Solenoid Servo Valve Layout for Precise Hydraulic Flow Control

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Solution Overview

Problem

Existing servo valve technologies, particularly those using electric motors and flappers, face limitations in precision and compactness, leading to weight and complexity issues, especially in aerospace applications, where finer and more accurate control of hydraulic fluid flow is required.

Innovation Solution

A servo valve design featuring a control rod and solenoid assembly that translates axially along a central axis, allowing precise control of fluid injection by varying the position of nozzles and a spool valve, with a biasing member and coil retainer to limit translation and enhance accuracy, replacing the traditional electric motor and flapper mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If traditional electric motor and flapper mechanism is used, then servo valve can control fluid flow, but device complexity and weight increase

Engineering Contradiction:
Improvemechanism complexityVSAvoidfluid control precision
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent replaces the traditional electric motor and flapper mechanical system with a solenoid assembly that directly translates axially to control the spool valve. This substitution eliminates the complex flapper-deflection mechanism while achieving precise fluid flow control through direct solenoid-driven spool translation, thereby reducing device complexity while maintaining control precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts and removes the electric motor and flapper components from the traditional servo valve system, retaining only the essential fluid control function. By eliminating unnecessary mechanical elements and keeping only the solenoid assembly and spool valve core components, the design achieves simpler structure with comparable or improved control precision.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If traditional electric motor and flapper mechanism is used, then servo valve can control fluid flow, but weight increases

Engineering Contradiction:
Improvefluid control precisionVSAvoidservo valve weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent substitutes the heavy electric motor and flapper assembly with a lighter solenoid assembly that provides equivalent or superior control capability. The solenoid's direct axial translation mechanism eliminates the need for complex mechanical linkages, resulting in significant weight reduction while maintaining precise fluid flow control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

By removing the electric motor and flapper components, the patent eliminates the associated weight. The streamlined design retains only the essential solenoid assembly and spool valve, achieving weight reduction without compromising the servo valve's ability to control fluid flow precisely.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If traditional electric motor and flapper mechanism is used, then servo valve can control fluid flow, but compactness decreases

Engineering Contradiction:
Improvefluid control precisionVSAvoidservo valve volume
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent merges the control function and fluid regulation function into a single integrated solenoid assembly and spool valve structure. By combining these functions that were previously separated in the motor-flapper system, the design achieves a more compact configuration while maintaining precise fluid flow control capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

By extracting and removing the bulky electric motor and flapper mechanism, the patent significantly reduces the overall volume of the servo valve. The remaining solenoid assembly and spool valve occupy minimal space while delivering the required fluid control precision, thereby improving compactness.

Inventive Principle:
Principle #2Taking out (Extraction)

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 a more compact, lightweight, and sensitive servo valve capable of making finer adjustments, improving fluid control and actuator movement precision, and reducing weight and complexity, particularly beneficial in aerospace applications.

Implementation Method 1

a solenoid assembly surrounding at least a portion of the control member and configured to translate the control member axially along a central axis of the servo valve in response to being energized

Methodology Applied
Scientific EffectSolenoid: Solenoid

Data Source

PatentEP3502487B1Servo valve
Publication Date: 2021.08.25 HAMILTON SUNDSTRAND CORP
  • EP3502487B1 patent drawingFigure 1
  • EP3502487B1 patent drawingFigure 2
  • EP3502487B1 patent drawingFigure 3A

AI summary

A servo valve (10) comprising first and second nozzles (12a, 12b) spaced apart from each other, an elongate control member (16) positioned between the nozzles (12a, 12b), and a solenoid assembly (14) surrounding at least a portion of the control member (16). The elongate control member (16) has a first end (17a) and an opposing second end (17b). The control member (16) is configured to translate in response to the solenoid assembly (14) being energised, such that the first end (17a) is moved towards the first nozzle (12a) and the second end (17b) is moved away from the second nozzle (12b) or the first end (17a) is moved away from the first nozzle (12a) and the second end (17b) is moved towards the second nozzle (12b).