Rotor Blade Retaining Ring Tabs to Prevent Dislodgement

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Solution Overview

Problem

Existing retaining rings in gas turbine engines are prone to dislodgement due to improper size or material selection, which can lead to the free movement of mated components within the engine, posing a risk of assembly failure and reduced durability.

Innovation Solution

A retaining ring assembly with integral tabs that trap the retaining ring within a circumferential slot, preventing radial movement and ensuring secure retention even under extreme conditions such as thermal cycling and G-load events.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional retaining ring is used without additional retention features, then the device complexity is reduced, but the reliability of component retention deteriorates due to potential dislodgement under thermal cycling and G-load events

Engineering Contradiction:

Improveretaining ring retention reliabilityVSAvoidretaining assembly complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the retaining ring with integral tabs that extend radially outward to engage with the circumferential slot, creating a unified retention assembly. This merging of the retaining ring and tab structures ensures that the assembly cannot dislodge axially while maintaining a relatively simple overall design without requiring separate retention mechanisms.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The retaining ring assembly is nested within the circumferential slot of the rotor assembly, with the integral tabs engaging the slot walls. This nesting arrangement allows the retention system to be compact and integrated within the existing engine structure without adding external retention components.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Reliability

If the retaining ring is made larger or more rigid to prevent dislodgement, then the reliability improves, but the ease of manufacture deteriorates due to difficulty in assembling into the circumferential slot

Engineering Contradiction:

Improveretaining ring retention reliabilityVSAvoidassembly ease

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The retaining ring includes a split or gap that divides the ring into two segments, allowing it to be compressed and inserted into the circumferential slot. After insertion, the segments spring back to their original shape, providing full circumferential retention. This segmentation enables easy assembly while maintaining reliable retention under extreme conditions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The retaining ring is designed with elastic properties that allow it to dynamically change shape during assembly (compressing to fit through the slot) and then maintain a rigid, stable configuration during operation. This dynamic behavior enables both easy assembly and reliable retention without requiring oversized or overly rigid components.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentEP3290640B1Gas turbine engine with a retaining assembly of a rotor blade with tabs and retaining ring

Publication Date: 2026.03.25 RTX CORP

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AI summary

A component retaining assembly (65) includes a housing (62) including a circumferential slot (76). A component (64) is mated to the housing (62). The component (64) includes a first face (86) including at least two tabs (78). The at least two tabs (78) extending at outward from the first face (86) at least partially past a portion of the circumferential slot (76). A retaining ring (66) is disposed within the circumferential slot (76) and abuts the first face (86) of the component (64). The at least two tabs (78) overlap a portion of the retaining ring (66). A gas turbine engine (20) and a method are also disclosed.