Abstract: A gear train mechanism includes a housing having side walls that are made of a material exhibiting a modulus of elasticity of at least 140 GPa. A pair of shafts is supported by slide bearings in the housing and exhibit a length of at least of 1.3 times the diameter of the shafts. A first gear of external-tooth type is mounted on one shaft and is defined by an addendum diameter, a top land width and a circular pitch, with the top land width being at least 15% of the circular pitch. A second gear is mounted on the other shaft and is in mesh with the first gear, with both gears disposed between the side walls, wherein the side walls have a wall thickness of at least 75% of the addendum diameter.

Abstract: A scroll compressor has a compression mechanism accommodated in a closed container and comprising a stationary scroll and an orbiting scroll. The stationary scroll includes a frame and a separate wrap element secured to the frame or otherwise movable relative to the frame. The orbiting scroll has a wrap element allowed to undergo circular translation with respect to the wrap element of the stationary scroll to compress gas. The wrap element of the stationary scroll is made of a readily machinable abrasion-resistant material to reduce the manufacturing cost of the scroll compressor.

Abstract: A rotary compressor comprises an outer casing, a rotary type compression mechanism accommodated in the outer casing in a sealed manner, and an electric motor for driving the rotary type compression mechanism. The rotary type compression mechanism is provided with a cylinder having an inner peripheral surface to which a discharge port is formed, and the inner peripheral surface of the cylinder has a portion formed of a valve sheet to which said discharge port is formed.

Abstract: A compressor comprising a roller made of a cast iron which has a hardness of HRC 50 or more after heat treatment, and contains not less than 5 area % of graphite, and not less than 2 area % of crystallized eutectic structure including iron phosphide, and either a vane made of a material which has a hardness of HRC 70 or more after heat treatment and contains not less than 25 area % of undissolved carbides and nitride particles in total, the undissolved carbides including not less than 10 area % of MC type carbides, the nitride particles including at least one of TiN and NbN of not less than 5 area %, the undissolved carbides and the nitride particles having a mean grain size of not more than 5 .mu.m, or a vane made of a material including at least one of TiN and NbN particles of not less than 5 area %, the TiN and NbN particles having a mean grain size of not more than 5 .mu.m, the material essentially consisting of, by weight, 2.0 to 4.0 % of C, not more than 2.0 % of Si, not more than 1.5 % of Mn, 2.5 to 8.

Abstract: A rotor assembly in which the front and back ends of the rotor are coupled by a shaft assembly extending therethrough. Preferably, the shaft assembly includes a slip joint, such that the shaft is able to accommodate for thermal expansion of the assembly, while maintaining a torsional and bending moment coupling between the front and back ends of the rotor. The rotor assembly is particularly advantageous for use in superchargers having large acceleration and pressure increase requirements, such as superchargers utilized in drag racing. However, the rotor assembly may also be utilized in other devices such as blowers, compressors, or vacuum pumps which may have large acceleration requirements.

Abstract: A sealing material for a scroll-type compressor consists essentially of, by weight, more than 20 and up to 40% PAN-system carbon fiber, 1 to 15% polytetrafluoroethylene resin, and the balance of polyphenylene sulfide resin. Further, not more than 10% hard particles formed of a copper alloy are added to the foregoing components. Thus, there can be provided a sealing material which can be applied to scroll members of a high surface hardness which have undergone Tufram process or Ni-P plating.

Abstract: In order to prevent the cracking of a coating of sliding material, in which an electroless Ni-B plating coating layer is formed on the surface of aluminum alloy, an electroless Ni-P plating coating layer is provided on the aluminum alloy.

