Circular Force Generator Mounting for Stiffness and Redundancy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current circular force generators (CFGs) used in Active Vibration Control Systems (AVCS) for helicopters are inadequate for generating large output forces, prone to structural failure, and lack safety redundancies, especially for CFGs with diameters exceeding 300 mm, posing risks of housing loss and insufficient stiffness.
Innovation Solution
The introduction of a circular force generator (CFG) with a center attachment point and redundant attachment points, including split lugs, compound fasteners, and crack-arresting ribs, enhances stiffness, safety redundancy, and damage tolerance, allowing for smaller, lighter designs capable of generating larger forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the CFG diameter is increased to generate larger output forces, then the force generation capability is improved, but the structural stiffness decreases and the housing becomes prone to failure
Solution Approach 1:
The patent transitions from conventional peripheral-only mounting to a three-dimensional mounting architecture that includes both peripheral mounting lugs and a central mounting point on the inner shaft. This adds a new spatial dimension (center of the housing) for attachment, creating multiple load paths that distribute forces more effectively throughout the structure, thereby maintaining stiffness in larger diameter CFGs
Solution Approach 2:
The mounting system is segmented into multiple independent attachment points: peripheral mounting lugs and a central inner shaft mounting point. This segmentation allows the structure to be divided into separate load-bearing zones, preventing stress concentration at any single point and improving overall structural integrity against vibration-induced failure
2Reliability
If conventional mounting methods are used, then the device complexity is low, but the safety redundancy is insufficient and the housing is prone to loss
Solution Approach 1:
The patent implements redundant mounting points and split lugs with multiple holes as preventive measures against housing loss. These features provide backup attachment paths before failure occurs, ensuring that if one mounting point fails, the housing remains secured through alternative paths, thereby cushioning against the harmful effect of complete detachment
Solution Approach 2:
The mounting lugs are designed with multiple holes (at least two holes per lug), allowing for multiple fastener configurations. This parameter change in the mounting structure enables flexible fastening options and creates inherent redundancy, where failure of one fastener does not compromise the entire mounting system
3Force
If the CFG is designed for larger diameters, then the force generation capability is improved, but the weight and mass increase
Solution Approach 1:
By adding the central inner shaft mounting point, the patent creates an additional load path that allows for more efficient force transmission. This enables the design of lighter CFGs with larger diameters, as the three-dimensional mounting architecture distributes loads more effectively, reducing the need for excessive structural reinforcement that would increase weight
Data Source
AI summary
The present disclosure provides an improved circular force generator having a housing configured to reduce vibrational forces transmitted to an aircraft structure. Additionally, the disclosed configuration provide the necessary safety redundancies required by the aviation industry. The circular force generator includes mounting point around the exterior of the CFG housing and a central mounting point thereby providing redundant mounting points.