Abstract: A screw compressor with two rotors held in a rotor housing has sealing arrangements 11, 11? to seal the pressurized side shaft pin of the rotors, wherein each sealing arrangement has a number of successive radial seal rings 11a, 11b and wherein it contains an annular relief chamber 51 at an intermediate position that is connected by means of a vent channel 53 to a chamber in the rotor housing in which a pressure is present that is higher than atmospheric pressure. It is preferred that the vent channel be connected to the intake chamber 10 of the rotor housing 1 and that this intake chamber be fed by a gas that is pre-compressed by a compressor stage.

Abstract: A liquid injection type screw compressor in which, in a compression stroke of an working space formed by male and female rotors, liquids such as oil or water is prevented from leaking from the high pressure working space to a gas inlet side, suction resistance of gas sucked from the gas inlet to a rotor casing is reduced to improve volumetric efficiency, and shape forming of the casing is simplified. The liquid injection screw compressor has the male and female rotor pair of screw rotors, the rotor casing (1a, 1b) having a bore for receiving the rotors, a gas suction opening and a gas outlet that are provided in both end sections of the casing and communicate with the bore, and a lip section (4) projected from a bore surface (2) positioned more on the upstream side than a suction seal line (5) of the casing in order to prevent a back flow of the liquid from the bore surface toward the gas inlet side.

Abstract: A rotor shaft sealing structure of an oil-free rotary compressor is provided, with which is reduced a risk of occurrence of lubrication oil intrusion into the compression chamber (9) of the compressor which is liable to occur when negative pressure is produced in the compression chamber (9). The rotor shaft sealing structure is composed such that two shaft seal means (20, 30) are provided in the rotor casing (1) between the oil lubricated bearing (10, 10?) and the compression chamber (9) such that an annular airspace (24) is formed between the two shaft seal means (20,31), at least one communicating hole (34,34?) is provided to communicate the annular airspace (24) to the outside of the rotor casing (1), and the annular airspace (24) of the male rotor shaft (6) sealing part and the annular airspace (24) of the female rotor shaft (7) sealing part are connected by a between-rotor shaft communication passage (35).

Abstract: A shaft seal device is provided, with which an optimum radial clearance is always maintained between the inner circumferential surface of a carbon ring and an outer circumferential surface of a rotor shaft sleeve when temperature thereof varies in operation of the oil-free rotary compressor, and gas leak through the radial clearance can be suppressed to a minimum not influenced by operation condition of the compressor and intrusion of lubricating oil into the rotor chamber is prevented. As a result, an oil-free rotary compressor can be operated to discharge clean compressed gas not contaminated with lubrication oil.

Abstract: In a gas compressor, a fastener part is fastened by a fastener member comprised of a bolt coated with a zincate bath and a gasket, any leakage from the fastener member is prevented, the gas compressor including a case 11 and a front head 12 fastened by a first fastener member 80, a housing 10 having a holding space in the interior portion, a compressor main body 60 that compresses gas held in the holding space and fastened to the housing 10 by a second fastener member 70, the second fastener member 70 being a fastener member comprised of a bolt 71 coated with a zincate bath in combination with a copper gasket 72 coated with tin.

Abstract: A magnet drive rotary vane pump has a casing with a pump cavity. A rotor carrying a plurality of vanes is disposed within the pump cavity to be rotatable about an eccentric axis with respect to the pump cavity for drawing the fluid into the pump cavity and expelling it out of the pump cavity. The rotor is configured to have a rotor magnet which is magnetically coupled to a stator magnet mounted on the casing outwardly of the pump cavity for driving the rotor. The rotor magnet is configured to have its major portion disposed in an overlapping relation with the stator magnet. Thus, the rotor magnet can be mechanically isolated from the stator magnet disposed outside of the casing to establish a sealless coupling therebetween for realizing leakage free pump.

Abstract: A variable displacement vane pump includes a pump body, a rotor, an annular cam ring, a rear body closing the pump body, a low pressure supply passage constantly connecting the inlet passage and the other of the first fluid pressure chamber and the second fluid pressure chamber, a low pressure introduction port formed in the other of the pressure plate and the rear body, and opened in the other of the first fluid pressure chamber and the second fluid pressure chamber, and a low pressure introduction passage formed in the other of the pressure plate and the rear body, the low pressure introduction passage connecting the low pressure introduction port and the inlet side vane back pressure grooves.

