Abstract: The back beam arms of the dual horse head pumping unit are composed of variable radius arc, whose effective length varies in the motion process with the changes of the driving rope and the back horse head, so that the universal dynamic simulation software can not achieve the simulation of this mechanism system. According to the transmission characteristics of the flexible linkage mechanism with variable parameters, the motion characteristics equation for the dual horse head pumping unit is built and its solution algorithm is put forward. The algorithm provides an effective mathematical model for the simulation of the dual horse head pumping unit. Aiming at the problem that the variable parameter flexible linkage mechanism lacks applicable dynamic simulation system, the dynamic simulation system for the dual horse head pumping unit is developed. The system includes virtual prototype subsystem, CAD analysis subsystem, data management subsystem and solid emulation subsystem. It provides 3D dynamic simulation and performance analysis in virtual environmental for the dual horse head pumping unit, and can be used as an effective reference for the design of pumping unit. Finally, the system practicality is verified through the simulation test of CYJ145.

Key words: Changeable parameter linkage, Dual horse head pump unit, Dynamic simulation, Mechanism simulation, Virtual prototype