall of the casing for controlled delivery of the pressure medium into the casing.

Abstract: An air compressor assembly of the rotary screw type. The air compressor assembly comprises a housing having an inlet end and a discharge end. An internal working chamber extends within the housing and terminates in a discharge end face at the discharge end of the housing. At least one rotor is mounted for rotation and axial movement within the working chamber. The rotor has a discharge end surface having a step defined thereon. A thrust piston extends from the rotor and is positioned within a thrust piston chamber. A pressure source is associated with the thrust piston chamber and is controllable between a high pressure condition and a reduced pressure condition to control the position of the rotor relative to the discharge end face. A method of mounting a rotor with a desired end clearance is also provided.

Abstract: A screw compressor having balanced axial thrust includes a housing having a fluid inlet and a fluid outlet; a rotor disposed in the housing for receiving low pressure fluid from the inlet and discharging increased pressure fluid from the outlet, the rotor having a discharge end and a motor end; a balance piston arranged to exert a balancing force on the motor end of the rotor; and a conduit for conveying a high pressure fluid to the balance piston so as to exert the balancing force.

Abstract: The area of the discharge end of a screw rotor acted on by the discharge pressure is reduced by locating a region of suction pressure acting on the discharge end of the rotor and separating the suction and discharge pressures by a labyrinth seal located between the discharge end of the rotor and the facing housing structure.

Abstract: A helical screw rotor machine is provided which has at least one trunnion having an axial thrust surface located in a chamber filled with pressure medium and actuated axially by the pressure medium. A casing is closely fitted around the trunnion. The casing has an outer end which is connected to a bottom wall that includes a hole in its center, and the casing is rotatably and slidably mounted on the trunnion and is movable between a first axial position in which the bottom wall is spaced from an end wall of the chamber and a second axial position in which the bottom wall is in abutment with said end wall. A supply channel is connected to an opening in the end wall of the chamber opposite the hole in the bottom wall of the casing for controlled delivery of the pressure medium into the casing.

Abstract: The area of the discharge end of a screw rotor acted on by the discharge pressure is reduced by locating a region of suction pressure acting on the discharge end of the rotor and separating the suction and discharge pressures by a labyrinth seal located between the discharge end of the rotor and the facing housing structure.

Abstract: A screw-type compressor comprises a housing (12) in which a primary rotor (14) and a secondary rotor (16) are arranged each of which is provided with a shaft (18,24) and a screw rotor (20,26). The secondary rotor (16) is axially supported by the primary rotor (14). Only the primary rotor (14) comprises an axial bearing part (22) which is supported in an axial bearing part (66) of the housing (12). The omission of an axial bearing between the secondary rotor and the housing simplifies the support of the secondary rotor.

Abstract: The invention relates to a rotary screw machine that is completely oil-free. Known rotary screw machines with cooling, sealing, lubrication of the screw rotors and oil-lubrication and oil-cooling of the bearings have been replaced with water-lubricated and water-cooled bearings. Each screw rotor (102) is mounted in a water-lubricated radial slide bearing (1) and one trunnion (31) of the rotor co-acts with a water-lubricated thrust bearing (9, 10) which acts both as an hydrodynamic and an hydrostatic bearing. The trunnion bearing housing (21) is in fluid connection with the rotor housing, both along the trunnion and via a conduit (27) from the bearing housing interior to the gas inlet (108) of the screw rotor or via a channel which is cut-off from said inlet.

Abstract: A hydraulic pump includes a pump mechanism having a driven shaft. The driven shaft is connected to an input shaft by a flexible coupling such as a splined connection. A housing extends completely around the driven shaft, and a high-pressure seal is disposed between the housing and the input shaft. A thrust bearing carries hydraulic axial forces on the input shaft to the housing. This arrangement provides balanced hydraulic forces on both ends of the driven shaft, thereby reducing friction and wear.

Abstract: A compressor in accordance with the present invention includes a male rotor which is axially aligned with and in communication with two female rotors. The compressor includes a housing and a thrust balance configuration. The thrust balance configuration includes a thrust balance disc mounted to a male rotor shaft in a discharge housing of the compressor. The thrust balance disc is exposed to fluid from the compressor at high pressure. The outside diameter of the thrust balance is sized to provide sufficient area to react thrust loads produced by the first rotor. The thrust balance configuration serves to balance the thrust loads imparted on the male rotor and allows for full axial discharge porting.

