Rebound Valve Assembly for Shock Strut Extension Damping
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Solution Overview
Problem
Existing rebound valve systems in shock strut assemblies for aircraft landing gear face manufacturing difficulties and assembly issues due to the use of slip rings, which can lead to inefficiencies in controlling piston extension velocity and damping.
Innovation Solution
A rebound valve system featuring a snubber assembly with a plurality of restrictor valves and seal valves, where the restrictor valves are configured to pivot and open during compression, allowing metered flow from a rebound chamber to a hydraulic chamber, and seal valves to prevent backflow during extension, thereby controlling piston extension rate and minimizing cavitation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If slip rings are used in rebound valve systems, then piston extension velocity control is achieved, but manufacturing difficulties and assembly issues occur
Solution Approach 1:
The patent removes the problematic slip ring component from the rebound valve system and replaces it with a simplified valve assembly that achieves the same piston extension velocity control function through alternative means, eliminating manufacturing and assembly difficulties associated with slip rings
Solution Approach 2:
The invention employs simpler, more easily manufactured valve components that can be produced at lower cost and with greater ease than slip rings, sacrificing the reusability aspect in favor of manufacturing simplicity and overall system reliability
2Speed
If restrictor valves are used to meter fluid flow, then piston extension rate is controlled, but device complexity increases
Solution Approach 1:
The rebound valve system is divided into multiple independent restrictor valves, each with its own orifice, allowing individual optimization of each valve while maintaining overall system functionality and simplifying the design of each individual component
Solution Approach 2:
The patent controls piston extension rate by varying the orifice size and flow resistance parameters of the restrictor valves, achieving precise speed control through parameter optimization rather than complex mechanical mechanisms
3Ease of manufacture
If multiple valves are disposed in valve receptacles, then assembly is simplified, but mis-assembly risk increases
Solution Approach 1:
The patent employs asymmetric keying features on the valves and corresponding asymmetric recesses in the valve receptacles, creating a unique geometric fit that prevents mis-assembly while maintaining the simplified multi-valve configuration
Solution Approach 2:
The keying features act as intermediary geometric elements between the valves and receptacles, providing a mechanical interface that guides proper alignment and prevents incorrect assembly without complicating the overall valve structure
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 effectively dampens piston extension, reduces manufacturing costs, simplifies assembly, and enhances the robustness of the shock strut assembly by allowing for a consistent and controlled flow of fluid, ensuring consistent performance and reduced risk of clogging.
Implementation Method 1
A fluid may be configured to flow from the rebound chamber through the orifice and a respective radial aperture in the plurality of radial apertures into the oil chamber during the extension of the strut piston
Implementation Method 2
A flow of fluid may be configured to pivot the plurality of restrictor valves about a pivot axis to open the plurality of restrictor valves during the compression of the strut piston
Implementation Method 3
The plurality of seal valves may include a first keying feature and the plurality of restrictor valves may include a second keying feature to prevent mis-assembly
Implementation Method 4
The gas acts as an energy storage device, similar to a spring, so that upon termination of a compressing force the shock strut returns to its original length
Implementation Method 5
Shock struts also dissipate energy by passing the oil through the orifice so that as the shock absorber is compressed or extended, its rate of motion is limited by the damping action from the interaction of the orifice and the oil
Data Source
AI summary
A snubber assembly may comprise a snubber having a snubber body with an inner diameter surface and an outer diameter surface, the snubber including a plurality of valve receptacles disposed in the outer diameter surface, the snubber including a plurality of radial apertures disposed through the snubber body, each radial aperture in the plurality of radial apertures disposed in a respective valve receptacle in the plurality of valve receptacles; and a plurality of restrictor valves, each restrictor valve in the plurality of restrictor valves disposed in a respective valve receptacle in the plurality of valve receptacles, each restrictor valve in the plurality of restrictor valves including an orifice disposed through a blade.