Blisk Grinding Jig for Concurrent Tip Machining

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The separate grinding stages required for blade-disk assembled wheels and blisks in axial-flow turbomachinery decrease working efficiency due to differing rotation speeds, with blisks rotating at lower speeds to prevent tip vibration and stress on the rotor blade.

Innovation Solution

A method and jig that restrict relative movement between blade cascades of a blisk and adjacent blade cascades, allowing concurrent grinding of blade tips during rapid rotation, using a jig inserted between blade cascades to stabilize the rotor blades and prevent vibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the rotation speed of a blisk is increased to match the blade-disk assembled wheel during grinding, then the working efficiency is improved, but the tip vibrates and stress damages the rotor blade

Engineering Contradiction:
Improveworking efficiencyVSAvoidrotor blade integrity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

A jig is introduced as an intermediary device between the grinding wheel and the blisk rotor blade. The jig includes a support portion that contacts the blade tip and a restraint portion that prevents excessive vibration during high-speed grinding, allowing the blisk to be ground at higher speeds without damaging the rotor blade

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The grinding process parameters are changed by introducing a jig that modifies the interaction between the grinding wheel and blade tip. This allows the rotation speed parameter to be increased from low speeds (without jig) to high speeds (with jig), thereby improving productivity while maintaining reliability through the jig's vibration control

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the rotation speed is suppressed to prevent tip vibration in blisks, then the rotor blade integrity is maintained, but the working efficiency decreases due to separate grinding stages

Engineering Contradiction:
Improverotor blade integrityVSAvoidworking efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The jig serves multiple functions simultaneously: it supports the blade tip during grinding, restrains vibration, and enables high-speed operation. This multi-functional device allows the same grinding setup to handle both blisks (with vibration restraint) and blade-disk assembled wheels (without restraint needed), improving productivity through concurrent processing

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

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

Enables concurrent grinding of rotor blade tips in both blade-disk assembled wheels and blisks under rapid rotation, enhancing working efficiency by suppressing vibration and stress on the blade roots.

Implementation Method 1

a sufficient centrifugal force needs to be given to a blade so that the position of the tip reaches a position similar to the position during actual operation

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP3415276B1Method for grinding tip of rotor blade, and jig for grinding tip of blisk
Publication Date: 2023.03.15 IHI CORP
  • EP3415276B1 patent drawingFigure 1
  • EP3415276B1 patent drawingFigure 2
  • EP3415276B1 patent drawingFigure 3

AI summary

When a tip (11c, 13c, 15c, 17f) of a blade cascade (11, 13, 15, 17) is ground with a grindstone (21, 23, 25, 27), a jig (30) is inserted between blade cascades (11, 13) of a blisk and a jig (40) is inserted between blade cascades (13, 15). A blade locking section (33, 43) of the jig (30, 40) locks with a side section in the width direction of a corresponding rotor blade (11b, 13b, 13b, 15b) via a damping member (33a, 33b, 43a, 43b) made from rubber or the like. A disk locking section (31, 41) of the jig (30, 40) locks with a disk (11a, 13a, 13a, 15a) of the blade cascade (11, 13, 13, 15) which the blade locking section (33, 43) locks with.