Gas Turbine Bearing Load Determination via Roller Displacement

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Solution Overview

Problem

In mechanical systems like gas turbine engines, determining the operating load on bearings is challenging due to uncertainties in axial thrust, leading to oversized bearings that are prone to skidding at low loads.

Innovation Solution

The use of sensors, such as microwave or eddy current probes, to measure displacement of roller elements and races within the bearing apparatus, coupled with a controller to determine and output the load, allowing for precise design modifications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the bearing is designed to be larger to compensate for uncertainty in axial thrust, then the bearing can handle higher loads, but the bearing becomes more susceptible to skidding at low loads and uses more material

Engineering Contradiction:
Improvebearing load capacityVSAvoidmaterial usage
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent replaces mechanical measurement methods with electromagnetic sensing (eddy current sensors) to detect roller element displacement. This substitution enables precise load measurement without mechanical contact, allowing the bearing to be optimized for actual operating conditions rather than worst-case scenarios, thus reducing material usage while maintaining reliability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements a feedback system where sensors continuously monitor roller element displacement and provide signals to a controller. The controller processes this information to determine actual load conditions, enabling real-time monitoring and optimization of bearing size based on actual operating loads rather than design assumptions, thereby reducing material usage while maintaining reliability

Inventive Principle:
Principle #23Feedback

2Reliability

If the bearing is designed to be larger to compensate for uncertainty in axial thrust, then the bearing can handle higher loads, but the bearing becomes more susceptible to skidding at low loads

Engineering Contradiction:
Improvebearing load capacityVSAvoidskidding
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces mechanical measurement methods with electromagnetic sensing (eddy current sensors) to detect roller element displacement. This substitution enables precise load measurement without mechanical contact, allowing the bearing to be optimized for actual operating conditions rather than worst-case scenarios, thus preventing skidding at low loads while maintaining high load capacity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The bearing system performs self-diagnosis through integrated sensors that monitor its own operating conditions. The sensors detect roller element displacement and provide feedback to determine actual load conditions, enabling the bearing to adapt to its own operating state and prevent skidding without external intervention, while maintaining reliability across varying load conditions

Inventive Principle:
Principle #25Self-service

3Measurement precision

If sensors are used to measure displacement of roller elements, then accurate load determination is achieved, but device complexity increases

Engineering Contradiction:
Improveload measurement accuracyVSAvoidsensor and controller system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary electromagnetic field-based sensing system that indirectly measures load through roller element displacement rather than directly measuring force. The eddy current sensors detect changes in electromagnetic properties caused by displacement, providing accurate load determination through a non-contact intermediary measurement approach that adds minimal complexity

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The sensor system serves multiple functions: it measures roller element displacement, determines actual load conditions, and provides feedback for potential control actions. This multi-functionality consolidates what could be separate systems into a single integrated solution, reducing overall device complexity while maintaining high measurement precision

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Enables accurate load determination, reducing bearing size and material usage, enhancing efficiency and preventing skidding, while maximizing service life and reducing fuel consumption.

Implementation Method 1

The first sensor may comprise a microwave probe

Methodology Applied
Scientific EffectMicrowave radiation: Microwave Radiation

Implementation Method 2

The first sensor may comprise a microwave probe or an eddy current probe

Methodology Applied
Scientific EffectEddy current: Eddy Currents

Data Source

PatentEP3015659B1Gas turbine and method of determining the load on a gas turbine bearing apparatus
Publication Date: 2020.04.01 ROLLS ROYCE PLC
  • EP3015659B1 patent drawingFigure 1
  • EP3015659B1 patent drawingFigure 2
  • EP3015659B1 patent drawingFigure 3

AI summary

Bearing apparatus comprising: an inner race; an outer race; a roller element positioned between the inner race and the outer race; a first sensor to sense displacement of one of: the inner race, the outer race, and the roller element, and to provide a first signal for the sensed displacement to enable a load on the bearing apparatus to be determined.