Abstract: Screw compressor (1) comprising: a male (2) and a female rotor (3) rotating respectively around a first axis (01) and second axis (02) of rotation, said rotors (2;3) showing, in cross section, meshing lobes (4) and valleys (6) and having profiles generated by enveloping a rack profile (p) including a first curve (z1) of the rack profile (p) extending between a first point (H) and a second point (Q) in a Cartesian reference frame (X, Y) and having a convexity in the positive direction of the axis of abscissa (X), said first point (H) lying on the axis of abscissa (X) at a distance from an origin (0) of the Cartesian reference frame (X, Y) equal to an addendum (hi) of the male rotor (2).

Abstract: A vane liner for use in a vane pump has a vane liner body defining an inner bore for providing a cam surface in a vane pump. The cam surface has a suction opening formed through the body at one circumferential extent, and a discharge opening through the body at a distinct circumferential extent. A pre-pressurization opening extends through the body at a location upstream of an upstream end of the discharge opening, but spaced by at least 90 degrees from a downstream end of the suction opening. A vane pump incorporating the above-discussed liner is also claimed. Further, a vane pump is also disclosed and claimed having the spacing from the downstream end of the suction opening at least X degrees wherein X equals 360 divided by N, N being the number of vanes in the vane pump.

Abstract: A gear pump rotor is provided including a combination of an inner rotor and an outer rotor whose numbers of teeth are different by one, and the discharge amount of the pump is increased by an increase of the tooth depth. At least one of an addendum curve and a dedendum curve of an inner rotor is formed by a locus of one point on formation circles that satisfy moving conditions that the formation circles move from moving start points to moving end points while changing the distances from an inner rotor center to the centers of the formation circles. The centers of the formation circles move by a distance in the radial direction of a base circle, and the formation circles rotate by an angle at a constant angular velocity in the same directions of the moving directions of the formation circles.

Abstract: A vane compressor according to the present invention, including a cylinder which is approximately cylindrical and whose both ends located in an axial direction are open, a cylinder head and a frame which close both the ends of the cylinder, a rotor shaft which includes a rotor part being cylindrical and rotating in the cylinder and a shaft part transmitting torque to the rotor part, and a vane which is installed in the rotor part and whose tip portion has the R-shape facing outward, performs the compression operation in the state where the normal to the R-shape of the tip portion of the vane and the normal to the inner surface of the cylinder are always approximately coincident with each other.

Abstract: An indexing system for a rotor assembly where the indexing system can regulate the rotational location of drive rotors that are configured to rotate about a shaft in one form.

Abstract: An oil pump rotor includes an inner rotor having (n) external teeth, an outer rotor having (n+1) internal teeth, and a casing forming a suction port and a discharge port for drawing/discharging fluid. In operation, fluid is drawn/discharged according to volume changes of cells formed between tooth faces. A tooth profile based on a mathematical curve has a tooth addendum circle A1 with a radius RA1 and a tooth root curve A2 with a radius RA2, a circle D1 has a radius RD1 satisfying Formula (1), and a circle D2 has a radius RD2 satisfying both Formulas (2) and (3): RA1>RD1>RA2 ??Formula (1) RA1>RD2>RA2 ??Formula (2) RD1?RD2 ??Formula (3) A tooth profile of the external teeth includes a modification either, in a radially outer direction, on the outer side of the circle D1 or, in a radially inner direction, on the inner side of the circle D2.

Abstract: A screw rotor is for use in a screw pump that pumps fluid by rotation of a pair of screw rotors engaged with each other in a rotor housing. The screw rotor includes a multiple-thread portion for pump suction side and a single-thread portion for pump discharge side. The screw rotor is formed so that the tooth profile of the multiple-thread portion is connected to the tooth profile of the single-thread portion through a boundary plane that is perpendicular to the rotation axis of the screw rotor. The first curved portion coincides with the third curved portion in the boundary plane.

