同时分析了下冲程抽油杆所产生的螺旋弯曲变形。

Deformation of helical buckling appeared on rod during down stroke is also analyzed.

youdao

同时分析了下冲程抽油杆所产生的螺旋弯曲变形。

Deformation of helical buckling appeared on rod during down stroke is also analyzed.

youdao