bearingsinfo/docs/technical/06_failures_diagnostics

06 Failures & Diagnostics

Purpose: Failure modes, defect terminology, and diagnostic references.

What goes here

• Failure mode catalog with definitions
• Defect terminology and surface damage types
• Diagnostics workflows and symptom mapping
• Motor and system-related failure notes
• Root-cause analysis checklists

Index

Core Documents

• ✔ 06_01_failure_modes.md - Comprehensive bearing failure mode catalog
• ✔ 06_02_defect_terminology.md - Standardized defect terminology and classification
• ✔ 06_03_diagnostics_workflow.md - Diagnostic procedures and condition monitoring

Coverage Checklist

Failure Modes (06_01_failure_modes.md)

• ✔ Failure statistics and distribution
• ✔ Failure analysis approach
• ✔ Fatigue Failures:
  • ✔ Normal fatigue (spalling)
  • ✔ Subsurface-initiated fatigue
  • ✔ Pitting (initial, progressive, micropitting)
• ✔ Wear Failures:
  • ✔ Abrasive wear
  • ✔ Adhesive wear
  • ✔ Corrosive wear
• ✔ Plastic Deformation:
  • ✔ True brinelling
  • ✔ False brinelling
  • ✔ Indentation from debris
  • ✔ Overrolling damage
• ✔ Cracking:
  • ✔ Fatigue cracking
  • ✔ Thermal cracking
  • ✔ Overload cracking
  • ✔ Grinding cracks
• ✔ Corrosion:
  • ✔ Moisture corrosion
  • ✔ Fretting corrosion
  • ✔ Electrical erosion (fluting, pitting)
  • ✔ Etching
• ✔ Smearing and Scoring:
  • ✔ Smearing mechanisms
  • ✔ Scoring damage
• ✔ Cage Failures:
  • ✔ Cage wear
  • ✔ Cage fracture
  • ✔ Cage overheating
• ✔ Seal Failures:
  • ✔ Seal wear
  • ✔ Seal damage
• ✔ Visual identification guide with appearance tables
• ✔ Failure mode decision tree
• ✔ Failure frequency by application type
• ✔ References to ISO 15243, ГОСТ 20407-75
• ✔ Manufacturer references (SKF, FAG, NSK, Timken)

Defect Terminology (06_02_defect_terminology.md)

• ✔ Surface Damage Terminology:
  • ✔ Spalling (size classification, location terms)
  • ✔ Pitting (types, severity)
  • ✔ Peeling
  • ✔ Flaking
  • ✔ Scoring and scuffing
  • ✔ Scratching
  • ✔ Indentation (brinelling, debris, impact)
  • ✔ Discoloration (thermal, corrosion)
  • ✔ Wear classifications
• ✔ Defect Classification Systems:
  • ✔ ISO severity classification (minor, major, critical)
  • ✔ ГОСТ 20407-75 complete classification structure
  • ✔ Dimensional tolerances for defects
  • ✔ Cage defect criteria
• ✔ Defect Location Terminology:
  • ✔ Raceway position descriptions
  • ✔ Ring location terms
  • ✔ Rolling element locations
  • ✔ Cage locations
• ✔ Surface Finish Defects:
  • ✔ Roughness parameters (Ra, Rz, Rmax)
  • ✔ Waviness
  • ✔ Grinding marks
  • ✔ Grinding burns
• ✔ Material Defects:
  • ✔ Inclusions
  • ✔ Heat treatment defects
  • ✔ Microstructure defects
• ✔ Visual Inspection Criteria:
  • ✔ Inspection conditions (lighting, magnification)
  • ✔ Inspection procedures (step-by-step)
  • ✔ Acceptance criteria (new and used bearings)
• ✔ Measurement and Documentation:
  • ✔ Measurement techniques
  • ✔ Documentation standards
  • ✔ Photography guidelines
• ✔ Rejection Criteria:
  • ✔ New bearing inspection criteria
  • ✔ Used bearing criteria
  • ✔ Application-specific variations
• ✔ Standards references (ISO, ГОСТ, ANSI/ABMA, DIN, JIS)
• ✔ Quick reference tables and terminology cross-reference

Diagnostics Workflow (06_03_diagnostics_workflow.md)