Abstract: A rotary internal combustion diesel engine (46) comprising: a posterior plate (78), an intermediate plate (80), and an anterior plate (82); a rotor-housing unit (46) on each side of the intermediate plate (80), each containing a yousroid chamber (48), and a 2-apex rotor (56) containing an aperture (58). The chamber (48) wall contains an intake valve (68), an exhaust valve (70), and a fuel supply device (72); in gasoline embodiments, an ignition device (76) is added; compressed air/gas and hydraulic embodiments, require an input port (74) and an output port (70a). A shaft (52) rotatably mounted, extends through the housing, having essentially rectangular segments (54) within the chambers (48). There are seals (not shown) on the rotor apices (60, 62) and on the anterior (82) intermediate (80), and posterior plate (78).

Abstract: A multistage vacuum pump has a pair of rotors disposed in each of pump chambers connected in stages. As the rotors rotate while intermeshing, a suctioned gas is compressed and discharged, angles of the rotors are adjusted so that a phase angle ?? of the rotors of adjacent pump chambers relative to a rotation angle C of the rotors during a single cycle of the pump chambers from intake to discharge and the number of stages S of the rotors satisfies ???C/S. When a rotor angle is ?1, an mth stage rotor angle is ?m, and an nth stage rotor angle is ?n in order from an upstream side of a gas flow direction, relationships of ?1<?m??n and ?1<?n, where n and m are natural numbers and n>m, are satisfied.

Abstract: The present invention is an apparatus that includes a chamber rotor with a chamber and an extension rotor with an extension. The rotors are housed in a rotor case. A pressure cavity is at least transiently formed by the extension rotor and the chamber rotor. The present invention also includes a compressor that includes a chamber rotor with a chamber and an extension rotor with an extension where the extension is adapted to be received in the chamber when the rotors are synchronously rotated. The compressor also includes a power input shaft attached to the extension rotor and a gear assembly attached to the rotors that is adapted to insure the synchronous rotation of the rotors. A rotor case houses the rotors and has an intake port and an exhaust port. The present invention also includes an engine that is similar to the compressor and includes a spark plug. Methods of compressing, pumping and generating electricity and mechanical power are also part of the present invention.

Abstract: A rotary compressor is provided. A suction hole is formed through a middle plate of the compressor to distribute refrigerant into both upper and lower cylinders. Coupling bolts having an appropriate length couple the cylinders to the middle plate. The length of the coupling bolts may be defined such that deformation of vane slots of the cylinders due to coupling of the cylinders may be minimized or eliminated, and friction loss and leakage loss between the vane and the vane slot may be reduced, thus improving compressor function.

Abstract: Flowmeter with a pair of helical gears using an oval pitch curve as a reference rack tooth profile. The tooth height ratio of the reference rack tooth profile is ?/4. The reference rack tooth profile is an oval pitch curve of two or less leaves. The moving radius of the oval pitch curve is expressed by ?=a/(1?b cos n?), where ? is a moving radius which is a distance between the center of rotation and the oval pitch curve, “a” is a similarity factor, “b” is a degree of flatness, n (n?2) is the number of leaves, and ? is an argument. The tooth height ratio is h=a/(1?b)?g0, where g0 is a distance between poles of the oval pitch curve and pitch line, wherein g0=a cos ?0/(1?b cos n?0). Values for the similarity factor “a”, degree of flatness “b”, and distance g0 are determined so that the tooth height ratio may be ?m/4.

Abstract: An oil pump rotor includes an inner rotor formed with n (n: a natural number) external teeth, and an outer rotor formed with n+1 internal teeth which are in meshing engagement with each of the external teeth. And the oil pump rotor is used in an oil pump that includes a casing having a suction port for drawing in fluid and a discharge port for discharging fluid and conveys the fluid by drawing in and discharging the fluid due to changes in volumes of cells formed between surfaces of the internal teeth and surfaces of the external teeth during rotations of the rotors under meshing engagement therebetween.

Abstract: A method of manufacturing a rotor to be used in a dual-rotor lobe pump system for pumping a material at a periodic rate is provided. The method includes selecting a desired periodic flow rate for the material, selecting a number of lobes for the rotor, and selecting either a thickness of the rotor or a spacing between the dual-rotors' axes of rotation in the lobe pump. The method also includes determining the profile for the rotor based on the desired periodic flow rate, so that when the rotor is operated within the dual-rotor lobe pump system, the material can be pumped at substantially the desired periodic flow rate. In another embodiment of the invention, a lobe pump rotor profile is formed by the method described above.

