Thrust Reverser Actuating Assembly Locking Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing thrust reverser actuating assemblies for aircraft engines have complex locking systems with multiple abutments and articulated locking bars, which are prone to misalignment and require complex designs to prevent undesired opening, leading to challenges in reliable locking and maintenance.
Innovation Solution
A simplified actuating assembly with a unique abutment secured to the drive shaft and a cotter that moves between locking and unlocking positions, utilizing an even reduction ratio between slave and master pinions, allowing for reliable locking and easy alignment during mounting, and providing a 2 mm clearance for effective locking despite dimensional tolerances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple abutments and articulated locking bars are used in the locking system, then the thrust reverser can be prevented from undesired opening, but the device complexity increases and misalignment becomes more prone
Solution Approach 1:
The patent removes the complex articulated locking bars and multiple abutments from the system, retaining only the essential elements: a single abutment on the drive shaft and a simple cotter for locking. This extraction of unnecessary components directly reduces device complexity while maintaining the core locking function through the simplified even reduction ratio mechanism.
Solution Approach 2:
The locking system is segmented into distinct functional elements: the abutment provides the locking surface, the cotter provides the locking action, and the even reduction ratio between master and slave pinions provides the synchronization mechanism. This segmentation allows each component to be simple and robust, avoiding the need for complex articulated structures.
2Reliability
If multiple abutments and articulated locking bars are used, then locking function is provided, but alignment difficulty increases during mounting
Solution Approach 1:
The patent eliminates the alignment-critical articulated locking bars and multiple abutments, leaving only a single abutment and simple cotter. The even reduction ratio between pinions inherently ensures proper alignment during mounting, removing the alignment difficulties associated with complex multi-component locking systems.
3Reliability
If complex locking systems are used, then thrust reverser locking is achieved, but weight increases
Solution Approach 1:
The patent removes the heavy articulated locking bars and multiple abutments from the actuating assembly, retaining only the essential locking elements. The simplified design with a single abutment and cotter, combined with the even reduction ratio mechanism, significantly reduces the weight of the moving parts while maintaining effective locking capability.
4Reliability
If multiple abutments and locking bars are used, then locking is provided, but maintenance cost and complexity increase
Solution Approach 1:
The patent eliminates the maintenance-intensive articulated locking bars and multiple abutments, leaving only a simple cotter and single abutment system. The even reduction ratio mechanism is inherently robust and requires minimal maintenance. This extraction of complex components directly reduces maintenance costs and simplifies repair procedures.
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 solution ensures reliable locking of the thrust reverser in the closed position during mounting and operation, reducing complexity, weight, and maintenance costs, while allowing for slight clearance to accommodate dimensional variations.
Implementation Method 1
a ball screw bearing a slave pinion engaging with said master pinion, a nut capable of translating over the ball screw as a result of the rotation thereof
Implementation Method 2
a master pinion, a ball screw bearing a slave pinion engaging with said master pinion
Data Source
AI summary
An actuating assembly for an aircraft engine thrust reverser includes a drive shaft bearing a master pinion; a ball screw bearing a slave pinion engaging with the master pinion; a nut capable of translating over the ball screw as a result of the rotation of the ball screw; an extension tube rigidly secured to the nut and a lock assembly to block the rotation of the drive shaft in a so-called direct jet position of the reverser. The extension tube includes, at its free end, a member for connecting to a portion of the reverser prior to being actuated. In particular, the lock assembly includes an abutment secured to the drive shaft, and a cotter moveable between a locking position and an unlocking position. The reduction ratio (R) between the slave and master pinions is even.