Abstract: A compressor in accordance with the present invention includes a male rotor which is axially aligned with and in communication with two female rotors. The compressor includes a housing and a thrust balance configuration. The thrust balance configuration includes a stepped up portion mounted at the suction end of the male rotor and is exposed to fluid from the compressor at high pressure. The outside diameter of the thrust balance configuration is generally less than the crest diameter of the male rotor and sized to provide sufficient area to react thrust loads produced by the first rotor. The thrust balance configuration serves to balance the thrust loads imparted on the male rotor and allows for full axial discharge porting.

Abstract: A screw compressor capable of increasing a pressure receiving area of a balance piston, employing a thrust bearing having a large load capacity, and preventing an occurrence of a reverse thrust load state when started. The rotor shaft extending beyond both sides of screw rotors 11, 12 is rotatably supported by radial bearings 13, 14. An input shaft 15 serves as a rotor shaft on the suction side. A rotor shaft on the discharge side is rotatably supported by a thrust bearing 16 at a position farther away from the screw rotors 11, 12 than the radial bearing 14. A balance piston 17 is mounted on the rotor shaft at a position farther away from the screw rotors 11, 12 than the thrust bearing 16. A partitioning wall 31 is provided between the thurst bearing 16 and the balance piston 17.

Abstract: The shaft portion of a screw rotor is axially loaded to offset the thrust loading of the screw rotor due to forces exerted on the screw rotor by fluid being compressed and tending to move the screw rotor from the discharge towards suction. This permits the elimination of the thrust bearings. Preferably, the discharge end of the lobes of the rotors is beveled canted so as to generate a hydrodynamic film during operation.

Abstract: A compressor in accordance with the present invention includes a male rotor which is axially aligned with and in communication with two female rotors. The male rotor is driven by a motor, in other words the male rotor is the drive rotor. The male rotor has a plurality of lobes which intermesh with a plurality of flutes on each of the female rotors. The male rotor comprises an inner cylindrical metal shaft with an outer composite material ring mounted thereon. The ring includes the lobes of the male rotor integrally depending therefrom. The lobes of the male rotor being comprised of a composite material allows positioning of the female rotors at a small clearance from the male drive rotor. This clearance is small enough that the liquid refrigerant itself provides sufficient sealing, cooling and lubrication. The positioning of the female rotors on opposing sides of the male rotor balances the radial loading on the male rotor thereby minimizing radial bearing loads.

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 rotary screw compressor having two rotors, liquid injection, a liquid separator (10), and a hydraulic thrust balancing piston (11) connected to at least one of the rotors. In order to vary the balancing force if suction and delivery pressures vary, there is provided first (5) and second (4) throttling devices in the return pipe from the oil separator to the liquid injection port. Between the first and second throttling devices there is a connection to a pipe branch (7) which ends in a cylinder (14) which houses the balancing piston (11). The balancing pressure acting on the balancing piston (11) will thereby vary as suction and delivery pressures vary in a way determined by the relation between the degree of throttling in the two throttling devices.

Abstract: A rotary screw compressor that includes a male rotor and a female rotor cooperating together within a casing. The casing has a discharge outlet connected to an outlet port at a high pressure end of the working space and a suction inlet at the low pressure end of a working space. The rotor is rotatably supported at one end thereof through a bearing arrangement that includes a bracket fixed to an end cover. The bearing bracket projects into an axial cavity provided in the rotor to form a first chamber between the bracket and the rotor. The bracket is provided with an oil feed channel to feed oil into the first chamber. The rotor is rotatably supported at the low pressure end thereof through the bearing arrangement. The corresponding bearing bracket is mounted at the low pressure end of the working space and the outer circumferential surface thereof is provided with at least a groove connected to the oil feed channel and a recess connected to an oil drainage channel provided in the bearing bracket.

