Abstract
The aim of this research is to study the nonlinear rotational speed characteristics of an eccentric-rotor type hydraulic vibro-hammering machine operating on an elastically supported base. The experiments are carried out on a single eccentric-rotor system. The rotational speed characteristics are analyzed by applying the harmonic analysis method on the nondimensional system equation. The results show the mechanism of stagnation, jump and hysteresis of the rotational speed characteristics of the machine. These phenomena are considered to be caused by the resonance vibration of the base which causes the increase of the load pressure and leakage through the bypass valve in the resonance frequency range.
