Gearbox Gutter Sizing and Variable Lubricant Flow for Windage Heat
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Solution Overview
Problem
Existing gearbox assemblies in gas turbine engines face efficiency losses due to windage and friction, leading to heat generation and improper lubricant management, with gutters often being either too large or too small, affecting engine performance and efficiency.
Innovation Solution
A gearbox assembly with a gutter configuration that optimally collects and removes lubricant, utilizing a variable flow lubricant pump and control system to regulate lubricant flow based on engine demands, ensuring efficient lubrication and heat removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional gutter is used to collect lubricant, then lubricant collection is achieved, but the gutter volume is either too large or too small, leading to inefficient lubricant management and heat removal
Solution Approach 1:
The patent applies parameter changes by optimizing the gutter volume to a specific ratio (0.01 to 0.3) of the gearbox volume, transforming the gutter from an oversized or undersized component to a precisely sized lubricant management system that efficiently collects and removes lubricant while maintaining reliability
Solution Approach 2:
The patent implements dynamics by using a variable flow lubricant pump instead of a fixed flow system, allowing the lubricant extraction rate to be dynamically adjusted based on operating conditions, thereby improving lubricant management efficiency without requiring excessive gutter volume
2Reliability
If lubricant is continuously supplied to lubricate gears, then gear lubrication is maintained, but heat generation from windage and friction increases, requiring excessive lubricant removal capacity
Solution Approach 1:
The patent implements feedback through a control system that monitors operating conditions and adjusts the variable flow lubricant pump accordingly, enabling the system to optimize the balance between lubricant supply for gear protection and lubricant removal for heat management, thereby maintaining reliable lubrication while minimizing energy loss to heat
Solution Approach 2:
By using a variable flow lubricant pump, the system dynamically adjusts lubricant flow rates based on real-time operating conditions, allowing optimal lubrication during high-load conditions while reducing lubricant flow during low-load conditions to minimize heat generation from excessive lubricant
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
Improves gearbox efficiency by optimizing lubricant scavenging and management, reducing heat generation and weight, and enhancing overall engine performance.
Implementation Method 1
a variable flow lubricant pump that delivers a variable flow of lubricant to the gearbox assembly
Implementation Method 2
a gutter configured to collect and remove lubricant from the gearbox assembly
Implementation Method 3
the variable flow lubricant pump that delivers a variable flow of lubricant
Data Source
AI summary
A gas turbine engine includes a gearbox assembly that 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, inclusive of the endpoints. The lubricant extraction volume ratio defined by:VGVGB.VG is a gutter volume of the gutter and VGB is a gearbox volume. The gas turbine engine includes a lubricant flow control system that includes a variable flow lubricant pump that generates a pump variable flow of lubricant to the gearbox assembly. The gearbox assembly has a variable consumption demand for delivery of lubricant. A lubricant flow controller is configured to generate a pump control command for the variable flow lubricant pump to produce the pump variable flow of lubricant based on the variable consumption demand.