Aircraft Fan Drive Shaft Connecting Module with Fusible Ball Joint
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Solution Overview
Problem
Existing aircraft engine designs with fan blades face challenges in managing the imbalance caused by the loss of fan blades, leading to high radial forces that can rupture mechanical connections, causing structural damage and requiring complex and costly adjustments to maintain engine integrity.
Innovation Solution
A connecting box with a ball joint mechanism is introduced between the fan rotor drive shaft and the intermediate rolling bearing, featuring a blocking member with radial support means that break upon excessive force, allowing for controlled decoupling and reducing the impact of resistant forces, facilitating easier operation and adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a mechanical fuse connection is used to maintain bearing support during normal operation, then the bearing support can withstand radial forces under normal conditions, but it ruptures under extreme imbalance forces causing structural damage and requiring complex adjustments
Solution Approach 1:
The mechanical connection is segmented into a fusible element that can break independently, separating the bearing support function from the rigid mechanical link. This allows the bearing support to remain intact while the fusible element fails safely under extreme forces, avoiding complex structural damage and adjustments.
Solution Approach 2:
A fusible mechanical link acts as an intermediary between the bearing support and the drive shaft, absorbing extreme forces through controlled rupture. This intermediary protects the main bearing support structure from damage while maintaining operational simplicity.
2Stability of the object's composition
If the drive shaft is rigidly connected to the intermediate bearing, then the shaft is properly guided during normal operation, but it cannot accommodate radial movement during blade loss causing excessive bending stresses
Solution Approach 1:
The connection between the drive shaft and intermediate bearing is made dynamic through a fusible mechanical link that transitions from a rigid constrained state during normal operation to a flexible decoupled state under extreme forces. This allows the shaft to accommodate radial movement and reduce bending stresses when needed.
Solution Approach 2:
The mechanical connection parameters change from rigid to flexible through controlled rupture of the fusible element. This parameter change allows the system to adapt to extreme conditions by permitting shaft movement that reduces bending stresses while maintaining proper guidance during normal operation.
3Stability of the object's composition
If the ball joint is maintained in a blocked state with tight fit, then the connecting box is stable during normal operation, but it creates significant resistant forces that disturb ball joint operation after unlocking
Solution Approach 1:
The blocking function is extracted from the ball joint's tight fit and placed in a dedicated fusible mechanical link. This allows the ball joint to operate smoothly after unlocking without the disturbance of residual resistant forces from a tight fit, while the connecting box remains stable during normal operation through the blocking member.
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
This solution enables quick and controlled mechanical decoupling, minimizing structural damage and simplifying adjustments, thus preserving engine integrity and reducing operational complexities.
Implementation Method 1
means forming a mechanical fuse providing the junction between the blocking member and the spherical seat, so that said ball joint is released following the rupture of these means forming a fuse
Data Source
Figure 1~2
Figure 3~4
Figure 5~6b
AI summary
The invention relates to a connecting module (18) arranged between a drive shaft (8) of an engine fan of an aircraft and a rolling element bearing (12b), said module comprising an inner structure (26) fixed to the shaft (8) and having a bonnet (32), and an outer structure (46) fixed to the bearing (12b) and radially supported on means (42) provided on the inner structure and defining a track (48) complementary to the bonnet (32) in such a way as to form a ball-joint connection (50) maintained in a blocked state by a blocking body (34) provided on the inner structure and projecting radially from the bonnet (32). Means forming a mechanical fuse (37) ensure the junction between the body and the bonnet (32) such that the ball-joint connection is released following the rupture of said means. According to the invention, the radial supporting means (42) are arranged on the body (34).