直升机的振动水平关乎乘客的舒适性、机械结构的可靠性、传感器的精确性等关键问题。随着科学技术的发展，人们对直升机振动水平的要求越来越高。尤其是近年来无人直升机行业的兴起，进一步带动了国内外学者对直升机振动控制技术的研究热情。本论文的目的是研究适用于交叉双旋翼直升机的主减速器隔振技术，交叉双旋翼直升机与常规构型直升机的区别在于有两个旋翼交替激振，且其激振频率较多。本文首先介绍了交叉双旋翼直升机相较其他构型直升机的优势和劣势，阐述了其主减速器隔振技术的研究必要性，也介绍了传统构型直升机的多种主减速器隔振技术。通过测量交叉双旋翼无人直升机的振动水平，并用理论推导证明了直升机旋翼产生旋翼转速一倍和偶数倍激振力和力矩的原因，明确了隔振系统设计的要点。基于这点，改进传统的DAVI技术，本文提出并设计了双频点动力反共振隔振器，结合聚焦式隔振器建立了适用于交叉双旋翼直升机的主减速器隔振系统。并基于JZ500型无人直升机进行了隔振系统的结构设计。其次，本文推导了隔振系统各个广义坐标之间的相互关系，通过数学方法描述了隔振系统的约束，使用拉格朗日方程建立了隔振系统的动力学模型，并使用数值方法对运动微分方程组进行了求解。利用有限元模态仿真计算系统的固有频率，与理论方法得到的固有频率进行对比，验证了动力学模型的有效性和隔振系统的有效性。基于运动微分方程组的解探究了双频点动力反共振隔振器和聚焦式隔振器的相互耦合情况，分析了各个参数对隔振效果的影响，为后续工程实物的调谐提供了理论基础。在此基础上，本文对隔振系统进行了工程研制。通过测量刚度和阻尼的试验确认了工程实物的相关参数，并据此调整了系统的质量参数，保证了隔振系统的隔振效果。将隔振系统装配到JZ500型无人直升机上进行了地面力锤试验和吊挂力锤试验验证了动力学模型的正确性和隔振系统的有效性、可靠性。最后进行了飞行试验，在实践中证明了隔振系统具备较好的隔振效果，且建立的动力学模型具备较高的工程使用价值。
The vibration level of helicopter is related to the comfort of passengers, the reliability of mechanical structure, the accuracy of sensors and other key issues. With the development of science and technology, people have higher and higher requirements for helicopter vibration level. Especially in recent years, the rise of unmanned helicopter industry has promoted the research of helicopter vibration control technology. The purpose of this paper is to study the vibration isolation technology of transmission of synchropter. The difference between synchropter and conventional helicopter is that there are two rotors alternately excited, and their excitation frequencies are more. This paper firstly introduces the advantages and disadvantages of synchropter compared with other helicopters, expounds the necessity of research on its main reducer vibration isolation technology, and also introduces various main reducer vibration isolation technologies of traditional configuration helicopters. By measuring the vibration level of the synchropter, and using theoretical derivation to prove the reason why the helicopter rotor produces the excitation force and moment of double and even times of the rotor speed, the key points of the vibration isolation system design are clarified. Based on this point, improving the traditional DAVI technology, this paper proposes and designs a dual-frequency point dynamic anti-resonance vibration isolator, combined with a focal isolation system, and establishes a main reducer vibration isolation system suitable for synchropter. And based on the JZ500 unmanned synchropter, the structural design of the vibration isolation system is carried out.Secondly, this paper deduces the relationship between the generalized coordinates of the vibration isolation system, describes the constraints of the vibration isolation system through mathematical methods, uses the Lagrange equation to establish the dynamic model of the vibration isolation system, and uses the numerical method to analyze the motion Differential equations were solved. The natural frequency of the system is calculated by finite element modal simulation, and compared with the natural frequency obtained by the theoretical method, the validity of the dynamic model and the effectiveness of the vibration isolation system are verified. Based on the solution of the differential equations of motion, the mutual coupling between the dual-frequency point dynamic anti-resonance isolator and the focal isolation system is explored, and the influence of each parameter on the vibration isolation effect is analyzed, which provides a theoretical basis for the tuning of subsequent engineering objects .On this basis, this paper conducts engineering research on the vibration isolation system. The relevant parameters of the engineering object are confirmed through the test of measuring stiffness and damping, and the quality parameters of the system are adjusted accordingly to ensure the vibration isolation effect of the vibration isolation system. The vibration isolation system was assembled on the JZ500 unmanned synchropter and the ground hammer test and hanging hammer test were carried out to verify the correctness of the dynamic model and the effectiveness and reliability of the vibration isolation system. Finally, the flight test is carried out, which proves that the vibration isolation system has a good vibration isolation effect in practice, and the dynamic model has high engineering use value.
