Snubber Rebound Valve Assembly for Controlled Piston Extension
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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 preventing bottoming impact loads.
Innovation Solution
A rebound valve system featuring a snubber assembly with pivotable restrictor valves and seal valves, which include orifices and keying features to prevent misassembly, allowing for controlled fluid flow between chambers to manage piston extension and prevent cavitation, while reducing manufacturing costs and simplifying assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional rebound valve systems use slip rings, 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 direct valve assembly that connects the rebound chamber to the oil chamber. This extraction of the problematic element eliminates the manufacturing difficulties and assembly issues associated with slip rings while maintaining the essential function of controlling fluid flow between chambers.
Solution Approach 2:
The patent employs simpler, more readily manufacturable valve components that can be produced at lower cost and with greater ease than traditional slip ring systems. These valves are designed to be functional and reliable without requiring complex precision machining or specialized assembly procedures, effectively replacing expensive, difficult-to-manufacture components with more accessible alternatives.
2Device complexity
If restrictor valves are made pivotable with orifices, then assembly is simplified and manufacturing cost reduced, but precise control of fluid flow may be compromised
Solution Approach 1:
The patent employs pivotable restrictor valves that can rotate to different positions, allowing the system to dynamically adjust fluid flow characteristics. The valves transition between closed, partially open, and fully open states based on operational requirements, providing precise control through motion rather than through complex fixed geometries. This dynamic approach simplifies the overall device structure while maintaining control precision.
Solution Approach 2:
The patent controls fluid flow precision by changing the orientation parameter of the pivotable valves rather than relying on fixed, precisely manufactured flow paths. By varying the valve angle and position, the system can precisely regulate flow rate and pressure without requiring extremely tight manufacturing tolerances on the valve bodies themselves, thus reducing manufacturing complexity while maintaining control accuracy.
3Reliability
If multiple restrictor valves are used around the piston, then piston extension control is improved and cavitation prevented, but device complexity increases
Solution Approach 1:
The patent divides the fluid flow control function into multiple discrete restrictor valves distributed around the piston periphery. Each valve handles a portion of the total flow, allowing independent optimization of each valve's design and simplifying the overall system. This segmentation provides redundant control paths, so if one valve is partially blocked or malfunctioning, others can maintain adequate flow control, thereby improving reliability without requiring each individual valve to be overly complex.
Solution Approach 2:
The multiple restrictor valves perform multiple functions simultaneously: they control piston extension velocity, prevent cavitation in the rebound chamber, and provide redundant flow paths. Each valve is a simple, universal component that contributes to several system objectives, reducing the need for specialized complex mechanisms while achieving comprehensive control and protection functions.
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 system effectively meters oil flow to control piston extension, preventing cavitation and bottoming forces, while being more cost-effective and easier to assemble than traditional systems, with a robust design that maintains performance even if one valve is clogged.
Implementation Method 1
each restrictor valve in the plurality of restrictor valves including an orifice disposed through a blade
Implementation Method 2
A shock strut generally accomplishes these functions by compressing a fluid within a sealed chamber formed by hollow telescoping cylinders. The fluid generally includes both a gas and a liquid
Implementation Method 3
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 4
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
Implementation Method 5
each restrictor valve in the plurality of restrictor valves configured to open during a compression of the strut piston relative to the strut cylinder, and each restrictor valve configured to at least partially close during an extension of the strut piston
Data Source
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AI summary
A snubber assembly may comprise a snubber (210) having a snubber body with an inner diameter surface and an outer diameter surface, the snubber including a plurality of valve receptacles (410) disposed in the outer diameter surface, the snubber including a plurality of radial apertures (212) 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 (220), 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.