Abstract: A scroll type fluid machine including two scroll members, each having a spiral body formed on a base plate, which are arranged to make their spiral bodies mesh with each other to form a confined space therebetween, one of said scroll members being arranged to make an orbiting movement relatively to the other scroll member to successively enlarge or reduce said confined space to expand or contract a fluid confined in said space, wherein said spiral body has a shape formed by an involute based on a circle having a radius which varies in accordance with an involute angle.

Abstract: In a rotary-piston engine, the contour of a normal section of the piston is either a composite trochoid or a translated composite trochoid. Each vertex of the normal section is either a generating point of the trochoid or has the form of a circular arc whose center is the generating point of the trochoid and whose radius is a fixed distance. Thus all the edges of the piston slide continuously on the inside face of engine cavity. The piston describes a planetary motion about a point at the same time as it revolves around an origin. Thus the volume of the working chambers changes. The opening and closing of connecting ducts for gas exchange are controlled. The resulting engine has only rotating moving parts, and they are in complete balance. The engine has no constrictions on the minor axis of the contour. Thus the movement of combustion gases is not impeded near top dead center. The engine has a high compression ratio.

Abstract: A rotary fluid displacement device having no indexing gearing between the rotor and the crankshaft therefor. Housing and rotor shapes are determined by equations, so that the rotor is guided at three apexes by the housing contour so that no gearing is required. The devices may be employed in pairs to produce a constant rate of fluid displacement.

Abstract: A positive displacement machine with planetary motion and hypertrochoidal geometry, including an enclosure arrangement essentially constituted by a cylindrical piston (11), and a cylindrical enclosure (10) and by a third device in rotoidal connection with this piston and this enclosure, characterized in that the directrix of the piston or of the enclosure is hypertrochoidal or uniformly distant from a hypertrochoid. The machine can carry any type of fluid and can convert mechanical energy into hydraulic energy or vice versa, depending on the nature of the distribution selected for assuring the admission and escape of the fluid. This admission may furthermore be adjustable, to assure a variation in the displacement. For well-chosen geometries, the direct contact between the enclosure and the piston may be used to create the relative motion between the piston and the enclosure and to make it unnecessary to use a separate transmission.

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: The radial cross sections of the three engagement parts of the external rr of an internal axis single-rotation machine are defined by outer and inner circular arcs. The shape of the internal rotor, having two engagement parts, is kinematically precisely adapted to the external rotor. In order that the internal rotor can be easily manufactured with high shape accuracy, that the machine be given a good volumetric efficiency, and that a good seal be obtained between the rotors, even in the case of high rotational speeds, the center of the circle containing the arcs of the inner faces of the engagement parts of the external rotor has a spacing from the rotational axis of the external rotor of at least approximately 9 times the amount of the eccentricity between the two rotors, and the radius of the external rotor inner faces is about to 7 to 7.5 times this eccentricity.

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: In a fluid pump, a pair of rotors having different rotation phases and designed to come into slidable contact with each other are rotatably contained in a rotor housing so as to be brought into slidable contact with a housing inner wall, and a large arcuated surface having the same radius of curvature as that of a housing inner circumferential surface and a small arcuated surface having a radius of curvature obtained by subtracting a radius of the large arcuated surface from a distance between axes of the rotors are formed on an outer circumferential surface of each of the rotors. A transitional surface crossing a virtual boundary line extending from a rotor center at an angle of 45.degree.

Abstract: The wraps of a scroll device are nonsymmetrical. Additionally, each wrap has a circular outer portion, an involute inner portion with a high order curve therebetween. To equalize displacement, the starting angles of the pockets can be adjusted.

Abstract: A rotary slide vane machine has a housing with the inner contour of a Pascalian screw. The rotary piston is a hollow circular cylinder with an axis of rotation within the zero point M' of the Pascalian coordinates. The control shaft with eccentric segments is arranged inside the piston and has an axis of rotation within the center M of the Pascalian base circle. Slide vanes of a length L are guided within grooves of the rotary piston. Bearing bushings are rotatably guided on the eccentric segments and having flanges connected to the wings of the vanes. The length L is 6D+2r.sub.8s +2d.sub.61 +2e+2s (D is the diameter of the base circle, r.sub.8s the radius of the eccentric segments, d.sub.61 the wall thickness of the bearing sleeves, e the minimal displacement of the wing, and s the minimal distance between bearing sleeve and machine parts moving thereto). The flange contour is limited by an arc having the minimal distance s to the inner mantle surface of the rotary piston and by distance S'E'.sub.