Abstract: An internal combustion engine includes in one aspect a source of a pressurized working medium and an expander. The expander has a housing and a piston, movably mounted within and with respect to the housing, to perform one of rotation and reciprocation, each complete rotation or reciprocation defining at least a part of a cycle of the engine. The expander also includes a septum, mounted within the housing and movable with respect to the housing and the piston so as to define in conjunction therewith, over first and second angular ranges of the cycle, a working chamber that is isolated from an intake port and an exhaust port. Combustion occurs at least over the first angular range of the cycle to provide heat to the working medium and so as to increase its pressure.

Abstract: A scroll type compressor with an enhanced sealing arrangement includes two sealing rings, mounted one between a first part of a gliding block and a first chamber of a fixed scroll and another one between a second part of the gliding block and a second chamber of the fixed scroll, respectively. The sealing ring has a U-shape cross section characterized in having a center depth smaller than half of a total height of the cross section. By providing such sealing rings, damage in mounting the sealing rings can be reduced to a minimum, possible leakage from the damage can be avoided, the assembly process in producing the compressor can be improved, and the compressor can be successfully merchandized.

Abstract: There is provided, at a low cost, a small-size and lightweight scroll compressor capable of preventing a decrease in compression efficiency by utilizing a medium pressure between a suction pressure and a discharge pressure as a back pressure. An independent minute gap in the axial direction is provided between a main frame 3 and a thrust ring 8. This minute gap is used as a second back pressure chamber C2, and the medium pressure between the suction pressure and the discharge pressure is introduced into the second back pressure chamber C2.

Abstract: In a rotary piston machine with an inner housing and rotors, the axes of the rotors are disposed at an angle to one another in order to equalize manufacturing tolerances and to reduce gap losses of such machines.

Abstract: A scroll compressor, which allows refrigerant in a compressor chamber to be partially discharged so that frictions generated in frictional surfaces between an orbiting scroll and an Oldham ring and between the Oldham ring and a main frame may be decreased. Also, an upper chamber may be formed on an upper surface thereof and a lower chamber may be formed on a lower surface thereof. An oil supply structure may be provided in a main frame such that lubrication is smoothly performed. Additionally, at least one key may be provided protruding from the lower surface of the Oldham ring. Further, the main frame may include at least one key groove configured to receive the at least one key of the Oldham ring. Additionally, the oil supply groove may be provided separately from and in communication with the at least one key groove.

Abstract: A scroll compressor having a housing with a motor-compressor unit disposed therein. The motor-compressor unit includes a crankcase, stator, rotor, and drive shaft assembly. The motor-compressor unit further includes a fixed scroll member and an orbiting scroll member. The scroll compressor has a separator plate disposed within the housing and secured to the fixed scroll member by a plurality of fasteners. A seal member is provided between the separator plate and the fixed scroll member and is disposed radially outwardly of at least one of the fasteners. In an exemplary embodiment, the seal member is an O-ring.

Abstract: In a gas compression apparatus, a space (41a) between oil seals (18, 23) and bearings (15, 21) is adapted to communicate with a low pressure lead hole (42) open to the atmosphere through a blow-down lead hole (41). The low pressure lead hole is opened/closed by an on-off valve (43) arranged on the side of the blow-down lead hole nearer to the low pressure lead hole. As a result, when the gas compression apparatus stops operation, the internal pressures of the space (41a) and a lubricant space (9) drop while the internal pressure of a compression chamber (10a) drops. A valve body (44) thus moves down and opens the low pressure lead hole, so that the internal pressure of the lubricant space becomes substantially equal to the atmospheric pressure. Thus, the lubricant is prevented from leaking from the lubricant space into the compression chamber.

