ESP Rotor Assembly With Axial Preload for Thermal Expansion

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Solution Overview

Problem

Existing electric submersible pump (ESP) assemblies face challenges with differential thermal expansion of rotor components, leading to potential misalignment and increased manufacturing costs due to varying coefficients of thermal expansion (CTE) among materials.

Innovation Solution

Implementing thermally compliant axial retention systems with spring elements and reconfigured rotor assembly designs that minimize thermal growth effects by using similar materials for axial force transmission and incorporating pre-loading mechanisms to compensate for thermal expansion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If rotor components are made from different materials to optimize performance, then functional properties are improved, but differential thermal expansion causes misalignment and reliability issues

Engineering Contradiction:

Improvematerial selection flexibilityVSAvoid rotor assembly alignment

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies thermal expansion principles by designing the rotor assembly to accommodate differential thermal expansion between materials with varying CTE. The support sleeve and axial retention system are configured to allow controlled movement and expansion of rotor components during temperature changes, preventing misalignment and maintaining reliability despite using materials with different thermal properties.

Inventive Principle:

Principle #37Thermal expansion

2Reliability

If rotor components are made from similar materials to minimize thermal expansion differences, then alignment stability is improved, but material selection is restricted and cost increases

Engineering Contradiction:

Improve rotor assembly alignmentVSAvoidmaterial selection flexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent resolves this contradiction by explicitly designing for thermal expansion accommodation. The support sleeve with axial retention features and spring elements creates a system that tolerates CTE variations, enabling the use of dissimilar materials (such as metallic lamination stacks with non-metallic cage rings) without compromising alignment stability.

Inventive Principle:

Principle #37Thermal expansion

3Manufacturing precision

If precise machining and tight tolerances are used to maintain alignment, then manufacturing precision is improved, but manufacturing cost increases

Engineering Contradiction:

Improvecomponent alignment precisionVSAvoidmanufacturing cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent reduces manufacturing precision requirements by designing the support sleeve and axial retention system to accommodate thermal expansion. This compliance approach allows for broader tolerance ranges and simpler manufacturing processes compared to rigid precision-machined assemblies, thereby reducing manufacturing costs while maintaining operational alignment.

Inventive Principle:

Principle #37Thermal expansion

4Manufacturing precision

If rigid axial retention systems are used to maintain precise positioning, then positioning accuracy is improved, but thermal expansion compensation is reduced

Engineering Contradiction:

Improveaxial positioning accuracyVSAvoidthermal expansion tolerance

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent employs a compliant axial retention system using spring elements and a support sleeve that can axially move along the drive shaft. This design maintains precise radial positioning of rotor components while allowing axial movement to accommodate thermal expansion, achieving both positioning accuracy and thermal tolerance simultaneously.

Inventive Principle:

Principle #37Thermal expansion

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

Reduces material and machining costs while enabling the use of materials with varying CTE, ensuring rotor assembly stability and durability across temperature variations, thus improving ESP performance and manufacturability.

Implementation Method 1

configured to compensate for differential thermal expansion of the rotor modules with respect to the drive shaft

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS12500497B2ESP rotor assemblies configured for thermal expansion compensation

Publication Date: 2025.12.16 HALLIBURTON ENERGY SERVICES INC

AI summary

Disclosed rotor assemblies can be configured to address differential thermal expansion in the rotor assembly during ESP motor use. Some rotor assembly embodiments can employ an improved stacking technique to minimize differential thermal expansion issues by removing certain components from the axial stack of supporting components of the rotor assembly. Alternatively, or in conjunction, some rotor assembly embodiments can use a biasing element which is configured to compensate for the differential axial thermal expansion, tolerance stack-up, and/or gravity.