📋 Case Study
Case Study: Premature V-Belt Failure on New Holland CR9090 Combine Harvester
Recurring belt shredding at 42–48 hrs of operation; no visible misalignment or contamination
🏗️ Project Overview
Midwest U.S. custom harvesting operation, 2023 season
🎯 Challenge
Recurring belt shredding at 42–48 hrs of operation; no visible misalignment or contamination
🔧 Design Approach
Root cause traced to incorrect pulley crown geometry on aftermarket idler assembly — verified via profilometer scan and comparative CAD overlay
📐 Key Calculations
Crown Radius Deviation
|Measured Radius − Spec Radius|
Result: 0.018 in
Caused edge loading and 3× normal lateral stress
Belt Edge Pressure
Tension / (Width × Crown Radius)
Result: 1,240 psi
Exceeded 850 psi design limit for EPDM belts
📊 Results
Replacement with OEM-spec idler extended belt life from 45 to 520+ hours; eliminated $18k/yr downtime cost💡 Lessons Learned
- •Aftermarket pulleys require geometric validation
- •Edge pressure modeling prevents premature failure
- •Profilometry should be standard for critical drive audits
✅ Key Takeaways
- 1Aftermarket pulleys require geometric validation
- 2Edge pressure modeling prevents premature failure
- 3Profilometry should be standard for critical drive audits