Bellows Accumulator Gap Damping for High-Frequency Pulsation
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Solution Overview
Problem
Conventional bellows accumulators fail to effectively dampen pressure peaks at high frequencies and vibration loads in safety-critical hydraulic systems, such as aircraft components, due to limitations in their operational safety and damping performance.
Innovation Solution
A bellows accumulator design featuring a gap size between 3.0 mm and 0.15 mm between the bellows and the housing, forming a sliding guide that provides hydraulic damping and protects against excessive vibration, with a hydrostatic sliding film, allowing the bellows to move parallel to the housing axis without additional mass, and using high-viscosity oils and nitrogen gas for enhanced safety and damping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional bellows accumulators are used, then they can provide basic damping, but they fail to effectively dampen pressure peaks at high frequencies and are subjected to excessive vibration loads
Solution Approach 1:
The patent introduces a guiding sleeve as an intermediary element between the bellows and the housing. This sleeve absorbs and reduces vibration loads transmitted to the bellows, protecting it from excessive vibration while maintaining operational safety in critical hydraulic systems
Solution Approach 2:
The patent optimizes the gap dimension parameter between the bellows outer diameter and housing inner diameter to a specific range (0.15-3.0 mm). This parameter change enables effective hydraulic damping at high frequencies while controlling vibration transmission to the bellows
2Reliability
If the gap between bellows and housing is increased, then hydraulic damping is reduced, but if decreased, then sliding guidance is compromised
Solution Approach 1:
The patent precisely defines the optimal gap dimension range (0.15-3.0 mm) between bellows and housing. Within this range, the gap is small enough to provide effective hydraulic damping at high frequencies while large enough to allow smooth sliding movement of the bellows along the housing axis
Solution Approach 2:
The guiding sleeve acts as a mediator that facilitates bellows movement while maintaining the optimized gap dimension. It ensures the bellows moves smoothly parallel to the housing axis without compromising the damping performance provided by the controlled gap
3Object-affected harmful factors
If a sleeve element is added to protect bellows from vibration, then protection is improved, but additional movable mass is introduced affecting response at high frequencies
Solution Approach 1:
The patent optimizes the guiding sleeve parameters (wall thickness, length, material) to minimize its movable mass while maintaining vibration protection functionality. This allows the sleeve to protect the bellows from vibration loads without significantly affecting the response characteristics at high frequencies
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 optimal damping behavior and response at high frequencies, providing effective hydraulic damping and protecting the bellows from vibration stress, while meeting safety requirements for aeronautical applications.
Implementation Method 1
a sliding guidance of the bellows folds in the storage housing is achieved, because with a small gap width a kind of sliding bearing with a lubricating film formed by the oil is created
Implementation Method 2
the size of the spaces for realizing the hydraulic damping on the oil side is selected such that, by including the oil in the gap between the outer diameter of the bellows and the inner wall of the housing, a sliding guidance of the bellows folds in the storage housing is achieved
Implementation Method 3
Such bellows accumulators are preferably used in hydraulic systems as pulsation dampers to reduce or smooth pressure peaks occurring in pressurized fluids
Implementation Method 4
a bellows (3), included in a storage housing (1), separates two media spaces, forming an oil side (27) and a gas side (28)
Data Source
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AI summary
The invention relates to a bellows accumulator, in particular a pulsation damper, comprising a bellows (3), which, arranged in an accumulator housing (1), separates two media chambers (27, 28) from each other and the bellows folds (19) of which can be moved at least partially along the inner wall (35) of the accumulator housing (1). Said bellows accumulator is characterized in that the outside diameter of the bellows folds (19) is selected to be slightly smaller than the associable diameter of the inner wall (35) of the accumulator housing (1) in such a way that spaces (37, 41) are formed, which together form a hydraulic damping means for at least one medium.