Abstract: A non-contact vane-type fluid-displacement machine includes a stator housing having an annular interior surface defining an interior bore and a rotor supported in an eccentric position in the interior bore of the stator housing relative to the annular interior surface thereof to undergo rotation relative to the stator housing about a central rotational axis. The rotor has a plurality of slots radially defined therein relative to the rotational axis. The machine also has a plurality of vanes disposed in the radial slots of the rotor. The vane is mounted to the rotor to undergo reciprocable movement in a radial direction relative to the rotational axis of the rotor such that an outer tip portion of the vane is maintained in a non-contacting substantially sealed relationship with the annular interior surface of the stator housing.

Abstract: A blade for the use of a rotary compressor includes a sintered body composed of 50 to 98.5 wt. % of zirconia, 1 to 49.5 wt. % of alumina and the reminder including 0.5 to 10 wt. % of a stabilizing material. The stabilizing material is comprised of at least one selected from magnesia, calcia, ceria and an oxide of an rare-earth metal and the grain size of the sintered body is less than 3 .mu.m. The zirconia in the sintered body is substantially formed with a tetragonal structure or a mixture of tetragonal and cubic structures.

Abstract: A high efficiency pump having relatively-moving parts constituted of a light weight material and a coating on at least one of the parts to effect essentially zero clearance between the parts where they merge together. The coating is comprised of solid lubricants in a polymer resin matrix stable up to 700.degree. F.

Abstract: A gear pump comprises rotors disposed in roller bearings. For the delivery of very viscous polymer meltings, bearings surfaces of at least one of inner races, outer races of the bearings and bearing surfaces of roller elements are made of a steel with a high-temperature stability. Bearing takes place on material pairings consisting of one of S6-5-2 high-speed steel and silicon nitride Si.sub.3 N.sub.4. The roller bearings are either unlubricated or lubricated by a lubricant remaining in the bearing, preferably a solid-substance lubrication. A distance of supported shafts, from a gearwheel face to a supporting area of the shafts, determined by the outer contact point in the roller bearing, is smaller than twice the median diameter of the shafts therealong.

Abstract: A cylindrical pin couples a driven member, such as a rotor, to a driving shaft by means of axially and angularly aligned cylindrical grooves in the shaft and driven member defining a cylindrical cavity for receiving the pin. The pin fits in the defined cavity and radially bridges the space between the shaft and the driven member to link the two together. The shaft and pin are formed of a metal having a lower thermal coefficient of expansion characteristic than the metal forming the driven member. Torque, applied by the shaft, is applied to the rotor distributed over a portion of the cylindrical side walls of the pin.

Abstract: A drilling motor has been developed with a hollow tubular stator having at least one rod recess therein and an exhaust port therethrough corresponding to each of the at least one rod recess; a rod movably disposed in each of the at least one rod recess; a tubular rotor movably disposed within the stator for rotation therein, the tubular rotor having a central motive fluid flow channel therethrough and extending along the length of the rotor, the rotor having one or more radial flow channels therethrough for providing a motive fluid flow path from the central motive fluid flow channel to at least one action chamber between the hollow tubular stator and tubular rotor; the tubular rotor having at least one rotor seal; and the at least one action chamber defined by an interior surface of the hollow tubular stator and an exterior surface of the tubular rotor, each of the at least one action chamber sealed at one end by the rod and at another end by one of the at least one rotor seals.

Abstract: A zirconia vane used in a rotary compressor, the zirconia vane being formed of a partially stabilized zirconia sintered body containing 92 through 98 molar percent of ZrO.sub.2 and being stabilized with Y.sub.2 O.sub.3, zirconia crystals constituting the zirconia sintered body having a mean grain diameter of 0.1 to 0.6 .mu.m and a maximum grain diameter of not greater than 2 .mu.m, the zirconia sintered body having a mean three-point flexural strength of not less than 120 kg/mm.sup.2 measured in conformity with JIS R1601, a surface of the zirconia sintered body in contact with a rotor of the rotary compressor having a first surface roughness in a direction of rotations of the rotor, specified by a ten-point mean roughness Rz, of not greater than 1 .mu.m and a second surface roughness in a direction perpendicular to the direction of rotation of the rotor, specified by the ten-point mean roughness Rz, of not greater than 0.6 .mu.m.

