本文阐述了“4G一2.5”收割机组的数学计算模型和激振法测定机组固有频率的方法。在对机组割麦工况和道路运输状态下的动态特性,收割机刀杆和机架动应力分析研究的基础上阐明拖拉机前、后轮,收割机拖板对机组振动响应的不同影响及机架、刀杆动应力的变化情况。初步探明该机组在割刀和发动机工作频段范围内具有较大的响应,是造成机组振动过大的主要原因。 This article describes the “4G a 2.5” harvester mathematical model and excitation method to determine the unit natural frequency method. On the basis of the dynamic characteristics of the unit under the conditions of wheat harvesting and road transport, the dynamic stress analysis of the cutter bar and the frame of the harvester, the different effects of the tractor front and rear wheels and the harvester carriage on the vibration response of the generating set Rack, arbor dynamic stress changes. It is initially proved that the unit has a large response in the working frequency range of the cutter and the engine, which is the main reason causing excessive vibration of the unit.