Abstract: A scroll compressor includes a fixed scroll having a fixed wrap, and an orbiting scroll having an orbiting wrap engaged with the fixed wrap to define a first compression chamber between an inner surface of the fixed wrap and an outer surface of the orbiting wrap, and to define a second compression chamber between an inner surface of the orbiting wrap and an outer surface of the fixed wrap. A rotation shaft is provided with an eccentric portion at one end thereof to drive the orbiting scroll. A protruding portion protrudes inwardly from an inner end of the fixed wrap, and contacts the orbiting wrap. A distance between a center of the eccentric portion and a tangent line at a contact point between the protruding portion and the orbiting wrap at an end of the first compression chamber is smaller than a radius of the eccentric portion.

Abstract: A Moineau pump or Moineau compressor includes a conically designed inner (4) and a conically designed outer (8) element, whose longitudinal axes (X1, X2) run at an angle to one another and intersect at a point. The pump or compressor has at least two sections (2a, 2b, 2c, 2d) in the axial direction. A part (4b) of the inner element (4) located in a second section (2b) is arranged rotated with respect to a part (4a) of the inner element located in a first section (2a) about the longitudinal axis (X1) of the inner element (4). A part (8b) of the outer element (8) located in the second section (2b) is arranged rotated with respect to an other part (8a) of the outer element (8) located in the first section (2a) about the longitudinal axis (X2) of the outer element (8).

Abstract: A screw pump includes a casing including a main accommodating bore and plural sub accommodating bores, a main rotor adapted to be rotatably accommodated in the main accommodating bore, and plural sub rotors adapted to be respectively rotatably accommodated in the sub accommodating bores. Each sub rotor is adapted to engage the main rotor. A cross sectional shape of a flank surface of the main rotor, which is taken in a direction perpendicular to an axial direction of the main rotor, is formed along an epitrochoid traced by an edge of the sub rotor not to include an undercut shape. Further, a cross sectional shape of a flank surface of each sub rotor, which is taken in a direction perpendicular to an axial direction of the sub rotor, is formed along an epitrochoid traced by an edge of the main rotor not to include an undercut shape.

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

Abstract: A rotary compressor, which contains a motor unit and compression mechanism in a sealed case, transmits the rotational power of the motor to the compression mechanism through a rotary shaft and crankshafts eccentrically provided in the rotary shaft, and compresses a refrigerant in the compression mechanism, wherein the rotary compressor is configured to have H/(?Da•E)=K, and K?0.065, and the formula 0.35+0.07•K•H?L/?Db?0.45+0.07•K•H, assuming that the inside diameter of the cylinder forming the compression mechanism is ?Da [mm], the cylinder height is H [mm], the crankshaft eccentricity is E [mm], the crankshaft diameter is ?Db [mm], and the sliding lengths of the crankshaft and a roller fitted over the crank are set to L [mm].

Abstract: There is disclosed a scroll compressor having an object of stabilizing the moving of an orbit scroll while suppressing the start load of the scroll compressor. In the scroll compressor, a slide bush having a slide face forming a predetermined angle with respect to the direction of gas load of a gas in a compression chamber is interposed on an eccentric shaft of a shaft for driving the orbit scroll, so that when the load of the gas in the compression chamber is applied, the eccentric amount of the eccentric shaft increases. The scroll compressor includes a spring member interposed between the slide bush and the eccentric shaft and configured to constantly urge the eccentric shaft to decrease the eccentric amount of the eccentric shaft, and this spring member urges the eccentric shaft to press the eccentric shaft onto the slide face of the slide bush.

Abstract: An oil pump rotor includes an inner rotor having (n) external teeth, an outer rotor having (n+1) internal teeth, and a casing forming a suction port and a discharge port for drawing/discharging fluid. In operation, fluid is drawn/discharged according to volume changes of cells formed between tooth faces. A tooth profile based on a mathematical curve has a tooth addendum circle A1 with a radius RA1 and a tooth root curve A2 with a radius RA2, a circle D1 has a radius RD1 satisfying Formula (1), and a circle D2 has a radius RD2 satisfying both Formulas (2) and (3): RA1>RD1>RA2 ??Formula (1) RA1>RD2>RA2 ??Formula (2) RD1?RD2 ??Formula (3) A tooth profile of the external teeth includes a modification either, in a radially outer direction, on the outer side of the circle D1 or, in a radially inner direction, on the inner side of the circle D2.

