Abstract: In a dry vacuum pump including: a casing having an inner cylinder (1a) communicating with an inlet (6) and an outlet (7) of the pump; shafts (15b) supported by the casing; spiral toothlike parts (15a) formed on the shaft (15b); a plurality of screw rotors (15), each of which includes the shaft (15b) and the spiral toothlike parts (15a) received in the inner cylinder (1a) intermeshing with each other; timing gears (16, 19), each of which is attached to the respective shafts (15b) of the screw rotors (15) and intermeshes with each other; and locking mechanisms (17), each of which for fixing the timing gear (16, 19) to the shaft (15b), both of the shaft (15b) and the toothlike part (15a) made of spheroidal graphite cast iron containing 20 to 30 wt % of nickel are casted integrally. With the construction described above, a problem such that a degree of vacuum deteriorates due to peeling of a resin coating is solved as to a dry vacuum pump pumping corrosive gas.

Abstract: A rotary compressor of the present invention includes a compression mechanism, motor and hermetically sealed housing. The compression mechanism includes compression elements, a rotary shaft and bearing. The compression elements includes a cylinder block, piston, and vane. The cylinder block has a cylinder hole and vane groove. The compression mechanism and the motor are housed in the hermetically sealed housing. The cylinder block is made up of sintered metal. The compression mechanism is welded to the hermetically sealed housing in a region other than the cylinder block. Preferably, the cylinder block includes a first cylinder block and a second cylinder block, and the first cylinder block and the second cylinder block are formed by machining sinter-molded blanks identical in shape. With this configuration, it is possible to reduce the machining processes and to make the blank parts usable in common, thereby realizing a low-cost compressor.

Abstract: A rotary compressor uses a freon without containing chlorine ions and uses polyol ester as a lubricant or plyvinyl ether as a base oil for providing a highly reliable rotary compressor, and for preventing abnormal abrasion. The rotary compressor has a roller and a vane sliding contact with an outer cirumference of the roller. A sliding contact portion between the vane and the roller is formed with a radius of curvature Rv, and satisfies T<Rv<Rr, wherein T is the thickness of the vane and Rr is the radius of curvature of the outer circumference of the roller.

Abstract: A rotary-vane pumping machine has a core structure that includes a stator assembly defining a contoured surface of a stator cavity, a rotor spinning around a rotor shaft axis that is fixed relative to the stator cavity, and end plates disposed on either side of the rotor. The rotor has a plurality of radial vanes slots for housing a corresponding plurality of vanes that slide within the radial vane slot of the rotor. Each of the plurality of vanes has side walls, a tip portion, and a base portion, and the base portion has one or more tabs extending from at least one axial end of the vane. The plurality of vanes, stator cavity, and rotor define a plurality of chamber cells. The core structure is substantially made of low coefficient of thermal expansion Invar materials to achieve precise non-contact sealing clearances between components of the machine.

Abstract: The present invention provides a hermetic or open compressor for hydrocarbon refrigerant having high reliability. According to the present invention, in the compressor using hydrocarbon as refrigerant, synthetic oil such as polyalkylene glycol oil, ester oil or ether oil is used as freezer oil. Sliding member of the compressor includes both a portion made of aluminum material and a portion made of iron material. Therefore, it is possible to realize a compressor having excellent wear resistance and high reliability.

Abstract: A geared feed pump has a rotatably driven pair of meshed gears (16, 19) arranged in a pump chamber (14) of a housing (10, 12). The feed pump supplies fuel from a suction chamber (16) between the peripheries of the gears (16, 18) and the peripheral walls (15) of supply channels (30) formed in the pump chamber into a pressure chamber (28). One of the gears (16) has a hole (32) and is secured onto the drive shaft (22), which is rotatably positioned in the housing (10). At least one radially, resilient connecting element (40) is arranged on the drive shaft (22), and the connecting element is pressed into the hole (32) of the gear (16). The connecting element (40) makes possible the rotationally determined securement of the gear (16) onto the drive shaft (22) and forms an overload-protection device. The connecting element (40) also makes possible, through its radial resiliency, a tolerance equalization between the drive shaft (22) and the gear (16) in a radial direction.

