Electrochemical Blade Root Recess Machining With Oscillating Electrodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Mechanical methods for machining blade root recesses in gas turbine blade disks often result in geometrical deviations and tool wear, especially when using heat-resistant materials.
Innovation Solution
A work station with an electrode carrier arrangement that includes a carrier frame and an electrode frame, allowing for translational and oscillating movements at angles of 45° to 90° relative to the axis of rotation, enabling precise electrochemical machining of rotationally symmetrical workpieces, such as blade root recesses, using interchangeable electrodes of different types for producing pre- and final contours.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If mechanical methods (broaching, milling, grinding) are used to machine blade root recesses, then material removal is achieved, but geometrical deviations occur in the profile groove
Solution Approach 1:
The patent replaces mechanical machining methods (broaching, milling, grinding) with electrochemical machining. The electrochemical process uses controlled anodic dissolution to remove material without mechanical contact, eliminating the geometrical deviations and tool wear associated with mechanical methods. The electrode is positioned close to the workpiece surface (0.1-10 mm gap) and material is removed through electrochemical reactions in an electrolyte solution.
Solution Approach 2:
The patent changes the fundamental machining parameter from mechanical force to electrochemical potential. By controlling voltage, current density, and electrolyte composition, the process achieves precise material removal without the geometrical deviations inherent in mechanical methods. The electrochemical parameters allow for controlled dissolution that maintains profile accuracy.
2Productivity
If mechanical tools are used for machining, then material is removed, but intensified wear occurs on tools with heat-resistant materials
Solution Approach 1:
The patent eliminates mechanical tool wear by replacing mechanical cutting tools with an electrochemical process. The electrode does not contact the workpiece mechanically; instead, material is removed through electrochemical dissolution. This eliminates the intensified wear that occurs when mechanical tools machine heat-resistant materials, as there is no mechanical friction or contact stress.
Solution Approach 2:
The electrode used in electrochemical machining can be relatively simple in construction and, if necessary, replaced when worn or when changing profiles. The electrode itself undergoes some material loss through electrochemical dissolution, but this is controlled and predictable, allowing for cost-effective operation compared to expensive mechanical tools that wear rapidly on heat-resistant materials.
3Manufacturing precision
If electrochemical machining is used, then geometrical precision is improved, but device complexity increases with multiple frames and movement mechanisms
Solution Approach 1:
The patent divides the electrode carrier arrangement into separate functional components: a carrier frame for holding the electrode, an electrode frame for positioning, and independent movement mechanisms for each frame. The carrier frame can move in translation along the first machining direction, while the electrode frame oscillates in the second machining direction. This segmentation allows for precise control of electrode position and movement while making the system modular and maintainable.
Solution Approach 2:
The patent introduces dynamic movement capabilities to the electrode carrier arrangement. The electrode frame is designed to oscillate in the second machining direction (perpendicular to the first machining direction) while the carrier frame translates along the first direction. This dynamic, multi-directional movement allows the electrode to follow complex contour paths and achieve high geometrical precision in machining the recesses, adapting to the workpiece geometry through controlled motion.
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 allows for high-precision machining of blade root recesses without geometrical deviations, reducing tool wear and enabling the use of heat-resistant materials by employing electrochemical methods that adjust amplitude based on material ablation and utilize pulsed electrochemical machining.
Implementation Method 1
a work station for electrochemical machining of a workpiece (12), in particular a rotationally symmetrical workpiece
Implementation Method 2
the electrode frame is movable relative to the carrier frame, oscillating in a second machining direction, wherein the first machining direction and the second machining direction are aligned at an angle of around 45° to around 90° with respect to each other
Data Source
AI summary
The invention relates to a work station for electrochemically machining a workpiece, having a number of recesses, including a base structure; a module which is fastened to the base structure and is configured to electrochemically machine the workpiece. A workpiece holder is fastened to the base structure. The workpiece holder is movable relative to the base structure along a feed axis which is parallel to the axis of rotation of the module. The module includes an electrode carrier arrangement, which is coupled to the module base body so the electrode carrier arrangement can be rotated together with the module base body about the axis of rotation of the module. The electrode carrier arrangement has a carrier frame and an electrode frame, where at least one electrode is detachably fastened to the electrode frame.