A progressive cavity pump for transporting liquids containing solids comprising - a helical rotor, - a stator having an inlet and an outlet, in which the rotor is rotatably disposed about a longitudinal axis (L 1) of the stator, and comprising a helical inner wall corresponding to the rotor, wherein the rotor comprises a shape tapering down toward the outlet or the inlet, preferably conical, and/or a variable eccentricity (e 1, e 2), and wherein the rotor and the stator are disposed relative to each other and arranged such that at least one chamber is formed for transporting the liquid, and the chamber is cut off by a constriction, particularly a sealing line, and comprising an adjusting device for adjusting a relative axial position of the rotor and the stator, wherein the adjusting device is adapted to expand the constriction between the rotor and stator, wherein the rotor is axially displaceably supported and the adjusting device is adapted to axially displace the rotor to at least partially expand the constriction between the rotor and the stator, characterised in that: a) a drivetrain, comprising a drive motor and a drive shaft of the rotor, is displaceable together with the rotor, or b) the rotor together with the drive shaft or a second part, coupled to the rotor, of a two-part drive shaft is displaceable relative to a drive motor. - a helical rotor, - a stator having an inlet and an outlet, in which the rotor is rotatably disposed about a longitudinal axis (L 1) of the stator, and comprising a helical inner wall corresponding to the rotor, wherein the rotor comprises a shape tapering down toward the outlet or the inlet, preferably conical, and/or a variable eccentricity (e 1, e 2), and wherein the rotor and the stator are disposed relative to each other and arranged such that at least one chamber is formed for transporting the liquid, and the chamber is cut off by a constriction, particularly a sealing line, and comprising an adjusting device for adjusting a relative axial position of the rotor and the stator, wherein the adjusting device is adapted to expand the constriction between the rotor and stator, wherein the rotor is axially displaceably supported and the adjusting device is adapted to axially displace the rotor to at least partially expand the constriction between the rotor and the stator, characterised in that: a) a drivetrain, comprising a drive motor and a drive shaft of the rotor, is displaceable together with the rotor, or b) the rotor together with the drive shaft or a second part, coupled to the rotor, of a two-part drive shaft is displaceable relative to a drive motor. wherein the rotor comprises a shape tapering down toward the outlet or the inlet, preferably conical, and/or a variable eccentricity (e 1, e 2), and wherein the rotor and the stator are disposed relative to each other and arranged such that at least one chamber is formed for transporting the liquid, and the chamber is cut off by a constriction, particularly a sealing line, and comprising an adjusting device for adjusting a relative axial position of the rotor and the stator, wherein the adjusting device is adapted to expand the constriction between the rotor and stator, wherein the rotor is axially displaceably supported and the adjusting device is adapted to axially displace the rotor to at least partially expand the constriction between the rotor and the stator, characterised in that: a) a drivetrain, comprising a drive motor and a drive shaft of the rotor, is displaceable together with the rotor, or b) the rotor together with the drive shaft or a second part, coupled to the rotor, of a two-part drive shaft is displaceable relative to a drive motor. a) a drivetrain, comprising a drive motor and a drive shaft of the rotor, is displaceable together with the rotor, or b) the rotor together with the drive shaft or a second part, coupled to the rotor, of a two-part drive shaft is displaceable relative to a drive motor.