Eccentric screw pump

An eccentric screw pump with an annular outer part (10;

• 40;
• 74) and with an inner part (12, 42;
• 72) arranged therein, wherein the inside of the outer part (10;
• 40;
• 74) and the outside of the inner part (12;
• 42;
• 72) taper towards an axial side (16;
• 46;
• 70) in a complementary manner, and the inner part (12;
• 42;
• 72) and the outer part (10;
• 40;
• 74) are movably mounted relative to one another in the axial direction (X, W),
• wherein either
• the axial side to which the inside of the outer part (10;
• 74) and the outside of the inner part (12;
• 72) taper, is the pressure side of the eccentric screw pump, and the inner part (12) in its inside comprises a channel (28) which is open to the pressure side or to a cavity in the inside of the eccentric screw pump and is in connection with a surface (26) of the inner part (12), which is distant to the pressure side, by which means a pressure prevailing on the pressure side of the eccentric screw pump or in the inside of the eccentric screw pump between the inner part and the outer part (10, 40, 74), produces a force acting on the inner part (12;
• 42;
• 72) axially in the direction in which the inner part (12;
• 42;
• 72) tapers, or
• the axial side to which the inside of the outer part (40) and the outside of the inner part (42) taper, is the suction side (46) of the eccentric screw pump, and a pressure channel (82) is provided, which connects the pressure side or a cavity between the inner part (42) and the outer part (40) of the eccentric screw pump, to a surface (84) of the outer part, which is distant to the pressure side, by which means a pressure prevailing on the pressure side of the eccentric screw pump or in the inside of the eccentric screw pump between the inner part and outer part (10, 40, 74), produces a force acting on the outer part (10;
• 40;
• 74) axially opposite to the direction in which the inner part (12;
• 42;
• 72) tapers.