Abstract: The present invention provides a method for designing lobe-type rotors which enables a defined rotor and a conjugate rotor with three or more than three lobes intermeshing and conjugating to each other; by setting suitable parameters to generate a curve portion of a single lobe of the defined rotor as a pattern including a curve E, an arc A, an arc B, a straight line Y, an arc C and an arc F, then imaging (N-1) copy of the curve portion in which N represents number of lobes and is bigger than or equal to three, and then respectively rotating each curve portion in sequence from an appropriate degree computed by 360/N to a terminal degree computed by (N-1)*360/N; whereby to integrately form the defined rotor with three or more than three lobes.

Abstract: The present invention provides a method for designing single-lobe rotors of the present invention includes: curve portions of the of a curve E, an arc A, an arc B, an arc F, an arc C, an arc H, a straight line Y, and an arc G, wherein a center of the arc H located in line with a center of the arc C through a center of the defined rotor, and a center of the arc G is same as the center of the defined rotor wherein a radius of the arc G is defined between a center of the arc G and an end point of the arc H, from which two end points of the arc G is smoothly connected with the arc H and the arc C. The single-lobe rotors generated by the method is able to provide higher compression ratio and larger discharge capacity, secure a smooth process while working chamber undergoing compression and expansion, and reduce leakage.

Abstract: According to an aspect of the present invention, an electric pump includes: a housing; an outer rotor; an inner rotor; a base member facing one side surface of the outer rotor and one side surface of the inner rotor; a side plate member, having a facing surface facing the other side surface of the outer rotor and the other side surface of the inner rotor and a non-facing surface opposed to the facing surface; a shaft; a suction port; a discharge port; a negative pressure applied region; a positive pressure applied region; and a relief valve, discharging the fluid from the positive pressure applied region to a non-facing surface side of the side plate member when a pressure applied at the positive pressure applied region exceeds a predetermined value.

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 method of designing rotors for a Roots blower comprising a housing having cylindrical chambers, the housing defining an outlet port (19). The blower includes meshed, lobed rotors (37,39) disposed in the chambers, each rotor including a plurality N of lobes (47,49), each lobe having first (47a,49a) and second (47b,49b) axially facing end surfaces. Each lobe has its axially facing surfaces defining a twist angle (TA), and each lobe defines a helix angle (HA). The method of designing the rotor comprises determining a maximum ideal twist angle (TAM) for the lobe as a function of the number N of lobes on the rotor, and then determining a helix angle (HA) for each lobe as a function of the maximum ideal twist angle (TAM) and an axial length (L) between the end surfaces of the lobe. A rotor designed in accordance with this method is also provided.

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: A closed system rotary machine has an inner shaped element (1) and an outer shaped element (2) which define therebetween cavities or capsules having a variable volume (V1, V9). The contact points which define the capsules (C1, C9) are disposed along lines of action (CA1, CA2, CA3) which are concurrent at junction points BN and BM, where the cavities begin and end respectively. The contacts (C2) at points located on the tangent (T) common to both pitch circles (6, 7) are osculating elements with a shared centre of curvature which is situated at the rolling point (R) of the pitch circles (6, 7). The invention can be used to ensure that the capsules form and disappear very gradually and to facilitate the distribution of the capsules when they are forming and disappearing in order to increase the leak paths.

Abstract: A double-screw compressor for supplying gas, such as air, to a gas consumer, is provided. The double-screw compressor includes two interacting rotors for compressing the gas and a toothed gearing. The toothed gearing includes a gearing housing with two opposite end walls made of a first material. Two gearwheels made of a second material which has a thermal expansion coefficient different from the thermal expansion coefficient of the first material are mounted in the end walls. In order to reduce the effect of the temperature on the backlash, both gearwheels are designed with one and the same pressure angle which is smaller than 15°.

Abstract: Rotary working machine provided with an assembly of working chambers with periodically variable volume, in particular a compressor, consisting of a stator with a controlling cam and a surrounding cylindrical rotator, with which are connected working elements, rotating together with it, driven by the cam and forming, together with an inner surface of the rotator and an outer surface of the cam, working chambers with variable volume, connected during the rotator's rotation with an intake and an outlet, respectively, of a medium being compressed. The compressor is characterized in that the assembly of working elements (10, 11, 12), forming a working unit (9) or separate working elements (10?), are connected with the cylindrical rotator (8, 8?) in a way enabling their oscillating motion.

