Research of Preload & Tightening Specification for Cummins ISDe Engine Main Bearing Capscrews

Cummins ISDe Main Bearing Capscrew clamp load was determined by theoretic calculation.The relationship curve of equal capscrew clamp load and elongation was found by test calibration method.According to calibrated relationship curve of clamp load and elongation,the capscrew assembly clamp load was validated by inner inserting method.At the same time,different tightening specification was researched how to impact capscrew assembly clamp load.And then the best tightening specification was chosen to meet the assembly clamp load requirement.