Abstract: A displacement type fluid machine has a sliding contact portion between a cylinder 4 and a displacer 5 made into a predetermined section, and the cylinder and the displacer so contoured that when they are made concentric, the normal distance in the sliding contact section between the cylinder contour and the displacer contour may be smaller than that of the remaining section, thereby to decrease the radial gap to lower the internal leakage of the working fluid and to improve the performance and the reliability.

Abstract: An oil pump that can be reduced in weight and is excellent in wear resistance and easy to manufacture is provided. The oil pump includes an oil pump housing formed of aluminum alloy, and an inner rotor and an outer rotor that slide along the oil pump housing with contact kept therebetween to suck and discharge oil. Composite layers including porous metallic bodies are arranged at parts of the oil pump housing that contact the inner rotor and the outer rotor. Pores of the porous metallic bodies are impregnated with the aluminum alloy constituting the oil pump housing.

Abstract: An internal gear oil pump made of Al alloys having less mutual damage property and superior wear resistance is provided. The internal gear oil pump has a casing with a gear compartment, a drive gear, and a driven gear, all of which are the structural members of the internal gear oil pump. The casing is constituted of an Al-alloy casting. The drive gear and the driven gear are constituted of a hot plastic working material of Al—Si alloy powder. The hot plastic working material is constituted of an Al—Si alloy having a structure in which unit crystal phases are dispersed in a base matrix by 10 to 40 area percent. by the structural observation with an optical microscope, the unit. crystal phases being harder than the base matrix. The base matrix is constituted of an Al—Si alloy which contains, on weight basis, 10% to 18% Si, 4% to 8% Fe, 1% to 3% Ni, 1% to 3% Cr, and the balance being Al and incidental impurities.

Abstract: A dry vacuum pump that includes a casting having an inner cylinder communicating with an inlet and an outlet of the pump, shafts supported by the casting, spiral toothed parts formed on the shaft a plurality of screw rotors each of which includes the shaft and the spiral toothed parts received in the inner cylinder intermeshing with each other. Timing gears each of which are attached to the respective shafts of the screw rotors that intermesh with each other. Locking mechanisms for fixing the timing gears to the shaft. Both of the shaft and the toothed part are made of spheroidal graphite cast iron containing 20 to 30 wt % of nickel are cast integrally.

Abstract: A scroll compressor, in which as a coolant is applied a mixture coolant obtained by mixing at least one or more kinds selected from a group of hydro fluoro carbon, within a closed container thereof, comprising: an electricmotor; a rotary scroll driven with said electric motor; and a stationary scroll, whereby forming a scroll compression mechanism between said rotary scroll for compressing said coolant, wherein said scroll compression mechanism comprises: Oldham ring for supporting said rotary scroll so that said rotary scroll perform a gyrating movement with respect to said stationary scroll without spinning around an axis thereof; and a frame for supporting said Oldham ring in movable manner for purpose of achieving supporting of said rotary scroll mentioned above, wherein said Oldham ring is formed from sintered alloy of iron group, while said frame and said rotary scroll are formed from cast iron, and after treating a steam process thereon, a sliding surface of said Oldham ring is machined by means of an

Abstract: A fluid compressor comprising a helical blade type compression mechanism that includes a cylinder, a roller arranged inside the cylinder and a helical blade interposed between the roller and the cylinder. The blade, the roller and the cylinder are formed of materials whose coefficients of thermal expansion satisfy relationships: Blade>Roller>Cylinder. According to this invention, pressure release can be easily performed in the case where the liquid flows back or under a low-temperature condition as at the time of actuation. In addition, the compression performance can be improved under a high-temperature condition during operation.

Abstract: An oscillating piston type compressor has a piston formed integral with a blade. The compressor accommodates in a casing a compression mechanism section and a motor section, the mechanism including the piston having a plate-shaped blade integrally formed on a cylindrical portion is fitted onto an eccentric portion of a crankshaft to perform orbital motion relative to an inner peripheral surface of a cylinder, the plate-shaped blade being formed at its radial end surface with a recess or a protrusion, which serves as a reference of position.