Abstract: A rotor pump assembly is disclosed which reduces noise emitted from an oil pump while preventing pumping performance and mechanical efficiency thereof from being decreased by properly forming the profiles of teeth of an inner rotor and an outer rotor which are engageable with each other. The tooth profile of an inner rotor and/or an outer rotor has curved lines obtained by dividing a cycloid curve into two segments to be separated from each other, and in which the separated segments are smoothly connected to each other using a straight line or a curve.

Abstract: Rotary working machine provided with an assembly of working chambers with periodically variable volume, in particular a compressor, consisting of a stator with a controlling cam and a surrounding cylindrical rotator, with which are connected working elements, rotating together with it, driven by the cam and forming, together with an inner surface of the rotator and an outer surface of the cam, working chambers with variable volume, connected during the rotator's rotation with an intake and an outlet, respectively, of a medium being compressed. The compressor is characterized in that the assembly of working elements (10, 11, 12), forming a working unit (9) or separate working elements (10?), are connected with the cylindrical rotator (8, 8?) in a way enabling 6 their oscillating motion.

Abstract: A roots-type fluid machine including a set of rotors and a rotor housing is disclosed. The rotor housing accommodates the rotors and has a suction space. The set of rotors mesh with each other and rotate in the rotor housing so that fluid is drawn into the suction space and discharged from the rotor housing. Each of the set of rotors includes a tooth having a twisted portion and a different shape variation portion. The twisted portion has a twist angle that changes linearly or non-linearly about a rotation axis of the corresponding rotor with respect to the variation of the position in the direction of the axis. The different shape variation portion has a twisted angle that changes by a smaller degree than the variation of the twist angle of the twisted portion.

Abstract: A roots pump including a pair of multi-lobe rotors is disclosed. The pair of rotors each include a first straight portion and a second straight portion. The first straight portion is provided on one of end portions of the rotary shaft of the rotor in an axial direction to extend straight along the axial direction. The straight portion is provided on the other one of the end portions to extend straight along the axial direction. The phases of the first straight portion and the second straight portion are displaced along the circumferential direction of the associated rotary shaft. Each of the pair of rotors further includes a coupling portion, which couples the first straight portion and the second straight portion. The coupling portions of the pair of rotors are engaged with each other to suppress fluid leakage between the pair of rotors.

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

Abstract: A roots type fluid machine includes a housing, a pair of parallel rotary shafts and two-lobe rotors. Each rotor includes two lobe portions and two well portions. Each lobe portion has a profile of convex arc with a radius R and each well portion has a profile of concave arc which is an envelope of the convex arc of the lobe portion. The rotor has a configuration defined by a curve which includes the convex arc, the concave arc and further an involute curve with a base radius r between the convex and concave arcs. The base radius r is set in a range L/(2?{square root over ( )}2)<r<0.3(?{square root over ( )}2)L where distance between axes of the rotary shafts is L, and the radius R is set in a range {(?{square root over ( )}2)/16}?L<R<{(27?5?{square root over ( )}2)/56}L.

Abstract: A roller cell pump having a shaped sliding surface composed of elliptical portions results from two different equations. The function of the unit is improved because the equations are modified and include adaptable parameters, so that by adaptation of the parameters, the shaped sliding surface can be adapted in portions optimally to the requisite function in that particular region of the shaped sliding surface, for instance the function of generating an underpressure or an overpressure. The course of the radii of the elliptical portions corresponds, at least in portions, to one of two equations that differ from the prior art.

Abstract: A double-lobe type rotor design process includes a process for forming a defined rotor and a process for forming a conjugate rotor, wherein the defined rotor and the conjugate rotor intermesh and conjugate to each other. The rotor profile curves suitably for the completed operation period of carryover, suction and exhaust could be well defined by proper parameters, thereby optimizing rotor performance, enhancing compression ratio, providing a smooth suction and exhaust process and avoiding noise and vibration.