Abstract: A viscous seal for fluid transfer devices that deviates from the conventional wisdom of avoiding contact between the seal and a rotating drive shaft of the fluid transfer device. Instead of avoiding contact, contact between the seal and drive shaft is used to effect axial alignment of a sealing sleeve with the shaft. As a result, the viscous seal is compliant in that the sealing sleeve can follow the axis of the drive shaft. Accordingly, the sealing sleeve can fit snugly around the drive shaft for more effective prevention of leakage of low or any viscosity fluid along the drive shaft, but without any significant radial load being applied to the sealing sleeve that might cause undue wear or damage due to galling.

Abstract: A multi-stage vacuum pump includes a plurality of casings connected in series and each casing defining a respective compression chamber, a plurality of partition plates each set in between each two casings. When compressed by rotors at shafts in one compression chamber, compressed air passes through the air path formed in the corresponding partition plate to the next compression chamber for further compression, and finally compressed air passes to the last compression chamber through the air path formed in the last partition plate. Because the invention is designed to let compressed air directly pass through the air path in each partition plate, the outer diameter and volume of the multi-stage vacuum pump can be minimized to reduce the weight and the manufacturing cost.

Abstract: A rotary combustion engine includes a peripheral housing, a front housing plate, a rear housing plate, a piston, and an eccentric shaft, where the piston rotates to form three working spaces separated from each other by the tips of the piston. Shaft seals and piston seals seal off the oil-carrying interior space of the internal combustion engine, and the piston is sealed off against the front and rear housing plates by arcuate strips, which are bounded radially on the inside by an envelope curve. The gas forming in the working space during the combustion phase is under high pressure. Some of this gas leaks around the arcuate strips and flows inward along the flat surfaces of the front and rear plates by way of ring-shaped channels in the piston, thus arriving in recessed areas inside the envelope curves, from which it is then escapes through vent channels.

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: An engine pump is provided which operates with an internal combustion engine or as a supplemental pump or as used in a stand alone device, and includes an internal vent for improved pump and motor durability. The pump is operably and sealably connected to a motor and adapted for connection with a source of fluid and a discharge means. An internal vent is positioned in between an armature shaft of bore along an inlet port thereby decreasing the pressure in the area of the seal. Alternatively, a valve is positioned between the inlet and outlet ports to selectively permit fluid pumped between the inlet and outlet ports to pass through when the outlet port is flow restricted.

Abstract: In a screw compressor for a refrigerator, suction-side rotor shafts of screw rotors are supported rotatably by angular ball bearings for forward thrust load, an annular gap is formed between the angular ball bearings and a suction-side bearing casing, and outermost end faces of outer rings of the angular ball bearings are pressed through a spring member by means of a presser member fixed to an end face of the suction-side bearing casing, whereby the angular ball bearings are held movably in the thrust direction within the suction-side bearing casing. Discharge-side rotor shafts of the screw rotors are supported rotatably by angular ball bearings for forward thrust load and an angular ball bearing for reverse thrust load which are held at predetermined certain positions within a discharge-side bearing casing. A screw compressor which permits structural simplification, reduction of size, and lightening of a maintenance burden is provided.

Abstract: A fluid delivery device, such as a geared machine or a gear pump, with a housing having at least one supply chamber and a displacement unit arranged within the supply chamber. The displacement unit serves to supply a medium to at least one pressure chamber provided within the housing. A pressure plate is arranged between the pressure chamber and the housing, and the pressure plate is uncoupled from the housing by at least one spacer element that is arranged between the pressure plate and the housing to provide a fluid delivery device that operates more quietly than conventional fluid delivery devices.

Abstract: A pneumatic cylinder of pneumatic tool capable of avoiding failure of bearings, including: a cylinder body having an internal cylindrical chamber in which a rotor is disposed, a rotary shaft being fixedly connected with the rotor, whereby high pressure air can flow into the cylinder body to drive and rotate the rotor and the rotary shaft; two end caps respectively covering two ends of the cylinder body, two ends of the rotary shaft respectively extending out of the cylinder body through the through holes of the two end caps; two bearings respectively installed in the cavities of the two end caps and fitted on two ends of the rotary shaft; and two airtight rings located between the bottom walls of the cavities and the bearings to achieve an airtight effect between the bottom walls of the cavities and the bearings.

