Rotor Blade Hook Extraction Without Compressor Casing Opening

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Solution Overview

Problem

Existing rotor blade detachment methods require opening the casing of an axial flow compressor, increasing the number of inspection steps and operational complexity.

Innovation Solution

A rotor blade detachment device and method that utilizes a hook and drawing portion to detach rotor blades from a disk without opening the casing, by contacting the blade from the axial direction and applying a load in the drawing direction to move the blade out of the root groove.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the extrusion mechanism is disposed on the axis line downstream-side to push the rotor blade, then the rotor blade can be detached, but the casing must be opened which increases inspection steps and complexity

Engineering Contradiction:
ImproveRotor blade detachment capabilityVSAvoidCasing opening requirement
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

Instead of pushing the rotor blade from the downstream side (conventional method), this invention pulls the rotor blade from the downstream side using a hook and drawing portion mechanism. This inversion of the force application direction enables blade detachment without requiring casing opening, as the pulling mechanism can be accessed from the downstream side while the blade is secured against the disk's first end surface

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The invention utilizes the axial dimension by positioning the hook to engage the blade root and the drawing portion to apply force along the axial direction from downstream to upstream. This dimensional approach allows force application through the axial gap without requiring radial or circumferential access that would necessitate casing opening

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of operation

If the casing is opened for blade detachment, then the blade can be removed, but the number of inspection steps increases

Engineering Contradiction:
ImproveRotor blade removal capabilityVSAvoidInspection process time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The hook is preliminarily positioned to engage with the blade root's axial surface before applying the drawing force. This preliminary engagement secures the blade in place, preventing it from falling or rotating during the detachment process, thereby enabling the entire operation to be completed without opening the casing and reducing inspection steps

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS20260009337A1Rotor blade detachment device and rotor blade detachment method
Publication Date: 2026.01.08 MITSUBISHI HEAVY IND LTD
  • US20260009337A1 patent drawing
  • US20260009337A1 patent drawing
  • US20260009337A1 patent drawing

AI summary

There is provided a rotor blade detachment device that detaches a rotor blade from a disk, the rotor blade detachment device including a hook that is contactable with the rotor blade, and a drawing portion that is connected to the hook and moves the hook in a drawing direction from a second end surface of the disk toward a first end surface of the disk, in which the hook has a contact portion that is contactable with the rotor blade from a second axis line side in an axial direction, and an arm that extends from the contact portion in the drawing direction, and the drawing portion is connected to the arm at a position opposite to the contact portion in the drawing direction, and applies a load to the hook in the drawing direction.