Single Actuator for Gas Turbine Variable Geometry Control

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Solution Overview

Problem

The existing control systems for gas turbine engines with variable-geometry equipment from distinct cores require multiple actuators, power sources, and control circuits, leading to increased weight, cost, and space requirements, while also posing risks during idle conditions due to the absence of certain control components.

Innovation Solution

A single actuator system controls multiple variable-geometry equipment across different cores of a gas turbine engine, utilizing a double-rack mechanism and gearwheel to actuate both high-pressure compressor stator blades and low-pressure compressor bleed valves, with a disengagement mechanism to prevent interference between equipment ranges of actuation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If distinct control systems are provided for variable-geometry equipments of different cores, then each equipment can be controlled independently, but the weight, cost and space requirement of the control systems increase

Engineering Contradiction:

Improveindependent control capabilityVSAvoidcontrol system weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent combines multiple control functions into a single integrated control system that can control variable-geometry equipments across different cores. Instead of having separate actuators and control circuits for each equipment, a single actuator with multiple output linkages controls multiple equipments (such as VSV and VBV) simultaneously, reducing overall system weight while maintaining independent control capability through selective actuation

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The control system is designed with universal functionality where a single actuator can perform multiple control functions. The actuator includes a drive mechanism with multiple output linkages that can selectively engage different variable-geometry equipments based on operating conditions, allowing one component to replace multiple specialized components

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If distinct control systems are provided for variable-geometry equipments of different cores, then each equipment can be controlled independently, but the cost and space requirement of the control systems increase

Engineering Contradiction:

Improveindependent control capabilityVSAvoidcontrol system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple control systems into a single integrated unit that controls variable-geometry equipments across different cores. The control architecture combines multiple control circuits and actuators into one unified system with shared components, reducing the number of separate systems while maintaining the ability to independently control each equipment through selective engagement mechanisms

Inventive Principle:

Principle #5Merging (Combining)

3Weight of moving object

If no VBV is installed to reduce weight, then significant weight saving is achieved, but the risk of engine stopping increases during idle conditions

Engineering Contradiction:

Improveequipment weightVSAvoidengine operation reliability

Core Design Contradiction:

Weight of moving objectVSReliability

Solution Approach 1:

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 number of parts and associated costs, maintains functionality across distinct cores, and mitigates risks by using a single actuator to control multiple equipment, ensuring efficient operation and reduced weight and volume.

Implementation Method 1

The actuator comprises a gearwheel (50) arranged to drive the racks (24A, 24B)

Methodology Applied

Scientific EffectGear mechanism: Gear

Implementation Method 2

The actuator comprises two racks (24A, 24B) mounted so as to be movable in a direction parallel to the axis X-X

Methodology Applied

Scientific EffectRack and pinion mechanism: Rack and Pinion

Data Source

PatentUS8337140B2System for controlling at least two variable-geometry equipments of a gas turbine engine, particularly by rack

Publication Date: 2012.12.25 SAFRAN AIRCRAFT ENGINES SAS

AI summary

A system for controlling at least two variable-geometry equipments of a gas turbine engine is disclosed. The engine includes at least a first core rotating at a first speed and a second core rotating at a second speed. The first equipment includes at least one variable-pitch stator blade of a compressor of the first core and the second equipment includes at least one air bleed valve of a compressor of the second engine core moving between an open position at idle speed and a closed position at high speed. The system includes an actuator which actuates both equipments.