Abstract: A screw rotor device has a housing with an inlet port and an outlet port, a male rotor with helical threads, and a female rotor with helical grooves. The helical threads and helical grooves are designed to eliminate the blow hole leak pathway for multiple-pitch screw rotor devices as well as single-pitch screw rotor devices. The male rotor has a pair of helical threads with a phase-offset aspect, and the female rotor has a corresponding pair of helical grooves. The female rotor counter-rotates with respect to the male rotor and each of the helical grooves respectively intermeshes in phase with each of the helical threads. The phase-offset aspect of the helical threads is formed by a pair of teeth bounding a toothless sector.

Abstract: The present invention is a cylindrical linear fluid motor comprising a plurality of reciprocating rotary piston sleeve intermediate an inner coaxial hollow drive shaft and an outer coaxial cylindrical housing. Rotating disc valves at both ends of the sleeve piston control the sequential flow of high-pressure and low-pressure fluid through ports in both the drive shaft and the housing. High-pressure fluid acts on one end of the sleeve piston causing the piston to travel laterally along the drive shaft, with an inner set of roller balls in linear raceways ensuring no rotation between each piston and the drive shaft. The linear motion simultaneously affects exhausting of low-pressure fluid at the other end of the piston. Outer balls are seated in the housing and a sinusoidal circumferential raceway of each piston, to affect rotation in the piston from the lateral motion.

Abstract: A mounting end of an engine-driven accessory includes a longitudinally-extending neck having imperforate lateral surfaces defining a central bore. A flange having a mounting face is disposed at the end of neck. A plurality of generally radially extending drain passages are formed through the flange, which communicate with the central bore to form a fluid flow path between the bore and the exterior of the flange. A seal is provided for blocking selected ones of the drain passages while leaving the remainder of the drain passages open. The accessory may include a cover having an integral sealing rim which cooperates with a notch in a mating component to compress a portion of a resilient seal while simultaneously allowing for expansion of the remainder of the seal.

Abstract: A screw rotor device has a housing with an inlet port and an outlet port, a male rotor, and a female rotor. The male rotor has a pair of helical threads with a phase-offset aspect, and the female rotor has a corresponding pair of helical grooves. The female rotor counter-rotates with respect to the male rotor and each of the helical grooves respectively intermeshes in phase with each of the helical threads. The phase-offset aspect of the helical threads is formed by a pair of teeth bounding a toothless sector. The arc angle of the toothless sector is a least twice the arc angle that subtends either one of the teeth. The helical grooves have a radially narrowing axial width at the periphery of the female rotor. The male and female rotors may include a buttress thread profile and may be limited in length to a single pitch.

Abstract: The invention concerns a metering gear pump comprising a set of gears supported and guided solely by the inner peripheral surface of the lobe of the chamber wherein they are housed. They do not comprise any shaft to act as support or guide, thereby enabling to reduce significantly useless spaced difficult to rinse when changing the product to be pumped. For the same purpose, the driving shaft is flexibly connected to the driving gear. Such arrangement provides the advantage of requiring only one single packing seal. Such a pump, connected to a drive motor and an encoder delivering a signal proportional to the number of pump cycles, enables to provide an accurate metering pump for numerous uses.

Abstract: A fluid delivery device, such as a geared machine or a gear pump, with a housing having at least one supply chamber and a displacement unit arranged within the supply chamber. The displacement unit serves to supply a medium to at least one pressure chamber provided within the housing. A pressure plate is arranged between the pressure chamber and the housing, and the pressure plate is uncoupled from the housing by at least one spacer element that is arranged between the pressure plate and the housing to provide a fluid delivery device that operates more quietly than conventional fluid delivery devices.

Abstract: In a rotary compressor to perform oil supplying to bearings (32,34,45) through a main oil-supply passage (51) formed in a drive shaft (17) by making use of pressure differential between high-level pressure and low-level pressure in the casing (10), sealing portions (65) having air-tight structure is formed at the both sides in the axis direction of each of sliding faces constituted between the drive shaft (17) and the bearings (32,34,45), putting bearing-portion oil-supply passages (59,60,61) between the sealing portion (65), to improve the reliability of the bearings (32,34,45) by preventing high-pressure gas flowing into a portion between the drive shaft (17) and the bearings (32,34,45).

