Gearbox Gutter Sizing for Lubricant Scavenging and Weight Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gearbox assemblies in gas turbine engines face efficiency losses due to windage and friction, and improper sizing of gutters for lubricant scavenging can lead to reduced efficiency and increased weight, with current gutter designs often being either too large or too small for optimal performance.
Innovation Solution
The implementation of a gearbox assembly with a gutter that maintains a lubricant extraction volume ratio (LEVR) between 0.01 and 0.3, ensuring optimal gutter sizing relative to gearbox volume, thereby maximizing lubricant scavenging efficiency while minimizing weight and size penalties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the gutter volume is increased to improve lubricant scavenging capacity, then the lubricant extraction efficiency is improved, but the weight and size of the gearbox assembly increases
Solution Approach 1:
The patent applies parameter changes by establishing a specific volume ratio range (0.01 to 0.3) between gutter volume and gearbox volume. This quantitative parameter optimization allows the gutter to be sized appropriately for effective lubricant scavenging without being excessively large, thereby resolving the contradiction between scavenging capacity and weight.
2Productivity
If the gutter volume is increased to capture more lubricant, then the lubricant extraction efficiency is improved, but the overall footprint of the gearbox assembly increases
Solution Approach 1:
The patent uses parameter changes by defining an optimal volume ratio range (0.01 to 0.3) between the gutter and gearbox. This ensures the gutter is large enough to effectively capture lubricant but not so large as to increase the overall footprint unnecessarily.
3Weight of stationary object
If the gutter volume is decreased to reduce weight and size, then the weight penalty is minimized, but the lubricant scavenging efficiency deteriorates
Solution Approach 1:
The patent applies parameter changes by establishing a minimum volume ratio threshold (0.01) to ensure the gutter maintains sufficient scavenging capability while being compact enough to minimize weight and size penalties.
4Ease of manufacture
If improper gutter sizing is used, then manufacturing simplicity is maintained, but gearbox efficiency is reduced due to windage and friction losses
Solution Approach 1:
The patent applies parameter changes by defining a specific volume ratio range (0.01 to 0.3) that optimizes gearbox efficiency. This quantitative approach ensures proper lubricant scavenging to minimize windage and friction losses while maintaining manufacturing simplicity.
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 enhances gearbox efficiency by ensuring proper lubricant scavenging, reduces the overall footprint and weight of the gearbox and scavenge system, and maintains optimal performance across varying engine power conditions.
Implementation Method 1
The gutter is for collecting a gearbox lubricant scavenge flow from the gearbox
Data Source
AI summary
A gearbox assembly includes a gearbox and a gutter for collecting a gearbox lubricant scavenge flow from the gearbox. The gutter is characterized by a lubricant extraction volume ratio between 0.01 and 0.3, and given byVGVGB.VG is a gutter volume of the gutter and VGB is a gearbox volume. A gas turbine engine includes a combustion section and the gearbox assembly. A fuel delivery system includes a fuel supply line for delivering fuel to the combustion section. A lubrication system includes a lubricant supply line for delivering lubricant to the gearbox assembly. A thermal management system includes a fuel-lubricant heat exchanger for cooling the lubricant with the fuel. The thermal management system selectively directs the fuel through fuel bypass lines or the lubricant through lubricant bypass lines to bypass the fuel-lubricant heat exchanger based on a fuel temperature or a lubricant temperature.