Patent ID: 7473082

Claim:
A pumping system comprising: a progressive cavity pump or Moineau pump comprising a helical rotor having a shaft and being housed inside a helical cavity of an outer stator, motor means for driving the rotor, said motor means driving a motor shaft which extends substantially coaxial to an axis of the stator cavity, an intermediate shaft which is coupled rotation-wise both to the motor shaft and to the shaft of the rotor, a first articulated coupling having one end connected to the motor shaft and another end connected to the intermediate shaft, a second articulated coupling having one end connected to the intermediate shaft and another end connected to the shaft of the rotor, and connecting means for connecting two devices made up of two of said connected parts, wherein said two connected devices are constructed in the form of a male device including an axial stub and a female device including an axial housing designed to receive said stub without appreciable play, wherein a lateral wall defining said axial housing of the female device is provided with at least two radial tapped drill holes, angularly offset and not mutually aligned and respectively accommodating two screws, at least one of which is a cone-point set screw, and wherein said axial stub of the male device includes at least two radial recesses respectively located in line with said radial drill holes and at least one of which is conical or tapered in line with said cone-point set screw to receive the end of same, and wherein only one screw is a cone-point set screw and wherein the other screw or screws are dog-point set screws, in line with which the respective recesses of the stub are axisymmetrical.