APU Mount Bracket Oil-Cooled Attachment for Fire Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional APU mount designs using aluminum housing fail to withstand flame exposure and mechanical stresses due to the material's properties, necessitating the use of complex and costly thermal blankets for fire resistance, which are cumbersome and difficult to maintain.
Innovation Solution
Aircraft strut system is mechanically attached to a gearbox bracket with lower attachment points located beneath the oil reservoir, allowing for cooling by oil and efficient heat conduction, using fire-resistant materials like steel alloys or nickel-based alloys to ensure structural integrity during flame exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermal blankets are used to protect mount attachment points from flame exposure, then fire resistance is improved, but device complexity, weight, and maintenance difficulty increase
Solution Approach 1:
The patent extracts the fire protection function from the thermal blanket and relocates it to the gearbox housing itself by positioning the mount attachment point within the oil reservoir. The oil serves as the fire protective medium, eliminating the need for separate thermal blanket components.
Solution Approach 2:
The gearbox oil serves dual purposes: lubrication and fire protection. The oil naturally cools and protects the mount attachment point from flame exposure without requiring external protection systems, making the system self-protecting.
2Reliability
If thermal blankets are implemented to ensure fire resistant mount attachment, then fire resistance is improved, but weight and cost increase
Solution Approach 1:
The gearbox oil performs multiple functions simultaneously: lubrication of gearbox components and fire protection of the mount attachment point. This multi-functionality eliminates the need for additional fire protection materials that would add weight.
Solution Approach 2:
The fire protection function is extracted from separate thermal blanket components and integrated into the existing oil reservoir system, eliminating redundant weight.
3Weight of moving object
If aluminum housing is used for gearbox, then weight is reduced, but fire resistance under mechanical stress is insufficient
Solution Approach 1:
The patent applies local quality by creating a fire-protected zone at the specific location of the mount attachment point within the oil reservoir, while the rest of the aluminum gearbox housing maintains its lightweight properties. The protection is localized where needed rather than requiring full housing material change.
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 solution provides a fire-resistant and lightweight APU mount that can withstand mechanical stresses and thermal loads, reducing maintenance complexity and costs by utilizing oil-cooled attachment points and fire-resistant materials, ensuring safe aircraft operation in emergency situations.
Implementation Method 1
The lower attachment point of the bracket is located beneath the oil level within the oil reservoir such that the lower attachment point will be cooled by oil in the oil reservoir
Data Source
AI summary
An auxiliary power unit is composed of a gas turbine engine, a gearbox, and a gearbox driven generator. A mount bracket is mechanically attached to the gearbox. The bracket is for connecting to an aircraft strut system. The aircraft strut system connects to the aircraft structure. The mount bracket has an upper mechanical attachment point and a lower mechanical attachment point to the gearbox. The gearbox includes an oil reservoir, and the lower attachment point is beneath the oil level within the oil reservoir such that said lower attachment point will be cooled by oil in the oil reservoir.