Patent ID: 11867176
Assignee: LEX SUBMERSIBLE PUMPS FZE COMPANY
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F  E | IPC E  F

Claim 9:
10. An apparatus for a submersible screw pump, the apparatus comprising:
a cylindrical pump housing;
a plurality of modular pump stages including a first modular pump stage, the plurality of modular pump stages being positioned between a first end and a second end of the pump housing, the first modular pump stage including:
a cylindrical stator with counter directional screw threads, wherein the cylindrical stator is rotationally fixed inside of the cylindrical pump housing;
a plurality of semicircular channels without rectangular edges formed in the stator;
a cylindrical rotor disposed inside of the stator, wherein the rotor has a screw thread with an opposite direction in relation to the screw threads of the stator, wherein the rotor includes an external surface having a shape and the stator includes an internal surface having the semicircular channels without the rectangular edges to obtain high speed performance of the apparatus with reduced vortices, wherein a gap between the internal surface of the stator and the external surface of the rotor is within a range of 0.1-0.2 millimeters;
a rotor blade formed on the external surface of the rotor, wherein the rotor blade has a curvilinear cross-sectional shape having a first convex shape and a second concave shape, the first convex shaped joined to a second concave shape, wherein the first convex shape is one half the length of the second concave shape;
a rotor shaft causes the rotor to spin;
a discharge end of the rotor is configured with a hole to discharge production fluid from the apparatus;
an intake end on the pump housing is configured with a hole to allow intake of production fluid to the rotor, wherein the production fluid received at the spinning rotor is compressed starting from an initial intake fluid pressure and rising to a higher discharge fluid pressure, wherein the compression of the production fluid creates an axial force on the rotor shaft that is opposite to the direction of fluid flow of the production fluid from the intake end of the rotor to the discharge end of the rotor;
an intake thrust bearing attached to the rotor shaft on the intake end of the first modular pump stage;
a discharge thrust bearing attached to the rotor shaft on the discharge end of the first modular pump stage;
an unloading thrust bearing attached to the rotor shaft positioned between intake thrust bearing and the intake end of the rotor;
a cavity formed in the unloading thrust bearing configured to receive production fluid from the discharge end of the rotor; and
rotor fluid channels located inside of the rotor positioned substantially half way between the rotor shaft and an outside edge of the rotor, wherein the rotor fluid channels are arranged between the discharge end of the rotor and the cavity of the unloading thrust bearing, wherein a counter action against an axial force on the rotor shaft is provided by the production fluid disposed in the rotor fluid channels from the discharge end of the rotor into the cavity in the unloading thrust bearing, wherein the production fluid in the cavity presses against the unloading thrust bearing thereby counteracting and reducing the axial force on the rotor shaft.