Abstract: A rotary compressor, such as a sliding vane compressor, comprises a housing having a bore, a rotor assembly operatively arranged to rotate within the bore, vanes operatively arranged at the rotor assembly to move linearly relative to the rotor assembly and to form, together with the housing and rotor assembly, variable chambers, and a valve assembly arranged in the housing. The bore has a configuration divided into a expansion region of elliptical shape, a circular transition region, a polynomial-shaped compression region and a circular sealing region. The lubricant seal is composed of an oil injection port and oil grooves for trapping and transporting the oil. The valve assembly is provided in a recess portion of the housing and is configured as a thin blade covering each discharge port which has been relieved to minimize undesirably large difference of the pressure forces between the two sides of the blade. Oil grooves are provided in the rotor assembly and in end cap assemblies.

Abstract: A rotary vane compressor includes two stator chambers allowing two compression strokes for each revolution of the rotor. The shape of the chamber walls is specifically designed through the use of a sine function to increase efficiency of breathing of the compressor by providing a larger initial starting volume which reduces to a smaller discharge volume. The invention further includes a vane guiding mechanism preventing the rotor vanes from falling into the bottom of their respective slots to prevent slamming of the vanes upon start-up of the compressor.

Abstract: A fluid compressor comprises a hollow cylinder closed at the axially opposite ends, a cylindrical turning body disposed within the cylinder and provided with a helical groove formed on the outer peripheral surface of the cylinder, the axis of the turning body being eccentrically displaced from the axis of the cylinder by a given distance, and a blade held and vertically movable in the groove in the direction of the depth of the groove as a compressing element, the compressor drawing operating fluid into the cylinder through a suction port disposed at an end of the cylinder, transferring the drawn-in fluid toward a discharge port disposed at the other end of the cylinder and eventually discharging the fluid through the discharge port by the rotary movement of the turning body as the object of compression, wherein, when the given formula is expressed in terms of the circumferential coordinate and the axial coordinate of the turning body, the values obtained as a result of "differentiation of second order" of th

Abstract: A rotating machine with variable volumes which can rotate in one and/or two directions like the transmission shaft, more of less than (2.pi.). The machine is composed of a body with an inner cavity holding an articulated rotating prismatic structure, composed of one or more sides. Between the inner cavity and the sides of the prismatic structure, and among the same sides in the inner area, are fluid-retaining variable-volume chambers. The cyclic volume machine exploits the variations of the physical characteristics of fluids whose movements are the cause or effect of transmission shaft rotation. In transverse bars, and/or appropriate hinges between the sides of the rotor, centripetal forces oppose centrifugal forces. Lubricating and cooling systems are foreseen. The cyclic volume machine can be coaxial to a common transmission shaft and may be used as a pump, compressor, motor, engine, valve, distributor, hydraulic joint, and heat generator.

Abstract: The invention refers to a hermetic compressor with rotary rolling piston, of the type of high internal pressure inside the shell (1) and small displacement volume, and with its cylindrical chamber, internal to the cylinder block (4), being internally divided by the rolling piston (50,500) and by a sliding vane (9), into suction and discharge chambers with internal pressure being considerably lower than the internal pressure of the shell during most of the rolling piston (50,500) operating cycles. An axial gap for the passage of lubricant oil is provided between the annular faces of the rolling piston (50,500) and the axial end walls (10a, 20a) of the cylindrical chamber. The rolling piston (50,500) presents an external diameter/internal diameter relation of about 1.63 up to 2.22, in order to increase the radial path of the lubricant oil through said axial gaps.

Abstract: The invention proposes in gear ring pumps for reciprocating internal-combustion engines and/or automatic transmissions allowing the hollow gear to run in the hollow gear housing with a play which is large enough for the pronounced fluctuations of the radial position of the crankshaft or input shaft carrying the pinion of the gear ring pump to be taken up thereby and selecting a toothing for the pump such that the effective mounting of the hollow gear on the pinion is achieved. If a correspondingly largeplay is provided between the shaft and the pinion, the hollow gear is mounted with minimum play in the housing. The pinion is then mounted in the hollow gear.

