一、引言 有杆抽油机工作时,抽油杆处于循环应力工作状态。对于常用的中等冲程以下的抽油机来说,为了使生产效率达到较高的水平,则要求抽油机达到较高的冲次,而高冲次对抽油杆的寿命是极为不利的。另一方面,冲程越短,由于抽油杆弹性变形所引起的冲程损失率也越大。加之我国稠油开采问题比较突出,采用短冲程、高冲次的抽油机难以获得较大的充满系 I. Introduction Sucker rod pumping work, sucker rod in a cyclic stress state. For the commonly used medium-stroke pumping unit below, in order to achieve higher production efficiency, the pumping unit is required to achieve a higher stroke, and high-stroke on the sucker rod life is extremely unfavorable. On the other hand, the shorter the stroke, the greater the stroke loss due to the elastic deformation of the sucker rod. Coupled with China’s heavy oil exploitation problems are more prominent, the use of short stroke, high-stroke pumping unit is difficult to obtain a large full