Viscous Friction Research to Hydraulic Hammer Working Performance by Simulation

Both predigested mathematical model and mathematical models of viscous friction are simulated according to power bond graph in hydraulic hammer and the data of them are also analyzed. The result of simulation is shown as follows: impact energy and work efficiency is reduced and average input pressure is increased because of the viscous friction, but impact frequency is affected less by the viscous friction. The viscous friction of piston velocity is much larger than that of pressure difference of piston and the pressure difference of piston is ignored when the viscous friction is calculated, so that mathematical model is predigested.