Abstract: In a scroll compressor, an outer wall curve of a scroll lap of a fixed scroll and an inner wall curve of a scroll lap of an orbiting scroll are formed of involute curves whose basic circle radius is defined as “a”, an inner wall curve of the scroll lap of the fixed scroll and an outer wall curve of the scroll lap of the orbiting scroll are formed of involute curves whose basic circle radius is defined as “b”, and a value of a/b which is a ratio of the basic circle radius a and the basic circle radius b is set to a value exceeding 1.0 and less than 1.5. With this structure, a compression chamber formed on the side of the inner wall of the scroll lap of the orbiting scroll is compressed faster than a compression chamber formed on the side of the outer wall of the scroll lap of the orbiting scroll, and leakage loss during compression process can be reduced.

Abstract: The invention relates to gerotor mechanisms for screw downhole motors used for drilling oil and gas wells, to screw pumps for producing oil and pumping fluids and to general purpose screw motors. The profiles of a rotor (3) and stator (1) are outlined in the end cross section thereof in the form of the envelop of the initial contour of a rack-type tool, which is formed by conjugation of circle arcs when said initial contour of the rack-type tool is run without sliding along corresponding tool circles. The arc radii of the circle arcs of the initial contour are calculated according to determined relations. Said invention makes it possible to improve energy characteristics, increase a life service and producibility, to reduce hydromechanical losses and costs.

Abstract: A gerotor mechanism is used to guide the rotation of a turntable having a Reuleaux triangle shape. In one version, the mechanism includes a gerotor having three lobes, and the gerotor guide has a guide profile including four recesses for receiving the lobes of the gerotor. Rotation is governed by a 4:3 hypocycloid function. The profiles of the gerotor and the gerotor guide are expanded uniformly from an original hypocycloid pattern so that rotation of the turntable results in execution of the hypocycloid function while retaining the gerotor in controlled contact with the profile of the gerotor guide. A reciprocal of the hypocycloid function yields a “cloverleaf” gerotor. Substantially planar bearing surfaces may be used at the interface of (a) the turntable and the gerotor guide, (b) the gerotor and the gerotor guide, or (c) the gerotor and the underlying support surface. The gerotor guide and turntable may be part of a cabinet or built into a kitchen countertop.

Abstract: A gerotor mechanism is used to guide the rotation of a turntable having a Reuleaux triangle shape. The mechanism includes a gerotor having three lobes; the gerotor guide has a guide profile including four recesses for receiving the lobes of the gerotor. Rotation is governed by a 4:3 hypocycloid function. The profiles of the gerotor and the gerotor guide are expanded uniformly from an original hypocycloid pattern so that rotation of the turntable results in execution of the hypocycloid function while retaining the gerotor in controlled contact with the profile of the gerotor guide. Substantially planar bearing surfaces may be used at the interface of (a) the turntable and the gerotor guide, (b) the gerotor and the gerotor guide, or (c) the gerotor and the underlying support surface. The gerotor guide may be part of a cabinet or built into a kitchen countertop.

Abstract: An oil pump rotor assembly for an oil pump which enables reduction of noise while preventing pump performance and mechanical efficiency from being degraded. In this oil pump rotor assembly, the tooth tip profile of each of at least one of external teeth of an inner rotor and internal teeth of an outer rotor the inner rotor is formed such that a base cycloid curve is divided at a midpoint thereof to obtain two tooth curve segments, and the two tooth curve segments are separated by a predetermined distance along the circumference of a base circle or in the direction of a tangent of the base cycloid curve drawn at the midpoint thereof and are smoothly connected to each other using a curve or a straight line.

Abstract: A scroll type fluid machinery includes first and second fluid volume changing mechanisms. The first fluid volume changing mechanism includes a first stationary scroll and a first orbiting scroll, and the first orbiting scroll is associated with the first stationary scroll so that the first orbiting scroll is able to orbit with respect to the first stationary scroll. The second fluid volume changing mechanism includes a second stationary scroll and a second orbiting scroll, and the second orbiting scroll is associated with the second stationary scroll so that the second orbiting scroll is able to orbit with respect to the second stationary scroll. The scroll type fluid machinery further includes a plurality of orbiting units. Each of the orbiting units includes a rotating member that is able to rotate relative to the first and second stationary scrolls, and a thrust-canceling shaft connected to the first orbiting scroll and to the second orbiting scroll.

