封隔器锁紧机构关键几何参数分析

Analysis of the Key Geometric Parameters for the Locking Mechanism of Packer

以封隔器锁紧机构即锁环的简化模型为研究对象,分析封隔器坐封时锁环齿牙与中心管上齿牙的接触情况,得出当量摩擦因数f当是检验锁环能否自锁的关键指标。锁环承受载荷时回弹卡紧中心管,上齿面与中心管齿牙接触,当量摩擦因数只与齿前角θ1有关,齿后角θ2的作用主要是增大锁环齿牙的强度。基于有限元分析和正交优化方法,分析齿后角θ2、齿牙间距p、齿牙高度h、齿牙尖角圆弧半径r等4个几何参数对锁环齿牙承载时的影响,得出影响最小的最优组合为:齿后角θ2=70°,齿牙间距p=3 mm,齿牙高度h=1 mm,齿牙尖角圆弧半径r=0.2 mm。

The simplified model of the locking mechanism, namely the locking ring of packer, was taken as the object of study. The contact of the locking ring tooth and center tube tooth in packer setting was analyzed. It was found that the equivalent friction coefficient is the key index to check whether the ring could be locked by itself. The locking ring springs back and clamps the center tube when it bears load. The upper tooth surface contacts the center tube tooth. The equivalent friction coefficient is related only to the tooth rake angle θ1. The effect of the tooth clearance angle θ2 is mainly to increase the strength of locking ring tooth. On the basis of finite element analysis and orthogonal optimization method, the effects of the four geometric parameters including the tooth clearance angle θ2, tooth spacing p, tooth height h and tooth front point arc radius r on locking ring tooth load bearing were analyzed. The optimal combination of the least influence was obtained as follows ： θ2 = 70° , p = 3 mm, h = 1 mm and r = 0.2 mm.