Abstract: A mud motor includes a rotor and a stator. Drilling fluid received by cavities of the mud motor drives the rotor to rotate within the stator. The rotor includes one or more rotor lobes extending helically and defining a rotor pitch. The stator includes two or more stator lobes extending helically and defining a stator pitch. The rotor and the stator together define a tapered profile of the mud motor that varies proceeding from a top end of the mud motor to a bottom end of the mud motor. At least one of the rotor pitch or the stator pitch vary as proceeding from the top end of the mud motor to the bottom end of the mud motor.

Abstract: A free-mold stator for a progressing cavity pump can comprise a housing include an inner housing surface defining an uninterrupted helical profile, and a liner including an inner liner surface and an outer liner surface. The inner liner surface and the outer liner surface can each define an uninterrupted helical profile, and the inner housing surface of the housing can be adapted to receive the outer liner surface to prevent lateral and rotational movement between the liner and the housing.

Abstract: Provided is a progressive cavity pump. The progressive cavity pump operates such that a viscous liquid is discharged by rotating an eccentric rotor with respect to a stator. The progressive cavity pump may be easily disassembled for repair and maintenance, and may be easily attached to an accurate position during re-assembly. Also, in the progressive cavity pump, main components such as a nozzle, a rotor, a stator, etc. may be easily replaced so as to easily adjust dispensing characteristic, while the driving units such as a motor and a rotary shaft are installed in a dispenser, and thus, an idle time of the dispenser may be reduced.

Abstract: A cartridge system for an eccentric screw pump, comprising a cartridge for receiving a medium to be dosed, a stator being provided on the cartridge, which cooperates with a rotor unit of the eccentric screw pump for dosing the medium, and a plug being movably supported in the cartridge for a fluid-tight closure of the cartridge, wherein the plug comprises a rotor breakthrough through which the rotor unit can be passed.

Abstract: A technique facilitates efficient well production in relatively low volume applications, e.g. applications after well pressure and volume taper off for a given well. According to an embodiment, use of an electric submersible progressive cavity pump is enabled in harsh, high temperature downhole environments. A pump stator facilitates long-term use in such harsh environments by providing a composite structure having an outer housing and a thermoset resin layer located within the outer housing and secured to the outer housing. The thermoset resin layer is constructed with an internal surface having an internal thread design. Additionally, an elastomeric layer is located within the thermoset resin layer and has a shape which follows the internal thread. In this manner, the elastomeric layer is able to provide an interior surface generally matching the shape of the internal thread of the thermoset resin layer and arranged for interaction with a corresponding pump rotor.

Abstract: A system includes a solids trap disposed in a well. The system includes an inner annulus, an outer annulus, and a chamber between the inner annulus and the outer annulus. A solids accumulation zone is formed in the chamber. A pump is fluidly connected to the solids trap. A fluid stream carrying solids flows from the pump. The fluid stream carrying solids is configured to follow a path delimited by the outer annulus and the chamber until the fluid stream deposits the solids in the solids accumulation zone and departs the solids trap via the inner annulus into a tubing.

Abstract: A rotor unit for an eccentric screw pump, comprising a drive shaft which is drivable by means of a drive element of the eccentric screw pump, a helical rotor, and a flex shaft connecting the drive shaft to the rotor, wherein the flex shaft is at least in part accommodated within in the drive shaft, and wherein between the flex shaft and the drive shaft a gap extending around the flex shaft is provided, which allows for a radial movement of the flex shaft within the drive shaft.

Abstract: A hydraulic tool includes a rotor rotatably disposed within a stator. At least an inner portion of the stator and/or at least an outer portion of the rotor is configured to be installed in a drill string in either of two inverted orientations along a longitudinal axis of the hydraulic tool. The rotor is configured to rotate within the stator in either of the two orientations. A method includes disposing a rotor within a cavity defined by a stator, passing a fluid through the stator to rotate the rotor, and reversing the stator or the rotor. A drilling system includes a fluid source, a hydraulic tool, a drive shaft operatively associated with the rotor of the hydraulic tool, and a drill bit operatively associated with the drive shaft.