• ✔ Diagnostic pyramid (4 levels of monitoring)
• ✔ Strategy selection by equipment criticality
• ✔ Vibration Analysis:
  • ✔ Vibration fundamentals (displacement, velocity, acceleration)
  • ✔ Bearing defect frequencies (BPFO, BPFI, BSF, FTF)
  • ✔ Frequency formulas with examples
  • ✔ Measurement techniques (sensor placement, settings)
  • ✔ Overall vibration level (ISO 10816 severity zones)
  • ✔ FFT spectrum analysis
  • ✔ Envelope analysis (acceleration enveloping)
  • ✔ Time waveform analysis
  • ✔ Trend analysis
  • ✔ Bearing condition assessment stages (1-5)
• ✔ Temperature Monitoring:
  • ✔ Measurement methods
  • ✔ Typical operating temperatures
  • ✔ Temperature analysis (causes of rise)
  • ✔ Thermographic patterns
  • ✔ Alarm levels
• ✔ Acoustic Emission:
  • ✔ AE principles
  • ✔ Measurement parameters
  • ✔ Interpretation
• ✔ Oil Analysis:
  • ✔ Sampling procedures
  • ✔ Particle counting (ISO 4406)
  • ✔ Ferrography (analytical and direct-reading)
  • ✔ Spectrometric analysis (ICP)
  • ✔ Water content
  • ✔ Viscosity
  • ✔ Acid number (TAN)
  • ✔ Decision matrix for oil analysis
• ✔ Visual Inspection:
  • ✔ In-service inspection procedures
  • ✔ Removed bearing inspection procedures
  • ✔ Disposition criteria
• ✔ Symptom-to-Failure Mapping:
  • ✔ Diagnostic decision trees (vibration, temperature, noise)
  • ✔ Symptom-cause-action tables
• ✔ Condition Monitoring Systems:
  • ✔ Online monitoring systems
  • ✔ Portable/route-based monitoring
  • ✔ Condition-based maintenance (CBM)
• ✔ Predictive Maintenance:
  • ✔ P-F curve concept
  • ✔ Remaining useful life (RUL) estimation
  • ✔ PdM workflow (8 steps)
• ✔ Inspection Intervals:
  • ✔ Interval determination factors
  • ✔ Recommended intervals by method and criticality
  • ✔ Interval adjustment guidelines
• ✔ Documentation and Reporting:
  • ✔ Inspection report templates
  • ✔ Failure analysis report structure
  • ✔ Trending databases
• ✔ Root Cause Analysis:
  • ✔ RCA process (6 steps)
  • ✔ RCA tools (5-Whys, Fishbone, Fault Tree, FMEA)
  • ✔ Common root causes for bearing failures
• ✔ Advanced Topics:
  • ✔ Machine learning in diagnostics
  • ✔ Wireless sensors
  • ✔ Lubrication condition monitoring
• ✔ Quick reference diagnostic method selection table
• ✔ ГОСТ vibration standards
• ✔ Complete workflow integration

Additional Materials TBD

• ☐ Motor-specific failure modes (electric motor bearings)
• ☐ Automotive bearing diagnostics (wheel bearings, hub units)
• ☐ High-speed bearing diagnostics (spindles, turbines)
• ☐ Slow-speed bearing diagnostics (large mills, kilns)
• ☐ Failure case studies with photos
• ☐ Diagnostic software comparison guide
• ☐ Training materials and checklists
• ☐ Field inspection forms (templates)
• ☐ Vibration severity charts by bearing size
• ☐ Lubricant compatibility and contamination guide
• ☐ Infrared thermography interpretation guide
• ☐ Ultrasonic testing procedures for bearings
• ☐ Eddy current and magnetic particle inspection
• ☐ Advanced failure analysis techniques (SEM, metallography)
• ☐ Industry-specific diagnostic guidelines (paper mills, mining, power generation)
• ☐ Bearing failure cost analysis and prevention ROI
• ☐ Reliability-centered maintenance (RCM) for bearings
• ☐ Integration with Industry 4.0 and IIoT platforms

Document Statistics

• Total Pages Created: 3 core documents
• Total Lines of Content: ~1,200 lines
• Coverage: Comprehensive foundation complete
• Standards Referenced: ISO 15243, ISO 10816, ISO 4406, ГОСТ 20407-75, ГОСТ ISO 10816, and others
• Manufacturer Sources: SKF, FAG/Schaeffler, NSK, Timken, NTN

Usage Notes

These documents provide a comprehensive technical reference for:

• Maintenance Engineers: Diagnosing bearing failures and planning maintenance
• Reliability Engineers: Implementing condition monitoring programs
• Technicians: Understanding failure modes and inspection procedures
• Training: Educational resource for bearing failure analysis
• Quality Control: Defect classification and acceptance criteria
• Failure Analysts: Structured approach to root cause analysis

The content follows industry best practices and international standards, with extensive references to both ISO and ГОСТ systems for global applicability.