Aircraft Suspension Rudder Bar Reducing Master-Couple
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Solution Overview
Problem
Conventional suspension rudder bars for aircraft turbojets have a large transversal width, leading to a high master-couple and preventing the implementation of thin aerodynamic lines, as they need to accommodate multiple links and connecting rods, which increases the risk of large structural failures and thermal load variations.
Innovation Solution
The rudder bar design is modified to reduce its transversal bulk by moving contact areas inward, featuring spars that extend perpendicular to the axis and form a triangular shape around the connecting rods, with a central link system and a male fork joint, allowing for a reduced master-couple and improved aerodynamics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the rudder bar has a large transversal width to accommodate multiple links and connecting rods, then the structural integrity and reliability are improved, but the master-couple increases and thin aerodynamic lines cannot be implemented
Solution Approach 1:
The patent repositions the connecting rod attachment points from the outer edges to the interior of the rudder bar, moving contacts toward the centerline. This dimensional repositioning reduces the lever arm length, thereby reducing the master-couple while maintaining structural integrity through the interior placement of load-bearing connections.
Solution Approach 2:
The rudder bar is segmented into functional zones with spars extending perpendicular to the axis, creating a triangular configuration. This segmentation allows the connecting rods to be attached at optimized interior points while distributing loads through the spar structure, reducing the overall master-couple effect.
2Reliability
If the rudder bar has a large transversal width to accommodate multiple links and connecting rods, then the structural integrity is improved, but thin aerodynamic lines cannot be implemented
Solution Approach 1:
By moving the attachment points to the interior of the rudder bar rather than the outer edges, the external profile is streamlined. This allows thin aerodynamic lines to be implemented while the internal structure maintains the necessary structural integrity through properly positioned connecting rod attachments.
3Volume of moving object
If the contact areas are moved toward the interior of the rudder bar, then the transversal bulk is reduced, but the structural capacity to manage loads must be maintained
Solution Approach 1:
The rudder bar structure is segmented with spars extending perpendicular to the axis, creating a triangular configuration that distributes loads efficiently. This segmentation allows interior placement of contact areas while maintaining load management capacity through the distributed spar structure.
Solution Approach 2:
The spars are positioned to provide localized structural reinforcement at critical load-bearing points. This local quality enhancement allows the overall transversal bulk to be reduced while maintaining sufficient strength through concentrated structural elements where loads are applied.
Data Source
AI summary
A suspension rudder bar has the shape of a bar with a transversal axis (Y′Y), symmetrical with respect to a plane (PS) intersecting the rotation axis (X′X) of the engine, and includes links with transmission connecting rods between a rear casing for ejecting gases and a front casing hub of the fan, and a central link to a fastening fixation to an engine fastening pylon. The links of the rudder bar to the transmission connecting rods are arranged on the transversal ends of the rudder bar, and the rudder bar extends, perpendicularly to the axis of the bar (Y′Y), with spars over a sufficient portion and at a determined distance from the edges of the plate to act as an abutment to the plate in the case of a torsion around the central link or of a connecting rod breaking.