Abstract: The present invention provides a hermetic or open compressor for hydrocarbon refrigerant having high reliability. According to the present invention, in the compressor using hydrocarbon as refrigerant, synthetic oil such as polyalkylene glycol oil, ester oil or ether oil is used as freezer oil. Sliding member of the compressor includes both a portion made of aluminum material and a portion made of iron material. Therefore, it is possible to realize a compressor having excellent wear resistance and high reliability.

Abstract: A subject of the present invention is to provide a water based hydraulic fluid and a hydraulic pressure device able to prevent burning and wearing in a sliding portion of a member constructed by an iron-based material as much as possible. Therefore, the water based hydraulic fluid relative to the invention contains copper ions for forming a film on addendum surfaces of a drive gear and a driven gear constructed by the iron-based material. A gear pump as the hydraulic pressure device relative to the invention uses the water based hydraulic fluid containing metallic ions for forming the film on the addendum surfaces of the drive gear and the driven gear constructed by the iron-based material.

Abstract: A progressive-cavity pump intended to impart energy to a fluid, includes at least a casing (1), a stator (2) and a rotor (3) arranged in the stator. The casing has at least two parts, a first part (2a) made of a material of low elasticity and a second part (2b) arranged between the inner wall (1a) of the housing and the first part 2(a), the second part (2b) being suited to apply and/or to maintain a stress &sgr; exerted by the first part (2a) on the rotor (3) in order to obtain the pressure gain required for the pumped fluid.

Abstract: A rotary compressor uses a freon without containing chlorine ions and uses polyol ester as a lubricant or plyvinyl ether as a base oil for providing a highly reliable rotary compressor, and for preventing abnormal abrasion. The rotary compressor has a roller and a vane sliding contact with an outer circumference of the roller. A sliding contact portion between the vane and the roller is formed with a curvature Rv, and satisfies T<Rv<Rr, wherein T is the thickness of the vane and Rr is the curvature of the outer circumference of the roller.

Abstract: The present invention provides a hermetic or open compressor for hydrocarbon refrigerant having high reliability. According to the present invention, in the compressor using hydrocarbon as refrigerant, synthetic oil such as polyalkylene glycol oil, ester oil or ether oil is used as freezer oil. Sliding member of the compressor includes both a portion made of aluminum material and a portion made of iron material. Therefore, it is possible to realize a compressor having excellent wear resistance and high reliability.

Abstract: In accordance with the invention, the vacuum pump cooling system includes tubes expanded along their entire length in bores through the vacuum pump body. The tubes can be made of stainless steel, and inserted into a vacuum pump body made of cast iron. This prevents the risk of corrosion of the vacuum pump body by a cooling liquid passing through the tubes to cool the vacuum pump body.

Abstract: When sliding elements, slide bushings, vanes and Oldham rings employed in various types of refrigeration compressors and other applications meet the following conditions, they resist sticking to aluminum-base components, resist depletion of the oil film on slide faces, and exhibit excellent wear resistance. Firstly, the elements must comprise an iron-base sinter having closed cells on at least the slide face. Secondly, in order for the oil film to be maintained on the slide face by the closed cells and to enhance lubricating properties, the proportion of closed cells having circular-equivalent diameter of 10 &mgr;m or less, i.e. the number of ≦10 &mgr;m cells/total number of cells, must equal 85% or more, and the opening area of the closed cells on the slide face must equal 5% or less. Finally, the sliding element density must be 7.3 g/cm3 or higher.

Abstract: A gear pump for delivering liquid media has a pump housing with at least two bores, in which at least two meshing gears with tooth tips are contained. The gears are radially mounted by bearing surfaces which on one side consist of areas of the tooth tips and on the other side, of areas of the interior of the bores. This arrangement requires no slide bearings in the conventional sense, which results in a smaller number of pump parts and hence to reduced manufacturing costs.