Abstract: Device and method for protecting a submersible pump. The device can include a housing for connecting to a downhole pump, and a plurality of shelves disposed throughout the housing, wherein at least two shelves are axially spaced from one another, and each shelf provides a surface for supporting and collecting sand or other solids within the housing. A restrictor assembly can be disposed at one end of the housing and configured to allow fluid flow through the housing in one direction and at least partially restrict flow through the housing in an opposite, second direction.

Abstract: The present invention relates to a Moineau pump-type quantitative liquid-discharging apparatus including a stator in which a slot hole is formed, a main shaft including a first shaft part and a second shaft part, which are eccentric with respect to each other, and a rotor which extends from the first shaft part and is inserted into the slot hole, first and second slide bearings to which the first shaft part and the second shaft part are rotatably coupled, respectively, and first and second sliders which guide the first and second slide bearings to move in directions to cross each other, wherein the movement directions of the first and second slide bearings are perpendicular to an extension direction of the rotor.

Abstract: An eccentric screw pump has a stator, a rotor rotating in the stator, a drive, and a pump housing connected to the stator and having at least one inlet or outlet opening for a medium to be conveyed. A connecting shaft driven by the drive rotates concentrically with an axis, and a connecting housing connected between the pump housing and the drive at least partially surrounds the connecting shaft. A coupling-side shaft seal lies between the connecting shaft and the connecting housing, and a coupling rod in the pump housing is connected to the connecting shaft at a drive-side end and to the rotor at a rotor-side end thereof and generating eccentric movement of the rotor-side end on concentric rotation of the connecting shaft. A sensor is mounted in or on the connecting housing adjacent the connecting shaft for detecting or measuring deviation from axially concentric rotation thereof.

Abstract: A hydraulic tool includes a rotor rotatably disposed within a stator. At least an inner portion of the stator and/or at least an outer portion of the rotor is configured to be installed in a drill string in either of two inverted orientations along a longitudinal axis of the hydraulic tool. The rotor is configured to rotate within the stator in either of the two orientations. A method includes disposing a rotor within a cavity defined by a stator, passing a fluid through the stator to rotate the rotor, and reversing the stator or the rotor. A drilling system includes a fluid source, a hydraulic tool, a drive shaft operatively associated with the rotor of the hydraulic tool, and a drill bit operatively associated with the drive shaft.

Abstract: Rotary positive displacement machines based on trochoidal geometry that includes a helical rotor that undergoes planetary motion relative to a helical stator are described. The rotor can have a hypotrochoidal-based cross-sectional shape, with the corresponding stator cavity cross-sectional shape being the outer envelope of the rotor cross-sectional shape as it undergoes planetary motion, or the stator cavity can have an epitrochoidal-based cross-sectional shape with the corresponding rotor cross-sectional shape being the inner envelope of the stator cross-sectional shape as it undergoes planetary motion. Such machines can be configured so that the stator axis is spaced from the rotor axis, the rotor is configured to spin about its axis and the stator is configured to spin about its axis, and/or the rotor and the stator are held at a fixed eccentricity so that the rotor undergoes planetary motion relative to the stator, but does not orbit.

Abstract: Rotary positive displacement machines based on trochoidal geometry and including a helical rotor that undergoes planetary motion relative to a helical stator can be designed and configured so that the axial load or rotor pressure force is positive, negative, or neutral. In some embodiments, a change in axial load, caused by a change in differential pressure across the machine, can be used to trigger a change in a mechanical configuration of the machine.

Abstract: A downhole motor or pump assembly that includes a housing that includes a metal. A stator that includes an elastomer compound with an uncured plasticizer is secured and sealed within the housing using an adhesive system that includes an adhesive and a dried film thickness of 2.5 mil to 7 mil. The assembly also includes a rotor rotatable within the stator. The motor or pump is operable by rotation of the rotor within the stator. In the case of a motor assembly, the motor assembly may be part of a drilling assembly that includes a drillstring and a drill bit to drill a borehole.

