Vibration-Isolating Fastener Assembly for Composite Engine Mounting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Composite engine components are prone to degradation due to transmitted vibrations, and existing vibration isolation systems face challenges in securely mounting these components without applying excessive strain, especially in tight spaces where tool access is restricted.
Innovation Solution
A vibration isolation fastening assembly with a two-piece insert, featuring a flexible vibration-absorbing element and a tiered nut configuration, allows for secure attachment of composite components by resisting rotational forces and axial compressive forces, enabling easy installation with a single tool and reducing material fatigue.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vibration isolating fasteners are used to mount composite components, then vibration transmission is reduced and component lifetime is prolonged, but the composite material's lower compression resistance and shear strength make it more prone to degradation from the fastening process itself
Solution Approach 1:
The fastening system is divided into multiple components: a fastener, a bushing element with head and shank, and a composite component. The bushing element acts as an intermediary that segments the force transmission path, distributing loads more evenly across the composite material to prevent localized degradation while maintaining vibration isolation benefits.
Solution Approach 2:
The bushing element serves as an intermediary component between the fastener and the composite component. It mediates the interaction by distributing compressive and shear forces over a larger area of the composite material, reducing stress concentration that would otherwise cause material degradation while still allowing the fastener to provide vibration isolation.
2Strength
If a bushing with enlarged head is used to distribute compressive stresses, then strain at the opening is diffused, but securing the fastener requires threading a nut that needs two tools (wrench and fastener driver) in tight spaces
Solution Approach 1:
The bushing element's head is designed to perform the function previously requiring a second tool (wrench). When the fastener is inserted and tightened, the bushing head automatically engages with the fastener head to prevent rotation, eliminating the need for a separate wrench-holding operation and enabling single-tool installation while maintaining proper stress distribution.
Solution Approach 2:
The bushing head and fastener are combined into a single integrated assembly where the bushing head's geometric features directly interact with the fastener head to provide rotational constraint. This merging of functions (support + rotation prevention) into one component eliminates the need for separate tools during installation.
3Weight of moving object
If composite material is used for engine components, then weight is reduced and manufacturing costs decrease, but the material has lower resistance to compression and shear strength compared to metals
Solution Approach 1:
The fastening system applies local quality by concentrating the reinforcement function in the bushing element at the specific location where the fastener interfaces with the composite component. The bushing's enlarged head and shank geometry provide localized structural support and stress distribution exactly where needed, allowing the rest of the composite component to maintain its lightweight properties.
Solution Approach 2:
The solution employs a composite fastening system where the bushing element (potentially made of metal or hybrid material) is integrated with the composite component. This composite approach combines materials with different properties - the bushing provides strength and stiffness where loading occurs, while the composite component maintains overall lightweight structure.
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 assembly effectively dampens vibrations, resists forces that could pull it out of the composite material, and simplifies the installation process in constrained spaces, thereby prolonging the life of composite components and maintaining structural integrity.
Implementation Method 1
elements of the fasteners may be formed of a softer, more flexible material than the surrounding components and may interrupt propagation of vibrations between the components by at least partially absorbing and dampening the vibrational energy
Data Source
AI summary
Methods and systems are provided for a fastening assembly. In one example, the fastening assembly includes a vibration dampening element, a two-piece insert, a lower portion, and a fastener configured to engage with the two-piece insert and the lower portion of the assembly. The fastening assembly may be at least partially assembled during manufacture of components to be coupled via the fastening assembly, allowing the components to be readily coupled during final installation of the fastening assembly.