Fluid Speed Sensor Using Magnetic Repulsion for Low Friction

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Solution Overview

Problem

Existing fluid speed measurement devices, such as drag anemometers, face issues with precision and reliability due to turbulence, friction, and the need for vertical alignment, making them unsuitable for measuring low wind speeds and fluid flows in non-vertical configurations.

Innovation Solution

A device with a moving assembly that pivots around its center of gravity, featuring a drag rod and stabilizing rod aligned and integral with each other, using repulsion magnets to return the assembly to a rest position, allowing measurement in any orientation and minimizing friction, enabling precise and reliable fluid speed measurement across a wide range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a flexible wire connects the sensor to the housing to enable movement, then the sensor can follow fluid flow, but friction in the wire sliding mechanism prevents accurate low-speed measurements

Engineering Contradiction:
Improvesensor movement capabilityVSAvoidlow-speed measurement accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent removes the flexible wire connection entirely and replaces it with a pivot mechanism. The sensor rod is extracted from the constrained flexible wire system and allowed to rotate freely on a pivot point, eliminating the sliding friction that plagued the previous design while maintaining the sensor's ability to follow fluid flow.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical flexible wire sliding system with a magnetic field-based restoration mechanism. Instead of using mechanical springs or wires to restore the sensor to its rest position, the invention uses magnetic attraction between a magnet on the sensor rod and a corresponding magnet in the housing to provide a frictionless restoring force.

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

2Device complexity

If the sensor rod is constrained to move in a single plane, then the structure is simple, but the device cannot measure fluid flow in multiple directions or orientations

Engineering Contradiction:
Improvestructural simplicityVSAvoidmeasurement orientation capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent transforms the sensor rod from a rigidly constrained single-plane movement system to a dynamic three-dimensional rotation system. The sensor rod can now pivot freely in any direction around the pivot point, allowing it to adapt to fluid flow from any orientation while maintaining relatively simple structural components.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If the drag anemometer is mounted on a wind vane to orient itself, then directional measurement is possible, but frictional forces prevent correct positioning at low wind speeds

Engineering Contradiction:
Improvedirectional measurement capabilityVSAvoidfrictional resistance
Core Design Contradiction:
Measurement precisionVSForce

Solution Approach 1:

The patent replaces the mechanical wind vane friction system with a magnetic field-based orientation mechanism. The sensor rod's natural tendency to align with fluid flow is enhanced by magnetic attraction that pulls the rod toward its rest position without the frictional resistance of mechanical contacts, enabling precise directional measurement even at very low flow speeds.

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

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

Enables accurate measurement of fluid speed from low velocities to high speeds in any direction, with minimal friction and no hysteresis, suitable for use in various orientations and environments, including those with turbulence and sudden movements.

Implementation Method 1

the housing contains at least one repulsive magnet arranged to repel the stabilizing magnet of the moving assembly towards said rest position

Methodology Applied
Scientific EffectMagnetic repulsion: Ion Repulsion/Attraction

Implementation Method 2

a drag rod disposed at least partially outside the housing... the drag rod... being aligned with each other and fixed to each other

Methodology Applied
Scientific EffectDrag: Drag

Data Source

PatentEP3598143B1Device for measuring the speed of movement of a fluid
Publication Date: 2021.10.27 CARRARD JEAN DANIEL
  • EP3598143B1 patent drawingFigure 1~4

AI summary

The present invention relates to a device (10) for measuring the velocity of a fluid. This device comprises a housing (12) and a moving assembly (11) partially disposed inside the housing (12) and partially disposed outside the housing. The measuring device (10) further comprises means for determining a deviation of the position of the moving assembly (11) from a rest position of this moving assembly, this rest position being the position of the moving assembly in the absence of fluid flow. The measuring device is characterized in that the moving assembly (11) comprises a stabilizing magnet (23) and in that the housing (12) contains at least one repulsive magnet (26) arranged to repel the stabilizing magnet (23) of the moving assembly (11) towards said rest position.