Servo Valve Nozzle Housing With Misaligned Apertures Against Contamination
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Solution Overview
Problem
Single stage air servo valves are vulnerable to contamination from external particles like sand and dust when there is no or low flow from the return nozzle, which can impair control and damage components.
Innovation Solution
A nozzle housing design with misaligned apertures in the first and second plates prevents linear axial flow between the return port and opening, incorporating debris removal passages and a separating ring to trap and eject particles, ensuring continuous protection from contaminants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a return nozzle is in fluid communication with the atmosphere to protect from external contaminants during operation, then protection from contaminants is improved, but vulnerability to contamination increases when there is no or low flow from the return nozzle
Solution Approach 1:
The return passage is segmented by inserting a first plate and a second plate with misaligned apertures, creating multiple flow paths rather than a single direct path. This segmentation disrupts linear flow while maintaining atmospheric communication during operation.
Solution Approach 2:
The apertures in the first plate and second plate are deliberately misaligned asymmetrically, so that no aperture in the first plate aligns with any aperture in the second plate when viewed along the axial direction. This asymmetric arrangement prevents linear axial flow paths while allowing turbulent mixing and contaminant trapping.
2Object-affected harmful factors
If plates with apertures are inserted to prevent linear axial flow paths, then contamination protection is improved, but device complexity increases
Solution Approach 1:
The first plate and second plate serve multiple functions: they maintain atmospheric communication through their apertures, prevent linear axial flow paths through misalignment, and work with the separating ring to trap and eject contaminants. This multi-functionality reduces the need for additional separate components.
Solution Approach 2:
The first plate, second plate, and separating ring are nested within the return passage in sequence, with each component fitting within the housing structure. This nested arrangement integrates multiple protective functions into a compact configuration without requiring separate external systems.
3Object-affected harmful factors
If misaligned apertures are used to block linear axial flow, then particle trapping is improved, but flow resistance increases
Solution Approach 1:
Both the first plate and second plate are provided with multiple apertures, ensuring that while linear paths are blocked, sufficient total aperture area remains to maintain adequate flow. The misalignment is partial rather than complete blockage, allowing turbulent flow to pass while trapping particles.
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 design effectively prevents contamination by blocking direct axial flow paths and utilizing debris removal passages to trap and eject particles, maintaining operational integrity even during low flow conditions.
Implementation Method 1
the first plate has at least one first aperture, and the second plate has at least one second aperture that is misaligned with the at least one first aperture such that there is no linear axial flow path between the return port and the opening
Implementation Method 2
incorporating debris removal passages and a separating ring to trap and eject particles
Data Source
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AI summary
A nozzle housing (6) for a servo valve (1), the nozzle housing (6) comprising a circumferential wall (9b) defining a return passage (8b) extending along a longitudinal axis (A) for holding a return nozzle (18), the return passage (8b) having an opening (13) for fluid communication with a spool valve and a return port (14) for fluid communication with atmosphere, a first plate (102) extending across the return passage (8b), the first plate (102) engaged with the circumferential wall (9b) and disposed between the opening (13) and the return port (14), and a second plate (106) extending across the return passage (8b), the second plate (106) engaged with the circumferential wall (9b) and disposed between the first plate (102) and the return port (14), wherein the first plate (102) has at least one first aperture (102a), and the second plate (106) has at least one second aperture (106a) that is misaligned with the at least one first aperture (102a) such that there is no linear axial flow path between the return port (14) and the opening (13).