Planetary Gear Carrier Flexible Mounting for Turbine Vibration Damping

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Solution Overview

Problem

Existing planetary gear reducers in turbomachines, particularly in dual-flow turbomachines with high bypass ratios, face challenges due to the inflexibility of the planet carrier connection to the stator element, which leads to dynamic instability and vibration issues.

Innovation Solution

A flexible connection is established between the planet carrier and the stator element using an elastically deformable annular member with projecting teeth and vibration damping systems, allowing for axial, radial, and torsional flexibility, and incorporating damping pads or oil films to absorb vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a rigid connection is used between the planet carrier and stator element, then structural strength is improved, but dynamic stability deteriorates due to vibration and instability

Engineering Contradiction:
Improvestructural strengthVSAvoiddynamic stability
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The patent applies the dynamics principle by replacing the rigid static connection with a dynamic flexible connection that can adapt to operating conditions. The elastically deformable annular member allows the planet carrier to move relative to the stator element, providing dynamic stability while maintaining structural integrity through controlled flexibility rather than rigid fixation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs a flexible shell (elastically deformable annular member) to connect the planet carrier to the stator element. This flexible connection absorbs vibrations and dynamic instabilities while maintaining the necessary structural strength, resolving the contradiction between rigidity and dynamic stability.

Inventive Principle:
Principle #30Flexible shells and thin films

2Stability of the object's composition

If a flexible connection is used between the planet carrier and stator element, then dynamic stability is improved, but load-bearing capacity deteriorates

Engineering Contradiction:
Improvedynamic stabilityVSAvoidload-bearing capacity
Core Design Contradiction:
Stability of the object's compositionVSForce

Solution Approach 1:

The patent uses composite materials principle by combining the elastically deformable annular member with vibration damping systems (damping pads or damping oil film). This composite structure provides both flexibility for dynamic stability and sufficient load-bearing capacity through the combined properties of the elastic member and damping elements.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The elastically deformable annular member acts as an intermediary between the planet carrier and stator element, transferring loads while absorbing vibrations. The damping pads or oil film serve as additional intermediaries that specifically address vibration transmission, allowing the flexible connection to maintain load-bearing capacity while improving dynamic stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If vibration damping systems are added to the flexible connection, then vibration absorption is improved, but device complexity increases

Engineering Contradiction:
Improvevibration absorptionVSAvoiddevice complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies the pneumatics and hydraulics principle by using damping oil film as a vibration damping system. The oil film provides vibration absorption through fluid damping mechanisms without requiring complex mechanical structures, thus improving vibration absorption while minimizing increases in device complexity compared to solid damping elements.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent uses parameter changes principle by selecting appropriate material properties and geometric parameters for the elastically deformable annular member and damping systems. By optimizing these parameters, the vibration damping performance is improved while keeping the structural complexity manageable through careful parameter selection rather than adding numerous components.

Inventive Principle:
Principle #35Parameter changes

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 solution provides a durable and efficient means to absorb vibrations, prevent transmission of excessive forces, and maintain structural integrity by ensuring the planet carrier and stator element are isolated from harmful torsional forces.

Implementation Method 1

an elastically deformable annular member extending around said axis X, the annular member being fixed to said planet carrier and to the stator element in order to ensure a flexible connection between the planet carrier and the stator element

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

vibration damping systems, of the vibration damping pad and/or damping oil film type, being interposed between said first faces and said stator element

Methodology Applied
Scientific EffectVibration damping: Damping

Implementation Method 3

vibration damping systems, of the vibration damping pad and/or damping oil film type, being interposed between said first faces and said stator element

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Data Source

PatentEP3699458B1Assembly with planetary gear for a turbine engine
Publication Date: 2025.09.03 SAFRAN TRANSMISSION SYST
  • EP3699458B1 patent drawingFigure 1
  • EP3699458B1 patent drawingFigure 2
  • EP3699458B1 patent drawingFigure 3

AI summary

An assembly comprising a planetary gear reducer carrier (130) and an elastically deformable annular member (160), for a turbomachine, particularly an aircraft turbomachine, - the planetary gear carrier (130) having a generally annular shape about an axis X, and - the annular member (160) extending about the axis X, this member being fixed to said planetary gear carrier and configured to be fixed to a stator element (162) of the turbomachine in order to ensure a flexible connection between the planetary gear carrier and said stator element, characterized in that the planetary gear carrier has a series of projecting teeth (180) extending substantially radially outwards with respect to said axis X, each of these teeth having opposing first lateral faces (180a, 180b) extending in planes passing through the axis X and adapted to cooperate by butting in a circumferential direction with said stator element,vibration damping systems being interposed between said first faces and said stator element.