柱塞自旋转装置的计算

在柱塞上端接一根外圆带有螺旋槽的自旋转装置，靠排出液流的螺旋上升流动产生分速度使柱塞在抽汲过程中产生随机自旋转运动，从而消除柱塞的偏磨现象，达到提高抽油泵寿命的目的。这就是旋转柱塞的工作原理。产生多大的旋转力才能克服柱塞与泵筒之间的最大内摩擦阻力而使柱塞旋转，根据已知条件推导出柱塞旋转力、螺旋槽宽度、深度和螺旋角之间的关系式，将计算结果与柱塞和泵筒之间的最大内摩擦阻力进行比较，从而找出合理的螺旋槽宽度、深度和螺旋角。

Calculations of the plunger self-rotation unit

A self rotation unit is installed on the upper end of the plunger with spiral groove on its round outside. The movement principle of this self rotation unit is that the branch velocity made by the discharge liquid stream flowing with spiral lift manner cause plunger do random self rotation movement so that it can remove partial friction of the plunger and to increase the pump life. In order to know how much the rotation force is big enough to prevent the maximum internal resistance force between plunger and pump barrel so that the plunger can rotates, from the given conditions the rotation force, rotation groove width and depth, and the relational express among the spiral angels can be derived. Comparing the calculation results with the maximum internal resistance force between plunger and pump barrel, the reasonable width and depth of the spiral groove and the spiral angle can be found out.