Abstract: A rotary compressor has a compression chamber defined by a rolling piston which is eccentrically rotated in a cylinder by a rotary shaft including an eccentric crank portion, and by a blade which slides in a groove formed in the cylinder and of which the tip contacts an outer-peripheral surface of the rolling piston.

Abstract: The present invention provides an Al--Si based sintered alloy of high strength and high ductility, a method for production thereof and use thereof. The alloy comprises 1-45% of Si, 0.1-20% of an element of Group IIIa, 0.01-5% of at least one element of Groups IVa and Va, the balance of substantially Al. This alloy can further contain at least one of 0.01-5% of Cu, 0.01-5% of Mg, 2.0% or less of Fe, 1.5% or less of Mn and 1.5% or less of Co and the oxygen content is reduced to 0.15% or less by sintering under vacuum. The present invention is applied to automobile parts such as a piston and scroll compressors. The alloy has a tensile strength of about 40 kg/mm.sup.2 or higher and an elongation of 1.5% or more at 150.degree. C.

Abstract: An orbiting scroll is made with a ceramic particle reinforced aluminum metal matrix composite. The resultant part has increased wear resistance, closer thermal expansion matching with cast iron, can be used without tip seals and offers the advantages associated with a reduced mass. In manufacturing the part, the part is pressure cast to a near net shape and machined to the final shape.

Abstract: A scroll type compressor has a movable scroll which is supported by a drive shaft by way of an eccentric pin in a housing. The movable scroll engages in an orbital movement for defining a compression chamber with a fixed scroll which is disposed opposite to the movable scroll. The compression chamber decreases in size in accordance with the orbital movement of said movable scroll for compressing gas in the compression chamber. A first ring orbits together with the movable scroll between the movable scroll and the housing, for receiving compressive reaction force acting on the movable scroll. A second ring which is secured to the housing receives the compressive reaction force received by and acting on the ring.

Abstract: A movable member slides on a fixed member. The movable member is made of aluminum alloy. An inner layer coats the movable member. The inner layer is made of a material capable of adhering to the aluminum alloy. An outer layer coats the inner layer and contacts the fixed member. The outer layer has greater hardness than the hardness of the inner coating layer.

Abstract: A rotary device in which a seal is formed between the rotor and the stator end members by a sealing material having a coefficient of thermal expansion which is greater than that of the material of the end member in which said sealing material is located. When exposed to normal service temperatures, the sealing material bulges out of the parent material to fill in the gap between the end member and the rotor. The sealing material is wearable such that as it expands into engagement with the rotor, it will eventually wear until it no longer contacts the mating surface and a small gap or "minimal clearance" exists.

Abstract: A scroll-type fluid machine in which the high-pressure chamber side (36) of a back pressure chamber (6a) using a fixed scroll (11) made of an aluminum base material can be fully sealed. The fixed scroll (11) is made of an aluminum base material, and a discharge cover (2) is made of a ferrous material. Between the U seals (35) interposed between the high-pressure chamber (36) side of the back pressure chamber (6a) and the low-pressure side, at least the U seal (35a) on the high-pressure chamber (36) side is made of glass-reinforced polytetrafluoroethylene resin, and is installed so as to be pressed against the fixed scroll (11). The U seal withstands a high temperature and large pressure difference and is installed so that the sliding mating part of the U seal (35a) is not the fixed scroll (11) made of an aluminum base material which is easily worn, but the discharge cover (2) made of a ferrous material which is less prone to wear.

Abstract: A rotary device containing a housing having a curved inner surface with a profile equidistant from an trochoidal curve, an eccentric mounted on a shaft disposed within the housing, a rotor mounted on the eccentric shaft which contains at least three intersecting faces and a partial bore located at the intersection of adjacent faces, and at least three rollers rotatably mounted within the partial bores of the rotor.

