Stepper Motor Balanced Flow Control Valve Design

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Solution Overview

Problem

Existing flow control valves operated by stepper motors often require complex gear systems or multiple directional component drives, leading to power loss, decreased position accuracy, and repeatability due to the complexity and tolerance of multiple moving parts.

Innovation Solution

A flow control valve design featuring a spool valve member with a non-circular geometrically-shaped head, pressure-balanced pistons, and a drive adapter that prevents axial rotation, directly translating rotational force from a stepper motor into axial movement without the need for additional clutch members or anti-rotational fasteners.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a gear system or multiple directional component drive system is used to change rotational force to longitudinal force, then the valve member can be translated to open or closed positions, but operating force is lost and position accuracy and repeatability decrease due to multiple moving parts

Engineering Contradiction:
Improvevalve member translationVSAvoidposition accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent extracts and eliminates the gear system and multiple directional component drive system from the valve actuation mechanism. By using a stepper motor that directly drives the valve member through a simple threaded engagement, the complex intermediate transmission components are removed, thereby preventing power loss and maintaining position accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of converting rotational force to longitudinal force through complex gear systems, the patent inverts the approach by using the stepper motor's inherent ability to provide both rotational and axial movement through direct threaded engagement. This eliminates the need for force conversion mechanisms and their associated losses.

Inventive Principle:
Principle #13The other way round (Inversion)

2Ease of operation

If a gear system or multiple directional component drive system is used, then the valve member can be actuated, but the complexity of multiple moving parts increases

Engineering Contradiction:
Improvevalve member actuationVSAvoidnumber of moving parts
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent removes the gear system and multiple directional component drive system from the actuation mechanism, leaving only the essential stepper motor and valve member with threaded engagement. This extraction of unnecessary components directly reduces device complexity while maintaining actuation functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the functions of multiple components (motor, drive mechanism, and valve actuation) into a integrated assembly where the stepper motor directly engages the valve member through threaded interaction, eliminating the need for separate gear systems and directional control components.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If a gear system is used to change rotational force to longitudinal force, then the valve member can be translated, but power loss occurs due to multiple moving parts

Engineering Contradiction:
Improvevalve member translationVSAvoidoperating force loss
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent extracts and eliminates the gear system from the power transmission path. By using direct threaded engagement between the stepper motor and valve member, the intermediate components that cause friction and power loss are removed, improving energy efficiency.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using a gear system to convert rotational force to longitudinal force with associated power losses, the patent inverts the approach by utilizing the stepper motor's direct threaded engagement capability, which maintains power transmission efficiency while achieving the same actuation function.

Inventive Principle:
Principle #13The other way round (Inversion)

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 enhances the repeatability and accuracy of valve positions by balancing fluid pressure forces, reducing the operating force required from the stepper motor, and eliminating power loss, thereby improving the precision and reliability of flow control.

Implementation Method 1

a first piston positioned at an opposite end of the spool valve member from the geometrically-shaped head, a second piston positioned between the first piston and the geometrically-shaped head whereby the first and second pistons operate to seal against cylinder walls of the body

Methodology Applied
Scientific EffectPressure balance: Pascal's Law

Data Source

PatentEP2593699B1Stepper motor operated balanced flow control valve
Publication Date: 2020.02.19 MAC VALVES INC
  • EP2593699B1 patent drawingFigure 1~2
  • EP2593699B1 patent drawingFigure 3~4
  • EP2593699B1 patent drawingFigure 5

AI summary

A flow control valve includes a body having a body bore oriented coaxially with a longitudinal axis of the body and a seat member extending into the bore. A valve member is slidably disposed in the bore and oriented coaxially with the longitudinal axis of the body. The valve member includes a non-circular geometrically shaped head having a bore. A drive adapter includes a head receiving cavity slidingly receiving the geometrically shaped head of the valve member and preventing axial rotation of the valve member. A stepper motor is connected to the drive adapter, the stepper motor incrementally rotating a shaft engaged with the bore of the valve member. First and second equal diameter pistons of the valve member provide pressure balanced valve member operating positions.