Bridged Blisk Preform Machining to Suppress Blade Chatter
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Solution Overview
Problem
The manufacturing of blisks often results in low rigidity rotor blades due to their thin thickness and long span, leading to chatter vibrations during finish milling, which reduces finish accuracy and productivity due to the need to slow down cutting speeds and feed rates to suppress these vibrations.
Innovation Solution
A method involving an intermediate product with bridges connecting adjacent rotor blade portions, allowing for increased rigidity and reduced chatter vibrations through a combination of forging, disk finishing, and rotor blade finishing steps, enabling higher cutting speeds and feed rates without compromising accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the cutting speed and feed speed of the rotor blade cutting tool are reduced to suppress chatter vibrations, then the finish accuracy of the rotor blades is improved, but the productivity of the blisk manufacturing is reduced
Solution Approach 1:
The patent applies preliminary action by performing rough milling before finish milling to remove the bulk of material, and by designing the intermediate product with bridges that provide rigidity during subsequent finishing operations. This allows the finish milling to be performed at higher speeds without chatter vibrations because the critical material removal has already been completed and the structural rigidity is ensured by the bridge design.
Solution Approach 2:
The manufacturing process is segmented into distinct stages: rough turning, finish turning, rough milling, and finish milling. The intermediate product is also segmented with bridges connecting rotor blade portions, creating a structured framework that maintains rigidity while allowing precise finishing of individual blade surfaces at higher cutting speeds.
2Manufacturing precision
If the cutting speed and feed speed are reduced to suppress chatter vibrations, then the finish accuracy is improved, but the surface conditions deteriorate due to frictional heat
Solution Approach 1:
Rough milling is performed as a preliminary action to remove the majority of material before finish milling. This reduces the total cutting time at high speeds, thereby reducing cumulative frictional heat generation. The intermediate product design with bridges also provides structural support that allows faster cutting speeds during finish milling without causing chatter, thus maintaining surface quality.
3Manufacturing precision
If the cutting speed and feed speed are reduced to suppress chatter vibrations, then the finish accuracy is improved, but the cutting time increases
Solution Approach 1:
The manufacturing process is divided into rough milling and finish milling stages. The rough milling stage removes the bulk of material using higher material removal rates, while the finish milling stage focuses only on achieving the final surface quality. The intermediate product design with bridges enables the finish milling to be performed faster by providing structural rigidity that prevents chatter vibrations, thus reducing the time penalty associated with precision finishing.
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
This method enhances blisk productivity by reducing chatter vibrations, minimizing material usage and cutting time, and maintaining high finish accuracy, thereby improving the overall manufacturing efficiency and reducing production costs.
Implementation Method 1
a blisk intermediate product including a disk-corresponding part and plural rotor blade-corresponding parts is molded by subjecting a metal block to forging processing
Data Source
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AI summary
A method for manufacturing a blisk (10) includes an intermediate product molding step of molding a blisk intermediate product (18) including a circular disk-corresponding part (20), a plurality of rotor blade-corresponding parts (22), and bridges (24) each connecting a front edge 22a of one of each pair of the rotor blade-corresponding parts (22) adjacent to each other and a rear edge (22b) of the other one of the rotor blade-corresponding parts (22). The method for manufacturing the blisk (10) further includes a disk finishing step of cutting the disk-corresponding part (20) so as to finish the disk-corresponding part (20) into the disk (12) in a product form, and a rotor blade finishing step of cutting each bridge (24) so as to finish the respective rotor blade-corresponding parts (22) into the respective rotor blades (16) in a product form.