Abstract: The present invention refers to a progressive cavity pump developed for tintometric dosing machines. The proposal set out in the present invention is to make precision dosages through pumping by just one stator and rotor stage. The PCP proposal enhances the traditional constructive arrangement for tintometric application. The object makes precision dosages through pumping by just one stator and rotor stage, reducing the length of the pump, facilitating the manufacture of its components and requiring less robustness of the transmission components and of the drive motor. Therefore, the present invention has a simplified transmission system, uses special geometry for fastening the stator, optimizes the bearing of the drive shaft and its sealing element, reduces the dimensions of the components and uses a low torque motor.

Abstract: Systems and methods for preventing rotation of an ESP motor when the motor is not powered on, thereby preventing the motor from acting as a generator when fluid flowing through the pump section of the ESP applies a torque to the motor. In one embodiment, an ESP has a motor section, a pump section. The ESP may include a directional coupling that allows unidirectional rotation between the motor shaft and a pump shaft of the pump section, and a directional lock that allows unidirectional rotation between the motor shaft and a housing of the motor section. The directional coupling and directional lock allow the pump shaft to freewheel in the forward direction without causing the motor shaft to rotate, and prevent the pump shaft and motor from rotating in the reverse direction.

Abstract: A downhole drilling motor assembly includes a first motor, a second motor aligned coaxially with the first motor, and a clutch assembly aligned coaxially with the first and second motors. The clutch assembly independently and selectively actuates each of the first and second motors to rotationally drive a drill bit. A related method includes: mounting a drill bit at a distal end of a drill string at a well site; and providing a downhole drilling motor assembly which rotationally drives the drill bit. The clutch assembly is controlled to independently and selectively actuate the first and second motors, and the drill bit is rotationally driven via the independent and selective actuation of the first and second motors.

Abstract: A rubber compound for use in a stator in a positive displacement motor. The rubber compound includes a fiber reinforcement, wherein fibers in the fiber reinforcement create a grain direction in which “with the grain” is generally orthogonal to “across the grain”. In some embodiments, the rubber compound has a first value for 25% tensile Modulus across the grain and a second value for 25% tensile Modulus with the grain, wherein the first value is at least 10% lower than the second value. In such embodiments, the fiber reinforcement may further include a fiber loading of greater than 5.0 phr of fibers. In such embodiments, the rubber compound may further have a 25% tensile Modulus of greater than 400 psi across the grain and a 50% tensile Modulus of greater than 700 psi across the grain.

Abstract: An oil field pump is installed within a pipe that connects to an oil field, and feeds accumulated extraction oil in a predetermined direction, the oil filed pump including a rotor with an internal flow path for the extraction oil, a stator installed on the outer circumference of the rotor, a thrust bearing that supports the axial weight of the rotor and the stator, a supply pipe that supplies a portion of the extraction oil in the flow path to the thrust bearing, and a filter that is installed at further upstream on the flow path than the supply pipe along the flow direction of the extraction oil, and traps foreign matter.

Abstract: A progressing cavity device operates as a motor to impart torque to a bit. A stator of the device defines an internal profile having uphole stages with a first dimension being less than a second dimension of downhole stage. A rotor has an external profile with a constant outer dimension along its length. Disposed in the stator, the rotor defines cavities with the stator and is rotatable with pumped fluid progressing in the cavities from the uphole to downhole to transfer torque to the drive toward the downhole end. Although the rotor is subjected at the downhole end to a reactive torque from the bit, the interference fit of the rotor's constant dimension with the stator's downhole stages is less than with the uphole stages, which can mitigate issues with heat buildup in the downhole stages. The device can also operates as a progressing cavity pump.

