US 12,410,808 B2
Crude oil extraction pump
Kimihiko Mitsuda, Tokyo (JP); and Shuhei Sasaki, Tokyo (JP)
Assigned to MITSUBISHI HEAVY INDUSTRIES, LTD., Tokyo (JP)
Appl. No. 18/275,482
Filed by MITSUBISHI HEAVY INDUSTRIES, LTD., Tokyo (JP)
PCT Filed Feb. 18, 2021, PCT No. PCT/JP2021/006058
§ 371(c)(1), (2) Date Aug. 2, 2023,
PCT Pub. No. WO2022/176092, PCT Pub. Date Aug. 25, 2022.
Prior Publication US 2024/0309875 A1, Sep. 19, 2024
Int. Cl. F04D 29/06 (2006.01); F04D 13/08 (2006.01); F04D 29/049 (2006.01); F04D 29/44 (2006.01)
CPC F04D 29/061 (2013.01) [F04D 13/086 (2013.01); F04D 29/049 (2013.01); F04D 29/448 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A crude oil extraction pump comprising:
a production pipe having a tubular shape along an axis extending in a vertical direction;
a pump rotor extending in a direction of the axis inside the production pipe; and
a pump stator which is provided between the production pipe and the pump rotor to surround the pump rotor,
wherein the pump rotor includes a pump shaft extending in the direction of the axis, and a plurality of impeller provided on the pump shaft and rotated together with the pump shaft to pump crude oil upward, and
wherein the pump stator includes a stator body having a tubular shape extending along the axis, a plurality of vanes protruding radially inward from an inner peripheral surface of the stator body and are provided above each impeller of the plurality of impellers, a diffuser hub which is formed on the radial inside of the plurality of vanes, a bearing device which is installed on an inner peripheral side of the diffuser hub and rotatably supporting the pump shaft, and a hub extension portion which is formed at an upper end portion of the diffuser hub and having an outer peripheral surface having a constant outer diameter centered on the axis,
wherein the crude oil extraction pump further comprises a return flow path,
wherein the return flow path is formed to extract a part of a working fluid from a negative pressure surface side of a corresponding vane of the plurality of vanes, the corresponding vane provided adjacent to an upper impeller of the plurality of impellers, and to return the part of the working fluid to a bearing device provided adjacent to a lower impeller of the plurality of impellers, and
wherein one end of the return flow path is opened on the negative pressure surface of the corresponding vane.