Bearing Temperature Gradient Detection for Rotating Machine Switching

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for monitoring the operating state of rotating machines, such as centrifugal pumps, face challenges in accurately detecting on/off cycles and wear due to the absence of direct sensors, especially in sealed or glandless pumps, where vibration measurements are unreliable and temperature-based methods lack quality.

Innovation Solution

A method utilizing a temperature sensor to detect temperature changes in the bearing area, analyzing temperature gradients to differentiate between machine operation and switching processes, with the sensor positioned non-invasively on the bearing support to record temperature changes caused by friction and environmental factors, enabling reliable detection of switch-on and switch-off events.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If vibration measurement is used to detect operating state, then operating time and switching cycles can be recorded, but measurement reliability is insufficient due to environmental influences and small vibration signals

Engineering Contradiction:
Improvedetection accuracyVSAvoidmeasurement reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces vibration-based mechanical measurement with temperature-based thermal measurement. Instead of using accelerometers or vibration sensors that are susceptible to environmental noise, the invention uses temperature sensors to detect thermal changes in bearing areas, which provide more reliable and environment-resistant signals for determining operating states and switching cycles.

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

Solution Approach 2:

The patent introduces temperature as an intermediary parameter to indirectly detect operating states. Rather than directly measuring vibration or mechanical parameters, the system uses temperature changes in bearing areas as a mediator that reflects the machine's operational condition, providing more stable and interpretable data.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If temperature sensor is used to detect operating state, then measurement reliability improves, but ability to distinguish switching processes from operational fluctuations is insufficient

Engineering Contradiction:
Improvemeasurement reliabilityVSAvoiddetection accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent applies dynamic analysis by calculating the first derivative (rate of change) of the temperature profile. This transforms static temperature values into dynamic change rates, enabling the system to distinguish between gradual operational temperature fluctuations and abrupt temperature changes caused by switching processes. The dynamic approach allows precise identification of switching events based on the magnitude and pattern of temperature变化 rates.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the evaluation parameter from absolute temperature values to temperature change rates (derivatives). By analyzing how quickly temperature changes rather than the temperature itself, the system can differentiate between normal operational variations and switching events, significantly improving detection accuracy while maintaining measurement reliability.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If direct sensors are installed in rotating components, then operating time and switching cycles can be directly recorded, but installation complexity and cost increase

Engineering Contradiction:
Improvedetection accuracyVSAvoidinstallation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses bearing area temperature as an intermediary measurement point that is externally accessible. Instead of installing sensors directly on rotating components like shafts or impellers, the system measures temperature in the bearing area through the housing or support structure, providing indirect but accurate information about operating states without requiring invasive installation in rotating parts.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct mechanical sensing in rotating components with external thermal sensing. By using temperature sensors mounted on stationary bearing supports or housings rather than on rotating parts, the system eliminates the complexity of rotating sensor installation while maintaining the ability to detect operating states through thermal signatures.

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

This approach allows for accurate detection of operating states and wear monitoring, providing insights into machine load and service life by analyzing temperature gradients, which are distinct from regular operational fluctuations, thus enhancing maintenance and operational efficiency.

Implementation Method 1

analyzing the gradient of the measurement data, thus enabling the recording of the corresponding switching-on or switching-off process

Methodology Applied
Scientific EffectTemperature gradient analysis: Temperature Gradient

Data Source

PatentEP3844398B1Method for detecting the operating state of a rotating machine
Publication Date: 2023.07.05 KSB SE & CO KGAA
  • EP3844398B1 patent drawingFigure 1
  • EP3844398B1 patent drawingFigure 2a~2b
  • EP3844398B1 patent drawingFigure 3

AI summary

The invention relates to a method for detecting the state of operation of a rotating machine, in particular a centrifugal pump, comprising at least one first temperature sensor for detecting a change in temperature in or at at least one bearing region of the rotating element, wherein an evaluation unit examines the temperature profile, which is ascertained by sensor, for temperature gradients and identifies a switch-on and/or switch-off process of the rotational movement of the machine on the basis of the characteristic of an ascertained temperature gradient.