Abstract: A stator segment is provided for a helical gear device. The stator segment includes a stator tube and modular stator inserts. The stator tube has an inner profile with at least two internal sides that extend longitudinally along an interior of the stator tube. The modular stator inserts each have an outer profile that substantially matches and fits within the inner profile of the stator tube. The modular stator inserts also each have an interior helical profile that defines a central opening. The modular stator inserts are configured to be removably inserted longitudinally into the stator tube along the inner profile of the stator tube. The inner profile aligns the modular stator inserts to form a continuous helical chamber and prevents rotation of the modular stator inserts relative to the stator tube.

Abstract: A stator for a helical gear device includes a first section having first helically convoluted chamber with a set of radially inwardly extending lobes and a second section adjacent to the first section. The second section includes a stack of cutter disks. Each cutter disk includes a front surface, a rear surface, an interior surface defining a central opening extending from the front surface to the rear surface, a forward cutting edge, and a rearward cutting edge. The interior surface forms a same number of lobes for the central opening as the set of radially inwardly extending lobes in the first section. Each cutter disk is aligned along a common centerline, and each cutter disk is rotated slightly relative to each other to form a second helically convoluted chamber with a same pitch as the first helically convoluted chamber. The second helically convoluted chamber exposes, to materials passing through, portions of the forward cutting edge or the rearward cutting edge of each cutter disk.

Abstract: The present invention aims to provide a long-life stator and a uniaxial eccentric screw pump provided with the stator, which enable a comparatively extended period of use by preventing damage of the stator due to repeating of attachment and removal to/from the uniaxial eccentric screw pump. A stator 20 includes an outer cylinder 30, and a stator main body 42 having flange-shaped gasket parts 46 and 47. The stator 20 includes fixing areas 24 and 25 to which the gasket parts 46 and 47 and the outer cylinder 30 are adhered. One or both of the outer cylinder 30 and the gasket parts 46 and 47 has a derricking part penetrating or being dented in axial directions X and made into such a shape where at least part of one of the outer cylinder and the gasket parts is fitted into the other.

Abstract: A progressive cavity pump for transporting a liquid containing solids comprises a helical rotor, a stator having an inlet and an outlet, within which the helical rotor is rotatably disposed about a longitudinal axis of the stator, and comprising a helical inner wall corresponding to the helical rotor. The helical rotor comprises a shape tapering down toward the outlet or inlet, and the helical rotor and stator are disposed relative to each other and implemented such that at least one chamber is formed for transporting the liquid, and the chamber is cut off by a constriction. The progressive cavity pump includes an adjusting device for adjusting a relative axial position of the helical rotor and stator, wherein the adjusting device is implemented for expanding the constriction between the helical rotor and stator.

Abstract: A stator for a progressive cavity pump may include a containment element with an inner surface and a casing. The casing may be arranged within the containment element, be generally isolated from the inner surface of the containment element, and define a stator cavity adapted for receiving a progressive cavity pump rotor and for accommodating substantially free rotation of the progressive cavity pump rotor therein.

Abstract: A hydraulic tool includes a rotor rotatably disposed within a stator. At least an inner portion of the stator and/or at least an outer portion of the rotor is configured to be installed in a drill string in either of two inverted orientations along a longitudinal axis of the hydraulic tool. The rotor is configured to rotate within the stator in either of the two orientations. A method includes disposing a rotor within a cavity defined by a stator, passing a fluid through the stator to rotate the rotor, and reversing the stator or the rotor. A drilling system includes a fluid source, a hydraulic tool, a drive shaft operatively associated with the rotor of the hydraulic tool, and a drill bit operatively associated with the drive shaft.

Abstract: A submersible pump assembly has a seal section between the motor and the well fluid pump, the seal section having a housing, a shaft and a thrust bearing unit. The thrust bearing unit includes a thrust runner mounted to the shaft that rotates against a thrust bearing base fixed in the housing. An annular, metal thrust runner wave spring has an inner diameter surface in contact with the shaft and an outer diameter surface in contact with the runner bore. The wave spring has a transverse width between the inner diameter surface and the outer diameter surface that is elastically deflectable, exerting an inward bias force against the shaft and an outward bias force against the runner bore.

