Rolling Bearing Arc Discharge Evaluation Method

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Solution Overview

Problem

Current methods for evaluating arc discharges in rolling bearings are inadequate as they do not allow for isolated control of operating parameters, leading to unsatisfactory correlations between arc discharge effects and bearing damage, and fail to provide reliable predictions for bearing damage caused by these discharges.

Innovation Solution

An evaluation method that sets a defined operating state for the rolling bearing and applies a pulse-shaped electrical voltage to generate arc discharges, recording characteristic values such as energy, power, voltage, and duration, and evaluating only those discharges exceeding a predetermined limit value, which is based on the material's enthalpy requirements for melting and boiling, to determine the volume-related energy input and predict potential bearing damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If measurements are carried out in the entire drive system (converter and motor), then arc discharges and bearing currents can be recorded, but isolated control of operating parameters of the rolling bearing is not possible

Engineering Contradiction:
Improveinformation on arc discharge characteristicsVSAvoidability to control operating parameters in isolation
Core Design Contradiction:
Loss of informationVSAdaptability or versatility

Solution Approach 1:

The patent segments the measurement system by installing individual sensors on the bearing components (inner and outer rings) to measure arc discharge characteristics locally, rather than measuring the entire drive system. This allows isolated control and evaluation of bearing operating parameters while still capturing comprehensive arc discharge information.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If current density of arc discharges is recorded, then some measurement data is obtained, but reliable correlations between load on the bearing and damage caused by arc discharges cannot be established

Engineering Contradiction:
Improvemeasurement data on arc discharge current densityVSAvoidcorrelation between arc discharge load and bearing damage
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent changes the measurement parameters from simply recording current density to measuring multiple characteristics including voltage, current, duration, and energy of arc discharges. By varying and measuring these parameters comprehensively, the system can establish reliable correlations between arc discharge characteristics and bearing damage by comparing against material enthalpy values.

Inventive Principle:
Principle #35Parameter changes

3Loss of information

If multiple operating parameters are measured to understand bearing damage, then comprehensive data is obtained, but the complexity of the measurement and control system increases

Engineering Contradiction:
Improvecomprehensive data on bearing operating stateVSAvoidcomplexity of measurement and control system
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent employs self-service by using the bearing's own operational characteristics (speed, temperature, load) as input parameters that automatically influence the arc discharge measurement system. The system leverages existing sensor data from the bearing operation itself rather than requiring separate complex measurement systems for each parameter.

Inventive Principle:
Principle #25Self-service

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 method enables reliable predictions of bearing damage by determining the energy distribution of arc discharges and their duration, allowing for classification of operating states as permissible or impermissible, thereby preventing material evaporation and potential bearing failure.

Implementation Method 1

applying a pulse-shaped electrical voltage between the bearing inner ring and bearing outer ring, a large number of arc discharges are generated

Methodology Applied
Scientific EffectArc discharge: Electric Arc

Implementation Method 2

at least one value is recorded for each arc discharge, which is characteristic of the energy, power, voltage, current and / or duration of the respective arc discharge

Methodology Applied
Scientific EffectElectromagnetic detection: Electromagnetic Induction

Data Source

PatentEP2539723B1Electric arc discharge evaluation method, and associated test stand
Publication Date: 2015.04.01 SIEMENS AG
  • EP2539723B1 patent drawingFigure 1
  • EP2539723B1 patent drawingFigure 2
  • EP2539723B1 patent drawing

AI summary

According to the invention, a defined operating state of an antifriction bearing (1) is set in a test stand. To do so, at least one of the following parameters is set: rotational speed (n) of the antifriction bearing (1); temperature of the bearing (1); imbalance on the bearing (1), causing vibrations; lubricant; axial, radial, and asymmetrical load; tilting of the inner bearing ring (8) relative to the outer bearing ring (9); pulse shape and pulse repetition rate of the applied voltage (U); play of and previous damage to the bearing (1). A plurality of arc discharges between the inner bearing ring (8) and the outer bearing ring (9) are generated in the defined operating state by applying a pulsating voltage (U) between the inner bearing ring (8) and the outer bearing ring (9) of the bearing (1). At least one value characteristic of the energy (E), the power, the voltage, the current, and/or the duration (t) of each arc discharge is acquired for each arc discharge. Only the arc discharges for which a qualifying value (Q) determined in accordance with at least one of the acquired characteristic values of each arc discharge exceeds a predetermined limit (G) are evaluated.