Abstract: A rotary-vane pumping machine has a core structure that includes a stator assembly defining a contoured surface of a stator cavity, a rotor spinning around a rotor shaft axis that is fixed relative to the stator cavity, and end plates disposed on either side of the rotor. The rotor has a plurality of radial vanes slots for housing a corresponding plurality of vanes that slide within the radial vane slot of the rotor. Each of the plurality of vanes has side walls, a tip portion, and a base portion, and the base portion has one or more tabs extending from at least one axial end of the vane. The plurality of vanes, stator cavity, and rotor define a plurality of chamber cells. The core structure is substantially made of low coefficient of thermal expansion Invar materials to achieve precise non-contact sealing clearances between components of the machine.

Abstract: In an H/A range in which the ratio H/A≧0.07, where H is the thickness of the bottom wall of a recess (8) provided with a discharge port (4) and a valve seat (9) and formed in the flange (5) of a bearing member (3,3′) and A is the width of the recess (8), the smaller the ratio H/A, the greater is the coefficient of performance (COP). In an H/A range in which H/A<0.07, the COP decreases due to the leakage of the refrigerant resulting from the deflection of the bottom wall of the recess (8) and, eventually, the bearing members (3,3′) are broken. The discharge port (4), the recess (8) and the valve seat (9) are formed so that the ratio H/A≧0.07 and the ratio T/B≦0.3, where T is the thickness of the valve seat (9) and B is the diameter of the discharge port (4). The valve seat (9) can be formed in the thickness T smaller than that of the valve seat of an equivalent conventional compressor, suppressing the deflection of the bottom wall of the recess (8).

Abstract: A drilling motor includes a non-elastomeric stator and rotor which are dimensioned for negative or zero interference. The amount of negative interference between the rotor and the stator is determined by the largest solid particle expected to pass through the motor. The negative interference or gap between the rotor and the stator is preferably at least two times the greatest particle size. According to the invention, stators are made by machining or casting stainless steel and are fabricated in sections having lengths of 20 to 40 centimeters. The sections are indexed so that each section may be properly aligned with another. The sections are aligned and welded together to form a motor stator of conventional length.

Abstract: There is disclosed a hydraulic or pneumatic machine having a first displacement element (8) that is rotatable about an axis of rotation connected to a shaft (10) so as to rotate therewith, which shaft is mounted rotatably in a housing (2), and co-operates with a second displacement element (9). The structure of such a machine is to be improved. For that purpose, the housing (2) has a pocket (3) in which the displacement elements (8, 9) are so arranged that the housing (2) covers the displacement elements (8, 9) axially on both sides (4, 5) at least in a working region and in the circumferential direction over a maximum of 180°.

Abstract: A rotary device containing a housing with two side plates, a shaft, an eccentric connected to the shaft, a rotor mounted on the shaft, a first gear, and a second gear. The rotor contains at least 3 sides, the housing has an interior surface defined by at least a first lobe and a second lobe, the first gear is an internal gear which is connected to the rotor, the second gear is an external gear connected to the housing, the difference between the pitch diameter of the first gear and the pitch diameter of the second gear is is equal to twice said eccentricity of the eccentric, and the ratio between the pitch diameter of the first gear and the pitch diameter of the second gear is equal to the ratio between the number of said sides in said rotor divided by the number of lobes in the interior surface of said housing.

Abstract: A conventional displacement type fluid machine is featured by a low sliding rate and in low vibrations and pulsations, but has a problem, that the radial gap in a displacer sliding portion is enlarged by the clearance of a shaft drive system and a rotating moment acting on a displacer so that the internal leakage of a working fluid is increased to lower the performance and the reliability. To eliminate this problem, the sliding contact portion between a cylinder 4 and a displacer 5 is made into a predetermined section, and the cylinder and the displacer are so contoured that when they are made concentric, the normal distance in the sliding contact section between the cylinder contour and the displacer contour may be smaller than that of the remaining section, thereby to decrease the radial gap to lower the internal leakage of the working fluid and to improve the performance and the reliability.