Abstract: An eccentric screw pump for pumping fluids or flowing conveying media from a suction side to a pressure side, which includes a rotor and a stator, the stator being flexible and is connected to the pump housing on one side, in particular on the suction side. The rotor is connected to the drive shaft by means of an articulation. When the eccentric screw pump is in the idle state, there is no sealing contact at least in areas between the rotor and the stator in the sealing areas. When the eccentric screw pump is in the operating state, the stator is surrounded, at least in sections and/or, essentially, on the periphery by the conveying medium. The rotor and the stator are brought into contact with each other in the operating state along the sealing area.

Abstract: A progressive cavity pump includes at least one of a jacketed stator casing and a jacketed inlet body. The jacketed stator casing includes a stator heating chamber, a stator assembly, and a rotor rotatably disposed within the stator assembly. The stator heating chamber forms a first space around the stator assembly and receives heating fluid therein. The stator assembly includes a cylindrical wall and a stator segment that forms a helically-convoluted chamber within the cylindrical wall. The jacketed inlet body includes an inlet heating chamber and a working fluid chamber in fluid communication with the helically-convoluted chamber. The inlet heating chamber forms a second space around the working fluid chamber and receives heating fluid therein. The stator heating chamber and the inlet heating chamber are isolated from each other, the helically-convoluted chamber, and the working fluid chamber.

Abstract: A method of forming a mud motor stator having a passage including a first end defining a first opening, a second end defining a second opening and an intermediate portion extending therebetween includes introducing a liner material into the passage at one of the first end and the second end of the stator, inserting a mandrel having a contoured surface into the passage through one of the first end and the second end of the stator, shifting one of the mandrel and the stator relative to the other of the mandrel and the stator, and flowing the liner material over the contoured surface of the mandrel from the one of the first and second ends toward the other of the first and second ends to form a liner on the inner surface of the passage.

Abstract: A hybrid elastomer/metal on metal motor for a helical gear device includes a rotor and stator comprising a hydraulic motor that produces work when a working fluid is pumped therethrough. The improvement involves the stator being, for part of its length, a conventional or even wall stator, using an elastomer to form a seal against the moving rotor. The stator's remaining length comprises a profiled rigid surface that forms a seal directly with the moving rotor. This gives the motor the high efficiency of the elastomer sealing against the rotor, and simultaneously provides a backup of the stator's rigid section allowing continued motor operation at reduced efficiency, if the elastomer part failed in service. The invention also includes combinations of a regular disk stack with a rubber lining, a rigid material disk stack (or unitized element) and a circular rigid sleeve which react to rotor sideloading while permitting proper rotor orbiting.

Abstract: An eccentric screw pump, comprising a rotor that extends along a longitudinal axis of the rotor from a drive end to a free end, a stator housing with an internal cavity that extends along the longitudinal axis from a stator inlet opening to a stator outlet opening and that is designed to accommodate the rotor, a drive motor with a drive shaft that is coupled with the rotor to transmit a torque, a first cardan joint which is placed within the transmission of the torque between the drive shaft and the rotor, and a stator outlet flange that is arranged in flow direction behind the rotor. The stator outlet flange comprises a flange connection plane that is oriented non-vertically to the longitudinal axis.

Abstract: A fluid displacement apparatus includes a stator section with a rotor therein. The stator section includes a cylindrical casing, a helically-convoluted chamber section within the cylindrical casing, and a rigid sleeve within the cylindrical casing and separate from the helically-convoluted chamber section. The rigid sleeve includes a circular internal bore. The rotor is rotatably disposed within the cylindrical casing. The rotor includes a helically-lobed section disposed within the helically-convoluted chamber section, and a circular cylinder section disposed within the rigid sleeve. The circular cylinder section provides a fluid passageway between the rigid sleeve and the circular cylinder section. Side loads from the rotor are distributed along a contact line at any point of rotation of the circular cylinder section within the rigid sleeve.

