Roller Bearing Spacing Detection via Strain Signal Analysis

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current methods for assessing roller spacing and cage integrity in large bearings, such as those used in wind turbines, are unreliable due to varying spacing patterns and the presence of low or no load sections, making it difficult to detect excessively small or large spacings that may indicate cage damage.

Innovation Solution

A method using Roller Load Induced Strain (RLIS) signals, processed by microcontrollers integrated into the bearing, to determine roller spacings by high-pass filtering, identifying zero crossings, and calculating spacing between adjacent rollers, with threshold-based validation to ensure accuracy and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If vibration measurements are used to assess roller spacing, then the assessment method is simple, but the reliability is poor due to varying spacing patterns and low load sections

Engineering Contradiction:

Improveassessment simplicityVSAvoidcage integrity detection reliability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent replaces vibration-based mechanical measurement with strain signal measurement using Roller Load Induced Strain (RLIS) sensors. This substitution allows direct measurement of roller load variations, which reliably indicate spacing changes regardless of vibration patterns or load section variations, thereby improving detection reliability while maintaining operational simplicity

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces strain signals as an intermediary measurement parameter that directly reflects roller spacing conditions. By measuring strain induced by roller loads on the raceway, the system obtains a reliable indicator of spacing variations without being affected by the problematic variables that plague vibration-based methods

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If single measurement points are used to detect spacing, then the measurement process is simple, but the detection accuracy is insufficient due to shifting spacing patterns

Engineering Contradiction:

Improvemeasurement simplicityVSAvoidspacing detection accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent segments the measurement approach by analyzing multiple individual roller spacings throughout the bearing circumference rather than relying on a single measurement point. By evaluating each roller's spacing individually and comparing against tolerance ranges, the system achieves high detection accuracy while maintaining simple processing through automated comparison logic

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs excessive measurement action by continuously monitoring all roller spacings rather than sampling at single points. This comprehensive measurement approach ensures that even transient or localized spacing anomalies are detected, significantly improving measurement precision without complicating the overall system architecture

Inventive Principle:

Principle #16Partial or excessive action

3Adaptability or versatility

If multiple cage segments are used to hold rollers, then the bearing design flexibility is improved, but the risk of cage breakage and spacing variation increases

Engineering Contradiction:

Improvebearing design flexibilityVSAvoidroller spacing consistency

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent implements feedback monitoring by continuously measuring strain signals from each roller and comparing the derived spacings against design tolerance ranges. This feedback mechanism detects cage segment failures or spacing anomalies early, allowing maintenance intervention before reliability is compromised, thus enabling the use of multiple flexible cage segments without sacrificing overall system reliability

Inventive Principle:

Principle #23Feedback

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 provides a reliable and cost-effective means to monitor roller spacings and cage integrity, reducing errors and false detections, and outputs a confidence level for improved data interpretation, enabling early detection of broken cages or misalignment.

Implementation Method 1

a strain sensor (14) for capturing Roller Load Induced Strain (RLIS) signals

Methodology Applied

Scientific EffectStrain measurement: Deformation

Data Source

PatentUS10564069B2Method and data processing device for determining a spacing of rolling elements

Publication Date: 2020.02.18 AB SKF SKF PATENT DEPARTMENT

AI summary

A method for detecting roller spacings in a roller bearing having at least one row of rollers wherein the rollers in the row are held by at least one cage, preferably by a plurality of roller cages. The method uses roller load induced strain signals for determining the roller spacings.