Abstract: A roller of a rotary type compressor is made of an iron base alloy essentially consisting of 2.0 to 3.9% carbon, 2.0 to 3.0% Si, 0.3 to 1.0% Mn, up to 0.10% S, more than zero and not more than 0.50% V, 0.3 to 1.0% P, 0.01 to 0.5% Sb, and balance of Fe and incidental impurities. Preferably, the iron base alloy further includes 0.001 to 0.5% B. This roller is suitable when hydrofluorocarbon is used as a refrigerant.

Abstract: A scroll type refrigerant compressor having an aluminum or aluminum alloy housing unit in which a stationary scroll unit having a stationary spiral member and a movable scroll unit having a movable spiral member are encased in such a manner that the movable spiral member moves along a predetermined orbiting path without rotating about an axis thereof, and a reinforcing ferric metal liner fixedly attached to an inner cylindrical face of a cylindrical wall portion of the aluminum or aluminum alloy housing unit so as to prevent the inner cylindrical face of the housing unit from being mechanically cracked by the movable spiral member of the movable scroll unit during the running of the compressor even if the movable scroll unit jams due to entrance of foreign materials between the outer face of the movable spiral member and the inner face of the housing unit.

Abstract: A refrigerant compressor comprises an hermetic type casing. There is refrigerant circulating in the casing. A compression mechanism in the casing has a first and a second part. These parts are made of iron-based metal and nodular cast iron, respectively. The first and the second parts may be coupled slidably.

Abstract: Compressor bodies, an accelerator and a main motor are disposed on a base, while an intercooler, an aftercooler, an oil cooler and a coolant cooler are disposed perpendicular to the axial direction of the motor so that the directions, in which the tube nests of the gas coolers are drawn out, are made to be the same. A control panel having a maintenance display is mounted on a front panel composed of panel portions which are mounted pivotally around respective remote or opposite side ends. Portions to be inspected daily are disposed near the front panel and one side panel adjacent thereto. The compressor bodies including rotors that have been coated with a melted and solidified substantially homogeneous and continuous layer of a tetrafluoroethylene-perfluoroalkylvinylether copolymer that is substantially devoid of pinholes.

Abstract: A rotor for a positive displacement motor or pump in which the rotor is coated with a metal carbide and metal alloy coating or a metal boride and metal alloy coating to impart excellent wear-resistance and corrosion-resistance properties to the rotor when used in abrasive and/or corrosion resistance environmental.

Abstract: A ceramic helical rotor expander using a double-ended or tandem herringbone type rotor arrangement with bearing and seal assemblies remote from the hot gas inlets and especially capable of operating at an inlet temperature of above 1100.degree. C. The rotors are solid or hollow and bonded to hollow metal shafts, and mounted in a composite or simple prismatic casing. The rotors, casing and shafts are constructed from low expansivity materials. In the preferred embodiment the rotors are constructed of silicon nitride and the shafts constructed of an molybdenum alloy, with the metal shafts being supported in bearings and secured to synchronizing gears. The rotors and casing may be provided with coolant channels therein, and are constructed to eliminate the problem of end leakages at inlet temperature and pressure, and the need for high temperature bearings and seals.

Abstract: Wear resistance, seizure resistance, durability and corrosion resistance of an Oldham ring made of an aluminum alloy engaging with a swivel scroll made of an aluminum alloy are improved. The Oldham ring comprises a substrate made of an Al--Si alloy which has a light weight and a high strength, a bond layer of a multiplex zinc base alloy containing Cu and Ni as a primary plating layer which is formed on the substrate, and an electroless Ni--P plating layer having a hardness of MHV550 which is formed on the outermost surface of the Oldham ring.

