Abstract: One embodiment of a pump may include an idler gear having a plurality of idler gear teeth extending radially outward, wherein at least one of the idler gear teeth may be formed with an idler gear cavity therein. The pump may include a drive gear having a plurality of drive gear teeth extending radially outward that may be intermeshed with the idler gear teeth during use. The drive gear may be formed with a recess at on axial end thereof, and the axial position of the recess may correspond to the axial position of the idler gear cavity. In one embodiment of a pump, each idler gear tooth may be formed with an identical idler gear cavity at the same relative position on each idler gear tooth.

Abstract: A container assembly (10) for a pump is described, provided with at least one pumping group (12, 14, 16, 18) and with at least one system (20) for transmitting power to such pumping group (12, 14, 16, 18). The container assembly (10) comprises at least one elastic element (26) sealingly housed inside such container assembly (10) at a predefined internal wall (28) thereof. Inside the elastic element (26), at least one cavity (32) is obtained which defines a corresponding air chamber configured for damping the variations of volume and the expansion of the fluid contained inside the pump following a possible change of state of the fluid itself when subjected to temperatures lower than its freezing point.

Abstract: A gear pump has a pump body, a pump cylinder connected with the pump body, a driving gear and a driven gear meshed with each other and disposed in the pump cylinder, and a motor driving the driving gear through a driving shaft. The pump cylinder is located between the pump body and the motor. The driving gear is mounted to or integrally formed with the driving shaft. A first bearing and a second bearing are disposed on respectively sides of the driving gear, one end of driving shaft is received in the first bearing, and the other end of the driving shaft extends through the second bearing and into the motor and forms a shaft of the motor.

Abstract: In a pump chamber (12), a male rotor (20) having claw portions and a female rotor (24) having recesses into which the claw portions enter are secured to rotating shafts (18a and 18b), respectively. The female rotor is provided with hollows on an upstream side in the rotational direction of the female rotor relative to a plane L containing the rotating shafts. For the hollows, the disposed position, size and configuration are selected so that a compression pocket P and a discharge opening remain in communication with each other through the hollow throughout the time from when the compression pocket stops communicating with the discharge opening and separates from the discharge opening until the compression pocket gradually reduces to disappear, and so that the hollow stops communicating with the discharge opening at the same time as the compression pocket disappears.

Abstract: This invention relates to machine-building, more specifically, to the design and manufacturing of positive displacement motors various embodiments of which are used for hydrocarbon production.

Abstract: According to one embodiment of the invention, an engine system comprises a housing, an outer gerotor, an inner gerotor, a tip inlet port, a face inlet port, and a tip outlet port. The housing has a first sidewall, a second sidewall, a first endwall, and a second endwall. The outer gerotor is at least partially disposed in the housing and at least partially defines an outer gerotor chamber. The inner gerotor is at least partially disposed within the outer gerotor chamber. The tip inlet port is formed in the first sidewall and allows fluid to enter the outer gerotor chamber. The face inlet port is formed in the first endwall and allows fluid to enter the outer gerotor chamber. The tip outlet port is formed in the second sidewall and allows fluid to exit the outer gerotor chamber.

Abstract: In an internal-gear type fluid device, guide teeth are formed by inner teeth at an outer rotor, and vane portions extending in the width direction are formed at tooth tip portions of the guide teeth. Further, guide teeth are formed by outer teeth at the inner rotor, and vane portions extending in the width direction are formed at tooth tip portions of the guide teeth. Since the vane portions are thus formed at the outer rotor and the inner rotor, the confinement timing when oil confinement is completed can be synchronized with the release timing when oil release is started, by adjusting, for example, the thickness of the vane portions without changing the profile of the guide teeth.

Abstract: A multistage vacuum pump includes a stator housing a multistage rotor assembly, each stage having intermeshing Roots rotor components, wherein the tip radius of the rotor components at an inlet stage of the pump is larger than the tip radius of the rotor components at an exhaust stage of the pump, wherein a meshing clearance between the rotor components at the inlet stage of the pump is greater than a meshing clearance between the rotor components at the exhaust stage of the pump.

Abstract: A single-screw compressor includes a screw rotor including a spiral groove, a casing, and a gate rotor. The gate rotor includes a plurality of radial gates configured to mesh with the spiral groove. A clearance between one of the gates disposed in the spiral groove and a wall surface of a discharge side portion of the spiral groove is larger than a clearance between the gate disposed in the spiral groove and a wall surface of a suction side portion of the spiral groove. The wall surface of the discharge side portion of the spiral groove is a portion extending from a predetermined position of the spiral groove at a certain point in a compression phase to the terminal end of the spiral groove. The wall surface of the suction side portion of the spiral groove being a portion other than the discharge side portion.