Abstract: An object of this invention is to prevent drop of life of a bearing by an axial force when using a pump as a compressor. In a vacuum pump 1 compressing and discharging gas in a direction of a rotor axis by rotation of screw rotors 3, 4 engaged together which are supported rotatably in a casing 2, balance pistons 13, 14 are disposed on shafts 6, 7 of said screw rotors at inlet side of said casing. The balance pistons separate a receiving section 17 at area of the screw rotor and a pressurizing section 16 at area of the balance piston, and a thrust force of the screw rotors at a pressurizing condition is canceled by acting the discharge pressure in the pressurizing section. The pump is used as a compressor when the discharge pressure is acted on the balance pistons 13, 14. When the pump is used as a vacuum pump, air at discharge side is sucked as cool air through a cooler toward a place near to the discharge side of the receiving section 17 at area of the screw rotor.

Abstract: A rotary internal combustion engine has a shaft, a compression chamber, an ignition chamber, a center wall, a first rotor, and a second rotor. The shaft is fixed to the rotors while being rotatably mounted to the compression and ignition chambers. The compression chamber has an oval shaped chamber wall and receives fuel and compresses the fuel. The ignition chamber has an oval shaped chamber wall and receives compressed fuel from the compression chamber and combusts the compressed fuel. The center wall is located between the compression chamber and ignition chamber and allows passage of compressed fuel from the compression chamber to the ignition chamber. The first rotor has a circular perimeter surface and is rotatably received within the compression chamber. The second rotor has a circular perimeter surface and is rotatably received within the ignition chamber.

Abstract: An internal gear oil pump rotor assembly which enables the construction of an oil pump that is compact and has high performance. In the oil pump rotor assembly having an inner rotor and an outer rotor, the number of teeth “Zi” of the inner rotor with trochoid tooth profiles is set to be equal to or fewer than “6”, and a ratio Si/So is set so as to satisfy the following inequalities: 0.8?Si/So?1.3, where Si is a cross-sectional area of one external tooth which is formed outside a root circle that is formed along the bottoms of the external teeth of the inner rotor, and So is a cross-sectional area of one internal tooth which is formed inside a root circle that is formed along the bottoms of the internal teeth of the outer rotor.

Abstract: A vacuum pump, in particular for brake booster systems in motor vehicles, with a drivable rotor via which a blade in a housing can be set in rotation is proposed. The vacuum pump is distinguished by the fact that the rotor consists of plastic and is formed as one piece.

Abstract: A noise-reduced internal gear pump incorporating an inner rotor having an addendum formed by a smooth curve and a dedendum formed by a hypocycloid. The tooth profile of the outer rotor is determined by the following steps. The center Oi of an inner rotor 1 is revolved around the center Oo of the outer rotor so as to form a circle S having a diameter of 2e+t, where “e” is the amount of eccentricity between the inner and outer rotors and “t” is the maximum value of the interrotor clearance between the outer rotor and the inner rotor pressed against it. The inner rotor 1 is rotated on its axis 1/n times while its center Oi makes one revolution in the circular orbit S, where “n” is the number of teeth of the inner rotor. The envelope of the group of the tooth profile-curves of the inner rotor formed by its revolution is used as the tooth profile of the outer rotor.

Abstract: An oil pump emits less noise by properly forming the profiles of teeth of an inner rotor and an outer rotor thereof which engage each other, whereby decreasing sliding resistance and rattle between the tooth surfaces of the rotors. The rotors of the oil pump are formed so the inner rotor having “n” teeth is formed such that the tooth tip profile and tooth space profile thereof are formed using cycloid curves which are formed by rolling a first circumscribed-rolling circle and a first inscribed-rolling circle along a base circle, respectively, and the outer rotor having “n+1” teeth is formed such that the tooth tip profile and tooth space profile thereof are formed using cycloid curves which are formed by rolling a second circumscribed-rolling circle and a second inscribed-rolling circle along a base circle, respectively, and in such a manner that the following equations are satisfied: øBo=øBi; øDo=øDi·(n+1)/n+t·(n+1)/(n+2); and øAo=øAi+t/(n+2).

