Lubricant Sensor Merging Level and Quality Detection

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Solution Overview

Problem

Existing methods for monitoring lubricant level and quality in engines, such as gas turbines, are inefficient and require separate systems for accurate measurement, which can be bulky and heavy, and do not effectively account for lubricant degradation over time due to increased temperatures and contamination.

Innovation Solution

A method and system using a lubricant sensor with multiple electrodes that switch between AC currents at different frequencies to measure capacitance for level determination and impedance or resistance for quality assessment, allowing for a single compact and lightweight device to accurately monitor both lubricant level and quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If separate systems are used for monitoring lubricant level and quality, then measurement accuracy is improved, but device complexity and weight increase

Engineering Contradiction:
Improvelubricant level and quality measurement accuracyVSAvoidsystem structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines separate lubricant level and quality monitoring systems into a single integrated sensor device. The sensor includes multiple electrodes that can measure both capacitance (for level) and impedance/resistance (for quality) simultaneously, eliminating the need for separate monitoring systems and reducing overall device complexity while maintaining measurement accuracy

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sensor device is designed with multi-functionality to perform both lubricant level monitoring and quality assessment using the same hardware platform. The electrode array can operate in different measurement modes (capacitance measurement for level, impedance/resistance measurement for quality), allowing one device to fulfill multiple monitoring functions that previously required separate systems

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

2Measurement precision

If separate systems are used for monitoring lubricant level and quality, then measurement accuracy is improved, but weight increases

Engineering Contradiction:
Improvelubricant level and quality measurement accuracyVSAvoidsensor system weight
Core Design Contradiction:
Measurement precisionVSWeight of moving object

Solution Approach 1:

The patent combines separate lubricant level and quality monitoring systems into a single integrated sensor device. The sensor includes multiple electrodes that can measure both capacitance (for level) and impedance/resistance (for quality) simultaneously, eliminating the need for separate monitoring systems and reducing overall device complexity while maintaining measurement accuracy

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sensor device is designed with multi-functionality to perform both lubricant level monitoring and quality assessment using the same hardware platform. The electrode array can operate in different measurement modes (capacitance measurement for level, impedance/resistance measurement for quality), allowing one device to fulfill multiple monitoring functions that previously required separate systems

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

3Device complexity

If a single sensor measures both level and quality, then device complexity and weight are reduced, but measurement precision may deteriorate

Engineering Contradiction:
Improvesystem structureVSAvoidlubricant level and quality measurement accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The sensor employs multiple electrodes segmented into different functional groups: some electrodes are dedicated to capacitance measurement for level monitoring, while others are configured for impedance or resistance measurement for quality assessment. This segmentation allows each electrode subset to be optimized for its specific measurement function, maintaining high precision for both parameters simultaneously within a single integrated device

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sensor utilizes different electrical measurement parameters to distinguish between level and quality measurements. By measuring capacitance (which correlates with lubricant level) and impedance or resistance (which correlates with lubricant quality), the system can simultaneously monitor both parameters with high precision using the same electrode array, avoiding cross-interference between measurement functions

Inventive Principle:
Principle #35Parameter changes

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 continuous and accurate monitoring of lubricant level and quality, reducing the need for separate systems and minimizing weight, while effectively detecting changes in lubricant properties due to degradation, thus improving maintenance efficiency and extending lubricant life.

Implementation Method 1

The capacitance between the electrodes is a function of the depth to which the electrodes are immersed in oil, because the dielectric strength of the oil is different to the dielectric strength of the gas surrounding the non-submerged portion of the electrodes

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

The capacitance between the electrodes is a function of the depth to which the electrodes are immersed in oil, because the dielectric strength of the oil is different to the dielectric strength of the gas surrounding the non-submerged portion of the electrodes

Methodology Applied
Scientific EffectDielectric: Dielectric

Implementation Method 3

measuring, at the second current, an impedance parameter (in the case of an AC second current) or resistance parameter (in the case of a DC second current) representative of the impedance or resistance between the electrodes

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Data Source

PatentEP2573525B1Oil sensor
Publication Date: 2020.08.12 ROLLS ROYCE PLC
  • EP2573525B1 patent drawingFigure 1~2
  • EP2573525B1 patent drawingFigure 3~4
  • EP2573525B1 patent drawingFigure 5~6

AI summary

A system and method for measuring oil level and quality is provided. The system and method uses an alternating current (AC) to determine oil level, and a lower frequency alternating current, or a direct current (DC), to measure oil quality. The system may comprise a single sensor that is used to measure both oil quality (by providing the lower frequency alternating current or direct current) and oil level (by providing the higher frequency alternating current). Using the lower frequency AC, or DC, enables the resistance of the oil to be determined, which gives an accurate indication of the oil quality.