双摆增程式抽油机的几何尺寸计算及运动分析

Geometric parameter calculation and motion analysis of pumping unit with twin wobble wheels

双摆增程式抽油机是利用链条行程为摆轮行程两倍的原理实现增程的。与其他类型的长冲程抽油机相比，这种抽油机具有整机重量轻、高度低、稳定性好等优点。给出了双摆增程式抽油机的几何尺寸计算公式。根据四连杆机构和滑轮组机构的特点和运动原理，对双摆机进行了运动分析；导出了四连杆机构的角速度和角加速度、悬点速度和悬点加速度的计算公式及光杆冲程的计算公式。指出若能克服链条寿命低这一缺点，这种抽油机将会有较大发展。

The pumping unit with twin wobble wheels realizcs stroke increment based on the principle of the chain stroke being twice the wheels stroke. Compared with other long stroke pumping units, this unit has the advantages of ligllt weight, rational height and good stability. The equations for calculating the geometric parameters of the unit are given. According tothe characteristics and principles of the linkage and pulley , the motion analysis of the unit is made, the equations for calculating the angular speed and angular acceleration of the four－bar linkage, and the speed , aceeleration and stroke of the polished rod are derived. It is pointed out that the pumping unit with twin wobble wheels will be popularized if the shortcoming of low chain life is overcome.