Waveguide Thrust Bearing Sensing for Rotor Cross-Over Control

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Solution Overview

Problem

Conventional gas turbine engines face challenges with thrust cross-over conditions, leading to unloaded ball bearings, reduced radial centering, and adverse impacts on rotor dynamics due to unidirectional thrust designs, which result in oversized and overweight bearings.

Innovation Solution

A rotor thrust balancing system that includes waveguide sensors to measure vibrational frequencies and communicate them to a control system, allowing for adjustment of thrust cavity pressure to maintain proper thrust alignment, preventing cross-over conditions and ensuring stable rotor dynamics with smaller, lighter bearings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If unidirectional thrust design is used to prevent cross-over conditions, then thrust bearing reliability is improved, but bearing size and weight increase

Engineering Contradiction:
Improvethrust bearing reliabilityVSAvoidbearing weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent applies dynamic thrust management by using waveguide sensors to monitor vibrational frequencies in real-time and actively adjusting thrust cavity pressure to maintain optimal thrust loading. This dynamic approach replaces the static unidirectional thrust design, allowing the bearing to operate efficiently in both forward and reverse directions without requiring oversized capacity, thereby reducing bearing weight while maintaining reliability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback control through waveguide sensors that continuously monitor bearing vibrational frequencies and provide data to the engine control system. This feedback loop enables real-time detection of cross-over conditions and automatic adjustment of thrust cavity pressure, preventing unloaded bearing operation and eliminating the need for oversized unidirectional bearings, thus reducing weight while maintaining reliability.

Inventive Principle:
Principle #23Feedback

2Reliability

If unidirectional thrust design is used to prevent cross-over conditions, then thrust bearing reliability is improved, but device size increases

Engineering Contradiction:
Improvethrust bearing reliabilityVSAvoidbearing size
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The patent applies dynamic thrust management by using waveguide sensors to monitor vibrational frequencies in real-time and actively adjusting thrust cavity pressure to maintain optimal thrust loading. This dynamic approach replaces the static unidirectional thrust design, allowing the bearing to operate efficiently in both forward and reverse directions without requiring oversized capacity, thereby reducing bearing size while maintaining reliability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback control through waveguide sensors that continuously monitor bearing vibrational frequencies and provide data to the engine control system. This feedback loop enables real-time detection of cross-over conditions and automatic adjustment of thrust cavity pressure, preventing unloaded bearing operation and eliminating the need for oversized unidirectional bearings, thus reducing size while maintaining reliability.

Inventive Principle:
Principle #23Feedback

3Weight of moving object

If thrust cross-over conditions occur, then bearing weight is reduced, but radial centering deteriorates

Engineering Contradiction:
Improvebearing weightVSAvoidradial centering
Core Design Contradiction:
Weight of moving objectVSStability of the object's composition

Solution Approach 1:

The patent implements feedback control through waveguide sensors that continuously monitor bearing vibrational frequencies and provide data to the engine control system. This feedback loop enables real-time detection of cross-over conditions and automatic adjustment of thrust cavity pressure, preventing unloaded bearing operation that would compromise radial centering, thus maintaining stability while allowing for lighter bearing design.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent applies preliminary anti-action by proactively preventing cross-over conditions through real-time monitoring and preemptive adjustment of thrust cavity pressure. By detecting early signs of thrust reversal through vibrational frequency analysis, the system takes corrective action before radial centering can deteriorate, maintaining stability while enabling optimized bearing weight.

Inventive Principle:
Principle #9Preliminary anti-action

4Length of moving object

If thrust cross-over conditions occur, then bearing size is reduced, but rotor dynamics are adversely impacted

Engineering Contradiction:
Improvebearing sizeVSAvoidrotor dynamics
Core Design Contradiction:
Length of moving objectVSStability of the object's composition

Solution Approach 1:

The patent implements feedback control through waveguide sensors that continuously monitor bearing vibrational frequencies and provide data to the engine control system. This feedback loop enables real-time detection of cross-over conditions and automatic adjustment of thrust cavity pressure, preventing unloaded bearing operation that would adversely impact rotor dynamics, thus maintaining stability while enabling smaller bearing design.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent applies preliminary anti-action by proactively preventing cross-over conditions through real-time monitoring and preemptive adjustment of thrust cavity pressure. By detecting early signs of thrust reversal through vibrational frequency analysis, the system takes corrective action before rotor dynamics can be adversely impacted, maintaining stability while allowing for reduced bearing size.

Inventive Principle:
Principle #9Preliminary anti-action

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

The system effectively prevents cross-over conditions, maintaining proper radial centering and bearing stiffness, enabling smaller, lighter thrust bearings while avoiding skidding damage and ensuring efficient rotor dynamics across a range of operating conditions.

Implementation Method 1

The waveguide sensor communicates a vibrational frequency from the thrust bearing to a second end of the waveguide sensor

Methodology Applied
Scientific EffectVibration: Vibration

Data Source

PatentEP3536901B1Bearing rotor thrust control
Publication Date: 2023.04.26 GENERAL ELECTRIC CO
  • EP3536901B1 patent drawingFigure 1
  • EP3536901B1 patent drawingFigure 2
  • EP3536901B1 patent drawingFigure 3

AI summary

A rotor thrust balancing system (200) for a turbomachine, wherein the turbomachine defines a centerline (12) extending the length of the turbomachine. The system (200) includes a rotating drive shaft (31), a thrust bearing (118), and a first waveguide sensor (201). The rotating drive shaft (31) couples a turbine section (29) and a compressor section (23) of the turbomachine. The thrust bearing (118) supports the drive shaft (31) of the turbomachine. The thrust bearing (118) includes a plurality of ball bearings (132), an inner race (128) coupled to the rotating drive shaft (31), and an outer race (130) coupled to a fixed structure. The first waveguide sensor (201) is coupled to the outer race (130) at a first end (204) of the waveguide sensor (201). The waveguide sensor (202) communicates a vibrational frequency from the thrust bearing (118) to a second end (206) of the waveguide sensor (201)