Abstract: A gear pump for metering resins is provided having the surfaces of interacting internal metal parts coated with a metal-based material to prevent seizing of the interacting moving parts as a result of resin curing therebetween. Parts made from such materials as heat treated carbon steel and stainless steel are preferably coated with a nitride, carbide or oxide of such metals as tungsten, titanium, aluminum and chromium at a thickness of between about 2-5 microns. The coating is applied to the surface of any part that comes in heated contact with the surface of another relatively moving part. The resulting gear pump exhibits high wear resistance, longevity, and low maintenance requirements.

Abstract: A rotary vane pumping machine have a core structure and peripheral components interfacing with the core structure. The core structure includes a stator assembly defining a contoured surface of a stator cavity, a rotor spinning around a rotor shaft axis that is fixed relative to the stator cavity, and end plates disposed on either side of the rotor. The rotor has a plurality of radial vanes slots for housing a corresponding plurality of vanes that slide within the radial vane slot of the rotor. The plurality of vanes, stator cavity and rotor define a plurality of chamber cells. The core structure is substantially made of low coefficient of thermal expansion Invar materials to achieve precise non-contact sealing clearances between components of the machine.

Abstract: A gerotor hydraulic pressure device using a powder metal wear plate to close off at least one end of a stator/rotor mechanism, with the wear plate having an axial length 0.003" greater than the cavity in the housing that contains it.

Abstract: A vane of a compressor is made of solid phase sintering material of which a sintering density is not less than 7.2g/cm.sup.3 and a hollow rate is not more than 10%, and to which CrN phase is adhered through a PVD process. A roller of the compressor is made of hardened and tempered material having a hardness equal to cast iron FC300 (specified by JIS). The roller may be made of hardened and tempered material including at least one of Ni, Cr and Mo, and having a hardness equal to cast iron FC300. The vane and roller are combined, so that a sliding section having excellent abrasion-resistance can be constructed. As a result, a rotary compressor, which employs R134a or R22 coolant as well as HFC system or HC system coolant both of which are R22 substitutes, having extremely high reliability can be realized.

Abstract: A scroll-type fluid displacement apparatus comprises a housing having an inlet port and outlet port and is made of non-ferrous metal. The housing has a first casing and second casing that is connected to the first casing. A fixed scroll is fixedly disposed within the housing and has a first circular end plate from which a first spiral element entered into the housing. An orbiting scroll has a pair of parallel first grooves formed on a second circular end plate. A second spiral element extends from the second circular end plate such that the first spiral element interfits the second spiral element at an angular and radial offset to make a plurality of line contacts to define a pair of fluid pockets within the housing. A driving mechanism is connected to the orbiting scroll to effect orbital motion of the orbiting scroll. An Oldham ring is coupled to the orbiting scroll for preventing rotation of the orbiting scroll during orbital motion.

Abstract: An outer rotor and an inner rotor are formed of sintered aluminum alloy. The sintered aluminum alloy contains 0.5 wt % to 11 wt % of aluminum nitride. Porosity of the sintered aluminum alloy for outer rotor is 3 vol % to 15 vol %. Porosity of the sintered aluminum alloy for inner rotor is 2 vol % to 10 vol %. Outer rotor and inner rotor are set in a pump case. A rotary driving shaft formed of steel is inserted to a through hole of inner rotor. A press fit member is inserted at a press fit surface of inner rotor and rotary driving shaft. Accordingly, sliding members formed of sintered aluminum alloy which reduces seizure and abrasive wear of the inner and outer rotors can be provided, and in addition, an oil pump of which wear and damage at the inner rotor inner diameter surface is suppressed, can be provided.

Abstract: The present invention provides an aluminium near net material for making a rotary scroll. Even when there is a displacement due to level of die accuracy, error in machines used for machining processes and shift of processing fiducial, the invented near net material makes it possible to manufacture rotary scrolls without having skin of the original material staying in a finished rotary scroll, by determining the cutting margin 4 for spiral fin smaller than the cutting margin 5 for axis.

Abstract: Gear pump, or Moineau pump, comprising two helical gears one inside the other, the internal helical gear, which is rotary (the rotor) having one tooth fewer than the external helical gear, which is stationary (the stator), characterized in that the rotor and the stator are made of respective materials which have respective coefficients of thermal expansion which lead to respective expansions of the rotor and of the stator which are such that an approximately constant clearance is maintained between the rotor and the stator over a range of ambient temperatures spanning between about 15.degree. C. and about 300.degree. C.

