Shock Strut Servicing System for Trapped Gas Removal
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Solution Overview
Problem
Conventional shock strut assemblies in aircraft landing gear degrade over time, leading to increased maintenance costs and complexity due to trapped gas issues, requiring time-consuming servicing procedures.
Innovation Solution
A shock strut servicing assistance system that uses sensors to monitor gas temperature, pressure, and oil levels, providing automated guidance for adding or removing fluids, simplifying the servicing process by calculating the required volumes and eliminating the need for reference charts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If shock struts are serviced using conventional single stage procedures, then the aircraft must be lifted and the shock strut cycled multiple times to remove trapped gas, but this process is time consuming and costly
Solution Approach 1:
The shock strut system transitions from a static single-stage design to a dynamic two-stage system where the piston can be positioned at different stages (first stage for initial servicing, second stage for complete gas removal). This dynamic positioning allows the servicing process to adapt to different phases of gas removal, enabling complete trapped gas elimination without requiring multiple full cycling operations.
Solution Approach 2:
The system changes the operational parameters by introducing a two-stage configuration that modifies the piston position and fluid pressure characteristics. By adjusting the stage position parameter, the system creates different pressure zones that facilitate progressive gas removal, replacing the conventional approach of repeated full cycling with a controlled parameter-based servicing sequence.
2Reliability
If shock struts use conventional servicing methods, then trapped gas must be removed through multiple cycling operations, but this increases maintenance complexity and costs
Solution Approach 1:
The servicing process is segmented into distinct stages corresponding to the two-stage shock strut configuration. The first stage handles initial fluid top-up and basic servicing, while the second stage is dedicated to complete trapped gas removal. This segmentation allows each stage to be optimized for its specific function, reducing overall procedure complexity compared to repeated full cycling operations.
Solution Approach 2:
The system performs preliminary actions by positioning the piston at the appropriate stage before servicing begins. The first stage is prepared for initial fluid addition, and the second stage is prepared for complete gas removal. This preliminary configuration eliminates the need for multiple trial-and-error cycling operations, streamlining the servicing procedure.
3Quantity of substance
If conventional shock strut designs are used, then trapped gas remains internal to the shock strut, but this causes performance degradation and component damage over time
Solution Approach 1:
The system extracts trapped gas from the shock strut by utilizing the second stage configuration. The piston position in the second stage creates a pathway and pressure differential that enables complete removal of trapped gas from the system. This extraction process eliminates the harmful trapped gas that would otherwise cause performance degradation and component damage over time.
Data Source
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AI summary
System and methods for servicing and monitoring shock struts are provided. A shock strut servicing assistance system may comprise: a controller (602) in electronic communication with a display (604); and a tangible, non-transitory memory configured to communicate with the controller, the tangible, non-transitory memory having instructions stored thereon that, in response to execution by the controller, cause the controller to perform operations comprising: calculating, by the controller, a dead volume of the shock strut; and determining, by the controller, if a dead volume of the shock strut is negative or not. The operations may further comprise receiving, by the controller, a temperature of a gas and at least one shock strut design parameter, wherein the calculating is performed using the temperature of the gas and the at least one shock strut design parameter.