Abstract: A rotary compressor, in which formulas Rc<Rm+e and RC?Rs+e are established, when the radius of a main shaft is Rm, the radius of a countershaft is Rs, the radius of a crankshaft is Rc, and the eccentricity is e, a connecting part has a A-periphery which is formed on the counter-eccentric side periphery of the second crankshaft, and a B-periphery formed on the counter-eccentric side periphery of a first crankshaft, and a formula H>L?H?Cr?Cs is established, when the axial direction of the connecting part is L, the axial length of the first roller is H, the axial length of a bevel formed at the inside edge of the first roller is Cr, and the axial direction of a bevel of the second crankshaft is Cs.

Abstract: In a scroll compressor, a center of a turning scroll body is shifted with respect to a drive central axis so that a distance between a gravity center and the drive central axis in a turning scroll becomes smaller than a predetermined allowable value set based on theoretical displacement and mass of the turning scroll. A moment force about the drive central axis acting on the turning scroll is reduced during revolving, and an alternating force acting on an autorotation preventing pin in the turning scroll is reduced to an allowable level.

Abstract: Embodiments of rotary vane engines include rotors that rotate about an axis of rotation. The rotors can be moved in directions substantially perpendicular to the axis of rotation to vary expansion and/or compression ratios of the rotary vane engines. The ability to vary the expansion and/or compression ratios can facilitate optimization of the performance of the rotary vane engines as operating conditions vary.

Abstract: In a scroll compressor configured to be capable of three-dimensional compression in a circumferential direction and a height direction of spiral wraps, in which top surfaces and bottom surfaces of spiral wraps (25B and 27B) are provided with step portions (25E and 27E) and the wrap height on the outer peripheral side of the step portion is made higher than the wrap height on the inner peripheral side, back-pressure introducing portions (55 and 57) where gaps between the back surfaces at step-portion ends of tip seals and groove bottom surfaces of tip seal grooves are made larger than a gap at the other portion are formed between the step-portion ends of tip seals (51 and 53) provided on top surfaces (25G and 27G) on the outer peripheral side of the spiral wraps and tip seal grooves (25L and 27L) to which the tip seals are fitted.

Abstract: A rotary expansible chamber device includes intersecting, two-piece vanes that provide expansion/compression chambers as the vanes rotate about a central axis of a rotor housing. The rotor housing has an inner contour defined by a conchoid of rhodonea having a shape coefficient of at least 3. The vanes are captured by a primary and secondary output shaft, with engagement arms of the primary output shaft being juxtaposed between the intersecting vanes. A vane spring helps maintain each vane at a constant length and in sealing engagement with the inner contour of the rotor housing.

Abstract: In the first variant, the device comprises a stator and a rotor eccentrically mounted in the stator. A planetary train consists of large and small gear wheels. The large gear wheel is fixedly arranged on the outside of the small gear wheel and it is enabled to run around the small gear wheel of the planetary train. The stator is coupled with the large gear wheel and the rotor is coupled with the small gear wheel. In the second variant, the device comprises a stator and a rotor. The small gear wheel is fixedly arranged and the large gear wheel is enabled to run around the small gear wheel of the planetary train. The stator is coupled with the small gear wheel and the rotor is coupled with the large gear wheel. The equations describing the outlines of the stator and rotor are disclosed for the first and second variant.

Abstract: An oil pump rotor for use in an oil pump includes an inner rotor having (n: “n” is a natural number) external teeth, an outer rotor having (n+1) internal teeth meshing with the external teeth, and a casing forming a suction port for drawing a fluid and a discharge port for discharging the fluid, such that in association with meshing and co-rotation of the inner and outer rotors, the fluid is drawn/discharged to be conveyed according to volume changes of cells formed between teeth faces of the two rotors.