Abstract: A fluid compressor has a cylinder (17), a rotary rod (21), and a helical blade (33) that defines work chambers (44) between the cylinder and the rod. The compressor successively compresses and conveys a fluid from a suction end to a discharge end through the work chambers according to the rotation of the rod. The continuous helical blade is formed by pressurizing and injecting synthetic resin material such as tetrafluoroethylene-perfluoroalkylvinylether polymer resin into a mold through two gates (39), so that a weld line (43) of the blade is located in an intermediate region between a suction pressure region and a discharge pressure region of the blade.

Abstract: The object of the present invention is to provide sliding members having preferable lubrication and seizure resistance. Sliding members comprising a columnar texture which is composed from at least one of metal nitrides, metal oxides, metal carbides, and metals on a base member, wherein the columnar texture is composed of assemblies of fine columnar asperities, with intervals formed between the columnar asperities being connected to each other so as to form a net work, and with gaseous, liquid, or solid lubricants being maintained in the intervals. The mutually connected intervals in the columnar texture are superior in filling and holding of lubricants, and the above described superiorities improve lubrication and seizure resistance and extend sliding life.

Abstract: A method of producing an oil-free screw compressor has the following steps: preparing a semi-finished metallic female rotor which has a spiral profile, and a semi-finished metallic male rotor which has a spiral profile; forming a metallic coating film containing particles of grinding material on the surface of the semi-finished female rotor; forming, on the surface of the semi-finished male rotor, a coating film of a material softer than the metallic coating film on the female rotor; grinding the surfaces of the semi-finished rotors into predetermined configurations; mounting the ground rotors on bearings so that the rotors are assembled in a rotor casing with a substantially constant spacing held between the axes of the semi-finished rotors; mounting timing gears on the rotors so as to drivingly connect the rotors each other; and driving the rotors by driving means while restraining the back lash in the rotating direction by means of the timing gears and applying a compression load to the rotors so that the

Abstract: A displacement machine for compressible mediums has several spiral-shaped conveying spaces (11a, 11b), which are disposed in a stationary housing lead from an inlet (12a, 12b), which lies radially on the outside, to an outlet (13), which lies radially on the inside. A displacement body, which is assigned to the conveying spaces has a disk (2) with spiral-shaped strips (3a, 3b) arranged perpendicularly on both sides. This displacement body, driven off-centered, is made of a magnesium alloy. During service, each of its points effects a circular movement defined by the circumferential walls of the conveying space. The ribs (45, 46) bordering the conveying spaces (11a, 11b) in the housing are made as one piece with the housing and the entire housing is made of the same or similar magnesium-based alloy as the displacement body (2, 3, 4, 5).

Abstract: A rotary vane compressor comprises a cylinder having two closed ends defining a cylinder chamber in which is rotatably mounted a rotor. The rotor carries a plurality of radially movable vanes which move radially into sliding contact with the inner surface of the cylinder chamber during rotation of the rotor to compress a refrigerant gas. The rotor is rotationally driven by a rotor shaft rotatably mounted by bearings in the cylinder ends. To prevent destruction of the ozone layer, a refrigerant containing no chlorine, such as HFC-134a (1,1,1,2-tetrafluoroethane; CH.sub.2 FCF.sub.3) is used, and to compensate for the inferior lubricating properties of the chlorine-free refrigerant, the bearings are provided with a manganese phosphate coating of 10 .mu.m-15 .mu.m thickness to prevent cohesion and seizure of the mutually contacting surfaces of the bearings and rotor shaft.

Abstract: An oil pump comprises a casing of aluminum alloy and at least one rotor housed therein. The rotor is produced by powder metallurgical with a rapidly solidified aluminum alloy comprising, by weight, of 5 to 25% of Si, up to 15% of one or more alloy elements selected from the group consisting of 3 to 10% of Fe, 3 to 10% of Ni and 1 to 8% of Cr, and the balance of Al and inevitable impurities. The casing may be produced by powder metallurgy or ingot metallurgy with an aluminum alloy consisting essentially, by weight, of 5 to 25%, preferably 5 to 17%, of Si, 1 to 5% of Cu, 0.2 to 1.5% of Mg, 0.2 to 1% of Mn, and the balance of Al and inevitable impurities. The rotor and casing are so combined that the sum of the Si content of said rapidly solidified aluminum alloy for casing and that of said rapidly solidified aluminum alloy for rotor being equal to or more than 15 percent by weight.

