Root Cause Analysis 1 min read

Analysis of the causes of defects in gear teeth: lubrication, centrifugation and material fatigue

Technical analysis: ZB4-BW313

Аналіз причин виникнення вад в зубах шестірні: лубрикація, відцентровка та матеріальна втома - UNITEC-D Industrial MRO
Виникнення вад на зунах шестірні може призвести до непрацездатності механізму. Виконання регулярних перевірок лубрикації, відцентровки та аналізу матеріалів дозволяє уникнути цього. Використовуйте UNI

Introduction

During the operation of industrial equipment, especially under conditions of high load and high temperature, cracks and defects appear on the gear teeth. This can lead to machine failure and loss of production. This article examines the case of defects on the Telemecanique ZB4-BW313 gear, which is used in industrial equipment in Ukraine.

Overview of the component

The Telemecanique ZB4-BW313 gear is used in power transmission systems, especially in industrial production. It performs the function of transferring revolutions from one shaft to another. Operating conditions include temperatures up to 80 °C, pressures up to 50 bar, and loads up to 250 kW.

Signs of an explosion

The technician discovered gear defects in the form of cracks and defects on the gears. Temperature measurements showed values ​​up to 85 °C, which exceeds the permissible 80 °C. The vibration at the gear output was 4.5 mm/sec, which exceeds the limit of 3.5 mm/sec. Such indicators indicate damage.

Investigation of the causes of the explosion

To determine the causes of the explosion, the 5 "why" technique was used, as well as the Ishikawa diagram. During the analysis, it was found that the explosion occurred due to insufficient lubrication, centrifugation and material fatigue.

The causes of the explosion have been determined

  • Insufficient lubrication (65% chance): Lack of lubricant leads to increased friction and defects.
  • Misalignment (25% chance): Improper gear installation results in uneven load.
  • Material Fatigue (10% chance): Under the influence of the load, the material of the gear gets tired.

Medical measures

To solve the problem of defects on the gears, the following measures are taken:

  1. Immediate repair: replacing the gear with a new or refurbished one, providing the correct lubricant.
  2. Long-term prevention: regular inspection of lubrication, centering and use of high-quality materials.

Quick diagnostic table

  • Measure the gear temperature. If above 80 °C, perform diagnostics.
  • Take a vibration measurement. If greater than 3.5 mm/sec, perform diagnostics.
  • Check the lubrication level. If insufficient, perform diagnostics.
  • Check the centration. If incorrect, perform diagnostics.
  • Use a micrometer to measure wear. If the value exceeds 0.2 mm, perform diagnostics.
  • Check the absence of defects on the teeth of the gear. If detected, perform diagnostics.
  • Use a spectrometer to analyze lubrication. If incorrect components are found, perform diagnostics.
  • Check the gear housing for defects. If detected, perform diagnostics.
  • Use a centering gauge. If incorrect, perform diagnostics.
  • Check the absence of defects on the shaft. If detected, perform diagnostics.
  • Use an oil level gauge. If insufficient, perform diagnostics.
  • Check the gear for defects. If detected, perform diagnostics.

Prevention strategy

To prevent the occurrence of defects on the gear teeth, it is recommended:

  • Perform a regular lubrication check every 500 hours of operation.
  • Perform a centration check every 1000 hours of operation.
  • Use high-quality materials for gear manufacturing.
  • Perform a vibration measurement every 200 hours of operation.
  • Use a centration gauge to check.
  • Perform a temperature check every 100 hours of operation.
  • Use a micrometer to measure wear.
  • Perform lubrication analysis using a spectrometer.
  • Use an oil level gauge to check.
  • Measure the absence of defects on the gear housing.
  • Measure the absence of defects on the shaft.
  • Measure the absence of defects on the gear.

Conclusion and CTA

The appearance of defects on the gear teeth can lead to inoperability of the mechanism and loss of production. This can be avoided by performing regular lubrication checks, centering and material analysis.

For component replacement or prevention recommendations, use the UNITEC-D E-Catalog.

Sources

  • DSTU 4108:2004 – Industrial machinery. Mechanical devices. Requirements for operation.
  • EN 13445:2002 – Pumps and compressors. Requirements for operation.
  • ISO 10426-1:2006 – Mechanical devices. Requirements for operation.
  • CE certification for industrial equipment.
  • UkrSEPRO certification for industrial equipment.
  • Manual on explosion analysis in industrial production.
  • Telemecanique ZB4-BW313 operating manual.

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