Zero Air Gap Propeller Shaft Seal Removal Using Radial Gap Creation
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Solution Overview
Problem
Existing propeller shaft seals in aircraft systems wear out and leak lubricant, causing environmental issues and customer dissatisfaction.
Innovation Solution
A removal tool assembly is used to radially move and axially remove the outer seal from the bearing housing, creating a gap between the inner and outer seals, allowing for efficient disassembly and replacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the outer seal is tightly fitted to the inner seal element to prevent lubricant leakage, then sealing performance is improved, but the seal becomes difficult to remove and replace
Solution Approach 1:
The seal assembly is divided into two separable components: an inner seal element that remains in the bearing housing and an outer seal that can be removed. This segmentation allows the seal to maintain tight fitting during operation for reliable sealing, while enabling easy removal and replacement by separating the outer seal from the inner seal element.
Solution Approach 2:
The removal tool creates a radial gap between the outer seal and inner seal element before axial removal. This preliminary radial separation action prepares the seal assembly for easy axial removal of the outer seal, resolving the contradiction between tight fitting during operation and ease of removal during maintenance.
2Object-affected harmful factors
If the seal components are tightly fitted together to prevent lubricant leakage, then environmental performance is improved, but disassembly time and complexity increase
Solution Approach 1:
By dividing the seal into separable inner and outer components, the system maintains tight fitting during operation to prevent lubricant leakage and environmental harm, while enabling quick disassembly by removing only the outer seal component using the specialized removal tool.
Solution Approach 2:
The removal tool acts as an intermediary device that facilitates the separation of the outer seal from the inner seal element. This intermediary tool enables rapid disassembly without requiring excessive time or complexity, resolving the contradiction between tight sealing during operation and ease of disassembly.
3Productivity
If the outer seal is removed axially while the inner seal element remains in place, then seal replacement efficiency is improved, but the tool complexity increases
Solution Approach 1:
The removal tool is designed with segmented functional portions: a first tool portion that creates radial gap and a second tool portion that performs axial removal. This segmentation of the tool itself enables efficient seal replacement by separating the removal actions into distinct steps, while the modular design manages tool complexity through functional division.
Solution Approach 2:
The first tool portion performs preliminary radial gap creation between the outer seal and inner seal element before the second tool portion performs axial removal. This preliminary action simplifies the subsequent axial removal process, improving seal replacement efficiency while organizing tool complexity into sequential functional steps.
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
Facilitates the efficient disassembly and replacement of worn-out seals, preventing lubricant leakage and improving environmental performance.
Implementation Method 1
a radial pulling nut installed onto the holder rod such that tightening the radial pulling nut onto the holder rod pulls the seal holder and the outer seal radially outwardly, thus creating the radial gap between the outer seal and the inner seal element
Implementation Method 2
Tightening the puller bolt against the tool plate generates an axial pulling load on the radial reaction puller, resulting in the retraction of the outer seal from the bearing housing
Data Source
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AI summary
A removal tool assembly (100) for a shaft bearing seal including a rotating inner seal element (42) and a stationary outer seal (44) includes a first tool portion configured to radially move the outer seal (44) radially outwardly to create a radial gap between the outer seal (44) and the inner seal element (42) disposed at a shaft (20), and a second tool portion operably connected to the first tool portion. The second tool portion is configured to axially remove the outer seal (44) from a bearing housing (26) while the inner seal element (42) remains in the bearing housing (26).