Disc Tool Machining for Turbine Airfoil Geometry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing Integrally Bladed Rotor (IBR) airfoils in gas turbine engines face challenges due to complex geometry, limited cutting speed, and short tool life, especially when machining titanium or nickel alloys, which restricts production efficiency.
Innovation Solution
A method using a disc tool with a grinding periphery that allows multi-axis simultaneous motion, enabling the tool to match predetermined airfoil geometries with up to three translational and two angular degrees of freedom, facilitating efficient machining of complex airfoil surfaces by removing material in a single pass.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a small diameter tool is used to fit between airfoils for point milling, then the tool can access the airfoil surfaces, but cutting speed is limited and production efficiency is restricted
Solution Approach 1:
The invention transitions from using small diameter end mills in point milling to using large diameter disc tools that approach the airfoils from a different spatial dimension (radially inward from the disc surface), enabling much larger tool diameters and higher cutting speeds while still accessing the airfoil surfaces effectively
2Productivity
If flank milling with tapered ball-end mill is used, then airfoil surface geometry can be generated in one or a few passes, but the tool diameter is limited by the space between airfoils
Solution Approach 1:
The invention uses large diameter disc tools that approach the airfoils radially from the disc surface rather than using small diameter end mills that must fit between airfoils, enabling much larger tool diameters while maintaining the capability to generate airfoil surface geometry in few passes through appropriate tool paths and multi-axis motion
3Manufacturing precision
If cup-shaped cutter is used to plunge into rotor and generate circular slots, then simple geometry airfoils can be completely machined, but the method is limited to roughing or very simple geometry airfoils
Solution Approach 1:
The invention employs dynamic multi-axis simultaneous motion of the disc tool (including radial, tangential, and axial movements) combined with controlled tool engagement depth, enabling the same tool to adapt to and machine complex three-dimensional airfoil geometries with high precision rather than being limited to simple circular slot generation
Solution Approach 2:
The invention changes the machining parameters by using large diameter disc tools with controlled engagement depths and multi-axis motion paths, transforming the capability from machining only simple geometries to machining complex airfoil geometries with high precision through appropriate parameter selection and control
4Reliability
If titanium or nickel alloys are machined with existing methods, then IBR airfoils can be manufactured, but tool life is short and cycle time is long
Solution Approach 1:
The invention replaces traditional small diameter end mill cutting mechanisms with large diameter disc tool grinding mechanisms, using abrasive removal instead of conventional cutting, which extends tool life and reduces cycle time when machining difficult-to-machine materials like titanium and nickel alloys
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 approach enhances machining efficiency by allowing the disc tool to effectively machine complex airfoil geometries in a single pass, reducing cycle time and extending tool life, thereby improving production efficiency and handling both concave and convex airfoil surfaces.
Implementation Method 1
a disc tool having a grinding periphery thereof adapted for removing material from the airfoils
Data Source
AI summary
A method for machining a rotor (30) having a disc and a plurality of integral airfoils (32) projecting outwardly from the disc, according to one aspect of the invention, comprises a step of machining each airfoil (32) with a disc tool (10) having a grinding periphery (16) thereof adapted for removing material from the airfoils (32). The grinding periphery (16) has a thickness greater than a thickness of an adjacent supporting portion (18) of a disc plate (12) to permit the grinding periphery (16) to pass a surface of an airfoil (32) in a multi-axis simultaneous motion, thereby matching the grinding periphery (16) with a predetermined geometry of a portion of the airfoil (32).