Abstract: An aluminum alloy scroll machine component having improved lubricity.

Abstract: There is provided a vane compressor which prevents leakage of refrigerant gas by decreasing the number of airtight interfaces between component parts and prevents seizure from occurring between its rotor and its side block without surface treatment of the side block. The vane compressor has a cam ring. The rotor is rotatably received in the cam ring. A first head is secured to one end face of the cam ring. A second head is secured to another end face of the cam ring in a manner such that the second head closes an opening of the another end face of the cam ring and one end face of the rotor can be brought into contact with the second head. The side block is received in the first head in a manner such that it closes an opening of the one end face of the cam ring and another end face of the rotor can be brought into contact with the side block.

Abstract: An internally or externally geared pump for conveying fluids lacking or only having insufficient lubricating ability, includes gearwheels moving in an operating chamber of the pump, conveying fluids and being mounted completely in parts formed of a carbon material. Supports are formed from accurately worked lateral walls and a jacket of the operating chamber formed of the carbon material. The jacket surrounds the gearwheels in the radial direction and is likewise constructed as a support. Chambers on the suction side and on the pressure side for fluid supply and fluid removal, which are necessary for the operation of the pump, are molded into side walls of the operating chamber which is formed of carbon.

Abstract: Vane for use in a rotary vane compressor or other rotary expansible chamber device and process for making the vane in which the vane comprises a vane body having a first tip, a second tip, and a vane body interconnecting the tips. At least one of the first and second tips comprises a metal alloy and a lubricating agent provided in admixture with the metal alloy. The vane body comprises a metal alloy and a plurality of inorganic particles provided in admixture with the metal alloy. The inorganic particles have a coefficient of thermal expansion which is less than the coefficient of thermal expansion of the metal alloy.

Abstract: Gears for pumping non-lubricating fluids at high pressure are provided which include special coatings. One of the gears is coated with a combination of nickel and polytetrafluoroethylene; the other gear is coated with a combination of carbon and tungsten carbide. Because the coatings are different and have different hardnesses, galling is prevented. Preferably, the gears are fabricated from stainless steel and, therefore, in the event a scratch or nick in the coating is produced, corrosion is prevented. The gears are useful for gear pumps used to pump fire fighting liquids and foam at high pressures.

Abstract: In a vane type vacuum pump comprising a rotor 5 having a rotary shaft offset in a pump chamber P of hermetically sealed structure, grooves 5a disposed on the outer periphery of the rotor, vanes 6 disposed in the grooves and sliding while in intimate contact with the inner wall of the pump chamber, an input shaft 1 having a rotary shaft coaxial with the rotor, and torque transmission means for transmitting the rotational torque of the input shaft to the rotor, the torque transmission means includes a carrier 7 disposed to the outer periphery of the input shaft integrally therewith, a flange unit 7a formed to the end surface of the carrier so as to confront the end surface of the rotor, recessed portions 5b, 7b formed to the respective end surfaces of the rotor and the flange unit, and pins 8 for coupling the rotor with the flange unit through the respective recessed portions, and the pins extending in the direction of the rotary shafts of the rotor and the input shaft are inserted into the respective recessed

Abstract: A rotary vane motor for efficiently extracting mechanical energy from an expanding gas at low rotational speeds is provided. The motor includes a housing having a cylindrical enclosure, a rotor having a plurality of radially oriented slots, a plurality of vanes slidably movable in the slots, a shaft for rotatably mounting the rotor in an eccentric position within the housing enclosure, and a slidable connection between the rotor and the shaft for equilibrating close clearances between the rotor and the side edges of the vanes and the inner surfaces of the housing to minimize inefficiencies due to blow-by and friction. Additionally, the materials forming the rotor, the vanes, and the housing are all selected to have the same thermal coefficient of expansion so that the vanes tightly interfit within their respective slots and the sealing surfaces of the housing over a temperature range spanning the cryogenic temperatures associated with the prefeffed drive gas, and maximum ambient temperatures.

