Gearbox Flapper Valve Sealing System for Lubricant Leakage
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Solution Overview
Problem
Gas turbine engine gearboxes lack a reliable mechanism to prevent lubricant leakage when the manual rotator cover is not replaced after maintenance, leading to potential lubricant loss and mechanical issues.
Innovation Solution
A sealing system featuring a flapper valve is integrated into the gearbox's outer housing, which translates between open and closed positions to allow tool access while maintaining a seal and preventing lubricant escape, even when the rotator cover is removed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the manual rotator cover is removed to allow tool access for manual rotation, then the ease of operation is improved, but the lubricant loss worsens due to potential leakage
Solution Approach 1:
The flapper valve is pre-positioned in a closed state that automatically opens when a tool is inserted into the manual rotation access passage. This preliminary positioning ensures that the valve is ready to open before the tool actually needs to access the manual rotation shaft, allowing tool access without requiring cover removal while preventing lubricant loss during normal operation
Solution Approach 2:
The flapper valve acts as an intermediary element between the manual rotation access passage and the lubricant reservoir. It mediates between the need for tool access and the need to prevent lubricant leakage by selectively opening or closing the passage based on the presence of a tool, thus resolving the contradiction between ease of operation and lubricant loss prevention
2Loss of substance
If a traditional cover is used to seal the manual rotation access passage, then the lubricant loss is prevented, but the ease of operation worsens due to the need to remove and replace the cover
Solution Approach 1:
The sealing function is extracted from the manual rotator cover and transferred to the flapper valve mechanism. This allows the cover to be eliminated entirely, as the flapper valve provides continuous automatic sealing without requiring manual intervention for cover removal or replacement, thus improving ease of operation while maintaining lubricant loss prevention
Solution Approach 2:
The flapper valve is designed to automatically open when a tool is inserted and automatically close when the tool is removed, without requiring any manual operation. This self-service mechanism eliminates the need for operators to remove and replace covers, significantly improving ease of operation while continuously preventing lubricant loss
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
The sealing system effectively inhibits lubricant loss from the gearbox, ensuring operational integrity by maintaining a seal regardless of the rotator cover's position, thus providing a fail-safe mechanism.
Implementation Method 1
a flapper valve translatable from a closed position to an open position to allow a rotation tool to pass through the manual rotation access passage and contact the manual rotation shaft
Implementation Method 2
translatable from the open position to the closed position after the rotation tool is removed from the manual rotation access passage to prevent a lubricant from escaping from the outer housing via the manual rotation access passage
Implementation Method 3
The manual rotation shaft is rotatably coupled to the outer housing by a bearing
Implementation Method 4
the lubricant is stored in a lubrication reservoir formed by the outer housing and a first side of the bearing
Data Source
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AI summary
A gearbox (50) includes an outer housing (72) including manual rotation access passage (84) and a manual rotation shaft (74) coupled to a spool (34,38) of an engine (10) to rotate the engine spool. The gearbox also includes a sealing system (90, 120) coupled to the outer housing that includes a flapper valve (92, 122) that, in a closed position, prevents a lubricant from escaping from the outer housing via the manual rotation access passage.