Telescoping Landing Gear Shock Strut for Compact Energy Attenuation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing landing gear shock struts for rotary wing aircraft face space constraints that limit their stroke and energy attenuation capability, necessitating a design that can provide more displacement and energy dissipation within a limited space.
Innovation Solution
A dual-stage shock strut design featuring a first piston nested within a second piston, which is then nested within a housing, utilizing pressurized fluid and viscous liquid to achieve extended compression stages, allowing for increased energy absorption in a compact form.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a traditional single-stage shock strut is used, then the structure is simple, but the stroke and energy attenuation capability are limited due to space constraints
Solution Approach 1:
The shock strut employs a nested piston configuration where a first piston is positioned inside a second piston, which is in turn positioned inside a housing. This nested arrangement allows multiple compression stages to occur within a compact footprint, effectively increasing the total stroke length without proportionally increasing the overall device volume, thus resolving the contradiction between structural simplicity and extended stroke capability
2Volume of stationary object
If a traditional single-stage shock strut is used, then the device occupies less space, but the energy attenuation capability is insufficient for crash landing scenarios
Solution Approach 1:
The shock absorption process is segmented into multiple distinct compression stages: a first compression stage involving the first piston, a second compression stage involving the second piston, and potentially a third stage with a floating piston. Each stage absorbs a portion of the impact energy, allowing the system to attenuate large crash landing energies within a limited volume by distributing the energy dissipation across sequential stages rather than requiring a single large-volume chamber
3Length of moving object
If the shock strut volume is increased to provide more stroke, then the energy attenuation capability improves, but the space constraints of the aircraft are violated
Solution Approach 1:
By nesting the first piston within the second piston, and both within the housing, the design achieves an extended effective stroke length without a proportional increase in external volume. The nested configuration allows the pistons to telescope during compression, providing multi-stage stroke action within a compact cylindrical envelope that fits aircraft space constraints
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 design enhances the energy attenuation capability of landing gear systems by providing additional stroke and improved impact dissipation within the limited space constraints of aircraft, effectively managing crash landing energies.
Implementation Method 1
utilizing pressurized fluid and viscous liquid to achieve extended compression stages
Implementation Method 2
In response to application of a force to the shock strut, the first piston is receivable within the second piston during a first stage of compression and together, the first piston and the second piston are receivable within the housing during a second stage of compression
Data Source
AI summary
A shock strut includes a first piston having a first hollow interior and a second piston having a second hollow interior. The first piston is movably mounted to the second piston. The shock strut additionally includes a housing having a third hollow interior, and the second piston is movably mounted to the housing. In response to application of a force to the shock strut, the first piston is receivable within the second piston during a first stage of compression and together, the first piston and the second piston are receivable within the housing during a second stage of compression.