Electronic Expansion Valve Hall Sensor Array for Rotor Phase Detection

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Solution Overview

Problem

The existing electronic expansion valves cannot accurately determine the rotation condition of the rotor, leading to abnormal operation if the controller fails to detect rotation blocking or incorrectly reports motor rotation blocking information.

Innovation Solution

The electronic expansion valve includes a frame body with an accommodating cavity and a mounting cavity, an induction magnetic ring movably arranged in the accommodating cavity, and multiple Hall sensors located in the mounting cavity around the accommodating cavity. The Hall sensors collect moving magnetic field curves to determine the motion conditions of the drive rotors, including whether they are in a rising or falling phase and whether they rotate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single Hall sensor is used to detect rotor position, then the device complexity is reduced, but the measurement precision of rotation condition is insufficient to determine rising or falling phase

Engineering Contradiction:
Improvenumber of Hall sensorsVSAvoidrotation condition detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The detection function is segmented into multiple Hall sensors positioned at different angular locations around the rotor. Each Hall sensor detects magnetic field information from a specific sector, and by comparing the detection results from multiple sensors, the system can determine both the rotor position and the rotation phase (rising or falling), thereby achieving precise rotation condition detection without requiring a single complex sensor.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If the Hall sensor is positioned close to the rotor to improve detection sensitivity, then the measurement precision improves, but the device complexity and mounting difficulty increase

Engineering Contradiction:
Improvemagnetic field detection sensitivityVSAvoidsensor arrangement complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The Hall sensors are integrated into the stator structure, which serves multiple functions: providing mechanical support for the sensors, establishing a reference coordinate system for position detection, and enabling both position and phase detection through strategic sensor placement. This multi-functional integration achieves precise detection without adding separate mounting structures or increasing overall device complexity.

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

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 configuration allows for accurate determination of the motion conditions of the drive rotors, effectively addressing the issue of undetermined rotation conditions and preventing abnormal operation of the electronic expansion valve.

Implementation Method 1

the Hall sensor, there are multiple Hall sensors, at least two Hall sensors of the multiple Hall sensors being located in the mounting cavity and being arranged around a circumferential side of the accommodating cavity

Methodology Applied
Scientific EffectHall effect: Hall Effect

Data Source

PatentEP4239232B1Electronic expansion valve and monitoring method for electronic expansion valve
Publication Date: 2025.04.30 ZHEJIANG DUNAN ARTIFICIAL ENVIRONMENT CO LTD
  • EP4239232B1 patent drawingFigure 1
  • EP4239232B1 patent drawingFigure 2~3
  • EP4239232B1 patent drawingFigure 4~5

AI summary

Disclosed are an electronic expansion valve and a monitoring method for an electronic expansion valve. The electronic expansion valve includes: a frame body (10), wherein the frame body (10) is provided with an accommodating cavity (20) and a mounting cavity (30); and an induction magnetic ring (40), wherein the induction magnetic ring (40) is movably arranged in the accommodating cavity (20) in a height direction of the accommodating cavity (20), and the mounting cavity (30) is at least located on a circumferential outer side of an active area of the accommodating cavity (20) in which the induction magnetic ring (40) is located; and a Hall sensors (50), there are multiple Hall sensors (50), at least two Hall sensors (50) of the multiple Hall sensors (50) is located in the mounting cavity (30), is arranged around a circumferential side of the accommodating cavity (20), and the at least two Hall sensors (50) of the multiple Hall sensors (50) is located at the same height, and the induction magnetic ring (40) is always whitin a detection range of the multiple Hall sensors (50). The problem that a rotation condition of a rotor may not be determined in an electronic expansion valve in the related art is solved.