An eccentric screw pump with a rotor, which forms a conveyor screw, and a stator, which forms a screw thread and in which the rotor circulates during a conveying operation. The stator includes a single-part or multipart stator housing, in which a stator lining made of an elastomer material is located, said lining forming the screw thread. The stator lining forms a projection at least on one side in the direction along the pump longitudinal axis, said projection protruding from the stator housing such that a free force introduction surface is formed. A force can be applied via the free force introduction surface, said force compressing the stator lining into the stator housing so that the stator lining is transversely elongated in the stator housing, leading to a constriction of the screw thread. The projection can be surrounded by a mobile support tube which is moved relative to the stator housing in the direction along the longitudinal axis of the stator housing for compression purposes.

Embodiments of the invention provide a system and method for induction heating a helical rotor of a progressing cavity pump in order to reduce the surface roughness of the rotor. In order to heat the rotor most evenly, it is desired to space the coil as closely around the rotor as possible. The invention provides a mechanism for threading the helical rotor through an induction coil having an interior diameter which is less than the major diameter of the rotor. The induction coil may include one loop and overlapping ends. The rotor to be heated is rotated about its longitudinal axis and advanced axially through the coil as it rotates. The axial speed and rotational speed are synchronized so that the rotor moves one pitch through the coil for each complete rotation.

The present invention corresponds to a check valve with an inertial mass that is installed in the bottom of the production tubing and above the progressive cavity pump (PCP) of an oil well, which prevents that the hydrostatic column that is inside of the production tubing go down in the moment where the artificial lift of the column stops for the detention of the PCP pump. If we prevent that this phenomenon to happen, the PCP pump will not rotate in the opposite direction of its normal operation and it will not be clogged by any particulate material that is contained in it.

A helical rotor intended to be arranged in a progressing cavity pump, said progressing cavity pump being capable of pumping a multiphase fluid from a fluid reserve, the helical rotor comprising at least one mixer capable of homogenizing the multiphase fluid located in said fluid reserve.

The present invention relates to a volume pulsed deformation plasticating and conveying method and device by an eccentric rotor. The rotation of the eccentric rotor and the rolling of the rotor in the inner cavity of a stator during constant reverse revolutions cause the volume of the material between the eccentric rotor and the stator to periodically change alternatively along the axial direction and the radial direction of the stator, thereby enabling the volume pulsed deformation plasticating and conveying of the material. The volume pulsed deformation plasticating and conveying device consists of a stator, of which the inner cavity comprises multiple alternatingly disposed spiral segments and straight segments, and an eccentric rotor comprising multiple alternatingly disposed eccentric spiral segments and eccentric straight segments. The eccentric rotor is disposed in the inner cavity of the stator. The eccentric spiral segments and the eccentric straight segments of the eccentric rotor correspond one-to-one with the spiral segments and straight segments of the stator. The present invention can be used as the extruding system of an extruder or be combined with different plunger injection units to form a plasticating injection device of an injection molding machine. The present invention has a short thermo-mechanical distance for the materials, low energy consumption, and wide adaptability.

A universal joint (U-joint) assembly transmits torque from a drive component to a driven component across an articulating joint. The U-joint assembly includes male and female U-joint members, a central ball joint, and a retaining device configured to secure the assembly in an assembled configuration. The female U-joint member includes a cavity extending into a receptacle end thereof. The cavity terminates in a circular receptacle and includes a plurality of rectangular channels extending radially outward from the cavity at equal intervals, each channel defined by three planar drive surfaces. The male U-joint member has a drive end with a plurality of corresponding rectangular extensions protruding from an outer periphery of the drive end, each extension including a plurality of axial angular surfaces. When assembled, each of the angular surfaces of the drive end opposes a corresponding one of the drive surfaces of the cavity. Other embodiments are also disclosed.

A uniaxial eccentric screw pump includes: a stator having a through hole 8a whose inner surface is formed in a female screw shape; a rotor that is a male screw shaft body inserted into the through hole of the stator; a plurality of shims that are arranged on a radially outside of the stator in a range from one end to the other end of the stator, are in surface contact with an outer surface of the stator, are capable of compressing the stator by moving radially inward with respect to the stator, and have, on an outer surface, an inclined surface gradually inclined radially inward or outward toward one end; and an adjustment member that is movable in an axial direction with respect to the stator and has a pressing part that can press the inclined surface of each of the shims.

A stator for a progressive cavity pump or motor includes a stator housing having a longitudinal axis. In addition, the stator includes a stator insert of a material moulded within the housing. The stator housing includes an outer tube having an inner surface. The stator housing also includes a plurality of framework elements disposed on the inner surface of the outer tube. Further, the stator housing includes at least one recess in the inner surface of the outer tube. The conjunction of the framework elements and the at least one recess define a plurality of chambers receiving insert material therein whereby the insert material is mechanically fixed axially, radially and torsionally within the outer tube.

A valve (11) for controlling the flow of a drilling fluid through a down-hole tool (10) positionable in a wellbore penetrating a subterranean formation. The down-hole tool has a housing with a drilling motor therein and a drill bit (1) at an end thereof. The drilling motor (9) has a housing with a rotor (206) rotationally movable in a rotor channel (204) as the drilling fluid passes through a rotor channel between the housing and the rotor. The rotor has a bypass channel therethrough for bypassing a portion of the drilling fluid therethrough. The valve includes a valve plate positionable upstream of the motor. The valve plate (200) has at least one flow passage (226) and at least one bypass passage (220) therethrough. The flow passage is in fluid communication with the rotor channel for passing the drilling fluid therethrough. The bypass passage is in selective fluid communication with the bypass channel when the rotor rotates about the housing and moves the bypass channel into alignment with at least a portion of the bypass passage for bypassing a portion of the drilling fluid therethrough whereby a hammering effect is generated on the bit.

A liquid polymer dosing and mixing chamber and pump having a pump housing, a mixing reactor, a spacing cup, an actuator, a drive shaft, a drive shaft coupling unit, and a progressive cavity pump adapted to create doses of a first substance and to mix it with one or more substances introduced into the mixing reactor via one or more inlets.