Gas Turbine Auxiliary Mounting Bracket With Mechanical Fuse
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional mounting systems for auxiliary components in gas turbine engines fail to withstand high shock loads from fan blade out events, leading to component separation or damage, and face challenges in balancing competing requirements of lightweight yet durable gearbox materials.
Innovation Solution
A mechanical fuse assembly is integrated into the mounting system, featuring a support bracket with a bearing member and a mechanical fuse that includes radially inner and outer walls with annular cuts, designed to fracture and absorb energy during overload events, maintaining attachment to the engine case.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional mounting systems are used to attach auxiliary components to the engine case, then the system structure is simple and easy to manufacture, but the mounting system cannot withstand high shock loads from fan blade out events, causing component separation or damage
Solution Approach 1:
The mounting system is segmented into a rigid support bracket for structural attachment and a separate mechanical fuse component with bearing member that absorbs shock loads. This segmentation allows each component to be optimized independently - the bracket provides structural strength while the fuse handles shock absorption, resolving the contradiction between strength and complexity.
Solution Approach 2:
The mechanical fuse acts as an intermediary element between the rigid mounting bracket and the auxiliary component. It mediates the shock loads by providing a controlled failure mechanism through its bearing member and fuse sections, protecting the main mounting system while adding only minimal complexity.
2Weight of moving object
If lightweight materials are used for gearbox hardware to reduce aircraft weight, then the aircraft weight is reduced, but the gearbox materials lack sufficient strength and durability to withstand fan blade out loads
Solution Approach 1:
The mechanical fuse is designed as a disposable sacrificial component that absorbs extreme shock loads through controlled fracture. By making this protective element replaceable rather than requiring the entire gearbox to be over-engineered, lightweight materials can be used in the permanent gearbox structure while still providing adequate protection against FBO events.
Solution Approach 2:
The mechanical fuse changes its structural parameters dynamically - remaining intact during normal operation to provide protection, then fracturing in a controlled manner during FBO events to absorb energy. This parameter change allows lightweight gearbox materials to suffice since the fuse compensates for reduced material strength during extreme events.
3Reliability
If the mounting system is designed to withstand high shock loads without failure, then component separation is prevented, but the auxiliary components may still be damaged by the transferred shock loads
Solution Approach 1:
The mechanical fuse converts the harmful shock loads into a beneficial controlled fracture event. The bearing member and fuse sections are designed to fail in a predetermined sequence, absorbing the harmful energy of FBO events and converting it into useful protective action that prevents both component separation and damage to auxiliary components.
Solution Approach 2:
The mechanical fuse provides beforehand cushioning by being pre-positioned between the rigid mounting system and the auxiliary components. During normal operation, it stands ready to absorb shock loads, cushioning the components against sudden impacts before they can cause damage, while maintaining secure attachment reliability.
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 mechanical fuse assembly effectively absorbs and dissipates shock loads, preventing component separation and damage, while allowing continued operation by maintaining attachment to the engine case, thus enhancing the durability and reliability of the mounting system.
Implementation Method 1
a mechanical fuse disposed within the bearing member... the first fuse section extending annularly about the radially outer wall with respect to the central axis... the second fuse section extending annularly about the radially inner wall
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
An assembly (200) for mounting an auxiliary component to an engine case (110) of a gas turbine (100) includes a support bracket (222), the support bracket (222) having a first end (230) configured for attachment to a first flange (232) of the engine case (110), a second end (236) configured for attachment to a second flange (238) of the engine case (110), and an intermediate portion (246) located intermediate the first end (230) and the second end (236); a bearing member (248) disposed within the intermediate portion (246); and a mechanical fuse (224; 324; 424; 524; 624) disposed within the bearing member (248).