标题：Load Distribution Balance Principle of Petroleum Buttress Casing Thread and Its NC Machining Method
作者：Xiaowei Wang;Peiquan Guo;Lianyi Zhao
作者机构：School of Mechanical Engineering, University of Jinan, Shandong, 250022, China;School of Mechanical Engineering, University of J
来源：Materials Science Forum
关键词：Variable pitch thread;casing thread;buttress thread;force analysis;NC machining
摘要：The force of each API standard buttress casing thread teeth under axial tension is uneven, so the bearing capacity of this kind of thread is seriously restricted. On the basis of structural characteristics, mechanical model of the casing thread under axial tension is established and the loading and deforming features of thread teeth are analyzed. Based on this, to improve force distribution of casing thread, the designing method of multi-segment variable pitch thread is put forward and NC machining method of variable pitch thread with equal tooth thickness is presented.