Rotor and/or stator designs and methods thereof to improve progressive cavity motor or pump durability. In one or more implementations, the rotor may have a variable outer diameter or variable stiffness along an axial length thereof. The stator may similarly have a variable inner diameter or variable stiffness, which may compliment or diverge from the variable outer diameter or variable stiffness of the rotor.

A rotor and/or stator dampening system includes a stator and/or rotor with a liner selected of one or more materials to achieve a desired dampening effect. In one implementation, a progressive cavity motor or pump includes a stator with an internal axial bore therethrough. The stator has a liner along an axial length thereof with an inwardly facing surface defining the internal axial bore therethrough. The liner has a plurality of axial sections with at least two of the plurality of axial sections being constructed of different materials. A compression resistant mechanism, such as a spring or spring-like device, is disposed within at least one of the axial sections of the liner. The progressive cavity motor or pump also includes a rotor that is disposed and is rotatable within the internal axial bore of the stator to form a moving chamber between the rotor and the stator.

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.

The invention pertains to an eccentric screw pump with a stator-rotor system, which includes a rotor with a rotor screw and a stator with an internal thread. The stator has a support element and an elastomer part, wherein the support element encloses the elastomer part sectionally over its entire circumference. The stator-rotor system has a mechanism for adjusting the stator, which is coupled to at least one sensor for determining actual operating parameters of the stator-rotor system by means of a control unit that activates the adjusting mechanism with consideration of the actual operating parameters determined with the aid of at least one sensor.

The dynamic fatigue and hysteresis performances of fiber reinforced rubber compounds are compared using different plasticizers. Fiber reinforced rubber compounds including a non-linear functionalized fatty acid ester, preferably a trimellitate, and more preferably Tris (2-Ethylhexyl) Trimellitate (TOTM) are shown to demonstrate greatly improved dynamic fatigue and hysteretic performance as compared to reference fiber reinforced rubber compounds including conventional reference plasticizers such as Di-isodecyl phthalate (DIDP).

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.

An eccentric screw pump with a rotor (2) and with a rotationally fixed stator (6; 6′) surrounding the rotor (2). The rotationally fixed stator includes at least one elastomeric portion, wherein a pressure chamber (16) is arranged on this elastomeric portion of the stator (6; 6′) at a side facing away from the rotor (2). The pressure chamber (16) is connected to a pressure region of the eccentric screw pump such that the at least one elastomeric portion of the stator (6; 6′) is subjected to a pressure produced by the eccentric screw pump.

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.

The invention relates to a progressive cavity pump, comprising at least: a stator (1); a rotor (2), which rotates in the stator (1); a drive (3); a pump housing (4), which is connected to the stator (1) and has at least one inlet opening or outlet opening for the medium to be conveyed; a connecting shaft (9), which is driven by the drive and rotates centrally about an axis (R) in ideal operation of the pump; a coupling rod (10), which is arranged, for example, in the pump housing (4), is articulated at the drive-side end to the connecting shaft (9) and is articulated at the rotor-side end to the rotor (2), and produces an eccentric motion of the rotor end (7) when the connecting shaft (9) rotates centrally. Said pump is characterized in that at least one sensor (15, 16) is arranged in the region of the connecting shaft (9) in order to detect or measure a deviation from true running, which sensor determines a motion profile of the connecting shaft (9) at a specified angular position of the connecting shaft by virtue of the fact that the distance of the surface of the connecting shaft (9) from the sensor (15, 16) is measured.

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.