Abstract: A screw compressor, especially adapted for use as a supercharger for an internal combustion engine, comprises a housing having a barrel section (2) preferably made from aluminum and two end sections (3,4), in which housing a pair of screw rotors (7,8) are mounted. The end sections (3,4) are provided with projections (29) inserted into the end portions of the barrel section (2) by forced fit between surfaces (30,31) of the projections. The end portions of the barrel section and are also secured to the barrel section by screw joints.

Abstract: A rotation piston internal combustion engine has a substantially stationary housing defining a plurality of blind holes, and a rotor rotatably mounted within the housing for rotation at a substantially uniform velocity about an axis. A hub has four pistons and is rotatably mounted within the rotor for rotation about the axis at a non-uniform velocity. Four crankshafts are each rotatably mounted through a respective rib of the rotor and coupled to a respective gear wheel so that the gear wheel rotates with the crankshafts. A ring gear is coupled to the housing for engaging the gear wheels to permit rotation of the gear wheels relative to the housing. The ring gear has a plurality of apertures having a second diameter, each corresponding in position to a respective blind hole in the housing.

Abstract: A rotor for a rotary screw machine has helical lobes (12) and grooves (14). A shell structure (18) forming the external surface of the rotor is made of pressed metal power. The rotor is manufactured by cold isostatic pressing of a powder in a vessel having a surface shaping rotor. The pressure is applied radially by means of a cast bag in which high pressure liquids acts. After the pressing process, the rotor blank is sintered and attached to a shaft (16).

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 scroll blade of a scroll fluid machine is formed of eutectic graphite cast iron in whose structure the average value of the largest eutectic shell is not more than one fourth of the height of a lap of the scroll blade. The scroll blade material thus formed will facilitate increasing working precision and reducing the number of working steps.

Abstract: A refrigerant compressor for using HFC 134a as a refrigerant and a refrigerator oil such as polyether type oil, polyester type oil, or the like which is compatible thereto is disclosed. The refrigerant compressor has a iron type substrate with a compound layer mainly made of iron sulfide on sliding portions such as sliding parts and shaft in the compression mechanism. The sliding parts in the compression mechanism are a cylinder and a rotor and a piston which are moving parts. In a rotary type compressor, the sliding parts are a blade and so forth. The hardness of the compound layer mainly made of the aforementioned iron sulfide is large and thereby effectively preventing metals from being contacted and preventing adhesive abrasion which is the primary cause of the abrasion of the sliding portions.

Abstract: A hermetic type refrigerant compressor operates using a refrigerant and a refrigerator oil in which the refrigerant is soluble. The refrigerant compressor includes slidable members adapted to slidably move and a compressing mechanism for compressing the refrigerant with the aid of the slidable members in a hermetic casing. The refrigerant, the refrigerator oil and the slidable members are selected and constructed in the following manner. The refrigerant is a 1,1,1,2-tetrafluoroethane or a 1,1-difluoroethane, the refrigerator oil is at least one kind of refrigerator oil selected from a polyalkylene glycol based oil and a polyester based oil, and at least one of the slidable members has a slidable surface which is prepared such that a surface hardened layer having a Vickers hardness of 400 or more and a thickness of 2 microns or more is formed on a substrate of ferrous metallic material, and subsequently, an iron oxide layer composed of Fe.sub.3 O.sub.4 as a main component and having a thickness of 0.

