Cyclic Blade Pitch Control System for Turbine Propeller

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Solution Overview

Problem

Current cyclic blade pitch control systems for turbomachines are inadequate in reducing parasitic moments and forces caused by non-homogeneous air flow distribution, particularly during maneuvering, crosswind, or climb phases, leading to asymmetrical thrust and increased wear on propeller components.

Innovation Solution

A cyclic blade pitch control system that includes a tiltable plate assembly, force sensors to measure air flow forces, and a jack system to adjust the blade pitch in real-time, ensuring symmetrical thrust and reducing parasitic moments by actively adapting to changing flight conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If collective blade pitch control systems are used to modify the pitch of all blades identically, then the system is simple to operate, but it cannot reduce the 1P moment resulting from non-homogeneous airflow distribution

Engineering Contradiction:
Improveblade pitch control operationVSAvoid1P moment reduction capability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent divides the blade pitch control into individual blade control units, allowing each blade to have its pitch independently adjusted. This segmentation enables the system to address non-homogeneous airflow by applying different pitch angles to different blades, thereby reducing the 1P moment while maintaining operational simplicity through modular control architecture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements a dynamic blade pitch control system where the pitch angle of each blade can be actively adjusted in real-time based on detected airflow conditions. This dynamic adaptation allows the system to respond to changing flight phases and crosswind conditions, optimizing thrust distribution and reducing parasitic moments.

Inventive Principle:
Principle #15Dynamics

2Reliability

If cyclic pitch control systems with multiple actuators are used to reduce the 1P moment, then the thrust asymmetry is reduced, but the device complexity increases

Engineering Contradiction:
Improvethrust symmetryVSAvoidpitch control system structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the cyclic pitch control functionality into an integrated system where multiple actuators work in coordination through a unified control mechanism. By combining the control functions and using a centralized control unit that manages all actuators, the system achieves thrust symmetry while minimizing the overall structural complexity compared to fully independent control systems.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent designs the pitch control system with multi-functional components that can perform multiple operations. The actuators and control mechanisms are designed to handle both collective and cyclic pitch adjustments, as well as respond to various flight conditions, thereby reducing the need for separate dedicated systems and lowering overall device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Device complexity

If passive cyclic pitch adjustment systems are used, then the system structure is simpler, but the system cannot actively adapt to changing flight conditions and flow inhomogeneities

Engineering Contradiction:
Improvepitch control system structureVSAvoidresponse to flight conditions
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent implements a feedback control system where sensors detect airflow conditions and flight parameters, and this information is fed back to the control unit which adjusts the blade pitch accordingly. This closed-loop feedback mechanism enables the system to actively adapt to changing flight conditions and flow inhomogeneities while maintaining a relatively simple structure through efficient sensor-actuator coupling.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent enables the pitch control system to self-adjust based on detected conditions without requiring complex external control mechanisms. The system uses onboard sensors and control units that automatically detect airflow asymmetries and adjust blade pitches in real-time, allowing the system to serve itself and adapt to varying flight conditions without additional complexity.

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

The system effectively reduces or cancels parasitic forces and moments, extending the lifespan of propeller components, reducing maintenance needs, and optimizing thrust alignment with the longitudinal axis, thereby enhancing operational efficiency and reducing wear.

Implementation Method 1

a force sensor mounted fixed in the stator frame, the force sensor being adapted to measure a force exerted in the normal plane by an airflow at the inlet of the propeller blades

Methodology Applied
Scientific EffectForce measurement: Force

Implementation Method 2

a cylinder adapted to tilt the entire plate assembly, the cylinder being adapted to be actuated in response to a force measured by the force sensor

Methodology Applied
Scientific EffectMechanical actuation: Mechanical Force

Data Source

PatentEP4041628B1Blade cyclic pitch setting system
Publication Date: 2024.06.26 SAFRAN AIRCRAFT ENGINES SAS
  • EP4041628B1 patent drawingFigure 1a~1b
  • EP4041628B1 patent drawingFigure 2a~3a
  • EP4041628B1 patent drawingFigure 3b~3c

AI summary

The invention describes a system for controlling the cyclic setting of blades (1) of a turbine engine propeller, the blades (1) being arranged in a plane normal to the axis of rotation (r) of the propeller, the system comprising: - a plate assembly (40) that can be tilted relative to the normal plane (P), - an articulation system (50) articulating the plate assembly (40) relative to the blades (1) such that tilting the plate assembly (40) modifies the setting of the blades (1), - a force sensor (5) designed to measure a force applied in the normal plane (P) by an air flow at the inlet of the propeller blades (1), - a cylinder (60) suitable for tilting the plate assembly (40) in response to a force measured by the force sensor (5).