Planar Locking Element with Actuable Spring for Gas Turbine Blades

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing lock plate systems in gas turbines are prone to detachment and damage during overhaul, leading to potential loss and costly repairs due to their destructive removal method.

Innovation Solution

A lock apparatus featuring a planar element with a spring that can be actuated between extended and compressed positions, guided by walls to ensure accurate placement and removal, and actuation features for tool engagement, allowing for secure blade-hub locking and non-destructive removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a lock plate is formed from a planar sheet and bent to provide a curved cross-section, then the lock plate can be inserted within the slot, but the lock plate may become detached during overhaul and requires destructive removal

Engineering Contradiction:

Improveinsertion of lock plateVSAvoidretention of lock plate

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The lock plate incorporates a spring element that provides dynamic retention capability. The spring can be compressed to release the lock plate from the slot during removal operations, and automatically extends to secure the lock plate during operation, transforming a static retention problem into a dynamic solution that adapts to different operational states.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The lock plate is divided into functional segments: a retention portion that engages with the slot, a spring element that provides the retention force, and a release portion that can be actuated. This segmentation allows each component to perform its specific function independently, improving both insertion ease and retention reliability.

Inventive Principle:

Principle #1Segmentation

2Ease of repair

If the lock plate is destructively removed by cutting or leveraging, then the blade can be released from the disc, but there is a risk of loss of the lock plate or damage to the disc

Engineering Contradiction:

Improverelease of bladeVSAvoiddamage to disc or loss of lock plate

Core Design Contradiction:

Ease of repairVSObject-affected harmful factors

Solution Approach 1:

The spring element provides self-service release capability. By compressing the spring, the lock plate automatically releases from the slot without requiring destructive external forces. This eliminates the need for cutting or leveraging operations that could damage the disc or result in loss of the lock plate.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The spring element acts as an intermediary between the lock plate and the slot. It mediates the release process by converting compressive force into controlled expansion, allowing the lock plate to be removed without direct destructive intervention on the disc or lock plate itself.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of operation

If a spring is used to secure the lock plate within the slot, then the lock plate can be easily inserted and removed, but the spring may deviate from the plane of the element

Engineering Contradiction:

Improveinsertion and removal of lock plateVSAvoidplanarity of spring movement

Core Design Contradiction:

Ease of operationVSStability of the object's composition

Solution Approach 1:

Guides are introduced as intermediary elements between the spring and the lock plate body. These guides constrain the spring's movement to remain within the plane of the lock plate element, preventing deviation while still allowing the spring to expand and contract for easy insertion and removal operations.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The guides add a dimensional constraint to the spring's movement. By introducing lateral guide surfaces, the system transforms the spring's potentially three-dimensional movement into a controlled two-dimensional motion within the lock plate plane, maintaining planarity while preserving operational ease.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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

The solution provides a secure locking mechanism that prevents axial movement of blades while enabling non-destructive removal and reinstallation, reducing the risk of loss and damage, thus enhancing maintenance efficiency and reducing repair costs.

Implementation Method 1

a planar element having a spring actuable between an extended position and a compressed position without deviation from the plane of the element

Methodology Applied

Scientific EffectSpring compression and extension: Spring

Data Source

PatentUS9995155B2Locking member

Publication Date: 2018.06.12 ROLLS ROYCE PLC

AI summary

A lock apparatus securing a blade to a hub, the lock apparatus comprising a planar element having a spring actuable between an expanded position and a compressed position without deviation from the plane of the element, wherein in the expanded position of the spring the planar element is partly located in a slot provided in the blade, the spring being compressible to its compressed position to disengage the planar element from the slot.