Abstract: A gear pump comprises a drive gear being mounted for rotation about a first axis and having a plurality of gear teeth at a radially outer location. A driven gear is mounted for rotation about a second axis, and having a plurality of teeth at a radially outer location. The drive gear teeth engage the driven gear teeth at a contact face to cause the driven gear to rotate. Slots are formed in the contact face of one of the drive and driven gear teeth.

Abstract: A pump comprises a driving rotor and a driven rotor that are positioned in a housing such that, as the driving rotor and the driven rotor rotate, the teeth of the driving rotor and the teeth of the driven rotor mesh to form a positive displacement seal. The teeth of the driving rotor and the driven rotor are configured such that seals between the inlet side and the discharge side of the pump are formed between only the leading surfaces of the teeth of the driving rotor and the trailing surfaces of the teeth of the driven rotor.

Abstract: A gear pump comprises a first gear to be connected to a source of drive, and having a first plurality of gear teeth. A second gear has a second plurality of teeth engaged with the first gear teeth. The first gear teeth contact the second gear's teeth on a contact face, causing the second gear to rotate. The first plurality of teeth is greater than the second plurality of teeth.

Abstract: A low noise gear set for use generally and preferably with a power plant having an engine driving a pump connected to a low pressure fluid source, generating high pressure fluid at an output. The idle gear meshes with the drive gear along two points of the profile of the corresponding gears. The first point being the root of one gear tooth meshing with the tip of the opposite gear tooth creating an initial first contact point and a subsequent second point along the profile when the teeth are disengaging at the first point and engaging at the second point, forming a sealed area, allowing the fluid to hydrostatically escape between the points.

Abstract: A multi-rotor compressor and method of manufacturing is provided. The compressor includes a housing with a plurality of identical planet rotors. The planet rotors are equally spaced apart at a fixed distance from a centerline. A single sun rotor is provided that is disposed to cooperate with the plurality of identical planet rotors in the compression of gas. The number and radial spacing of the plurality of identical planet rotors about said single sun rotor may be arranged in different configurations to change an output capacity parameter for said compressor.

Abstract: A gear pump is provided and includes an inlet port which terminates, in the pumping direction of the rotor set, in a radially inwardly extending ramp portion. The ramp portion operates to direct working fluid from an inlet radially inwardly into a pumping chamber of the rotor set which is passing over the ramp portion. By closing the pumping chamber at a radially inwardly point, the filling efficiency of the pumping chamber is improved, reducing cavitation and/or operating noise of the pump.

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: 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: A trochoid oil pump, which enables the endurance to be increased and the reduction of discharge pulsations and noise to be achieved, and in which those results can be realized with a very simple structure. An interdental space constituted by an inner rotor and an outer rotor having trochoid tooth profile or substantially trochoid tooth profile starts a compression stroke in the location of a partition section between an intake port and a discharge portion, and a linking gap L is composed by the interdental space and a preceding adjacent interdental space realized in a discharge stroke. The linking gap expands gradually from the start of compression stroke to the discharge stroke.

Abstract: A gerotor device having a rotor and a stator, the rotor including a plurality of teeth defining a profile, each tooth being divided by a tooth axis. At least one tooth includes an inner recess and an outer recess spaced from the inner recess along the profile.

Abstract: A pump comprises a driving rotor and a driven rotor that are positioned in a housing such that, as the driving rotor and the driven rotor rotate, the teeth of the driving rotor and the teeth of the driven rotor mesh to form a positive displacement seal. The teeth of the driving rotor and the driven rotor are configured such that seals between the inlet side and the discharge side of the pump are formed between only the leading surfaces of the teeth of the driving rotor and the trailing surfaces of the teeth of the driven rotor.

Abstract: The invention concerns a hydraulic machine with a toothed set comprising a toothed ring with an inner toothing, whose circumferential surface extends in parallel with its axis, and a gear wheel (3) with an outer toothing, whose circumferential surface (24) extends in parallel with its axis, at least one tooth flank having an edge as an axial end of a section, which is located between the circumferential surface and a surface directed radially inwards. It is endeavored to reduce the wear. For this purpose it is ensured that in the radial direction an edge (22, 23) ends so as to be offset inwards in relation to the circumferential surface (24).

