Topological optimal design of the pumping unit horsehead;

Horsehead Design of Rotating Horsehead Pumping Unit;

Optimum design for double-horse head beam pumping unit with rear horse head′s outline of spiral of Archimedes;

Under the condition that the backarmofforce is constant, the radiusofcurvature of the mule head may be increased .

Kinematics and dynamics analysis about double horse head pumping unit with arc back horse head;