Spring-Biased Thrust Reverser Compression Rod
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Solution Overview
Problem
The existing compression rod systems in gas turbine propulsion systems for commercial aircraft face challenges in ensuring precise engagement and preload between thrust reverser halves, leading to potential loose fits, rattling, and vibration due to large tolerances and rigidity, requiring time-consuming and skill-intensive rigging with shims for adjustment.
Innovation Solution
Incorporating a spring member, such as a washer with a plurality of leaf springs, between the compression rod ends and thrust reverser engagement points to ensure proper engagement and take up tolerance gaps, providing a preload and damping to prevent vibration and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a rigid compression rod system is used to connect thrust reverser halves, then structural strength is maintained, but engagement precision deteriorates due to large tolerances and rigidity, causing loose fits and vibration
Solution Approach 1:
The compression rod system transitions from a completely rigid structure to a dynamic system incorporating spring members that can deflect and adapt. The spring members allow the rigid compression rod to accommodate tolerance variations through elastic deformation, achieving precise engagement without sacrificing structural strength during thrust reverse operations.
Solution Approach 2:
The system changes the physical state of the compression rod by introducing spring members that can change their length and stiffness characteristics. This allows the rod to transition between a rigid load-bearing state during thrust reverse and a flexible engagement state during assembly, resolving the contradiction between strength and precision.
2Force
If a rigid compression rod system is used, then load bearing capacity is maintained, but device complexity increases due to requirement for shims and rigging adjustments
Solution Approach 1:
The spring members provide self-adjusting functionality, automatically compensating for tolerance gaps and setting appropriate preload without requiring external shims or complex rigging procedures. The system serves itself by using the spring deflection to absorb dimensional variations and establish proper engagement conditions.
Solution Approach 2:
The invention extracts the adjustment function from the rigid rod system and places it in the spring members. This separates the load-bearing function (performed by the rigid rod) from the adjustment function (performed by the flexible spring members), eliminating the need for shims and complex rigging while maintaining load capacity.
3Manufacturing precision
If spring members are added to the compression rod system, then engagement precision is improved, but device complexity increases due to additional components
Solution Approach 1:
The spring members serve multiple functions simultaneously: they act as precision adjustment elements to eliminate tolerance gaps, provide preload to ensure engagement, and function as vibration dampers. By combining these functions in a single component, the invention improves precision without proportionally increasing overall system complexity.
Solution Approach 2:
The invention merges the adjustment, preload, and damping functions into the spring member components. This consolidation means that while additional components are introduced, each component performs multiple critical functions, thereby improving engagement precision without a linear increase in overall device complexity.
4Reliability
If spring members are used between compression rod and engagement features, then vibration and wear are reduced, but manufacturing complexity increases due to spring assembly requirements
Solution Approach 1:
The spring members are pre-assembled between the compression rod and engagement features during manufacturing, providing beforehand cushioning against vibration and impact loads. This pre-assembly approach, while adding a manufacturing step, ensures proper preload and positioning is established before the product reaches the customer, reducing field adjustments and improving 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 spring member ensures consistent and secure engagement of the compression rod with thrust reverser halves, reducing the need for complex adjustments and minimizing wear by maintaining contact and preload, thus enhancing the reliability and stability of the thrust reverser system.
Implementation Method 1
a spring member located between the engagement feature and the compression rod, wherein in response to the aircraft nacelle moving to the closed position, the spring member is compressed
Implementation Method 2
providing a preload and damping to prevent vibration and wear
Data Source
AI summary
An arrangement may comprise a spring member. A proximal end and a distal end of a compression rod may contact engagement features via the spring member in a core cowl of a gas turbine engine. The compression rod may transmit loads between halves of the core cowl. The spring member may compress and decompress in response to vibrations or other relative movement between halves of the core cowl.