Labyrinth Seal Support Axial Bolt Assembly for Turbine Rotor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Labyrinth seals in gas turbine engines are prone to crack formation due to fretting at the edges of extraction holes during tightening, leading to potential seal failure and increased maintenance costs without modifying existing engine parts.
Innovation Solution
Attaching the labyrinth seal support to the turbine engine shaft using axial bolts with tightening screws inserted into extraction holes, which include a screwing insert and a guiding bush to apply force and reduce vibrational stresses, while an anti-rotation plate prevents unscrewing during operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If extraction holes are provided on the shaft for dismantling the drive cone, then ease of operation is improved, but cracks are liable to form at the edges of the extraction holes due to fretting during tightening
Solution Approach 1:
A reinforcement element is introduced as an intermediary component between the extraction holes and the shaft structure. This reinforcement element distributes the stress away from the extraction hole edges, preventing fretting-induced cracks while preserving the ease of dismantling function. The reinforcement element acts as a mediator that protects the shaft from the harmful effects of repeated tightening and loosening operations.
2Reliability
If the labyrinth seal support is tightened onto the shaft, then reliability of sealing is improved, but stress concentration occurs at the extraction holes leading to crack formation
Solution Approach 1:
The reinforcement element provides localized strengthening at the extraction hole regions without affecting the overall structure. This local quality enhancement addresses the stress concentration problem at specific points (extraction holes) while maintaining the global sealing reliability. The reinforcement is applied only where needed - at the extraction holes - rather than throughout the entire shaft.
3Reliability
If existing parts are modified to prevent crack formation, then reliability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The solution segments the shaft structure by adding a separate reinforcement element rather than modifying the existing shaft geometry. This segmentation allows the reinforcement to be added as a distinct component that can be manufactured and installed separately, reducing overall device complexity compared to redesigning the entire shaft or extraction hole structure.
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 effectively secures the labyrinth seal support without increasing engine weight or operating costs, reducing the risk of crack formation and maintaining seal integrity, and can be applied to existing engines with minimal modifications.
Implementation Method 1
tightening screws introduced into the extraction holes... apply force
Implementation Method 2
guiding bush to apply force and reduce vibrational stresses
Implementation Method 3
anti-rotation plate prevents unscrewing during operation
Data Source
AI summary
A method of attaching a labyrinth seal support to a turbine engine shaft is disclosed. The method includes inserting axial bolts to secure the labyrinth seal support, the shaft and a device for driving the turbine module with the shaft, and screwing tightening screws in extracting holes, for extracting the drive device with respect to the shaft, provided on the shaft to tighten the labyrinth seal support onto the shaft.