Abstract: To reduce noise caused by pulsation generated when fluid is expelled, in a trochoidal pump comprising an inner rotor and outer rotor having trochoidal toothed shapes. [Means of Solution] The inner rotor 5 and outer rotor 6 having trochoidal toothed shapes are set in such a manner that when they are in a mutually intermeshing state, a tip clearance d0 is created between the respective tooth crests 5a of the inner rotor 5 and the outer rotor 6. In at least one position of this group of tip clearances d0, a large clearance d1 forming a large interval is provided.

Abstract: A screw compressor comprises a casing, and a male and a female rotor formed with axially twisted screw grooves and accommodated in the casing, the both rotors being rotated by timing gears fixed to the respective rotors while a desired minute gap is kept therebetween, and a method of manufacturing rotors therefor. In the screw compressor, the male and female rotors formed with axially twisted screw grooves in the casing comprise concave stripes having a minute depth and provided on the respective screw grooves to extend along directions of twist thereof, and leakage of a compressed air is less to give a high compression efficiency.

Abstract: A rotary fluid pressure device (11) comprising a gerotor motor of the type including a spool valve member (51) cooperating with a housing (13) to define a nominal valve overlap (X). The motor has a drive shaft (53) for transmitting the rotational movement of a gerotor star (27) to the spool valve member (51) and output shaft (49), such that, under high torque loads, the drive shaft (53) is subjected to drive twist, which would normally effect valve timing. In accordance with the invention, the spool valve member (51) and the housing are provided with a valve overlap (Y) which is substantially greater than the nominal overlap (X). The star (27) defines, on its profile (85), first (87) and second (89) recesses which permit communication between the minimum (30) and maximum (32) volume transition chambers and the respective expanding (29) and contracting (31) volume chambers (FIG. 8).

Abstract: A pair of elliptic gear wheels to be installed in a metering chamber casing of positive displacement type flow meters and have a modified gear wheel and the change of gear form of an effective gearing pressure angle of an involute gear form side of long radius and of an elimination of trapping phenomenon of cycloid gear form of short radius of wheels. This pair of gear wheels has super precision measuring functions and excellent repeatability, by utilizing a computer which compensates flow rate errors instantaneously and send signals for indicating corrected values. Meshing of the pair of wheels at a top of an involute gear form on a middle portion of a pitch circle can keep meshing of the pair of wheels and a cycloid gear form side of short radius eliminates trapping phenomenon.

Abstract: A volume sensor for liquids comprising a measuring chamber in which toothed meter wheels mesh with one another and are mounted on stationary pivots. Flow paths are formed in at least one of the measuring-chamber end walls and are separated by a web in the pivot plane, the edges of which are substantially symmetrical with the pivot plane. The tooth spaces of the meter wheels, at least on the side facing the flow paths, are formed with a recess which extends radially inwards compared with the root circle and is symmetrical in respect to the tooth space. The web is constructed so that whenever a tooth space of the two meter wheels is in the centre position in the pivot plane, the edges of the web substantially coincide in shape with the neighbouring flanks of the teeth adjacent the tooth space so that the latter is cut off from the flow paths in the end walls. The flow paths allow the liquid pressure to be reduced before the tooth space is closed off.

Abstract: In a gear-type machine, in particular in a ring gear pump with internally toothed ring gear meshing with a pinion having only one tooth less, for reducing the noise the pinion teeth are only half as wide as the internally toothed ring gear teeth and the cycloids are flattened in order to ensure adequate free passage of the teeth heads opposite the point of deepest teeth engagement in spite of minimum clearance.

Abstract: A screw compressor has a male rotor and female rotor rotatably engaging each other in a casing. The male rotor has a radius R and Z-number of helical convex teeth, each of which is chamfered on a leading edge of an end facing the discharge end of casing to allow lubricating liquid to escape from a space between rotor teeth during discharge stages of operation. This prevents drastic increases in pressure upon the bearings due to a liquid compression phenomenon. Thrust forces produced by the liquid against a flat chamfer surface prevent scoring of the edges of the rotors and thus permit designs with narrow gaps between the rotors and the casing to improve the efficiency of the compressor.

Abstract: An improved Roots type supercharger for use with high performance vehicle engines. In Roots type superchargers as the lobes of the two cooperating rotors mesh, air is compressed between the approaching lobe on one rotor and inter-lobe area on the other rotor. This rapidly and severely compressses the air caught at that nip, tending to bend the rotors, overload the bearings and the rotor end seals. Also, compression heating of that air overheats the supercharger and charge air. Both of these phenomena tend to shorten the useful life of the supercharger. To overcome this problem, a row of relief passages is provided through the face of each lobe communicating with a large interior volume within the lobe. As the perforated lobe approaches the inter-lobe area of the second rotor, the air in the nip passes through the relief passages, only slightly increasing the pressure of the relatively large volume within the lobe rather than highly increasing the pressure in the nip.