Abstract: A gear.rear shaft containing main body of a bottomed type is penetrated with a bearing hole and a rear face of the gear.rear shaft containing main body is coupled with a closing plate to seal in airtight from outside. Shafts extended from two gears to a side of the rear face are set to be more less shorter than a length of the bearing hole in an axis core direction. Bushes are also set to a length the same as that of the shafts. The gear.rear shaft containing main body is formed with a recess portion at the rear face and the bearing hole is penetrated to open to the recess portion. The gear.rear shaft containing main body is bored to penetrate with a low pressure port communicating with a low pressure region in an axis core direction.

Abstract: A hydraulic motor (10) comprising a front housing (12) which includes a first port (14) and a second port (16), a drive assembly (18), a drive link (22), and a shaft (24). The front housing (12) and the drive assembly (18) form a central bore (26) in which the drive link (22) and the shaft (24) are rotatably mounted. The drive assembly (18) comprises a spool valve (48) rotatably positioned within the central bore (26) and coupled to the shaft (24) by a key (140). Sealing rings (104) having a rotationally incompatible geometry (e.g., waved shapes) are used to seal interface surfaces of the rotor (54) and a high pressure seal assembly (156) is used to seal the front of a fluid chamber (154).

Abstract: A vacuum pump draws gas by operating a gas conveying body in a pump chamber through rotation of a rotary shaft. The vacuum pump has an oil housing member. The oil housing member defines an oil zone adjacent to the pump chamber. The rotary shaft has a projecting portion that projects from the pump chamber into the oil zone through the oil housing member. Stoppers are located on the rotary shaft to integrally rotate with the rotary shaft and prevent oil from entering the pump chamber. The stoppers are located along the axial direction of the rotary shaft.

Abstract: A vacuum pump draws gas by operating a gas conveying body in a pump chamber through rotation of a rotary shaft. The vacuum pump has an oil housing member, a stopper and a circumferential wall surface. The oil housing member defines an oil zone adjacent to the pump chamber. The stopper has a circumferential surface. The stopper is located on the rotary shaft to rotate integrally with the rotary shaft and prevents oil from entering the pump chamber. The center of curvature of the circumferential wall surface coincides with that of the rotary shaft. The circumferential wall surface surrounds at least a part of the circumferential surface of the stopper that is above the rotary shaft. The circumferential wall surface is inclined such that the distance between the circumferential wall surface and the axis of the rotary shaft decreases toward the oil zone.

Abstract: A Roots pump rotates a plurality of rotors by a pair of rotary shafts to draw gas. Each rotary shaft extends through a rear housing member of the Roots pump. An annular shaft seal is fitted around each rotary shaft and is received in a recess formed in the rear housing member. A helical groove is formed in a circumferential side of each rotary shaft. Each helical groove urges oil between the circumferential side of the associated shaft seal and the circumferential wall of the recess to move from a side corresponding to pump chambers toward a gear accommodating chamber when the associated rotary shaft rotates. This preferably prevents oil from leaking to the pump chambers.

Abstract: A Roots pump rotates a plurality of rotors by a pair of rotary shafts to draw gas. Each rotary shaft extends through a rear housing member of the Roots pump. An annular shaft seal is fitted around each rotary shaft and is received in a recess formed in the rear housing member. A labyrinth seal is located between an end surface of each shaft seal and the bottom of the associated recess. This enlarges the diameter of each labyrinth seal, thus preferably preventing oil from leaking to a pump chamber.

Abstract: A Roots pump rotates a plurality of rotors by a pair of rotary shafts to draw gas. Each rotary shaft extends through a rear housing member of the Roots pump. An annular shaft seal is fitted around each rotary shaft and is received in a recess formed in the rear housing member. A labyrinth seal is located between an end surface of each shaft seal and the bottom of the associated recess. A resin layer is firmly attached to the end surface of each shaft seal. As a result, oil is reliably prevented from leaking into a pump chamber.

