Vibration evaluation and optimization of coaxial high-speed helicopter main transmission system and its experimental verification

Abstract

To reduce the vibration of the Coaxial Helicopter Main Transmission System (CHMTS) considering both level and vertical flight conditions, a vibration evaluation and optimization model for the CHMTS was built. The vibration simulation model of the CHMTS was set up by gear dynamics theory and loaded contact analysis. For better evaluation of the system vibration, a vibration evaluation method for the CHMTS was established by the G1 method-variation coefficient method. A hybrid Gravitational Search Algorithm-Simulated Annealing (GSA-SA) algorithm was combined to balance convergence speed and searching accuracy. The principle test was conducted to prove the accuracy of theoretical method, in which the maximum relative error is 16.26%. The optional results show that the vibration of the optimized transmission system decreases significantly, in which the maximum reduction of key vibration indicators reaches more than 20%. The theoretical results have been compared to the experiment to verify the effectiveness of the vibration optimization method. The proposed method could be extended to other fields.