Abstract: A progressing cavity pump or a positive displacement motor includes an external member having three or more lobes and an internal member extending through the external member and having one less lobe than the external member. One of the internal member and the external member rotates with respect to the other. The curvature of a profile of each of the internal member and external member is finite at all points. A ratio of a lobe volume of the external member to a valley volume of the external member enclosed between a minor external member diameter and a major external member diameter is between 0.9 and 1.2. A lobe height of the external member is related to a ratio of a minor internal member diameter to one less than the number of internal member lobes.

Abstract: Rotary positive displacement machines based on trochoidal geometry, that comprise a helical rotor that undergoes planetary motion within a helical stator are described. The rotor can have a hypotrochoidal cross-section, with the corresponding stator cavity profile being the outer envelope of the rotor as it undergoes planetary motion, or the stator cavity can have an epitrochoidal cross-section with the corresponding rotor profile being the inner envelope of the trochoid as it undergoes planetary motion. In some embodiments, the geometry is offset in a manner that provides structural and/or operational advantages in the rotary machine.

Abstract: A stator assembly for a progressing cavity pump is provided. The stator assembly includes a number of stator laminates having a planar body defining a primary, inner passage and a number of outer passages, the outer passages disposed effectively adjacent the inner passage whereby the inner passage is at least partially defined by a band, wherein the band is outwardly flexible. The stator laminates are coupled to each other in a stack wherein the stator laminate body inner passages define a helical passage. The helical passage is a flexible helical passage.

Abstract: A pump housing for an eccentric screw pump, with a longitudinal axis and a hollow space constituted running axially between a drive-side opening and a pump-side opening, wherein the pump-side opening is enclosed by a main housing body and a lid fastened removably thereto, wherein the main housing body includes a ring segment-shaped axial guiding surface lying opposite the lid.

Abstract: A stator-rotor system of an eccentric screw pump including a rotor with a rotor screw and a stator with an internal thread. The stator includes a support element and an elastomer part. The support element surrounds the elastomer part in sections around the whole circumference. The stator-rotor system includes a mechanism for adjusting the stator, having two adjustment elements arranged on the stator-rotor system, which are distance-variable relative to one another. In a first working position the two adjustment elements have a first distance from one another and in a second working position, a second distance. The cross-section and the length of the elastomer part of the stator in the second working position are changed compared to the cross-section and the length of the elastomer part in the first working position.

Abstract: The invention relates to an eccentric screw pump, comprising at least one stator (1) composed of an elastic material and a rotor (2) that can be rotated in the stator (1), the stator (1) being surrounded by a stator casing (3) at least in some regions. The stator casing (3) consists of at least two casing segments (19) as a longitudinally divided casing and forms a stator clamping device, by means of which the stator (2) can be clamped against the rotor (1) in the radial direction.

Abstract: A stator assembly for a progressing cavity pump is provided. The stator assembly includes a number of stator laminates having a planar body defining a primary, inner passage and a number of outer passages, the outer passages disposed effectively adjacent the inner passage whereby the inner passage is at least partially defined by a band, wherein the band is outwardly flexible. The stator laminates are coupled to each other in a stack wherein the stator laminate body inner passages define a helical passage. The helical passage is a flexible helical passage.

Abstract: A mud motor stator or a pump comprising of a tubular outer portion; a number of lobes extending radially inwardly from the tubular outer portion, at least one of which comprises a skeletal structure and method for producing a mud motor stator or a pump comprising of placing material and bonding the material together in a pattern dictated by the design shape of the stator or pump.

Abstract: A sealing arrangement having inboard and outboard dynamic seals in a housing separated by a barrier fluid and having a sealed relationship with a relatively movable bearing-guided shaft. A bearing chamber having bearing lubricant exposed to the inboard dynamic seal. The inboard dynamic seal is a hydrodynamic seal having a hydrodynamic pumping action in response to relative rotation between the shaft and the inboard dynamic seal. The hydrodynamic pumping action forcing a film of the bearing lubricant between the inboard dynamic seal and the shaft. The hydrodynamic pumping-related leakage of the inboard dynamic seal being returned to the bearing chamber in which the shaft guidance bearings are located.

