Hybrid Jet-Flapper Servo Valve for Linear Pressure Control

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Solution Overview

Problem

Existing hydraulic servo valve technologies, such as jet pipe and flapper and nozzle arrangements, face limitations including a lack of compactness, increased complexity and cost due to calibration requirements, non-linear force variation, and limitations in weight reduction, operational pressures, and frequencies.

Innovation Solution

A hybrid 'jet-flapper' servo valve design incorporating a flapper connected to an armature with an electromagnet, optionally using a piezoelectric element, and featuring a return line with adjustable nozzles and control orifices to manage fluid pressure and spool movement, allowing for linear pressure imbalance and actuator control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a jet pipe arrangement is used, then the servo valve can control hydraulic actuators, but the device lacks compactness and has increased complexity

Engineering Contradiction:
Improvevalve complexityVSAvoidcalibration requirements
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent combines the jet pipe and flapper into a single integrated component with a T-shaped cross-section, where the flapper is formed as an integral part of the jet pipe body. This merging eliminates separate calibration requirements for the flapper-nozzle gap and reduces assembly complexity while maintaining the hydraulic control function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated jet pipe-flapper component performs multiple functions simultaneously: it serves as both the jet pipe for fluid delivery and the flapper for flow modulation, eliminating the need for separate calibration procedures for each component and reducing overall device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of operation

If a flapper and nozzle arrangement is used, then the servo valve can provide accurate control, but the force variation is non-linear and calibration is required

Engineering Contradiction:
Improvecontrol linearityVSAvoidassembly complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent merges the flapper and nozzle into a single integral component, eliminating the need for precise gap calibration between separate flapper and nozzle parts. The T-shaped cross-section design provides inherent linear control characteristics without requiring complex assembly procedures.

Inventive Principle:
Principle #5Merging (Combining)

3Weight of moving object

If traditional servo valve designs are used, then the valve can function, but weight reduction is limited

Engineering Contradiction:
Improvevalve weightVSAvoidstructural complexity
Core Design Contradiction:
Weight of moving objectVSDevice complexity

Solution Approach 1:

The integrated jet pipe-flapper design with T-shaped cross-section reduces the number of separate components and fasteners required, thereby reducing overall valve weight. The unified structure eliminates redundant materials while maintaining structural integrity and hydraulic function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent specifies that the integrated jet pipe-flapper component can be manufactured from lightweight materials such as titanium or aluminum alloys, reducing valve weight while maintaining the structural strength and hydraulic performance required for aerospace applications.

Inventive Principle:
Principle #40Composite materials

4Volume of moving object

If separate jet pipe and armature components are used, then the valve can be assembled, but the device is not compact

Engineering Contradiction:
Improvevalve volumeVSAvoidmanufacturing simplicity
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The patent integrates the jet pipe and flapper into a single monolithic component with a T-shaped cross-section, significantly reducing the overall valve volume by eliminating gaps and interfaces between separate parts. The integrated design maintains manufacturing simplicity through conventional machining or additive manufacturing processes.

Inventive Principle:
Principle #5Merging (Combining)

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 hybrid design achieves a more compact, lighter, and simpler servo valve with improved operational pressures and frequencies, enabling linear force adjustment and reduced assembly complexity, suitable for aerospace applications.

Implementation Method 1

an electromagnet configured to move the armature

Methodology Applied
Scientific EffectElectromagnetic force: Electromagnet

Implementation Method 2

a piezoelectric element configured to position the flapper

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 3

hydraulic servo valve...supply pressure inlet...fluid passes through a filter...jet pipe...nozzle

Methodology Applied
Scientific EffectHydraulic pressure: Pressure Gradient

Data Source

PatentEP3628904B1Jet-flapper servo valve
Publication Date: 2022.04.27 HAMILTON SUNDSTRAND CORP
  • EP3628904B1 patent drawingFigure 1
  • EP3628904B1 patent drawingFigure 2
  • EP3628904B1 patent drawingFigure 3A

AI summary

A hydraulic servo valve (30; 40) is provided. The servo valve (30; 40) comprises a fluid injection cavity (316) and at least one fluid injection opening (314) disposed in the cavity (316) that is configured to supply fluid to the cavity (316). A pair of fluid receiving openings (313a, 313b) is disposed in the cavity (316), and a member (301; 401c) is disposed between the pair of openings (313a, 313b). The member (301; 401c) is bendable and/or rotatable in order to selectively open or occlude each of the openings (313a, 313b).