Reason Analysis on Pull-off of Hydraulic Pump Body Thread

In order to analyze the reason for pull-off of hydraulic pump body thread, the means, such as fracture analysis, chemical composition analysis and hardness testing, were conducted. The results showed that the hydraulic pump body thread failed due to cutting fatigue fracture, and the main cause of thread fatigue fracture was the joint to the circle radiating pipe was assembled too tightly, it made the hydraulic pump body thread damaged. In order to void the thread fracture again, the effective thread conjugate length between hydraulic pump body and pipe joint should be increased.