Turbine Vane Actuation via Passive Axial Guidance

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Solution Overview

Problem

Conventional variable pitch vane assemblies in turbine engines face axial deflection issues due to the rigidity of driving rods, which can lead to uneven angular pitch of vanes, and adding a second driving means increases mass, dimensions, and maintenance complexity.

Innovation Solution

A single driving means is used with a slidingly connected passive element, featuring a sliding pivoting link on the actuating ring and a ball-joint link on the casing, to restrict axial deflection and maintain identical vane pitch without the need for additional driving mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If a single driving means is used to rotate the actuating ring, then the mass and dimensions of the assembly are reduced, but axial deflection of the ring occurs causing uneven vane pitch

Engineering Contradiction:

Improvemass of assemblyVSAvoidvane pitch uniformity

Core Design Contradiction:

Weight of moving objectVSManufacturing precision

Solution Approach 1:

A passive guiding element is introduced as an intermediary component between the actuating ring and the casing. This element provides axial guidance to the ring during rotation, preventing deflection without requiring a second active driving means. The mediator absorbs the guidance function while allowing the single driving means to maintain low mass and dimensions.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the functional parameters of the actuating ring by adding a constraint that allows rotational movement while restricting axial deflection. The passive guiding element modifies the degree of freedom of the ring, permitting rotation around the longitudinal axis while constraining radial and axial deviations, thus maintaining pitch uniformity.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If a second driving means is added to prevent axial deflection, then vane pitch uniformity is improved, but mass and dimensions of the assembly increase

Engineering Contradiction:

Improvevane pitch uniformityVSAvoidmass of assembly

Core Design Contradiction:

Manufacturing precisionVSWeight of moving object

Solution Approach 1:

Instead of adding a second active driving means, a passive guiding element serves as an intermediary that provides the necessary constraint. This element transfers the axial guidance function from what would be a second active component to a passive structure, eliminating the need for additional motors or actuators while maintaining pitch uniformity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The guidance function is extracted from the driving means and assigned to a separate passive guiding element. This separation allows the driving means to remain simple and lightweight while the guidance function is performed by a structural element that does not require active control or additional mass.

Inventive Principle:

Principle #2Taking out (Extraction)

3Manufacturing precision

If a second driving means is added to prevent axial deflection, then vane pitch uniformity is improved, but device complexity and maintenance requirements increase

Engineering Contradiction:

Improvevane pitch uniformityVSAvoidcomplexity of driving means

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

A passive guiding element is introduced as a simple mechanical intermediary that provides axial constraint without requiring complex control systems. This element reduces device complexity by replacing what would be a second active driving means with a passive structural component that has no moving parts requiring maintenance.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The passive guiding element performs its guidance function automatically through its geometric configuration and mechanical constraints, without requiring external control or active intervention. The element self-regulates the axial position of the actuating ring during rotation, eliminating the need for complex control systems.

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 solution reduces the overall mass and dimensions of the assembly, prevents axial deflection, and simplifies maintenance by using a passive element that controls axial displacement without risk of breakage, ensuring consistent vane pitch and reducing fuel consumption.

Implementation Method 1

a slidingly connected passive element, one end of which is connected by a sliding pivoting link on the actuating ring and a second end is connected by a ball-joint link on the casing

Methodology Applied

Scientific EffectMechanical constraint:

Implementation Method 2

the passive cylinder allows to restrict the axial deflection of the actuating ring when the latter is moved in rotation by the driving means, thereby ensuring identical pivoting of all the vanes

Methodology Applied

Scientific EffectMechanical guidance:

Data Source

PatentUS10502087B2Assembly for controlling variable pitch vanes in a turbine engine

Publication Date: 2019.12.10 SAFRAN AIRCRAFT ENGINES SAS

AI summary

An assembly for controlling variable pitch vanes in a turbine engine, the assembly comprising an actuating ring surrounding a casing of the turbine engine and connected by rods to variable pitch vanes. The actuating ring is configured to rotate around the casing. The assembly further includes a passive element including a first end sliding connected to a second end. The first end is connected by a sliding pivoting link on the actuating ring, and the second end is connected by a ball-joint link to the casing.