Abstract: A compressor in accordance with the present invention includes a male rotor which is axially aligned with and in communication with two female rotors. The male rotor is driven by a motor, in other words the male rotor is the drive rotor. The male rotor has a plurality of lobes which intermesh with a plurality of flutes on each of the female rotors. The male rotor comprises an inner cylindrical metal shaft with an outer composite material ring mounted thereon. The ring includes the lobes of the male rotor integrally depending therefrom. The lobes of the male rotor being comprised of a composite material allows positioning of the female rotors at a small clearance from the male drive rotor. This clearance is small enough that the liquid refrigerant itself provides sufficient sealing, cooling and lubrication. The positioning of the female rotors on opposing sides of the male rotor balances the radial loading on the male rotor thereby minimizing radial bearing loads.

Abstract: In a rotary screw machine, a shaft journal (7) of one of the rotors (6) is mounted in main thrust bearings (9, 10) and a balancing thrust bearing (11 ), the latter being located outermost on the shaft journal (7). The main thrust bearings (9, 10) are clamped towards the low pressure end of the machine. The balancing thrust bearing (11) is affected by a thrust balancing device for counter-acting the gas forces on the rotor (6), thereby reducing the force that has to be transferred by the main thrust bearing.

Abstract: A fluid rotating apparatus includes a casing having gas inhaling inlet and a gas discharge outlet, rotors driven in the casing by a driving mechanism and having fluid-transporting grooves which engage each other in synchronous rotation, and bearing portion for supporting the rotors. A communicating path is formed at one of the rotor and the casing for communicating a gas discharge-side inner space and a space defined by an inner surface of the casing and the fluid-transporting groove of an outer surface of each rotor with each other. The gas discharge-side inner space is defined by an end surface of the rotor opposite to a gas inhaling-side surface thereof, and a sealing portion is formed between the rotor and the casing to prevent fluid from flowing into the gas discharge-side inner space.

Abstract: The invention relates to a rotary screw machine in which the shaft journals (20, 22) of the rotors (10) are journalled in a main thrust bearing (24) and a thrust balancing bearing (26). The thrust balancing bearing (26) is preloaded by springs (36) and by fluid pressure means (40, 44). According to the invention the fluid pressure means (40, 44) can excert a force on the thrust balancing bearing (26) in either axial direction. This increases the possibility for an optimal distribution of the forces on the thrust bearings (24, 26) at various running conditions.

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: An oil flooded screw compressor wherein a thrust force acting upon a bearing is controlled within a fixed range to prevent possible damage to the bearing. The oil-cooled screw compressor comprises a pair of meshing screw rotors, a balance piston mounted for axial movement in parallel to axes of the screw rotors for causing, when operated, a force to act upon one of the screw rotors in a direction from the sucking side to the discharging side, and a slide valve for adjusting the volume of the screw compressor. A flow path of pressure fluid is provided for operating the balance piston and and is controlled such that it is opened when the slide valve is positioned on the full load side with respect to a preset position, but is closed when the slide valve is positioned at any other position.

Abstract: A rotary pump comprises a housing and at least a pair of rotatable, meshing gears positioned within the housing. The meshing gears define teeth which extend helically in the general direction of the axis of each gear rotation. A flow inlet and a flow outlet are positioned in the housing to permit fluid to flow longitudinally along the gears generally in the direction of said axis as the gears rotate relative to each other. By this invention, the helically extending teeth define on at least one of the gears a total angle of wrap from end-to-end of the gear upon which they are carried of essentially 360 divided by twice the number of teeth on the gear, in degrees, multiplied by a number N of 1/2 to 3. This relatively low total angle of wrap provides significant improvements in gear pumps.

Abstract: A system and method are provided for the automatic regulation of a balancing pressure to be applied to a rotor of a rotary screw compressor. The system includes a microprocessor which computes a balancing pressure to be applied to the rotor in response to an input of various compressor operating parameters such as suction pressure, discharge pressure, and percent capcity.

Abstract: A housing (1) of a rotary machine comprises a low-pressure side (2) and a high-pressure side (3), working-fluid inlet and outlet channels, and at least one rotor (7), which when the machine is working is urged by a working fluid towards the low-pressure side (2). The rotor includes a thrust balancing arrangement (15, 16) for relieving the load on the thrust bearings (11) of the machine, through the medium of an auxiliary bearing (17) and in dependence on pressure fluid supplied to the thrust balancing arrangement, the pressure of which fluid is contingent on the operating conditions of the machine. A relatively large part of the axial load is taken-up by an auxiliary thrust bearing (17), which is readily replaceable. The auxiliary bearing (17) is mounted on an outermost part of the rotor journal shaft (18), on the high-pressure side (3) of the rotor, between a detachable locking device (27) for the auxiliary bearing (17) and the thrust balancing arrangement.

