Jet Pipe Servovalve Spool Isolation for Clean High-Flow Control
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Solution Overview
Problem
Conventional servovalves face challenges in handling large fluid flows while maintaining a compact design, being less vulnerable to contamination and leakage, and providing effective fluid filtering.
Innovation Solution
A servovalve design that fluidly isolates the control fluid pathway from the regulated fluid pathway within the spool, allowing independent pressure and quality control, with a secondary fluid supply conduit for filtering the control fluid before it enters the spool, and a steerable nozzle assembly that eliminates the need for an external supply pipe, reducing complexity and vulnerability to damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If jet pipe servovalves are used to handle large fluid flows, then flow capacity is improved, but device complexity and vulnerability to damage increase due to external supply pipes
Solution Approach 1:
The patent merges the fluid supply function into the spool structure itself by creating internal fluid pathways within the spool body. The spool acts as both the control element and the fluid distribution manifold, eliminating the need for separate external supply pipes and connectors. This integration reduces structural complexity while maintaining the ability to handle large fluid flows through properly sized internal orifices.
Solution Approach 2:
The patent implements nesting by placing the fluid supply pathways and control mechanisms inside the spool structure. The internal channels are nested within the spool body, and the control orifices are embedded in the spool surfaces. This nested arrangement consolidates multiple functions into a single compact component, reducing overall device complexity while preserving flow capacity.
2Ease of manufacture
If external supply pipes are used for jet pipe systems, then fluid supply is simplified, but reliability decreases due to vulnerability to damage and external leakage
Solution Approach 1:
By merging the supply pipe function into the spool structure itself, the patent eliminates external pipes that are vulnerable to damage. The spool body becomes self-contained with internal channels that cannot be externally damaged, significantly improving reliability while maintaining ease of assembly through a reduced number of external connections.
Solution Approach 2:
The patent extracts the vulnerable external supply pipe from the system and replaces it with internal pathways. By taking out the external piping element and integrating its function directly into the spool, the system removes the weak link that causes external leakage and damage vulnerability, thereby improving reliability.
3Device complexity
If control fluid and regulated fluid pathways are not isolated, then device complexity is reduced, but manufacturing precision and control accuracy deteriorate due to contamination risks
Solution Approach 1:
The patent segments the fluid pathways by creating distinct internal channels within the spool for control fluid and regulated fluid. These segmented pathways are separated by spool surfaces and internal partitions, preventing cross-contamination while maintaining a compact single-component structure. This segmentation ensures control accuracy by isolating sensitive control fluid from the regulated fluid stream.
Solution Approach 2:
The patent applies local quality by providing different pathway characteristics in different regions of the spool. Control fluid pathways are designed with specific tolerance requirements and sealing arrangements in certain local areas, while regulated fluid pathways have different characteristics. This localized differentiation maintains precision where needed without unnecessarily complicating the overall 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
This design enables efficient handling of large fluid flows with a compact and reliable servovalve that is less susceptible to contamination and leakage, while maintaining precise control and filtering capabilities, enhancing the overall performance and reliability of the system.
Implementation Method 1
a torque motor arranged to generate electromagnetic torque to rotate the jet pipe and nozzle
Implementation Method 2
The filter is arranged to remove particles from the control fluid
Data Source
Figure 1
Figure 2
Figure 2A
AI summary
A servovalve is provided comprising a fluid transfer valve assembly (5) comprising a primary fluid supply port (14) and a control port (15), a moveable valve spool (4) arranged to regulate flow of fluid through a first fluid pathway from the primary fluid supply port (14) to the control port (15), and a jet pipe assembly configured to axially move the spool (4) relative to the fluid transfer valve assembly (5) in response to a control signal to regulate the fluid flow along the first fluid pathway. The jet pipe assembly comprises a steerable nozzle (19') from which fluid is directed to the ends (4a, 4b) of the spool in an amount determined by the control signal. The spool comprises an opening (28') and an interior passage (50) fluidly coupling the opening to the jet pipe assembly via a second fluid pathway. The first fluid pathway is fluidly isolated from the second fluid pathway within the spool.