Screw pump ground driving device with three-end-face mechanical seal

Abstract

The invention discloses a screw pump ground driving device with a three-end-face mechanical seal. The device comprises a motor and a speed reducer connected with the motor, wherein an output main shaft of the speed reducer is a hollow shaft; a central pipe which is coaxial with the output main shaft is arranged in the output main shaft of the speed reducer; the lower end part of the central pipe is fixedly connected with the bottom of the speed reducer; the lower end of the central pipe is connected with a blowout prevent in a sealing way; the three-end-face mechanical seal is arranged in an annular space formed by the output main shaft of the speed reducer and the central pipe, and comprises a sealed shell which is fixed through a packing box and an inner cavity of the output main shaft of the speed reducer in the circumferential direction and a sealed shaft sleeve which is fixedly connected to the outer circle of the central pipe; three-stage mechanical seals are arranged in the annular space formed by the sealed shell and the sealed shaft sleeve sequentially from top to bottom; a mechanical seal upper cavity is formed between a first-stage mechanical seal and a second-stage mechanical seal; and a mechanical seal lower cavity is formed between the second-stage mechanical seal and a third-stage mechanical seal. The device has a good sealing effect and long service life and can be quickly replaced.

Description

technical field [0001] The invention relates to a mechanical oil recovery equipment in the field of oil recovery, in particular to a screw pump ground drive device with three-end mechanical seals. Background technique [0002] The ground driving device of the screw pump drives the sucker rod by decelerating the pulley and the gear reducer, and then converts the high speed and low torque of the motor into a low speed and high torque suitable for the operation of the screw pump, thereby driving the sucker rod to rotate. In order to achieve the purpose of driving the downhole screw pump. Based on this transmission structure, it is necessary to install a set of dynamic sealing device between the sucker rod (commonly called polished rod) connected to the driving device and the surface driving device of the screw pump to prevent leakage of well fluid. At present, the commonly used sealing methods are packing seal and mechanical seal. The packing seal structure is simple, but it ...

AI Technical Summary

Problems solved by technology

The packing seal structure is simple, but it needs to be replaced frequently, and it is prone to leakage of well fluid and pollutes the environment; the mechanical seal currently uses two types of mechanical seals: single-end mechanical seal and double-end mechanical seal, and the sealing pressure of single-end mechanical seal is mostly 2MPa Below, and the life is short, once the seal fails, there will be leakage of well fluid, which will seriously pollute the well site and the surrounding environment, while the double-end mechanical seal is an under-mounted type (the mechanical seal is called an under-mounted type at the lower part of the reducer), and the seal After failure, the entire driving device needs to be removed before replacement, which is very inconvenient

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