Turbine Wheel Axial Retaining Ring Tab Design

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Solution Overview

Problem

Conventional turbine wheels require precise machining and positioning of retaining rings, limiting versatility and assembly ease due to fixed tab positions, and are prone to mechanical stresses and unbalanced masses.

Innovation Solution

A retaining ring with a tab placed between two adjacent blade roots, allowing for azimuth movement restriction without specific machining, facilitating assembly of identical blades and accommodating thermal expansion, while avoiding contact with second hooks to reduce mechanical stresses and ensuring balanced operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a tab is fixed at a specific position on the retaining ring, then the assembly position is precisely defined, but the versatility of assembly is reduced and requires precise machining

Engineering Contradiction:

Improveassembly position precisionVSAvoidassembly versatility

Core Design Contradiction:

Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The tab is designed with a length that allows it to be positioned between any two adjacent blade roots, making the retaining ring universally applicable regardless of the starting position. This eliminates the need for precise machining of specific positions while maintaining assembly precision, as the tab can engage with any blade root pair.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Stability of the object's composition

If the tab is made long to extend between blade roots, then azimuth movement is restricted, but the ring's ability to accommodate thermal expansion is reduced

Engineering Contradiction:

Improveazimuth stabilityVSAvoidthermal expansion accommodation

Core Design Contradiction:

Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The tab's length is optimized to provide sufficient azimuth stability during operation while allowing the retaining ring to expand radially due to thermal effects. The tab engages with the blade roots to prevent azimuth movement, while the ring's radial expansion capability remains intact to accommodate thermal growth.

Inventive Principle:

Principle #15Dynamics

3Strength

If the tab contacts second hooks, then mechanical retention is enhanced, but mechanical stresses and unbalanced masses increase

Engineering Contradiction:

Improvemechanical retentionVSAvoidmechanical stresses

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The tab is positioned and dimensioned to contact only the blade roots, which are specifically designed to receive the tab. This localized engagement provides sufficient mechanical retention without involving the second hooks, thereby avoiding the generation of unbalanced masses and excessive mechanical stresses that would result from tab contact with second hooks.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS9163520B2Turbine wheel fitted with an axial retaining ring that locks the blades relative to a disk

Publication Date: 2015.10.20 SAFRAN HELICOPTER ENGINES

AI summary

A turbine wheel having an axis of rotation and including: a disk having a periphery and a side face; a plurality of blades assembled on the disk, each blade having a blade root and a first hook oriented radially and defining a first groove that opens radially towards the axis of rotation of the turbine wheel. The disk includes a series of second hooks oriented radially and defining a second groove that opens radially towards the axis of rotation of the turbine wheel. An axial retaining ring for placing in the first and second grooves includes a tab for placing between two adjacent blade roots to limit movements of the ring in azimuth.