Abstract: A pump is proposed, in particular a vane pump, for a liquid or gaseous medium, which can be driven with the help of a motor, in particular an electric motor, and which comprises a rotor (15) that can be coupled to a drive shaft (29) of the motor and is arranged in an operating chamber and at least one pressure plate (25) that closes the operating chamber (11) in the axial direction and on its lateral face (27) facing away from the rotor (15) is connected to a pressure chamber (23), and also a coupling element (47; 47′) which surrounds part of the drive shaft (29), cooperates with at least one seal and contributes to sealing off the pressure chamber (23) with respect to the motor, the drive shaft (29) extending through a through opening (35) in the pressure plate (25). The pump (1) is characterized in that the coupling element (47; 47′) has a sleeve-like section (49) which engages in the through opening (35) in the pressure plate (25).

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: The proposed positive-displacement sphere-shaped rotor machine is intended for use as an engine, a pump or a compressor and comprises a casing consisting of two parts 1 and 2, in the spherical cavity of the casing three rotors 4, 5 and 6 being disposed, the central disk rotor 4 being connected from each side by means of a diametrical hinge with sector rotors 5 and 6. The rotors 4, 5 and 6 define four chambers 9, 10, 11 and 12. The chamber-forming radial surfaces of the rotors 4, 5 and 6 have a radius form. Inlet-outlet ducts 15, 16, 17 and 18 are disposed in the zone of overlapping by the sector rotors at the moment of changeover of the cycles in the chambers, the ducts having a nozzle portion and a tangential tilt. The diametrical hinge has two secured semi-axles 21 and 22, whose journals enter into spherical meniscus 25; the second diametrical hinge 5 has a non-split cylindrical axle.

Abstract: To provide a screw compressor comprising a compressor screw housing, two screw rotors with intermeshing screw bodies arranged in the compressor screw housing and with shaft sections arranged on both sides of the screw bodies, the screw rotors being mounted by means of the shaft sections in bearing housings arranged on both sides of the compressor screw housing, which prevents pressure losses, it is proposed that an intermediate portion of the respective shaft section adjoining an end of the respective screw body at the pressure side and extending as far as a bearing section be sealed off in the area of a closure wall of the compressor screw housing at the outlet side from an inside surface of an opening in the closure wall, which surrounds the intermediate portion.

Abstract: A compressor assembled under desirable working conditions at a low cost is disclosed. In the compressor, the first rolling bearing for permitting axial movement of the shaft is inserted into the first housing from the side where the compression mechanism is to be provided, and the second rolling bearing for restricting axial movement of the shaft is inserted into the first housing from the other side where the driving source is to be provided. The shaft is inserted into the first housing from the side where the compression mechanism is to be provided. A seal member is further provided between the rolling bearings for sealing an area between the insertion hole and the shaft, wherein the seal member is inserted into the insertion hole of the first housing from the side where the compression mechanism is to be provided before the shaft is inserted into the insertion hole.

Abstract: A vacuum pump has a housing accommodating a rotary shaft and a gas transferring assembly driven by the rotary shaft. The housing has an exhaust passage for exhausting gas outside the housing. The gas transferring assembly creates a vacuum. A lip seal for shaft seal is disposed between a pump chamber communicating with the exhaust passage and a region in which oil exists so as to slide relative to a circumferential surface of the rotary shaft. The lip seal has a back pressure surface in a back pressure region facing the pump chamber and a pressure surface facing the region in which the oil exists. A communicating passage in the housing intercommunicates the back pressure region and the exhaust passage for applying at least substantially the pressure in the exhaust passage to the back pressure surface.

Abstract: A scroll-type compressor for a fuel cell 1 of the present invention comprises: a fixed scroll for compression 31; a movable scroll for compression 61; a movable plate 6, which has the movable scroll for compression 61 erected on the surface thereof and a shaft insertion portion 60 into which a drive shaft 5 is inserted; a bearing 7, which is provided inside the shaft insertion portion 60 and supports the drive shaft 5 with a lubricant; a fixed scroll for expansion 41; and a movable scroll for expansion 62; and comprises a seal member 8 that prevents the lubricant from leaking and an obstruction member 51 that is provided between the seal member 8 and the inflow port 43 to change the direction of passage of the gas that flows in through the inflow port 43.

