Compressor Rotation Sensor Positioning Outside Magnetic Leakage Paths

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Solution Overview

Problem

Existing compressor systems face challenges in accurately monitoring the rotation of the drive shaft to prevent seizure and associated damage, particularly at high rotational speeds, due to complex magnetic field measurements and magnetic leakage currents.

Innovation Solution

A rotation sensor is positioned outside magnetic leakage paths, using a magnetic field sensor like a Hall Sensor, with magnetic portions on the drive shaft or hub, and optionally permanent magnets, to measure changing magnetic fields without interference from stray fields, improving sensitivity and accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a magnetic sensor is positioned within the magnetic field path to measure rotation, then rotation detection is enabled, but magnetic leakage currents and stray fields cause measurement inaccuracy and system complexity

Engineering Contradiction:
Improverotation detection accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the magnetic sensor from the complex magnetic field environment by positioning it outside the compressor housing. This removes the sensor from the source of magnetic leakage currents and stray fields, enabling accurate rotation detection without the complexity of shielding or filtering mechanisms that would be required if the sensor were placed inside the magnetic field path.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses the compressor housing itself as an intermediary element. By positioning the magnetic sensor outside the housing and utilizing the housing as a magnetic shield, the system leverages the existing structure to block magnetic leakage currents and stray fields, simplifying the overall system design while maintaining measurement precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the magnetic field changes rapidly to enable flux measurement, then rotation detection is possible, but at high rotational speeds the magnetic field delay causes near permanent 'on' readings

Engineering Contradiction:
Improverotational speed detection capabilityVSAvoidrotation reading accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent extracts the magnetic sensor from the time-varying magnetic field environment by positioning it outside the compressor housing. This eliminates the magnetic field delay problem that occurs at high rotational speeds, as the sensor now detects the magnetic portion's position without being subjected to the rapid changes and delays inherent in the internal magnetic field dynamics.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If all magnetic parts are used in the compressor to enable magnetic field measurement, then rotation monitoring is achieved, but magnetic leakage currents are set up causing system complexity

Engineering Contradiction:
Improvecompressor operation monitoringVSAvoidmagnetic system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the magnetic sensor from the magnetic system by positioning it outside the compressor housing. This allows rotation monitoring to be achieved without requiring the sensor to be part of the magnetic circuit, thereby eliminating magnetic leakage currents and reducing system complexity while maintaining reliable compressor operation monitoring.

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 solution simplifies the monitoring system, reduces complexity, and enhances accuracy by positioning the sensor in low magnetic field regions, effectively detecting the rotation of the drive shaft without magnetic leakage current interference, thus preventing compressor seizure and damage.

Implementation Method 1

A rotation sensor is positioned outside magnetic leakage paths, using a magnetic field sensor like a Hall Sensor, with magnetic portions on the drive shaft or hub, and optionally permanent magnets, to measure changing magnetic fields

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

using a magnetic field sensor like a Hall Sensor

Methodology Applied
Scientific EffectHall effect: Hall Effect

Data Source

PatentEP2372153B1Speed sensor
Publication Date: 2020.07.29 VALEO COMPRESSOR EURO S R O
  • EP2372153B1 patent drawingFigure 1
  • EP2372153B1 patent drawingFigure 2
  • EP2372153B1 patent drawingFigure 3

AI summary

The present disclosure relates to a compressor (1), comprising a pulley (2) for connection to a drive system (3) and a magnetic clutch assembly (4) for connecting a drive shaft (5) to the pulley (2) such that the rotation of the pulley (2) is transferred to the drive shaft (5). The clutch arrangement (4) itself comprises an electromagnet (6), a hub (7) attached to the drive shaft (5) and an armature plate (8). The compressor (1) is provided with a rotation sensor (20) comprising a magnetic field sensor (21) and one or more magnetic portions (22) attached to, or forming part of, the drive shaft (5) or hub (7), wherein at least the magnetic field sensor (21), and preferably also the magnetic portions (22), are positioned outside of any significant magnetic leakage paths within the compressor (1). The disclosure also relates to a method for placing a rotation sensor (20) within a compressor (1).