Multi-blade Platform for Turbomachine Axial Retention

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Solution Overview

Problem

The existing bladed wheels of turbomachines, particularly low-pressure compressors, face challenges in assembly and sealing due to the one-piece nature of blades, leading to increased complexity, additional manipulations, and risks of air recirculation with individualized inter-blade platforms.

Innovation Solution

A multi-blade platform with stiffeners and axial bearing faces that cooperate with the drum to retain the platform axially, reducing air recirculation and allowing for separate manufacturing of platforms and blades without increasing assembly complexity, using a traditional locking system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If individualized inter-blade platforms are used to allow separate manufacturing of blades and platforms, then manufacturing flexibility is improved, but assembly complexity and the number of manipulations increase

Engineering Contradiction:
Improveseparate manufacturing of blades and platformsVSAvoidassembly complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent merges multiple individual inter-blade platforms into a single multi-blade platform that supports multiple blades simultaneously. This platform integrates several blade mounting positions and sealing functions into one component, reducing the total number of parts from many individual platforms to just one multi-blade platform per blade row, thereby simplifying assembly while maintaining separate manufacturability of blades and platforms.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The multi-blade platform serves multiple functions: it supports multiple blades, provides sealing surfaces for each blade, maintains axial positioning, and enables separate manufacturing of blades and platforms. This multi-functional design consolidates what would otherwise require multiple separate components, reducing assembly complexity while preserving manufacturing flexibility.

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

2Device complexity

If one-piece blades are used, then structural simplicity is improved, but assembly complexity and manipulation time increase due to reduced platform design

Engineering Contradiction:
Improveblade structure simplicityVSAvoidassembly time
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The invention segments the blade assembly into separate components: the blade itself and the multi-blade platform. This segmentation allows the blade to be manufactured and prepared separately, then quickly installed on the platform which is already positioned on the drum. The platform pre-provides all mounting positions and sealing surfaces, so multiple blades can be installed in sequence without repeated positioning operations, reducing total assembly time.

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If reduced blade platforms are used with individualized inter-blade platforms, then manufacturing flexibility is improved, but sealing reliability deteriorates due to increased air recirculation risks

Engineering Contradiction:
Improvemanufacturing flexibilityVSAvoidsealing reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The multi-blade platform integrates all sealing surfaces for multiple blades into a single continuous structure. This merged design eliminates the gaps and misalignment risks between multiple separate inter-blade platforms, providing continuous sealing surfaces that prevent air recirculation while still allowing blades to be manufactured separately and assembled to the platform.

Inventive Principle:
Principle #5Merging (Combining)

4Adaptability or versatility

If multiple separate platforms are used for each blade, then adaptability is improved, but the number of parts and assembly operations increase

Engineering Contradiction:
Improveplatform adaptabilityVSAvoidassembly productivity
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The multi-blade platform combines multiple platform functions into one component, reducing the number of assembly operations from installing many separate platforms to installing just one platform that supports multiple blades. This merging maintains adaptability because each blade can still be independently positioned and removed, but dramatically improves productivity by reducing the total number of assembly steps.

Inventive Principle:
Principle #5Merging (Combining)

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 minimizes air recirculation, simplifies assembly and disassembly, and reduces the risk of errors while maintaining effective sealing and axial retention, thereby optimizing the bladed wheel's performance.

Implementation Method 1

two stiffeners comprising lateral bearing faces constituting axial bearing surfaces, capable of cooperating with the drum in order, on their own, to retain the platform axially on the drum

Methodology Applied
Scientific EffectMechanical contact and bearing surfaces: Friction

Implementation Method 2

the foot 22 and the circumferential groove 31 have support faces 22a, 22b and 31a, 31b (see picture 3) opposite which cooperate with each other two by two from which it follows a blocking in the radial and axial direction of the blades 20 with respect to the drum 30 (during rotation and under the effect of the force centrifugal, the inclined bearing surfaces 22a and 31a come into contact)

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP2075417B1Platform for a bladed wheel of a turbomachine, bladed wheel and compressor or turbomachine comprising such a bladed wheel
Publication Date: 2016.04.06 TECHSPACE AERO
  • EP2075417B1 patent drawingFigure 1~4
  • EP2075417B1 patent drawingFigure 5~8
  • EP2075417B1 patent drawingFigure 9~14

AI summary

The invention relates to a platform (150) for a bladed turbine wheel of a turbomachine comprising a drum (130) and hammer-type blades (120) whose foot (122) is retained in a circumferential groove (131) of the drum (131), having bearing and/or retention faces cooperating with the drum (130). Characteristically, the platform (150) has at least two circumferentially spaced openings (151), each adapted to receive the foot of a blade (120), thereby constituting a multi-bladed platform in the form of a component separate from the blades (120). Application to a bladed turbine wheel or a turbomachine compressor.