Hydraulic Bearing Load Sharing for Gas Turbine Thrust

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Solution Overview

Problem

Current bearing load sharing systems in gas turbine engines face challenges in effectively managing axial thrust forces, particularly during periods of high power output when thrust loads are maximized and can be unpredictable, leading to potential overloading of thrust bearings.

Innovation Solution

A bearing load sharing system where the outer races of thrust bearings on different rotors are flexibly joined via a hydraulic connection, allowing for adjustable axial spacing and load distribution between bearings, enabling the bearing with greater capacity to carry the load and reducing the load on less capable bearings based on physical and operational constraints.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If thrust bearings are positioned to support rotors against maximum thrust loads, then reliability is improved, but device complexity increases due to the need for adjustable and movable components

Engineering Contradiction:
Improvethrust bearing support capabilityVSAvoidbearing system structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs a hydraulic connection system linking the outer races of multiple thrust bearings. This hydraulic linkage enables automatic load distribution and sharing among bearings based on their individual capacities, eliminating the need for complex mechanical adjustment mechanisms while maintaining reliable support under varying thrust loads.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The outer races of the thrust bearings are designed to be movable relative to each other through the hydraulic connection, allowing the bearing assembly to dynamically adapt to changing thrust load conditions. This dynamic capability enables the system to automatically optimize load distribution without requiring complex control systems.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If fixed axial spacing between bearing outer races is used, then device complexity is reduced, but adaptability worsens under varying operational conditions

Engineering Contradiction:
Improveload distribution flexibilityVSAvoidadjustable spacing mechanism
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The hydraulic connection between outer races provides a simplified mechanism for achieving adaptable axial spacing. The hydraulic pressure automatically adjusts the spacing based on load conditions, providing flexibility without requiring complex mechanical adjustment devices or control systems.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The bearing system automatically adjusts its own configuration through the hydraulic connection between outer races. The system self-regulates the axial spacing and load distribution based on operating conditions without requiring external control or adjustment mechanisms.

Inventive Principle:
Principle #25Self-service

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

This system allows for tailored load distribution between rotors, ensuring that the bearing with the greatest capacity carries the most load, thereby reducing the risk of overloading and optimizing performance under varying operational conditions.

Implementation Method 1

the outer races of the first and second bearings are flexibly joined via a hydraulic connection such that the outer race of the first bearing and/or the outer race of the second bearing is movable to vary axial spacing between the outer races of the first and second bearings

Methodology Applied
Scientific EffectHydraulic connection: Hydraulic Press

Data Source

PatentEP3032070B2Bearing load sharing system
Publication Date: 2020.12.16 ROLLS ROYCE PLC
  • EP3032070B2 patent drawingFigure 1
  • EP3032070B2 patent drawingFigure 2
  • EP3032070B2 patent drawingFigure 3

AI summary

The present invention provides a bearing load sharing system comprising: first and second rotors extending in an axial direction; a first thrust bearing having an inner race and an outer race, the inner race connected to the first rotor; a second thrust bearing having an inner race and an outer race, the inner race connected to the second rotor; and an inter-rotor bearing having an inner race and an outer race, the inner race connected to one of the first and second rotor and the outer race connected to the other of the first and second rotor; wherein the outer race of the first bearing and/or the outer race of the second bearing is movable to vary the axial spacing between the outer races.