Abstract: A rolling piston compressor includes substantially cylindrical casing having a variable diameter inner circumferential surface. A radially extending vane recess is formed in the casing. A first lateral surface is defined as a portion of the inner circumferential surface disposed immediately laterally of the vane recess on a first side. A second lateral surface is defined as a portion of the inner circumferential surface disposed immediately laterally of the vane recess on a second side, the second side being opposite to the first side. The first and second lateral surfaces are radially offset relative to each other. A rolling piston is mounted for rotational travel about the inner circumferential surface. A longitudinal contact line is defined between the first and second lateral surfaces across the vane recess. An impact reducer limits the severity of impact between the rolling piston and the second lateral surface during travel of the piston along the contact line.

Abstract: The present invention relates to an internally constrained vane rotary compressor employing a floating carrier ring, containing a plurality of non-continuous cam surfaces to guide a corresponding plurality of vanes about the interior of a stator, resulting in improved compressor performance. The invention features a triple roller assembly operating in conjunction with the carrier ring to both guide and constrain each vane. In addition, the invention describes a method for increasing the operating efficiency in rotary vane compressors.

Abstract: A crescent pump gear including: a housing having a chamber communicating with an intake port and a discharge port; a shaft journaled for rotation within said chamber; an externally toothed inner gear mounted centrally on said shaft about a first axis; an internally toothed annular gear eccentrically mounted for rotational engagement with said inner gear about a second axis; a crescent contacting a portion of said inner gear has a dual cycloidal tooth profile generated about a first generating circle and said outer gear has a dual cycloidal tooth profile generated about a second generating circle.

Abstract: A fluid displacement machine of the vane type which can be operated as a compressor or motor utilizes a cylindrical rotor equipped with one or more tethered sliding vanes wherein the rotor and vane set is rotatably located eccentrically inside an internal conforming casing profile between opposing endplates to define enclosed variable volume compartments. [Each vane is fitted on opposite sides eith tethers which are pivotally-mounted remotely from the vane tips. The tethers engage, through anti-friction means, circular annuli located within the endplates which are eccentric with the hollow casing profile.] Anti-friction tether-to-annuli means are used, one in the form of freely-rotating caged roller bearings interposed between the tethers and the respective internal annuli, and another in the form of tethers equipped with trunnioned bearings which directly engage these internal annular surfaces.

Abstract: A dual rotor Roots type vacuum pump has an improved rotor profile contour resulting in high area efficiency, high volumetric efficiency, reduced backstreaming and simplified economical manufacturing which yields a compact, cost effective pump.

Abstract: A rotary positive-displacement machine of the type having intermeshing lobed rotors, comprising first and second two-lobed rotors mounted respectively in the two housing bores for synchronous rotation. The first, valve rotor has a hub portion which periodically occludes an outlet port to control the generation and discharge of high pressure fluid from the housing. Each lobe of the valve rotor has a leading tip portion which is radiussed so that it does not define a sharp edge. Each lobe also has an outer flank, a major portion of which is a convex curve, which is generated to correspond to the form of the tip of the second, displacement rotor and which merges with a convex arcuate portion whose center is offset from the valve rotor axis.

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

Abstract: A screw rotor for a screw pump device includes a male rotor and a female rotor meashing with the male rotor and adapted to be driven by the male rotor, wherein a tooth profile of the female and male rotors is unsymmetrical such that the sum of absorbing torques of the female rotor is negative. Accordingly, a negative torque is always positively applied to the female rotor, thereby preventing the generation of abnormal noise and abnormal vibration due to collision of the tooth surfaces of both the rotors. As a result, a volumetric efficiency and an adiabatic efficiency can be improved.

Abstract: A Roots blower has two rotors in which each of said rotors, as viewed in plan view thereof in the direction of the rotational axis thereof. The rotor has a center and orthogonal short and long axes and has a final shape of a contour offset from a basic profile curve by an offset distance at every point thereof in the normal line direction thereto. The offset distance is also determined in accordance with a function which assumes a maximum value when the angle between a line connecting the rotor center with the point and either of the short and long axes is 45 degrees, which assumes a minimum value when the line coincides with either of the short and long axes, and the function comprises an exponential power of a sine function.

Abstract: A scroll fluid machine in which a stationary scroll member and an orbiting scroll member each have an end plate and involute wrap on said end plate and mesh with each other. A winding-start portion of the wrap has such a section such that a base thereof is thick and the tip thereof is thin, with a curve of an inside line at each of the bases of the wraps is made as thick as possible while avoiding mutual interference between the wrap of fixed scroll member and the wrap of orbiting scroll member. A curve of an inside line at each of tips of the wraps has such a shape that it gradually thinned toward an inner periphery end thereof, and a section of each wraps in the wrap axial direction has such a shape that it is gradually reduced in thickness from the base toward the tip.