Abstract: Provided is a scroll compressor that is capable of three-dimensional compression, ensuring a required wrap strength while increasing a shoulder section height of a spiral wrap, and facilitating wrap processing. The scroll compressor includes shoulder sections at an end surface and a bottom surface of spiral wraps of a paired fixed scroll member and revolving scroll member and configured to be capable of three-dimensional compression in a circumferential direction and a height direction of the spiral wraps by setting a spiral wrap height of the spiral wraps further toward the outside of the shoulder sections greater than the spiral wrap height of the inward side, and wherein the shoulder sections provided on the end surface and the bottom surface at the spiral wrap are constructed of a plurality of shoulder sections, and the heights of the shoulder sections are set to heights in which base stresses at the shoulder sections are substantially equal.

Abstract: The present invention is an engine, which includes a positive displacement compression process, a variably fueled, continuous combustor and/or heat exchanger, and a positive displacement, work-producing expander. This arrangement avoids the traditional stochiometric mixture requirements utilized in spark-ignition based engines and the emission problems associated with diesel engines.

Abstract: Gearwheel pump, having a housing with at least two intermeshing gears with shafts supported by slide bearings lubricated with pumping medium (M) fed from a suction side to a pressure side, a return duct which leads pumping medium which flows outward through the plain bearing back to the suction side, and a valve (5) having a stationary part and a moveable part (20, 21). The valve (5) has a setting characteristic which runs, as a first approximation, linearly at least in one region, wherein the setting characteristic is defined by a differential pressure (?p) across the valve as a function of a setting path (x) in the valve (5) thereby significantly improving capability for setting the pressure in the transition region between the plain bearing and a dynamic seal of a driveshaft which is guided outward.

Abstract: A vane machine includes a housing with a inlet port and an outlet port, a rotor mounted in a cavity of the housing. The rotor has a faceplate and a guide cylinder mounted eccentrically on an end surface of the housing opposite to the faceplate. The guide cylinder is rotatable and provided with a diametrical face groove open from a side of the faceplate, and one or more working vanes mounted on the faceplate such that the faceplate is rotatable and movable in the grooves of the guide cylinder as the faceplate rotates. The diameter of the guide cylinder 7 is D>4a?L, where e is the eccentricity of the axis of the guide cylinder and the length of the working vane is L?4e×sin 90°/N, where N is the number of working vanes.

Abstract: The present invention enables the manufacture of a trochoid pump having a crescent which has been considered theoretically impossible by employing an inner rotor of a trochoid pump. An inner rotor having a predetermined number N of teeth that is equal to or larger than 4 is formed in advance.

Abstract: The present invention enables the manufacture of a trochoid pump having a crescent which has been considered theoretically impossible, by employing an inner rotor of a trochoid pump. An inner rotor having a predetermined number N of teeth that is equal to or larger than 4 is formed in advance.

Abstract: The present invention is an apparatus that includes a chamber rotor with a chamber and an extension rotor with an extension. The rotors are housed in a rotor case. A pressure cavity is at least transiently formed by the extension rotor and the chamber rotor. The present invention also includes a compressor that includes a chamber rotor with a chamber and an extension rotor with an extension where the extension is adapted to be received in the chamber when the rotors are synchronously rotated. The compressor also includes a power input shaft attached to the extension rotor and a gear assembly attached to the rotors that is adapted to insure the synchronous rotation of the rotors. A rotor case houses the rotors and has an intake port and an exhaust port. The present invention also includes an engine that is similar to the compressor and includes a spark plug. Methods of compressing, pumping and generating electricity and mechanical power are also part of the present invention.

Abstract: A rotary compressor is provided. A suction hole is formed through a middle plate of the compressor to distribute refrigerant into both upper and lower cylinders. Coupling bolts having an appropriate length couple the cylinders to the middle plate. The length of the coupling bolts may be defined such that deformation of vane slots of the cylinders due to coupling of the cylinders may be minimized or eliminated, and friction loss and leakage loss between the vane and the vane slot may be reduced, thus improving compressor function.

