Variable-Pitch Stator Vanes Independent Control Actuation

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Solution Overview

Problem

Existing turbomachines with variable-pitch vanes controlled by an actuating ring face challenges due to bulky and heavy transmission kinematics, difficulty in fitting linear electric motors within the casing, and misalignment issues caused by temperature variations, making individualized control of each stator stage complex and inefficient.

Innovation Solution

A compact motor unit in the shape of a cylinder with a rod and body, where the rod is articulated to the actuating ring and the body is articulated to the casing, allowing for independent control of each actuating ring with a direct articulated connection, using contactless linear electric motors like the XTB3810 for efficient and space-saving actuation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a common cylinder with complex transmission kinematics is used to control multiple stator stages, then the control function is achieved, but the system becomes bulky, heavy, and expensive

Engineering Contradiction:
Improvecontrol capabilityVSAvoidtransmission kinematics
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent divides the control system into separate drive units, with each stator stage having its own independently controllable actuating ring and drive unit. This segmentation eliminates the need for complex transmission kinematics by directly controlling each stage individually, reducing overall system complexity while maintaining full adaptability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of using a single common cylinder that controls multiple stages through complex transmission mechanisms, the patent inverts the approach by using multiple simple drive units that directly control each actuating ring. This inversion simplifies the control architecture by eliminating the transmission kinematics layer.

Inventive Principle:
Principle #13The other way round (Inversion)

2Power

If linear electric motors are placed radially outside the actuating ring, then the actuation function is achieved, but the motors become bulky and difficult to integrate into the casing space

Engineering Contradiction:
Improveactuation capabilityVSAvoidmotor size
Core Design Contradiction:
PowerVSVolume of moving object

Solution Approach 1:

The patent places the linear electric motors inside the actuating ring structure, nesting them within the existing spatial envelope. This allows the motors to be integrated into the casing space without adding radial protrusions, effectively hiding the motor volume within the actuating ring's footprint while maintaining full actuation capability.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Power

If the actuating ring is not satisfactorily centered due to temperature variations, then the actuation function is achieved, but misalignment issues occur

Engineering Contradiction:
Improveactuation functionVSAvoidcentering accuracy
Core Design Contradiction:
PowerVSManufacturing precision

Solution Approach 1:

The patent introduces a flexible coupling element between the actuating ring and the drive unit that acts as a mediator to accommodate thermal expansion and contraction. This flexible connection allows the actuating ring to maintain proper alignment with the drive unit even when temperature variations cause dimensional changes, eliminating misalignment issues while preserving actuation function.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Power

If a single high-power drive unit is used to control multiple actuating rings, then the power requirement is met, but the drive unit becomes radially large and heavy

Engineering Contradiction:
Improvedrive capabilityVSAvoiddrive unit weight
Core Design Contradiction:
PowerVSWeight of stationary object

Solution Approach 1:

The patent segments the drive system into multiple separate drive units, each with sufficient average power to control a single actuating ring. This segmentation allows each drive unit to be compact and lightweight, avoiding the need for a single large high-power unit, while the distributed arrangement provides sufficient total power for all stator stages.

Inventive Principle:
Principle #1Segmentation

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 simplifies and lightens the system by distributing multiple compact motor units around the casing, enabling precise control of each stator stage with reduced bulk and weight, improving the turbomachine's operational efficiency and adaptability to varying conditions.

Implementation Method 1

The actuator is of the linear displacement electric motor type

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentEP2501941B2Turbine engine including a stage of variable-pitch stator vanes having independent control
Publication Date: 2024.10.30 SAFRAN AIRCRAFT ENGINES SAS
  • EP2501941B2 patent drawingFigure 1

AI summary

The invention relates to a turbine engine provided with variable-pitch vanes, controlled stage by stage. The actuator ring (18), connected by connecting rods (26) to the variable-pitch vanes, is coupled to at least one specific adjacent drive unit (32) in the general shape of a cylinder.