Dynamics Modeling and Dynamic Response Analysis of Helicopter Tail Transmission System

The helicopter tail drive system constitutes a vital element of the helicopter’s overall propulsion system, with a long drive chain and single-way power transmission. Rolling bearings, splines, diaphragm couplings, spiral bevel gears, and other components are all vibration transmission components or vibration sources within the helicopter’s tail drive system, and there is also coupled vibration between the components, resulting in complex vibrational response of the tail drive system. This study employs the shaft segment element approach, using the Timoshenko beam model to establish shaft segment elements. Equivalent element models are established for rolling bearings, splines, diaphragm couplings, spiral bevel gears, etc., the stiffness, mass, and damping matrices for each component are determined. The comprehensive system matrix is derived through the assembly of individual element matrices, based on their installation interrelationships. The system’s vibrational response is computed by addressing the differential formula governing the overall dynamics through the application of the Newmark-β method. This research contributes valuable insights for the dynamic modeling and resolution techniques of dynamic responses in helicopter tail drive systems.