Turbine Blade Mounting Structure With Centrifugal Shielding

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Solution Overview

Problem

In jet engine turbine blade mounting structures, excessive cooling air flowing into the gap between the turbine blade and disc can degrade engine performance by reducing the mainstream air flow rate.

Innovation Solution

A turbine blade mounting structure with a shielding member that uses inclined guiding and guided surfaces to adjust the flow rate of cooling fluid, where the shielding member is supported to cover the gap between the disc and turbine blade, converting centrifugal force into a pressing force to shield the fluid flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cooling air flows into the gap between the turbine blade and disc, then the disc is cooled, but excessive cooling air reduces the mainstream flow rate and degrades jet engine performance

Engineering Contradiction:
Improvedisc temperatureVSAvoidjet engine performance
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The invention changes the physical state and position of the shielding member by utilizing centrifugal force generated during disc rotation. The shielding member transitions from a stationary or loosely positioned state to a pressed state against the turbine blade, dynamically adjusting the gap parameters to control cooling air flow. This parameter change allows optimization of both disc cooling and mainstream flow rate without requiring separate control systems.

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If a shielding member is added to control cooling air flow, then cooling air flow rate is adjusted, but the device complexity increases

Engineering Contradiction:
Improvecooling air flow rateVSAvoidmounting structure complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The shielding member is designed to automatically perform its flow control function by utilizing the centrifugal force generated during normal disc operation. The member self-adjusts its position and pressing force against the turbine blade based on the rotational speed, eliminating the need for external actuators, sensors, or control systems. This self-service mechanism adds minimal structural complexity while achieving effective cooling air flow rate adjustment.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The shielding member is designed as a dynamic component that responds to operational conditions. During disc rotation, centrifugal force causes the shielding member to press against the turbine blade, dynamically adjusting the gap size. This dynamic behavior allows the structure to adapt to varying operational speeds and cooling requirements without requiring complex static design modifications.

Inventive Principle:
Principle #15Dynamics

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 effectively adjusts the cooling fluid flow rate to the disc side, preventing excessive cooling air from entering and maintaining optimal engine performance by ensuring the right balance of air flow.

Implementation Method 1

A support section which supports an end portion on an outer circumferential side of the shielding member at least when the disc is rotationally driven. A guiding surface expanding to the outer circumferential side from the upstream side toward the downstream side is formed on the support section... the shielding member covers a gap between the disc and the turbine blade in the fitting section in a state in which the guided surface abuts against the guiding surface at least when the disc is rotationally driven

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP3296518B1Turbine blade mounting structure
Publication Date: 2021.03.10 IHI CORP
  • EP3296518B1 patent drawingFigure 1
  • EP3296518B1 patent drawingFigure 2
  • EP3296518B1 patent drawingFigure 3

AI summary

A guiding surface expanding to the outer circumferential side from the upstream side toward the downstream side is formed on the support section, a guided surface expanding to the outer circumferential side from the upstream side toward the downstream side is formed at an end portion on the outer circumferential side of the shielding member, and the shielding member covers a gap between the disc and the turbine blade in the fitting section in a state in which the guided surface abuts against the guiding surface at least when the disc is rotationally driven.