Blade Stabilization Device for Machining Thin-Walled Impeller Blades

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The machining of impeller blades in BLISK design faces challenges due to their complex, thin-walled, and cantilevered structure, leading to undesired workpiece deflections and vibrations during machining, resulting in inaccurate material removal, high tool wear, and increased costs, with existing solutions like elastic damping elements and complex CAM corrections being inefficient and environmentally harmful.

Innovation Solution

A stabilization device is clamped to the blade to be machined, using clamping elements that contact the workpiece at multiple points, providing mechanical stabilization to reduce or eliminate vibrations and deflections, and can be reused and automated for efficient machining.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If blades are machined with thin-walled and cantilevered structure, then weight is reduced and BLISK construction is achieved, but workpiece deflections and vibrations occur during machining

Engineering Contradiction:
Improveblade weightVSAvoidmachining accuracy
Core Design Contradiction:
Weight of moving objectVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by pre-clamping the blade in a specialized fixture that provides support at the blade root and along the blade length before machining begins. This preliminary support structure prevents deflections and vibrations during the machining process, allowing accurate material removal while maintaining the thin-walled design. The fixture is configured to match the blade geometry and provides stable support without adding significant weight to the final product.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If complex thin-walled blade structures are machined, then BLISK design with integrated blades is achieved, but process forces cause large static workpiece deflections

Engineering Contradiction:
ImproveBLISK construction capabilityVSAvoidworkpiece stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent introduces an intermediary support system consisting of a specialized fixture with multiple contact points along the blade length. This intermediary structure mediates between the machining forces and the workpiece, distributing the process forces and preventing large static deflections. The fixture acts as a temporary support during machining that can be removed after processing, enabling BLISK construction without compromising workpiece stability during the critical machining phase.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If CAM program corrections are made to account for workpiece deflection, then machining accuracy can be improved, but time consumption and cost increase

Engineering Contradiction:
Improvematerial removal accuracyVSAvoidprocess time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by designing a fixture system that prevents workpiece deflection before machining begins, rather than requiring post-processing corrections to CAM programs. The fixture is configured to provide optimal support that eliminates the need for complex compensation calculations, allowing standard CAM programs to be used without time-consuming iterative corrections. This approach reduces both programming time and production time while maintaining high machining accuracy.

Inventive Principle:
Principle #10Preliminary action

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 stabilization device effectively minimizes workpiece deflections and vibrations, improving machining accuracy and reducing tool wear, while being reusable and automatable, thus lowering costs and environmental impact.

Implementation Method 1

at least one spring-elastic element (10) acting between the clamping element (11) and the base body (7), wherein the clamping element (11) is pressed against the blade (6)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The stabilizing device (5) is clamped onto the blade (6) to be machined in such a way that workpiece vibrations occurring during the machining process are dampened or eliminated

Methodology Applied
Scientific EffectVibration damping: Damping

Data Source

PatentEP3034234B1Method and system for machining a workpiece
Publication Date: 2019.02.13 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP3034234B1 patent drawingFigure 1
  • EP3034234B1 patent drawingFigure 2~3
  • EP3034234B1 patent drawingFigure 4~6

AI summary

A method for machining a workpiece using a machining tool is proposed, in which the workpiece (1, 20) is held in a workpiece holder (2) and a stabilizing device (5, 21), distinct from the workpiece holder (2) and mechanically stabilizing the workpiece (1, 20) during machining, is attached to the workpiece (1, 20). A device system for machining a workpiece, comprising a machine body having at least one workpiece holder (2) and at least one machining tool, is characterized by at least one stabilizing device (5, 21) that is distinct from the workpiece holder (2) and suitable for clamping attachment to the workpiece (1, 20). A stabilizing device (5, 21) comprises a base body (7) with at least one workpiece receptacle (12, 18) and at least one clamping element (11) movable in the at least one tool receptacle (12, 18) relative to the base body (7).