Abstract: A self-modulating scroll compressor includes a built-in volume ratio that is defined as the ratio of a volume of a compression pocket just after completion of suction, i.e. at a beginning of a compression cycle, to the volume of the compression pocket just prior to discharge, i.e. at the end of the compression cycle. The built-in volume ratio can be controlled by the geometry of the scrolls and can be modified by, for example, extending the wrap or adding more turns to the wrap. Because the built-in volume ratio decreases to an effective volume ratio at lower capacity operation, the built-in volume ratio is at least 2.4 in order to optimize overall compressor efficiency.

Abstract: In an internal gear pump of the present invention, a first angle that is formed by a first straight line that connects a rotation axis of an inner rotor to a tooth tip portion of an external tooth in the rotational direction of the inner rotor and an outer rotor, and a second straight line that connects the rotation axis to a meshing portion of the external tooth is not less than 1.4 times the size and not more than 1.8 times the size of a second angle that is formed by a third straight line that connects the rotation axis to a tooth bottom of the external tooth, and the second straight line.

Abstract: Disclosed is a pressurized internal oil management system, comprising an oil dam, at least one oil separator, at least one oil collection manifold, at least one oil pump, and one or more paths for returning the separated oil; said system integrated within the casing of a fluid displacement device to supply adequate lubrication regardless of orientations under zero to full gravity, and methods and applications related thereto. Fluid displacement devices useful herein include oil lubricated rotary or reciprocating machinery, such as compressors, expanders, pumps and engines, in the casing of which exists one or more drive mechanisms that can be utilized to operate the oil management system, in most cases without even increasing the size of the casing.

Abstract: A rotary compressor including a housing having first and second compressing chambers separated from each other, first and second flanges coupled to the housing, to close the first and second compressing chambers, respectively, an intermediate plate to separate the first and second compressing chambers from each other, first and second rollers rotatably installed in the first and second compressing chambers, respectively, first and second vanes to reciprocate in a radial direction of the first and second compressing chambers to divide the first and second compressing chambers, respectively, and a vane control device to control the reciprocating movement of the first vane by use of a suction pressure and a discharge pressure, for a variation in compression capacity. A first gap, defined at an end of the first roller, is smaller than a second gap defined at an end of the second roller.

Abstract: A novel crescent gear pump and pump rotor set for a crescent gear pump. The rotor set includes an outer rotor with teeth having a composite profile formed over the portion adjacent their root to conform to a circular arc and formed over the portion adjacent their tip to conform to a hypocycloid arc. The unique shape allows for increased volumetric capacity of the rotor set, when compared to trochoidal rotor sets of the same size. Further, operating noise is reduced, as are pulsations in the output of the pump when compared to the same pump with a trochoidal rotor set.

Abstract: A rotary working machine is provided. The machine includes an assembly of working chambers with periodically variable volume disposed in a central block defining a stator. The inside surfaces of the stator direct a pendulum motion of one or more blade-type working elements disposed in respective one or more cylindrical sockets of a cylindrical rotator that is disposed within an interior of the camshaft form stator. The rotator is connected to an external prime mover for providing torque thereto. An angle of contact between a front cylindrical surface of the blade-type working elements and the internal curved space of the camshaft form stator defines a working chamber of variable volume, the working chamber of variable volume is connected during rotator revolution correspondingly with an inside pipe of a camshaft and an annular slot that is configured to evacuate compressed gas disposed within the working chamber of variable volume.

Abstract: A fuel pump (10) supplying fuel to an internal combustion engine includes an electric motor (14), a shaft (16) driven by the motor, and a pump assembly (18) including a pumping element (20) mounted on the shaft. A fuel pump improvement includes the shaft being a multi-sided shaft with the pumping element having a central opening (22) through which the shaft extends. This opening is a contoured opening having a plurality of sides each of which is in contact with a side (22a-22c) of the shaft to distribute wear which occurs between the shaft and the pumping element. This construction prolongs the operating life of the pump. In a roller vane type pump having N vanes, the motor shaft has a number of sides S determined by the formula S=N±1, and N>3.

Abstract: A gerotor pump includes an outer rotor having a first toothed surface and lobes that extend inwards. An inner rotor is eccentrically aligned relative to the outer rotor and includes a second toothed surface and lobes that extend outwards. Planetary gears are located between the outer rotor and the inner rotor. Each planetary gear has a third toothed surface that intermeshes with the first toothed surface and the second toothed surface.

