Abstract: The device comprises a tubing (4) whose lower end is connected to a seat (5) on which bears a gear pump (6). The pump (6) comprises a pump case whose lower portion (10a) is engaged in a bore (5b) of the pump seat (5) and is connected to a cylindrical heavy body (20) which facilitates placing the pump (6) in position and maintaining the pump (6) on the seat (5). The weight of the heavy body (20) is determined as a function of the gear pump characteristics. The invention may be applicable to the pumping of petroleum fluids.

Abstract: The invention relates to improvements in or to Moineau pumps comprising a stator having an axial cavity, a helicoidal rotor adapted to rotate in said cavity of the stator by cooperating with it and coupling means to couple the rotor to another driving or driven rotary member. The helicoidal rotor projects axially out of the stator and the coupling means comprise a rigid and elongated coupling sleeve, hollowed by an axial housing of which the shape is complementary to that of the helix of the rotor, said sleeve being engaged on and gripping the end of the rotor projecting out of the stator.

Abstract: The invention relates to screw pump stators having a rigid tubular body lined on the inside with a resilient sleeve.The sleeve comprises a twisted liner (4) having inner bosses (5) and outer bosses (6) in the zones thereof corresponding to the highest sliding speeds of the rotor, the outside bosses projecting more than the inner bosses, and the inside surface of the rigid body (3) is hollowed out so as to sealingly receive the outer bosses of the liner.

Abstract: An elastic rotational coupling in which two rotational heads partially embedded in a body of elastic material each comprise a base connected to an end-plate by a neck to define therebetween a groove in which a bead of the elastic material is received. Each end plate has radial notches and an axially outer face which is slightly conical or domed and the groove is shaped to trap said bead therein.