Abstract: A stator and a method of manufacturing at least a portion of a progressive cavity motor or pump include disposing a cylindrical shell within a cylindrical housing, disposing a stator mold within the cylindrical shell, disposing an elastomeric material between the stator mold and the cylindrical shell, removing the stator mold from within the elastomeric material, thereby forming an elastomeric material layer having a stator profile within the cylindrical shell, and removing the cylindrical shell from within the cylindrical housing, thereby forming a cartridge having the elastomeric material layer disposed within the cylindrical shell.

Abstract: An improved flexible endoscopic instrument to precisely and efficiently obtains samples of flat polyps and multiple polyps from a patient by debriding one or more polyps and retrieving the debrided polyps without having to alternate between using a separate cutting tool and a separate sample retrieving tool and may be used with an endoscope. In one aspect, the cutting tool is coupled to a flexible torque coil or torque rope that is configured to transfer rotational energy from a powered actuator through the length of the endoscope onto the cutting tool.

Abstract: In a nondestructive means of ectopic pregnancy management, a baby is delivered with the gestational sac intact and then submerged in an incubator containing ventilating fluid; the baby is placed in an absorbable transfer capsule and transcervically transferred to the uterine cavity; the capsule dissolves after a period of time to leave the gestational sac abutted to the endometrium so the baby can reattach. To maintain the baby's life support, the means includes fluidic ventilators and ventilation catheters to perfuse the gestational sac with ventilating fluid during such times as delivery, incubation, transfer, and reimplantation. Advantageously, the transfer capsule protects the baby during transfer and serves as a convenient vehicle for placing devices such as the ventilation catheter in the uterus along with the baby.

Abstract: A uniaxial eccentric screw pump includes: a casing; a stator having one end portion thereof connected to the casing and having an inner peripheral surface which is formed into a female threaded shaped; a rotor configured to be insertable into the stator and formed of a shaft body having a male threaded shape; and an end stud connected to the other end portion of the stator. The stator is configured to be expandable and shrinkable in a radial direction.

Abstract: Provided are a sliding member for pumps in which generation of a wear substance is quickly and accurately grasped even if the wear substance is generated when the sliding member slides while being in contact with another member, and a pump operation state detection system using the sliding member. The pump operation state detection system includes a uniaxial eccentric screw pump, a detection device capable of detecting metal powder in a fluid discharged from the uniaxial eccentric screw pump, and a determination device. In the uniaxial eccentric screw pump, a stator is arranged so as to be exposed to a fluid conveyance path through which the fluid flows. The stator is configured to slide while being in contact with a rotor along with operation of the uniaxial eccentric screw pump. The stator is made of a resin or a rubber and contains 10-30% of metal powder by weight ratio.

Abstract: A system for cryocooling an optical sensor on a satellite to a temperature below 200K with minimal vibration comprising a miniature conical rotary screw compressor comprising an inner element configured to only rotate around a first stationary axis and an outer element configured to only rotate around a second stationary axis so that both elements revolve with minimal vibration; with at least one of a) a length of at least one of the inner element and the outer element is between 10 mm and 100 mm; b) a diameter of at least one of the inner element and the outer element is between 2 mm and 45 mm; c) a compression ratio of the rotary screw compressor is between 1:2 and 1:20; and d) a shaft speed of the conical rotary screw compressor is between 1001 and 20000 revolutions per minute.

Abstract: A screw compressor includes compressor bodies, a motor disposed in a side of the compressor bodies, a gear box coupled to the compressor bodies and transmitting the drive force of the motor to a screw rotor, and a tubular coupling casing coupling the gear box and the motor and having horizontal axis. The coupling casing has a work hole in the horizontal direction. The work hole is used for maintaining a coupling accommodated in the coupling casing. The coupling casing has a rib extending in the up-down direction. It is thus possible to avoid reduction in the rigidity of the coupling casing with no cost increase, and to improve maintainability.