Collision vibration characteristics with interspace in knife driving system of combine harvester

It is necessary to develop a design theory of the knife driving system of combine harvesters in order to derive the control parameters of the balance weights used for vibration reduction. A collision vibration model of the knife driving system that is equipped with a slider-crank mechanism was constructed in order to examine the influence of the interspace that arises at the joint of the drive knife and the end of the link arm. The simulation result revealed that the harmonic frequency components varied with an increase in the width of the interspace although the highest harmonic frequency in the simulation without the interspace was three times the crank wheel rotation frequency. However, the vibration reduction by the balance weight was not dependent on the width of the interspace.