Abstract: The invention relates to rotary vane type Positive Displacement Pumps having rotating slotted shaft in which is inserted single blade whose both ends touch the stationary shell assembly at all times because the blade's length substantially fits between the two intercepted interior surfaces of the shell assembly, thus maintaining separate suction (low pressure) and discharge (high pressure) regions always. The rotation of the shaft and the limited boundary imposed by the shell assembly actuate the blade to oscillate in the slot of the shaft while sweeping round the pumping chamber effecting continuous enlargement of the suction region and contraction of discharge region, with the end result of pumping liquid at constant flow per shaft rotation irrespective of head and pump power output.

Abstract: A prime mover or pump comprising of a first stationary plate and a second plate arranged parallel to the stationary plate and spaced therefrom. The second plate is rotatably mounted about its central axis. A plurality of elongated wall elements are disposed between the plates. The wall elements slidably bear on the plates to form a seal therewith such that working chambers are created. Each wall element is articulated at one end point to a further wall element such that the wall elements form a movable grid. The grid is rotatably secured at at least one point to the stationary plate and at at least two points to the rotatable plate such that the working chambers assume their maximum and minimum volumes upon rotation of the rotatably plate.

Abstract: A Roots type blower has two rotors enclosed within a housing and each having alternately and contiguously therearound a plurality of lobes each having an outer profile of a convex arc and recesses each having an inner profile of a concave arc, the lobes of one rotor meshing cyclically in turn with respective recesses in the other rotor as the rotors rotate in opposite direction. The rotors are formed and assembled with their profile in relation to respective pitch circles with such dimensional configuration that the radius of the convex arc of each lobe is smaller than the radius of the concave arc, and that the point of intersection between each convex arc and the concave arc of the adjacent recess of a rotor is positioned outside the pitch circle of that rotor.

Abstract: A two-shaft rotary machine for use in a vacuum pump system includes rotors having a specific profile whereby any vibration and noise generated by the machine is minimized and its efficiency is increased. The number of lobes of each rotor is three or more. The tip and root portions of each rotor are defined by circular arcs, respectively, which are made smoothly continuous with each other through an involute curve. The ratio of the diameter of the tip circle to the diameter of the root circle is selected to fall within a range which is given by a specific expression.

Abstract: A rotary fluid machine includes two intermeshing rotors rotatably mounted in a double-cylinder bore portion of a casing, each rotor having two lobe portions disposed on two opposite ends of a long coordinate axis of the rotor and having a waist portion confined by two shallow recess portions formed on two opposite sides of a short coordinate axis of the rotor so that one rotor can be smoothly rotatably engageable with the other rotor in a single-point contact for a smooth running of the two rotors. For a buffer of a higher output fluid pressure, a balancing chamber is formed between the bore portion and a fluid outlet so that a fluid suddenly increased with fluid pressure may be backflowed into the bore portion through a plurality of holes formed in a partition plate between the chamber and the bore portion for preventing water or air hammer when handling high-pressure fluid.

Abstract: A scroll-type fluid machine comprises a stationary scroll member, an orbiting scroll member, a rotation-prevention mechanism for the orbiting scroll member, and a casting accommodating therein both members and the mechanism. The involute angle of a terminal end of a wrap of the orbiting scroll member is selected to be less than that of the wrap of the stationary scroll member by an angle which ranges between 60.degree. and 120.degree., preferably, about 90.degree., thereby reducing a level of force applied to the rotation-prevention mechanism which prevents the orbiting scroll member from rotating about its own axis.

Abstract: A rotary compressor includes a top clearance volume formed between a cylinder chamber and at least one delivery valve. Another top clearance volume, in communication with the cylinder chamber, produces a reverse flow of compressed fluid which generates pulsations adapted to offset a high frequency component of pulsations generated in the cylinder chamber by compressed fluid reversely flowing from the first top clearance volume to the cylinder chamber. Thereby the high frequency component of pulsations generated in the cylinder chamber is eliminated, and a low-noise rotary compressor is provided.

Abstract: A scroll-type fluid machine includes a stationary spiral element and a revolving spiral element having a substantially identical configuration and a central small chamber defined between abutting points of both the spiral elements a volume of which is adapted to be reduced to substantially zero with relative rotation of both the spiral elements. Basically, each of the both spiral elements is formed of an outer curve segment and an inner curve segment formed of involute curves and a connection inner curve expressed by a particular equation and a connection outer curve expressed by another particular equation formed between the outer and inner curve segment. The strength of the spiral elements can be enhanced or a delivery port having a large area can be provided.