Abstract: A rotor with lobes for use in a turbomachine having a rotation shaft is disclosed. The rotor comprises a rotor shell having a shell member, which is made of a sheet strip metal and having profile curvatures to conform to a required shape of the lobe of the rotor, and a connecting portion for connecting the rotor to the rotation shaft. By making a rotor from a sheet strip metal through bending process to form a rotor shell, a rotor having thin walls can be produced efficiently and economically to provide a light weight rotor of reduced inertial moment so that the startup process or shut down process can be performed quickly.

Abstract: A differential expansion control assembly is provided for a pump. The pump has a pump body with a base portion and cover portion of a first material with a first thermal expansion coefficient and a pumping mechanism of a second material with a second thermal expansion coefficient different from the first thermal expansion coefficient. The differential expansion control assembly includes at least one member disposed between the base portion and cover portion to negate a difference between the first thermal expansion coefficient and the second thermal expansion coefficient and maintain a relative controlled clearance between the cover portion and the pumping mechanism. The differential expansion control assembly also includes a seal disposed between the cover portion and base portion to allow for differential expansion of the pump body without leakage of fluid between the cover portion and base portion.

Abstract: There are provided a highly durable and efficient refrigerating apparatus and a lubricating oil composition that uses an HFC type refrigerant and is still free from the problem of thermal hydrolysis of polyol-ester type oil and resulting generation of carboxylic acid and sludge so that the refrigerating apparatus and the lubricating oil composition may be used stably for a prolonged period of time. A lubricating oil composition according to the invention comprises as base oil components a polyol-ester type oil formed by reacting specific polyhydric alcohol with a fatty acid, to which tricresylphosphate and epoxy compound comprising glycidyl ether or carbodiimide are added at respective specific rates.

Abstract: A gear-type pump having an inner rotor and an outer rotor and in which the outer rotor is supported for rotation by a plurality of roller bearings interposed between a support housing and the outer rotor and in which the inner and outer rotors and the support housing are made of the same material and have essentially the same width dimension so that the thermal contraction of the support housing and the thermal contraction of the inner and outer rotors while pumping super-cooled fluid does not adversely affect the end-clearance between the end plates and the inner and outer rotors to an extent where the efficiency of the pump would differ if it were pumping fluid at a temperature of 70 degrees Fahrenheit.

Abstract: A drilling motor has been developed with a hollow tubular stator having at least one rod recess therein and an inlet 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 exhaust flow channels therethrough for providing a motive fluid flow path to the central motive fluid flow channel from 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: An improved gear pump having members with different hardnesses includes a housing defining an internal bore with inlet and outlet passageways. A head member includes a wall between the inlet and outlet passageways and extends toward a toothed rotor. A toothed idler gear meshes with the rotor. The head member and idler gear are made of materials having a hardness greater than that of the rotor material. In one embodiment the idler gear is made of ceramic material whereas the head member and rotor are made of cast iron, with the head member treated to have a hardness greater than that of the rotor.

Abstract: A hermetic compressor which compresses compressed gas, comprising a sealing container, a compression mechanism, contained within said sealing container, for compressing said compressed gas, said compression mechanism including a rotary shaft, a motor for actuating the compression mechanism by driving the rotary shaft, first and second bearings, arranged individually on both sides of the compression mechanism, for journaling said rotary shaft, and a frame for fixedly supporting the compression mechanism, the frame comprises a frame body having a hollow portion in which said first bearing is situated, said frame body being fixed on one end surface of the compression mechanism and a bearing support portion for sealing the hollow portion of the frame body and supporting an outer peripheral portion of the first bearing.

Abstract: A motor driven by air or other fluid, or a pump for pumping air or another fluid, including a rotor having a porous metal body formed of compacted and sintered metal particles and containing polytetrafluoroethylene embedded within the pores of the body. The metal particles are preferably primarily of iron, with a smaller amount of copper at least partially dissolved in the iron. The metal body carries vanes which are received slidably within slots in the body and are movable radially relative thereto and are preferably formed of resinous plastic material.