Abstract: To provide a scroll compressor that has a lower sliding friction loss and high compression efficiency, taking the diameter of a main shaft (61) as Dm and the diameter of a crank shaft (62) as Dc, the crank shaft (62) formed at one end of the main shaft (61) is arranged so that the eccentricity e thereof with respect to the main shaft (61) has a relation of e>(Dm?Dc)/2. Further, to support a main bearing (31) of a main frame (3) by the main shaft (61) serving as a sliding bearing and to support a crank bearing (421) of an orbiting scroll (42) by the crank shaft (62) serving as a sliding bearing, a joint shaft (65) for connecting the main shaft (61) and the crank shaft (62) to each other is formed so as to have a shape that falls within the main shaft diameter and within the crank shaft diameter when viewed in the axial direction.

Abstract: An object of this invention is to prevent drop of life of a bearing by an axial force when using a pump as a compressor. In a vacuum pump 1 compressing and discharging gas in a direction of a rotor axis by rotation of screw rotors 3, 4 engaged together which are supported rotatably in a casing 2, balance pistons 13, 14 are disposed on shafts 6, 7 of said screw rotors at inlet side of said casing. The balance pistons separate a receiving section 17 at area of the screw rotor and a pressurizing section 16 at area of the balance piston, and a thrust force of the screw rotors at a pressurizing condition is canceled by acting the discharge pressure in the pressurizing section. The pump is used as a compressor when the discharge pressure is acted on the balance pistons 13, 14. When the pump is used as a vacuum pump, air at discharge side is sucked as cool air through a cooler toward a place near to the discharge side of the receiving section 17 at area of the screw rotor.

Abstract: A noise-reduced internal gear pump incorporating an inner rotor having an addendum formed by a smooth curve and a dedendum formed by a hypocycloid. The tooth profile of the outer rotor is determined by the following steps. The center Oi of an inner rotor 1 is revolved around the center Oo of the outer rotor so as to form a circle S having a diameter of 2e+t, where “e” is the amount of eccentricity between the inner and outer rotors and “t” is the maximum value of the interrotor clearance between the outer rotor and the inner rotor pressed against it. The inner rotor 1 is rotated on its axis 1/n times while its center Oi makes one revolution in the circular orbit S, where “n” is the number of teeth of the inner rotor. The envelope of the group of the tooth profile-curves of the inner rotor formed by its revolution is used as the tooth profile of the outer rotor.

Abstract: A rotary internal combustion engine has a shaft, a compression chamber, an ignition chamber, a center wall, a first rotor, and a second rotor. The shaft is fixed to the rotors while being rotatably mounted to the compression and ignition chambers. The compression chamber has an oval shaped chamber wall and receives fuel and compresses the fuel. The ignition chamber has an oval shaped chamber wall and receives compressed fuel from the compression chamber and combusts the compressed fuel. The center wall is located between the compression chamber and ignition chamber and allows passage of compressed fuel from the compression chamber to the ignition chamber. The first rotor has a circular perimeter surface and is rotatably received within the compression chamber. The second rotor has a circular perimeter surface and is rotatably received within the ignition chamber.

Abstract: A pair of interacting gear rims of rotary machine has been invented as a basic structural element for engines, motors and compressors. This is the most simple and most effective design to predetermine the optimal ratio of volumes of expansion and compression processes only at the expense of the form of profile of contact surface of pair gear rims of the rotary machine. This is the ideal basic element for engines, working according to an extended indicator diagram, and for single stage compressor, working with multistage effect. Applications: light and heavy vehicle engines; space power systems; heat pump systems; solar, thermal, nuclear energy systems.

Abstract: To provide a scroll compressor that has a lower sliding friction loss and high compression efficiency, taking the diameter of a main shaft 61 as Dm and the diameter of a crank shaft 62 as Dc, the crank shaft 62 formed at one end of the main shaft 61 is arranged so that the eccentricity e thereof with respect to the main shaft 61 has a relation of e>(Dm−Dc)/2. Further, to support a main bearing 31 of a main frame 3 by the main shaft 61 serving as a sliding bearing and to support a crank bearing 421 of an orbiting scroll 42 by the crank shaft 62 serving as a sliding bearing, a joint shaft 65 for connecting the main shaft 61 and the crank shaft 62 to each other is formed so as to have a shape that falls within the main shaft diameter and within the crank shaft diameter when viewed in the axial direction.