Abstract: A screw compressor comprises a casing and a pair of male and female rotors respectively having herical teeth and grooves formed in their outer peripheries. The rotors are arranged within the casing in meshing relation to each other through the teeth and grooves. Each rotor is rotatably supported by a pair of first and second radial plain bearings and a thrust plain bearing which is arranged at an end of the rotor shaft and adjacent the second radial plain bearing. Each of the thrust plain bearings is of dynamic-pressure type in which with rotation of a corresponding one of the shafts of the respective rotors, pressure is applied to lubricant by sliding movement of the thrust plain bearing to produce an anti-thrust force.

Abstract: A first shim mounted on the shaft extending from the high pressure end face of a screw rotor in a screw compressor establishes the operating clearance between the high pressure end face of the rotor and the high pressure end wall of the compressor's working chamber by fixing the axial position of a bearing group which is likewise mounted on the rotor shaft. A second shim, disposed between the bearing group and a spring biased spacer element, is determinative of the distance the spacer element, and therefore the rotor, can travel in a direction toward the high pressure end of the compressor under the impetus of reverse axial thrust. Contact of the rotor with the high pressure end wall of the working chamber is positively precluded because movement of the spacer element, under the influence of rotor movement toward the high pressure end of the compressor, collapses the biasing spring which causes the spacer element to contact a fixed surface of the compressor.

Abstract: A hydraulic screw machine including a drive screw and at least one running screw co-operating therewith are arranged inside a housing, the drive screw being united with a shaft extending out through the housing at the high pressure side of the machine and being provided with a balancing piston for balancing a part of the axial force acting on the drive screw and also with a collar which together with a wall portion of the housing forms a hydrostatic axial bearing for taking up the remaining axial force acting on the drive screw. The bearing surfaces of the axial bearing are kept separated by a spring means during starting and similar operating conditions. An axially limitedly movable rolling bearing is mounted in association with the hydrostatic axial bearing and takes up axial forces on the drive screw occurring in certain operating conditions.

Abstract: A device preferably utilized for pumping oil or other fluid from a drill hole in the ground, said device including a pump lowered into the hole and coupled to a drive motor situated under it. The pump comprises a hydraulic screw pump including a housing in which there is mounted a screw array in the form of a drive screw provided with a shaft coupled to the drive motor, and at least one running screw meshing with the drive screw. The rotational direction of the drive motor is such that the screw array pumps the liquid from an inlet, made radially in the housing and in communication with the liquid in the drill hole, to an outlet arranged at the end of the screw array remote from said shaft.

Abstract: A motor-pump unit consists of a screw shaft pump and a slot-barrel motor located on the pressure side of the pump. The motor-pump unit is provided with a rigid, preferably one-piece, shaft by which the motor drives the pump. The motor is located on the pressure chamber of the pump with a bearing between the motor and pump. The shaft is supported within the pump, in part by the bearing, and the rotor of the motor is cantilevered on the free end of the shaft outside the pressure chamber. The pot-shaped stator part of the motor is telescoped over the rotor and fastened directly to the pressure side of the pump.

Abstract: This invention relates to a method at oil-injected screw-compressors for balancing axial forces at at least one of the rotors of the compressor, for sealing the gaps between rotor housing and rotor shafts and for cooling and lubricating the bearings of the rotor shafts. At the high-pressure end of the compressor oil under pressure of such magnitude is supplied to the bearing spaces (28a,28b) at the ends of both rotors that an oil flow inward to the compression space along the gaps (32a,32b) between the rotor shafts and the rotor housing is obtained for sealing against leakage from the compression space. Oil at this pressure further is supplied via a connection (42) from the bearing space (28b) of the female rotor to a pressure space (38) at the low-pressure end of the female rotor for balancing the axial force arising on the shaft end (31) of the female rotor on the high-pressure side due to the oil supplied to the bearing space (28b) of the female rotor.