Paper Title
Dynamic Stiffness Of Shaft For Thresher In Combine Harvester

Abstract
This paper deals dynamic stiffness of shaft for thresher in Combine Harvester. In this research, the amplitude, phase angle and stiffness can then be determined in a dynamic sense. Especially, the most synchronous excitation force in rotating machinery is the residual unbalance in the shaft. Therefore, the value of original response vector, new response vector, response due to calibration weight alone, applied force, synchronous dynamic stiffness, modal stiffness, modal mass of unbalance weight, modal damping, influence vector and response vector can be solved based on Hooke’s Law equation. Result of applied force is 1.6636 N for calibration weight alone. Modal mass (m) of unbalance weight is 1.2575 kg. Mass of shaft is 34.68 kg with 75 mm diameter and 7850 kg/m3 density of carbon steel. Finally, outcome of modal stiffness for unbalance weight (K) is 209.03 N/m, and stiffness of shaft (Kt) is 3.9716 × 109 based on rotating speed (1351 rpm) and engine speed (2800 rpm). Index terms— Amplitude (Response), Combine Harvester, Synchronous Dynamic Stiffness, Shaft, Speeds