Abstract: A rotary internal combustion engine has a shaft, a compression chamber, an ignition chamber, a center wall, a first rotor, and a second rotor. The shaft is fixed to the rotors while being rotatably mounted to the compression and ignition chambers. The compression chamber has an oval shaped chamber wall and receives fuel and compresses the fuel. The ignition chamber has an oval shaped chamber wall and receives compressed fuel from the compression chamber and combusts the compressed fuel. The center wall is located between the compression chamber and ignition chamber and allows passage of compressed fuel from the compression chamber to the ignition chamber. The first rotor has a circular perimeter surface and is rotatably received within the compression chamber. The second rotor has a circular perimeter surface and is rotatably received within the ignition chamber.

Abstract: An expansion unit (4) for converting an expansion energy of pressure-increased steam into a rotation energy of an output shaft, wherein a cover member (26) is provided on the casing outer surface of the expansion unit (4). The cover member (26) has a function of sealing the end section of an output shaft (23) protruding beyond the casing outer surface against the outside and a function of recovering steam led out from the casing and has its pressured reduced after the conversion. The end section of the output shaft (23) provided inside the cover member (26) and a driven-side transmission shaft (119) disposed outside the cover member (26) are coupled with each other via a magnet type shaft coupling (120) so as to be able to transmit power, whereby the output shaft (23) and the driven-side transmission shaft (119) can be coupled without steam in the expansion unit leaking outside.

Abstract: An oil pump rotor assembly for an oil pump which enables reduction of noise while preventing pump performance and mechanical efficiency from being degraded. In this oil pump rotor assembly, the tooth tip profile of each of at least one of external teeth of an inner rotor and internal teeth of an outer rotor the inner rotor is formed such that a base cycloid curve is divided at a midpoint thereof to obtain two tooth curve segments, and the two tooth curve segments are separated by a predetermined distance along the circumference of a base circle or in the direction of a tangent of the base cycloid curve drawn at the midpoint thereof and are smoothly connected to each other using a curve or a straight line.

Abstract: A roller vane pump, in particular suited for pumping fluid in a continuously variable automatic transmission of a motor vehicle, is provided with a pump housing (12) accommodating a carrier (4) rotatable around a central axis (4a) of the carrier in a direction of rotation by a pump shaft (5), on the periphery of the carrier (4) there is provided a slot (6), which extends in a substantially radial direction and accommodates an essentially cylindrically shaped roller element (7) having a roller diameter (DR) for interaction with a radially inner cam surface (2a) of a cam ring (2) encompassing the carrier (4) in radial direction. The cam surface (2a) is located at a radial distance (R) from the central axis (4a) that varies in dependence on an angular rotation (&phgr;) according to a cam curve (R{&phgr;}).

Abstract: An industrial robot including a manipulator having a control system. The manipulator includes a common gear housing having first and second inner compartments connected with a passage channel. First and second gears are arranged in the first and second inner compartments and are adapted to move the manipulator. A cooling and lubricant medium is disposed in the common gear housing and circulates between the first and second inner compartments through the passage channel.

Abstract: Rotary type fluid machine includes a casing 7, a rotor 31 and a plurality of vane-piston units U1-U12 which are disposed in a radiate arrangement on the rotor 31. Each of the vane-piston units U1-U12 has a vane 42 sliding in a rotor chamber 14 and a piston 41 placed in abutment against an on-slide side of the vane 42. When it functions as an expanding machine 4, the expansion of a high pressure gas is used to operate the pistons 41 thereby to rotate the rotor 31 via vanes 42 and the expansion of a low pressure gas caused by a pressure reduction in the high pressure gas is used to rotate the rotor 31 via the vanes 41. On the other hand, when it functions as a compressing machine, the rotation of rotor 31 is used to supply a low pressure air to the side of pistons 41 via vanes 42 and further, the pistons 41 are operated by the vanes 42 to convert the low pressure air to the high pressure air.

Abstract: Rotary type fluid machine includes a casing 7, a rotor 31 and a plurality of vane-piston units U1-U12 which are disposed in a radiate arrangement on the rotor 31. Each of the vane-piston units U1-U12 has a vane 42 sliding in a rotor chamber 14 and a piston 41 placed in abutment against a non-slide side of the vane 42. When it functions as an expanding machine 4, the expansion of a high pressure gas is used to operate the pistons 41 thereby to rotate the rotor 31 via vanes 42 and the expansion of a low pressure gas caused by a pressure reduction in the high pressure gas is used to rotate the rotor 31 via the vanes 41. On the other hand, when it functions as a compressing machine, the rotation of rotor 31 is used to supply a low pressure air to the side of pistons 41 via vanes 42 and further, the pistons 41 are operated by the vanes 42 to convert the low pressure air to the high pressure air.

