Compared with conventional beam pumping unit, the swing-rod beam pumping unit can reduce the maximum crankaxle torque markedly, reduce and even eliminate negative crankaxle torque.
The utility model has the advantages of increasing the mechanical strength of the crank of the bent axle so that the utility model will not break even being overloaded.
优点是增强了曲轴曲柄的机械强度，使其在超负荷的情况下运行也不易折断。
3
The bottom bracket axle is permanently mounted to the right hand crank and has splines for the left hand crank.