Abstract: An engine prelubrication pump includes a pump housing with a pump cavity in which a first and second gear are positioned for pumping fluid. The first gear is operably and sealably connected to a motor for rotation and the second gear is rotatably mounted to a second shaft for geared rotation with the first gear. Fluid inlet and outlet ports are located in communication with the pump cavity and adapted respectively for connection with a source of fluid and a discharge means and an internal vent is positioned in between the armature shaft of bore and the pump housing along the inlet port. Alternatively, a valve is positioned between the inlet and outlet ports to selectively permit fluid pumped between the inlet and outlet ports to pass through when the outlet port is flow restricted.

Abstract: A screw pump has two parallel shafts mounted in a pump body, each shaft thereon and each rotor has at least one helical vane or thread. When the helical vanes or threads inter mesh causing a fluid to be pumped from an inlet towards an outlet of the pump. The bearings associated with each shaft are being positioned in cavities within the first and second rotors which are sealed at their ends closest to the pump inlet. A thermal shield is provided between the bearing arrangements and the internal cavity surfaces.

Abstract: The invention relates to a device for delivering fuel from a tank to an internal combustion engine, wherein a pump chamber is embodied in the housing of the feed device. Rotary driven displacing elements are contained in the housing. The shaft supporting a displacing element is provided with bores which connect an end of the shaft to the suction side of the feed device.

Abstract: A vacuum pump draws gas by operating a gas conveying body in a pump chamber through rotation of a rotary shaft. The vacuum pump has an oil housing member. The oil housing member defines an oil zone adjacent to the pump chamber. The rotary shaft has a projecting portion that projects from the pump chamber into the oil zone through the oil housing member. Stoppers are located on the rotary shaft to integrally rotate with the rotary shaft and prevent oil from entering the pump chamber. The stoppers are located along the axial direction of the rotary shaft.

Abstract: A vacuum pump draws gas by operating a gas conveying body in a pump chamber through rotation of a rotary shaft. The vacuum pump has an oil housing member, a stopper and a circumferential wall surface. The oil housing member defines an oil zone adjacent to the pump chamber. The stopper has a circumferential surface. The stopper is located on the rotary shaft to rotate integrally with the rotary shaft and prevents oil from entering the pump chamber. The center of curvature of the circumferential wall surface coincides with that of the rotary shaft. The circumferential wall surface surrounds at least a part of the circumferential surface of the stopper that is above the rotary shaft. The circumferential wall surface is inclined such that the distance between the circumferential wall surface and the axis of the rotary shaft decreases toward the oil zone.

Abstract: A Roots pump rotates a plurality of rotors by a pair of rotary shafts to draw gas. Each rotary shaft extends through a rear housing member of the Roots pump. A plurality of stoppers are located on each rotary shafts to integrally rotate with the corresponding rotary shafts, and prevent oil from entering a fifth pump chamber of the Roots pump. A tapered circumferential surface is located about an axis of each rotary shaft. Each tapered circumferential surface is located adjacent to an end surface of the stopper and is closer to an oil zone than the end surface is. Each tapered circumferential surface is formed such that the distance between the circumferential surface and the axis of the rotary shafts increases from the side closer to the pump chamber to the side closer to the oil zone. This effectively prevents oil from entering the pump chamber.

Abstract: The drive gear 19, 21 and the synchronizing gear 25, 27 for the two rotors 9,11 of a screw compressor are both located at the pressurized end of the rotor housing 3. At the suction end of the rotor housing 3 is only the bearing 53 for the suction side shaft journal 55, 57 that is free of oil lubrication. Inlet openings 13 in a suction side inlet housing are located in such a way that the intake air cools the oil-free shaft bearing 53. Each shaft journal has a tool interface 63 accessible through the inlet housing on which to attach a rotating tool. The inlet housing 4 can be removed from the shaft journal 55, 57 together with the bearing 53 and seal 87, for example to exchange the bearing, without having to remove the rotors 9, 11 or without throwing off their adjustment.