【摘要】 复合天轮式长冲程抽油机主架由四柱扁框架、两个悬臂梁和两个后支腿组成。介绍了用有限元法对主架的应力和变形的计算及对四柱扁框架的稳定性计算，计算结果表明．在悬臂梁附近区域的四柱扁框架各杆的应力超过了许用应力，应作局部加强。为了使整机工作平稳，主架的刚度十分重要，天轮轴的前后摆动幅度应控制在１４ｍｍ以内。更多还原

【Abstract】 The framework of the long-stroke pumping unit with compound crown sheave consists of a flat frame with four columns,two cantilever beams and two back legs.The authors calculate the stress and deformation of the framework and the stability of the flat frame with four columns by the finite element method.The result of calculation shows that the stress on the flat frame bars near the cantilever beam exceeds the allowable stress, therefore these bars should be locally reinforced.To achieve the stable performance of the unit,the backward and forward swing of the crown sheave shaft should be controlled within 14mm.更多还原