Casing Inner-Surface Slot Milling With Self-Guided Axial Positioning
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Solution Overview
Problem
The installation of equipment for testing and validation of gas turbines is labor-intensive and time-consuming, requiring efficient methods to machine slots in the turbine casing for sensor systems without damaging the casing.
Innovation Solution
A milling system with a sled-style milling device that includes a frame assembly and a milling cutter, configured to engage structural guides on the casing for precise axial positioning and movement in a circumferential direction, allowing for machining of slots on damaged, warped, or worn casings, and enabling single-person operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional machining methods are used to machine slots in gas turbine casings, then the slots can be machined, but the process becomes labor-intensive and time-consuming
Solution Approach 1:
The patent replaces traditional complex mechanical machining systems with a simplified sled-style milling device that uses magnetic attraction forces to hold and position the cutter against the casing inner surface, enabling more efficient slot machining
Solution Approach 2:
The patent introduces magnetic fields as an intermediary force between the milling device and the casing, allowing the cutter to be held in position without direct mechanical contact or complex clamping mechanisms, thus reducing installation time and labor
2Adaptability or versatility
If equipment is installed for testing and validation of gas turbines, then testing capability is provided, but the installation process is labor-intensive and time-consuming
Solution Approach 1:
The testing equipment is divided into modular components including the sled-style milling device with interchangeable structural guides, allowing easy assembly, disassembly, and reconfiguration for different testing scenarios, thereby reducing installation complexity
Solution Approach 2:
The milling device incorporates movable and adjustable components such as the sled mechanism that can be displaced along the inner surface and structural guides that can be interchangeably coupled, enabling adaptable positioning for various casing sizes and shapes without complex installation procedures
3Manufacturing precision
If precise positioning is achieved for machining slots, then machining accuracy is improved, but the device complexity increases
Solution Approach 1:
The milling device uses the casing's own structural features (such as protrusions or ribs) as reference points for positioning, allowing the device to self-align and maintain precise axial position without requiring complex external positioning systems or additional casing modifications
Solution Approach 2:
The structural guides are designed to engage with various structural features on the inner surface of different casing types, providing universal positioning capability across multiple casing configurations without increasing device complexity
4Adaptability or versatility
If the milling device is designed to accommodate damaged, warped, or worn casings, then adaptability is improved, but device complexity increases
Solution Approach 1:
The milling device allows for adjustment of parameters such as the position and orientation of the cutter and structural guides to accommodate variations in casing geometry, including damaged, warped, or worn surfaces, without requiring a completely different device design
Data Source
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AI summary
A milling device (74, 96, 134) is provided for machining a slot (45) into an inner surface of a casing (42) for a gas turbine engine (11). The milling device (74, 96, 134) includes a frame assembly (76, 98, 136) including multiple structural guides (88, 132) configured to engage structural features (66) on the inner surface of the casing (42) to maintain an axial position of the milling device (74, 96, 134) relative to a longitudinal axis (36) of the casing (42). The milling device (74, 96, 134) also includes a milling cutter (78, 100, 138) coupled to the frame assembly (76, 98, 136). The milling device (74, 96, 134) is configured to be displaced in a circumferential direction (34) relative to the longitudinal axis (36) to machine the slot (45), via the milling cutter (78, 100, 138), along the inner surface of the casing (42) in the circumferential direction (34).