Abstract: Rotary type fluid machine includes a casing 7, a rotor 31 and a plurality of vane-piston units U1-U12 which are disposed in a radiate arrangement on the rotor 31. Each of the vane-piston units U1-U12 has a vane 42 sliding in a rotor chamber 14 and a piston 41 placed in abutment against a non-slide side of the vane 42. When it functions as an expanding machine 4, the expansion of a high pressure gas is used to operate the pistons 41 thereby to rotate the rotor 31 via vanes 42 and the expansion of a low pressure gas caused by a pressure reduction in the high pressure gas is used to rotate the rotor 31 via the vanes 41. On the other hand, when it functions as a compressing machine, the rotation of rotor 31 is used to supply a low pressure air to the side of pistons 41 via vanes 42 and further, the pistons 41 are operated by the vanes 42 to convert the low pressure air to the high pressure air.

Abstract: This invention is directed to a novel wave tooth gear having a non-circular pitch curve and uniform wave teeth to create a tighter seal between meshing gears. The non-circular wave tooth gear has a major axis and a minor axis disposed perpendicular to the major axis, wherein the major axis is longer than the minor axis and includes a central hub, a plurality of teeth radially extending from the hub at locations surrounding the hub and a plurality of roots, each root positioned between adjacent teeth at locations surrounding the gear. The teeth include a head portion shaped as an arc segment of a first radius and the roots include a recess shaped as an arc segment of a second radius. The teeth heads are joined to adjacent roots by lines of tangency.

Abstract: An oil pump emits less noise by properly forming the profiles of teeth of an inner rotor and an outer rotor thereof which engage each other, whereby decreasing sliding resistance and rattle between the tooth surfaces of the rotors.

Abstract: The present invention provides an internal combustion engine and a method of manufacturing the internal combustion engine. The internal combustion engine comprises a housing, a first rotor, first and second impellers and a compression cam. In a preferred embodiment, the housing has a first inner surface defining a first cavity therein, the first rotor is journalled for rotation within the first cavity and is situated to define compression and exhaust cavities on opposing sides therein, first and second impellers located in, and slidable with respect to, first and second opposing radial apertures in the first rotor, and the compression cam is fixedly coupled to the housing. The compression cam has a working surface portion that corresponds to a profile of the inner surface to force the first and second impellers to contact the inner surface and a dead surface portion that departs from the profile to allow the first and second impellers to withdraw from the inner surface.

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

Abstract: Rotary type fluid machine includes a casing 7, a rotor 31 and a plurality of vane-piston units U1-U12 which are disposed in a radiate arrangement on the rotor 31. Each of the vane-piston units U1-U12 has a vane 42 sliding in a rotor chamber 14 and a piston 41 placed in abutment against a non-slide side of the vane 42. When it functions as an expanding machine 4, the expansion of a high pressure gas is used to operate the pistons 41 thereby to rotate the rotor 31 via vanes 42 and the expansion of a low pressure gas caused by a pressure reduction in the high pressure gas is used to rotate the rotor 31 via the vanes 41. On the other hand, when it functions as a compressing machine, the rotation of rotor 31 is used to supply a low pressure air to the side of pistons 41 via vanes 42 and further, the pistons 41 are operated by the vanes 42 to convert the low pressure air to the high pressure air.

Abstract: In a variable capacity type pump, in the inner diameter of a cam ring, an inner diameter of a portion forming a middle section between a suction section and a discharge section in a pump chamber is constituted by a negative slope curve in which an end portion of a suction port is set to be a start point, and a complete round curve and a negative slope curve are connected by a high-order curve.

Abstract: A fluid machinery driven equipment such as a rotary pump has a simple structure and high efficiency with a small size and low cost. The driven equipment includes a tubular casing having an inner surface which is substantially elliptic in shape, a rotor provided in the tubular casing where the rotor having a first arm provided with a rotatable piston at its end and a second arm in perpendicular to the first arm provided with a rotary plate at its end, and a rotary shaft provided in the tubular casing and connected to the rotor where at least one end of the rotary shaft is projected from the tubular casing to be connected to the external force.