Abstract: Impulsive sound of an Oldham ring is reduced and a driving noise of a scroll compressor is prevented from increasing. When a width of the key of the Oldham ring made of iron-based material is defined as t and a width of the orbiting-side key groove in the back surface of the surface plate of the orbiting scroll made of aluminum-based material and a width of the fixed-side key groove of the main bearing member made of aluminum-based material on the side of a thrust surface are defines as s, a gap d generated at s?t with respect to a key pitch L of the Oldham ring I set in a range of (6×10?5)?d/L?(3.5×10?4). With this, even if the key of the Oldham ring vibrates in the key groove, a collision force against the key groove is weakened, impulsive sound of the Oldham ring becomes small, and a driving noise of the scroll compressor is can be reduced.

Abstract: Rotary displacement machine having a housing and at least two twinned rotors of asymmetrical profile, the twinned rotors each made of a core on which projects a helicoidal thread which extends above the core like a tooth. The helicoidal thread having a first predetermined dimension in a direction radial to the longitudinal axis of the twinned rotors and above the surface of a rotor. The machine having a first flank with a position and length of arc predetermined such that the shape of the first flank and the shape of the second flank each connect to one of the opposite ends of a connecting segment which constitutes a helicoidal surface. The connecting segment having a second predetermined dimension in a direction radial to the longitudinal axis of the twinned rotors such that the ratio of the second dimension over the first dimension ranges between 0.005 and 0.1.

Abstract: The present invention provides methods for designing single-lobe or double-lobe rotors which enable a defined rotor and a conjugate rotor intermeshing and conjugating to each other and by parameterized sets to generate curve portions of half two lobes of the defined rotor including a curve E, an arc A, an arc B, an arc F, an arc C, an arc G and a horizontal line Y. The main feature is that a radius of the arc C being defined by following equation: r C = x + r F = ? x ? ? sin ? ? ? + D 2 ? ? x = ( D / 2 ) - r F 1 - sin ? ? ? ; ? r C = ( D / 2 ) - r F 1 - sin ? ? ? + r F in which rF is two times pitch circle radius(Rp) of the defined rotor deducting the maximum radius(R) of the defined rotor(rF=2 Rp?R), and a center of the arc C is located in a straight extension direction from a center of the defined rotor and an end point of an arc F.

Abstract: An oil pump rotor assembly is disclosed. An inner rotor formed with n external teeth is based on cycloid curves which are generated by a first circumscribed-rolling circle and a first inscribed-rolling circle by rolling the first circumscribed-rolling circle and first inscribed-rolling circle along an inner base circle. An outer rotor formed with n+1 internal teeth (n+1 is the number of teeth) is based on cycloid curves which are generated by a second circumscribed-rolling circle and a second inscribed-rolling circle by rolling the second circumscribed-rolling circle and second inscribed-rolling circles along an outer base circle.

Abstract: A rotary machine with orbiting twin blades, especially for expansion drive units and compressors, includes a stator housing bounding an internal chamber, a rotor part received in the chamber for rotation and including at least two entraining rings axially spaced from one another and at least four entraining bars interconnecting the entraining rings and defining respective slots between themselves. A carrier shaft is mounted in the internal chamber for rotation and carries for joint rotation therewith at least two pairs of eccentric members. At least two twin blades are each supported on one of the pairs of eccentric members for relative turning therebetween and each includes two blade portions passing through oppositely located associated ones of the slots into close proximity of the inner peripheral surface of the stator housing.

Abstract: The present invention provides a method for designing lobe-type rotors which enables a defined rotor and a conjugate rotor having three or more than three lobes intermeshing and conjugating to each other and by setting suitable parameters to generate curve portions of a single lobe of the defined rotor as a pattern including a curve E, an arc A, an arc B, an arc F, and a straight line Y; the main feature of the present invention is that a radius rB of the arc B is defined by following equation: r B + ( R - r B ) ? sin ? ? ? = D 2 r B = D / 2 - R ? ? sin ? ? ? 1 - sin ? ? ? moreover, the straight line Y is the external common tangent line of the arc B and the arc F, and respectively getting two tangent points therefrom to be defined as two end points of the straight line Y.