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: In an apparatus accommodating a rotor of light alloy and a rotor shaft of steel secured to each other, the rotor shaft consists of a first shaft and a pair of second shafts integrally formed with or rigidly secured to the first shaft. The first shaft has a structure with a thermal coefficient of expansion close to that of the rotor whereas each of the second shafts has a structure with a thermal coefficient of expansion less than that of the first shaft.

Abstract: A cheek plate for a vane pump is provided which is made of an aluminum alloy. The cheek plate has a first or casing face which faces towards the casing of the pump when installed in the pump. A second or rotor face of the cheek plate faces the rotor when the cheek plate is installed in the pump. The cheek plate further includes a first radially outwardly located pressure control passage configuration, a second pressure control passage configuration located radially inwardly with respect to the first pressure control passage configuration. A first radially outwardly suction control passage configuration located diametrically opposite to the first pressure control passage configuration and a second suction control passage configuration located radially inwardly with respect to the first suction control passage configuration. The first and second pressure control passage configurations and the first and second suction control passage configurations extend between the casing face and the rotor face.

Abstract: A compressing mechanism includes a slidable section which is constructed by combining a first slidable member made of a cast iron having a Vickers hardness within the range of 200 to 300 with a second slidable member made of a carbon steel having a Vickers hardness within the range of 200 to 300 and an average number of crystalline grains per 1 mm.sup.2 within the range of 2000 to 3200. The slidable section is composed of a shaft and a bearing. Additionally, the slidable section includes a cylinder, a rotor and a piston. Each crystalline grain in the carbon steel constituting the second slidable member has a substantially isotropic shape and a size of the crystalline grain is suitably enlarged to exhibit a coarse structure. As a result, elasticity of the grain structure of the carbon steel is increased and a very small number of crystalline grains are peeled off from the surface of the substrate.

Abstract: A rotary sliding vane pump having vanes fabricated from a carbon/carbon based material that provides improved performance by inhibiting vane wear, chipping or fracture. The advantages provided by carbon/carbon based materials may be further enhanced by impregnating each carbon/carbon sliding vane with a teflon based coating.

Abstract: A rotational speed variable type refrigerant compressor includes a closed vessel in which a refrigerator oil is received and stored, a rotational speed variable type motor mechanism and a compressing mechanism driven by the motor mechanism to compress a refrigerant. The compressing mechanism includes a slidable part which comprises a first slidable member made of a ferrous material with a nitrided layer composed of an iron nitride as a main component formed on the surface thereof and a second slidable member made of a ferrous material with an iron oxide layer composed of Fe.sub.3 O.sub.4 as a main component formed on the surface thereof along which the first slidable member comes in slidable contact with the second slidable member. For example, a shaft is constituted by the first slidable member. In addition, for example, each of the bearings for rotatably supporting the shaft is consituted by the second slidable member.

Abstract: A gear pump is described for pumping extremely low volumes of fluid at extremely low rates of flow. The pump includes a housing with a cavity therein and a pair of gears rotatable within said cavity. One of the gears is shafted and the other is shaftless, and the gears are made of resilient material with the diameter of the periphery of the tips of the gear teeth exceeding the diameter of the cavity in which they rotate. The face width of the gears also exceeds the depth of the cavity in which they rotate.

Abstract: The invention relates to a method of making a pump ring for a two-stage vacuum pump (1) with a one-piece rotor system (14) having three sections (14a, b, c), whose end sections (14a and 14c form the two pumping stages and whose middle section (14b) forms an intermediate bearing, the diameters of the bearing section (14band of the rotor section (14a) forming the forepumping stage being equal. To reduce the tolerances that occur it is proposed that two bores be made in a single set-up from one end of a substantially cylindrical workpiece, the one forming the anchor contact (51) of the forepumping stage as well as the bearing bore (12) and the other forming the anchor contact (52) of the high-vacuum stage, and that before or after these bores aremade, additional bores (11, 13) are made in order to form the pump chambers (21, 17).