基于发动机曲轴轴系激振力矩减振器设计分析

Design and Analysis of Torsional Vibration Damper Based on Vibration Torque of Shaft System of Engine Crankshaft

曲轴扭转振动是发动机振动噪声的主要来源,对其加装减振装置可有效降低噪声并延长设备使用寿命。针对发动机激振力矩的来源进行分析。对激振力矩进行谐次分析,分析如何在无发动机动特性曲线的情况下得到发动机各谐次激振力矩的幅值与相位差。获得发动机转速范围内的主谐次与次主谐次激振力矩,基于激励力矩分析结果,设计硅油橡胶减振器主要参数,基于扭转振动测试台对减震器的减振效果进行分析,对比分析结果可知:根据根据轴系固有频率特性,在转速范围内主、次谐次为6谐次与5谐次;设计的硅油橡胶减振器,将轴系5、6谐次的扭振振幅最大值降低了51%以上;在发动机怠速工况下,前4谐次的振幅明显减小;试验结果表明所采用分析方法和设计过程的准确性,为此类设计研究提供参考。

The torsional vibration of crankshaft is the main source of vibration noise of the engine,the installation of vibration reduction device can effectively reduce the noise and prolong the service life of the equipment.The source of engine excitation torque is analyzed and the harmonic analysis of the excitation moment is carried out.The amplitude and phase difference of each harmonic exciting moment of the engine are analyzed in the condition of no engine dynamic characteristic curve.The main and sub-main harmonics sub-harmonic excitation torque is obtained in the engine speed range.Based on the analysis results of the excitation torque,the main parameters of the silicone rubber shock absorber are designed,and the vibration damping effect of the shock absorber is analyzed based on the torsional vibration test bench.The comparative analysis results show that the main and secondary main harmonics within the engine’s speed range are 6 and 5 respectively according to the first two orders of crankshaft axis torsional natural frequency.The design of the silicone oil shock absorber can reduce the maximum vibration amplitude of the 5 and 6 harmonic oscillators by more than 51%.The torsional vibration amplitude of the crankshaft system which the shock absorber is added is smaller under the action of 1,2,3 and 4 harmonic excitations when the engine is idle.The test results show the accuracy of the analysis method and design process used,providing reference for such design and research.