Eccentric screw pump with split stator
An eccentric screw pump has a plurality of segments extending along an axis and together forming a tubular casing generally centered on the axis and a plurality of axially extending stator shells of elastic material together forming inside the casing a tubular stator having axially opposite ends each having centered on the axis a frustoconical end seal surface. The stator shells are separable from the casing segments. An intake housing has a connecting flange formed centered on the axis with a frustoconical flange surface fitted with one of the end seal surfaces of the stator, and an output fitting has a connecting flange formed centered on the axis with a frustoconical flange surface fitted with the other of the end seal surfaces of the stator. A rotor extends axially in the stator, the stator being clamped by the casing against the rotor.
1. An eccentric screw pump comprising:
a plurality of segments extending along an axis and together forming a tubular casing generally centered on the axis;
a plurality of axially extending stator shells of elastic material together forming inside the casing a tubular stator having axially opposite ends each having centered on the axis a frustoconical end seal surface, the stator shells being separable from the casing segments;
an intake housing having a connecting flange formed centered on the axis with a frustoconical flange surface fitted with one of the end seal surfaces of the stator;
an output fitting having a connecting flange formed centered on the axis with a frustoconical flange surface fitted with the other of the end seal surfaces of the stator; and
a rotor extending axially in the stator, the stator being clamped by the casing against the rotor.
2. The eccentric screw pump according to claim 1 , further comprising;
respective adaptors connecting the flanges to the end surfaces of.
3. The eccentric screw pump according to claim 1 wherein an apex angle of the seal surfaces is approximately 10° to 50°.
4. The eccentric screw pump according to claim 1 wherein the casing segments bear externally against the stator and have end attachment flanges for attachment to the connecting flanges.
5. The eccentric screw pump according to claim 4 , further comprising:
fasteners clamping the attachment flanges to the connecting flanges.
6. The eccentric screw pump according to claim 5 , wherein the fasteners are screw assemblies.
7. The eccentric screw pump according to claim 4 wherein the attachment flanges form an adjustable annular gap with the connecting flanges.
8. The eccentric screw pump according to claim 4 wherein the attachment flanges overlap or surround the connecting flange.
9. The eccentric screw pump according to claim 1 wherein one or more of the stator shells has at least one externally projecting rotation-blocking formation.
10. The eccentric screw pump according to claim 9 , wherein the rotation-blocking formations us longitudinal ridge attached onto outside of the stator shells.
11. The eccentric screw pump according to claim 10 , wherein the longitudinal ridge has end faces acting as axial stops.