Abstract: In a rotary piston engine which can be produced by simple manufacturing techniques and which has an outer and an inner rotor which rotate in a housing about different axes of rotation, wherein strip-like projections on inwardly extending engagement members generate the contour of the piston of the inner rotor, whereby a well-defined contact seal can be realized in use, the projections have two sealing corners adjacent to but spaced from one another in the direction of rotation of the outer rotor.

Abstract: A horizontal type rotary compressor incorporating an oil feeding means comprises, in a casing, a lubricant reservoir retaining the lubricating oil, a compression section, a horizontally disposed electrical motor and a frame incorporating a journal-bearing in the middle thereof for supporting the shaft of the electric motor directly connected to the said compression section. The oil feeding means comprises an oil flow passage which is formed inside the said frame and lower part of which extends below the surface of the oil, an annular space formed between the journal-bearing and the shaft to communicate with the said oil flow passage and oil supply grooves formed on the periphery of the shaft to communicate with the annular space wherein the said oil supply grooves extends to the outside of the sliding portion of the axis to be exposed to the inside of the casing and the depth of the oil supply grooves is limited below the value, h, represented by the relationship. ##EQU1## where .mu.

Abstract: In reversible compressed air rotary motors for compressed air tools, particularly for wrenches, it is known to discharge the waste air radially from the casing of the motor, which results in a considerable nuisance, in particular as regards noise. Furthermore, due to the close positioning of the compressed air inlet and air outlet, poor efficiency is achieved. To avoid those drawbacks in a rotary sliding vane motor having an elliptical working chamber, the rotor end over on the inlet side is rotatably mounted, and air outlet means is arranged axially and lies in both the clockwise as well as in the antic-clockwise direction or rotation of the rotor relative to the major semi-axis of the elliptical working chamber. Thus by rotating the end cover to one or other of its limit positions, the outlet means communicate with different pairs of passageways.

Abstract: A vane compressor in which a plurality of pumping chambers are defined by a cam ring, side blocks closing respectively opposite axial open ends of the cam ring, a rotor rotatably arranged within the cam ring, and a plurality of vanes slidably fitted for radial movement in an outer peripheral surface of the rotor. The pumping chambers have their respective volumes varying with rotation of the rotor.

Abstract: There is disclosed a scroll-type machine suited for use as a gaseous fluid compressor. The machine incorporates symmetrical scroll members of substantially one wrap that have modified inner ends to provide continued sealing to a single separation point. The one wrap configuration and modified ends provide a very compact compressor design that enhances manufacturability and yet is able to deliver fluid gas with much greater pressure ratio versatility than conventional multi-wrap scroll compressors. The machine incorporates a discharge valve in the discharge port that allows various pressure ratios to be attained for a variety of end uses.

Abstract: A scroll type pump has a fixed scroll and an orbiting scroll engaging therewith, wherein a curve of a wrap of either of the scrolls is offset inwardly or outwardly relative to a set curve so as to prevent formation of a gap between the wraps due to thermal expansion of the scroll wraps.

Abstract: A hydraulic vane which includes a housing; a cam ring disposed in the housing and having an inner peripheral surface formed in a cam curve; a drive shaft rotatably mounted in the housing; a rotor connected coaxially to the drive shaft for being driven thereby, the rotor having a plurality of vane slots defined radially in an outer peripheral wall of the rotor and fluid reservoir slots for introducing a fluid provided at the bottom of the vane slots; a plurality of vanes slidably inserted in the vane slots plurality of vane chambers defined among the rotor, the vanes and the cam ring and inlet and outlet ports defined in the housing and connected to the vane chambers wherein the maximum slanting angle of the inner peripheral surface of the cam ring in an expansion section of the cam curve has a ratio in the range of 0.9 to 1.7 to a slanting angle in an expansion section of a reference cam curve.

Abstract: A movable vane compressor has a cylinder profile such as to reduce a pulsation of the driving torque for movable vane. This cylinder profile includes in series a region where the amount of vane projection increases; a region where the vane retracting speed increases; a region where the vane retracting speed decreases; a region where the vane retracting speed increases; a region where the vane retracting speed decreases; a region where the vane retracting speed increases; and a region where the vane retracting speed decreases.

