Cam-Profile Servo Valve for Fast, Compact Fluid Control

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Solution Overview

Problem

Conventional servo valves are bulky, complex, and prone to contamination, leakage, and slow response due to large size and complex construction, making them inefficient for high-frequency fluid flow management with high power consumption.

Innovation Solution

A compact servo valve design featuring a moveable valve spool with a torsion spring or mechanical position feedback, utilizing a cam-profiled flapper element to control fluid flow paths, eliminating the need for extensive channels and springs, and integrating a distribution sleeve for improved fluid dynamics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If conventional servo valve designs are used, then fluid flow control capability is achieved, but the valve becomes bulky and complex with slow response time

Engineering Contradiction:
Improveresponse timeVSAvoidconstruction complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The valve body is divided into multiple segments that can be assembled together, allowing complex internal flow paths to be created through modular construction rather than monolithic machining. This segmentation enables sophisticated fluid control functionality while maintaining manufacturing simplicity and reducing overall complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a vertical stacking arrangement where valve components are arranged in multiple layers or levels. This dimensional reorganization allows complex fluid pathways to be achieved through vertical integration rather than horizontal expansion, reducing the valve's footprint and simplifying internal flow path design.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Quantity of substance

If large valve orifice areas are used to handle high flow rates, then fluid flow capacity is improved, but the valve size increases and becomes bulky

Engineering Contradiction:
Improvefluid flow rateVSAvoidvalve size
Core Design Contradiction:
Quantity of substanceVSVolume of moving object

Solution Approach 1:

The valve employs nested or concentric flow paths where multiple fluid channels are arranged one within another or in overlapping configurations. This nesting allows the valve to handle multiple fluid streams or higher total flow rates within a compact cross-sectional area, effectively increasing flow capacity without proportionally increasing valve size.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent utilizes vertical stacking to arrange flow paths in multiple levels, allowing high flow rates to be achieved through three-dimensional space utilization rather than increasing horizontal orifice area. This dimensional approach maintains compact valve dimensions while accommodating high fluid throughput.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of operation

If extensive fluid channels and long fluid paths are used, then fluid flow control is achieved, but response time slows down and contamination risk increases

Engineering Contradiction:
Improvefluid flow controlVSAvoidresponse time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The fluid control function is segmented into discrete, localized control stages distributed throughout the valve structure. Each segment handles a specific aspect of flow control, allowing rapid local response without requiring fluid to traverse long continuous paths. This segmentation maintains precise flow control capability while minimizing transit time.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent reorganizes fluid pathways into compact three-dimensional configurations with short vertical and horizontal distances. By stacking control elements vertically and creating direct fluid pathways between them, the design achieves effective fluid control with minimal path length, thereby reducing response time and contamination exposure.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Adaptability or versatility

If conventional servo valve designs with multiple moving parts are used, then fluid flow control functionality is achieved, but the system becomes vulnerable to contamination, damage and leakage

Engineering Contradiction:
Improvefluid flow control functionalityVSAvoidcontamination and leakage resistance
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent extracts and eliminates unnecessary moving parts from the conventional servo valve design, retaining only the essential components required for fluid control functionality. By removing redundant mechanical elements, the design reduces potential failure points, leakage paths, and contamination sources while maintaining adequate flow control capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The valve incorporates self-centering mechanisms and automatic sealing features that eliminate the need for additional actuators or complex positioning systems. These self-service features reduce the number of moving parts required while ensuring reliable operation and sealing, thereby improving resistance to contamination and leakage without sacrificing functionality.

Inventive Principle:
Principle #25Self-service

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 results in a smaller, lighter, and more responsive servo valve with reduced power consumption, improved fluid dynamics, and enhanced reliability, capable of handling high-frequency fluid flows while minimizing contamination and leakage risks.

Implementation Method 1

A compact servo valve design featuring a moveable valve spool with a torsion spring or mechanical position feedback

Methodology Applied
Scientific EffectTorsion spring: Torsion Spring

Implementation Method 2

utilizing a cam-profiled flapper element to control fluid flow paths

Methodology Applied
Scientific EffectFluid pressure: Pressure Gradient

Implementation Method 3

control fluid flow paths, eliminating the need for extensive channels

Methodology Applied
Scientific EffectFluid flow:

Data Source

PatentEP3875783B1Servo valve
Publication Date: 2024.01.03 HAMILTON SUNDSTRAND CORP
  • EP3875783B1 patent drawingFigure 1a
  • EP3875783B1 patent drawingFigure 1b~1c
  • EP3875783B1 patent drawingFigure 2~4

AI summary

A servo valve comprising: a fluid transfer valve assembly (100) comprising a supply port (13) and a control port (PA, PB); a moveable valve spool (2) arranged to regulate flow of fluid from the supply port to the control port in response to a control signal; and a drive means configured to axially move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow; wherein the drive means comprises an elongate member (120) arranged to rotate in response to the control signal, the elongate member having a cam profile in the fluid flow path such as to vary the pressure acting on the ends of the spool as the cam profile rotates.