ESP Drive Shaft Coupling With One-Way Clutch for Thrust Bearing Protection

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Solution Overview

Problem

Electrical submersible pumps (ESP) face damage due to reverse rotation of the thrust bearing, which can occur during shutdowns or accidental motor shaft reversals, leading to potential damage and operational issues.

Innovation Solution

Incorporating a one-way clutch mechanism in the couplings between the motor and pump shafts to prevent reverse rotation of the thrust bearing, allowing torque transfer only in the forward direction and enabling ratcheting to prevent reverse spinning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional rigid coupling is used between motor shaft and pump shaft, then torque transfer is reliable and direct, but reverse rotation can occur damaging the thrust bearing

Engineering Contradiction:

Improvethrust bearing protectionVSAvoidcoupling structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

A one-way clutch mechanism is introduced as an intermediary element between the motor shaft and pump shaft. This clutch allows torque transmission in the forward direction while preventing reverse rotation, thereby protecting the thrust bearing without requiring a completely complex coupling structure

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The coupling structure transitions from a static rigid connection to a dynamic system with a one-way clutch that can selectively engage or disengage based on rotation direction. The clutch mechanism dynamically adapts to prevent reverse rotation while maintaining forward torque transfer

Inventive Principle:

Principle #15Dynamics

2Loss of energy

If the motor is shut down during operation, then energy consumption is reduced, but reverse flow can cause reverse rotation of the thrust bearing

Engineering Contradiction:

Improvemotor energy consumptionVSAvoidthrust bearing integrity

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The one-way clutch mechanism is pre-configured to automatically prevent reverse rotation before damage can occur to the thrust bearing. When reverse flow attempts to rotate the pump shaft backward, the clutch engages to block the reverse motion, protecting the bearing during motor shutdown periods

Inventive Principle:

Principle #9Preliminary anti-action

3Productivity

If power conductors are accidentally reversed during installation, then installation speed is maintained, but the motor rotates in reverse damaging the thrust bearing

Engineering Contradiction:

Improveinstallation speedVSAvoidmotor rotation direction control

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The one-way clutch acts as a protective measure installed beforehand that cushions against the harmful effect of reverse rotation. Even if power conductors are accidentally reversed, the clutch prevents the reverse rotation from damaging the thrust bearing, allowing installation to proceed without extensive reverse-polarity checking

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Prevents damage to the thrust bearing by ensuring it does not rotate in reverse, maintaining operational integrity during normal and reverse flow conditions, and preventing electrical issues from reverse motor rotation.

Implementation Method 1

At least one of the couplings has a one-way clutch that allows forward direction rotation of the thrust bearing shaft and prevents reverse direction rotation

Methodology Applied

Scientific EffectOne-way clutch mechanism: Ratchet

Data Source

PatentUS11225972B2One-way clutch drive shaft coupling in submersible well pump assembly

Publication Date: 2022.01.18 BAKER HUGHES OILFIELD OPERATIONS LLC

AI summary

An electrical submersible pump assembly for pumping well fluid from a well has a motor and a pump. The motor having a motor shaft that drives a pump shaft of the pump. A thrust bearing unit between the motor and the pump has a thrust bearing shaft that rotates a thrust runner in sliding engagement with a non-rotating thrust bearing base. A pump shaft coupling couples the thrust bearing shaft with the pump shaft. A motor shaft coupling couples the thrust bearing shaft with the motor shaft. At least one of the couplings has a one-way clutch that allows forward direction rotation of the thrust bearing shaft and prevents reverse direction rotation.