Abstract: The endless camming inner peripheral surface of the pump housing, which performs one cycle of suction, compression and discharge of fluid in cooperation with the vanes and the rotor, has a cam profile including an increasing radius portion along which the amount of protrusion of each vane from the rotor gradually increases with movement of the vane, and a decreasing radius portion along which the amount of protrusion of each vane from the rotor gradually decreases with movement of the vane. The increasing radius portion and the decreasing radius portion are continuously arranged in the order mentioned and in the moving direction of the vanes. The increasing radius portion terminates in a first half of the whole circumferential length of the one cycle performing portion of the endless camming inner peripheral surface. The cam profile of the one cycle performing portion of the camming surface is calculated by the use of a single equation.

Abstract: A rotary type fluid machine including a stationary spiral element and a revolving spiral element respectively having a substantially identical configuration and disposed therein 180 degrees apart from each other in mutually nested relationship, the revolving spiral element being adapted to revolve in solar motion relationship with respect to the stationary spiral element with a radius of revolutionary motion .rho.

Abstract: A rotary fluid machine of the type including two spiral elements, or a stationary spiral element and a revolving spiral element having identical configurations and disposed 180 degrees apart from each other in mutually nested relationship. The revolving spiral element is adapted to revolve in solar motion relationship with respect to the stationary spiral element with a radius of revolutionary motion .rho..

Abstract: A roller or vane type pump is described of the kind in which the cam ring is pivotally mounted within an external casing to vary the throw of the cam ring and hence the pump delivery means is provided whereby a constant flow is obtained regardless of the pump speed. The cam surface of the cam ring is not wholly circular. The two portions of the cam surface extending between the inlet and outlet ports of the pump at opposite sides respectively of the pump axis have curvatures such that the instantaneous distance R.sub.2 of the point of contact of one of the sealing rollers or vanes with the cam surface from the axis of rotation of the rotor is given by R.sub.2 =.sqroot.R.sub.1.sup.2 +k where k is a constant and R.sub.1 is a corresponding instantaneous distance of the point of contact of the other sealing roller or vane with the cam surface from said axis.

Abstract: A rotary pump device and an inner gear rotor therefore in which the inner gear rotor has a outer peripheral profile surface whose cross section perpendicular to its central axis is in the form of an inner envelope curve derived by moving a locus circle on an epitrochoidal curve. If the epitrochoidal curve is defined by a base circle of diameter A, a rolling circle of diameter B and an eccentricity of length e, and the locus circle has a diameter C, the inner rotor therefor having an eccentricity ratio f.sub.e =e/B, a locus circle ratio f.sub.c =C/B and a base circle ratio n=A/B, the ratios f.sub.e, f.sub.c and n are selected so as to make the inner envelope curve smooth without any edge portions by selecting the ratios to have values such that f.sub.c /K.sub.i .ltoreq.1.1, wherein K.sub.i =(n+1).times..vertline.1-2f.sub.e .vertline.. The inner gear rotor is rotatable in an outer gear rotor having circularly arched radially inwardly extending teeth.

Abstract: Helical screw rotors for a screw rotor machine having improved profiles on both male and female rotors, wherein the female rotor leading and trailing flanks comprise first and second circular arcs with the first circular arc subscribed by a first radius whose center lies inside the pitch circle and a second circular arc subscribed by a second radius whose center also lies inside the pitch circle. The leading and trailing flank portions of the male rotor are travel generated by first and second radii on the female rotor resulting in effective driving and driven lobe surfaces on the leading and trailing lobe surfaces. This also results in minimized blowholes and effective sealing surfaces on the intake and discharge sides of the screw rotor machine. The female rotor lobes have a main peripheral surface defined by a true circular arc swung from the axis of the female rotor.

Abstract: A screw rotor mechanism which includes a female rotor F having tooth crests each being formed by a leading side arc g2-a2 overlying a tooth tip circle Cf thereof and a following side are a2-b2 having its center at a point 07 on a pitch circle Pf thereof, and a male rotor M having tooth tips each being formed by an arc c1-d1 having its center at an interaxial line passing through axes Of,Om of the female and male rotors F,M. The male rotor M also has tooth bottoms being complementary to tooth female tooth crests or tips and forms no seal grooves thereon. The thus shaped rotors are adapted to be machined with a high efficiency by a gear hobbing machine.

Abstract: A Roots type blower wherein a secondary gap distance for rotor is determined in accordance with a cross angle between a normal line at a point of the outer periphery of theoretical base curve of the rotor and a line extending through said point and the rotor center.