Abstract: A spur pump gear system comprising; a housing have a sealed chamber communicating with an intake port and a discharge port; a shaft journalled for rotation within said chamber; a drive spur gear mounted concentrically on said shaft about a first axis within said chamber, said drive spur gear presenting epi and hypo cycloid tooth profiles; a driven spur gear disposed internally within said chamber for rotation about a second axis, said driven spur gear presenting epi and hypo cycloid tooth profiles; said epi hypo cycloid tooth profile of said drive spur gear engagedly driving said hypo cycloid tooth profile of said driven spur gear.

Abstract: A trochoid type gear pump features an outer rotor formed with internal teeth and an inner rotor formed with external teeth which can be receivable in the external ones. The profiles of one or both of the internal and external teeth are rendered asymmetric and arranged to engage only in the region of an intake opening formed in the casing in which the two rotors are housed.

Abstract: An external-axial rotary piston blower with two-arm or two-lobe pistons having cylindrical inner and outer advance surfaces and transitional surfaces between the advance surfaces, which extend from inner advance surfaces defining a partial circle or arc of 90.degree. into smooth, level or even inner transitional surfaces at right angles to the tangent to this partial circle or arc as far as to a curve or rounding-off, over which the pistons roll-off or move and from this rounding-off or curve into smooth, level or even outer transitional surfaces, which are inclined to the longitudinal axis of the piston at an angle of 120.degree., whereby the outer edges of the inner transitional surfaces of both of the two pistons then contact or engage, when these transitional surfaces are located or lie in a plane with the positioning of the pistons of 45.degree. to the longitudinal housing axis.

Abstract: An internal-gear machine such as a pump comprises an internally toothed annular gear and an externally toothed pinion which meshes with the internal teeth of the annular gear over a portion of the periphery thereof, an arcuate filling member being disposed between the annular gear and the pinion. The annular gear has openings which connect the outside periphery of the annular gear with the inward side thereof in the region of the gaps between the teeth. Each opening is set into the non-bearing flank of the respective tooth which delimits on one side the gap between a pair of teeth, to such an extent that at the same time each opening forms a communication between the root of the respective tooth and the tip of the tooth.

Abstract: A gear pump has a pair of externally meshed gears, and an inlet port and an outlet port on respective sides of the zone of mesh of the gears. The teeth of the gears have their non-working flanks relieved so as to increase an inter-tooth volume lying between two adjacent contact areas of the gears, this inter-tooth volume first decreasing and then increasing as the gears rotate. The relief of the non-working flanks is such that each successive inter-tooth volume communicates with the inlet port before that volume increases from its minimum value.

Abstract: A 1:1 ratio rotary piston machine, with an external axle, which operates with interengaging teeth. Each piston has two teeth which mesh with recesses of the counter piston. That entire flank of each tooth which trails in the direction of rotation is set back with respect to the cycloid described by the trailing corner of the pertaining recess of the counter piston. Each recess is deeper than the path of the corners of the intermeshing teeth.

Abstract: A hydrostatic gear machine is described which comprises a pair of gear wheels meshing with one another, one of the gear wheels being an internally toothed annular gear wheel and the other an externally toothed pinion, the tooth profile of at least one of said wheels being at least substantially trochoidal; the tooth profile of a first one of the two wheels being defined as being obtained by rolling the first wheel with meshing on the other wheel. The teeth of at least one of said wheels bear the thus defined profile only on a limited zone having a length just sufficient for the ratio of the angles of rotation of the two wheels to be constant throughout rotation of the wheels, and have their profile set back, outside the said limited zone, by a sufficient distance to eliminate contact, outside the limited zone, with the teeth of the other gear wheel.

Abstract: A gear pump or motor includes a housing having an 8-shaped chamber, a pair of meshed gears in the chamber and a pair of ports opening into the chamber on opposite sides of the zone of mesh of the gears. The teeth of the gears have on their non-working flanks relieved portions adjacent the tip and the root of the tooth which are arranged to leave an unrelieved land across the entire non-working flank.

Abstract: A gear pump or motor includes a housing having an 8-shaped chamber, a pair of meshed gears in the chamber and a pair of ports opening into the chamber on opposite sides of the zone of mesh of the gears. The teeth of the gears have on their non-working flanks relieved portions adjacent the tip and the root of the tooth which are arranged to leave an unrelieved land across the entire non-working flank.