Small Hydraulic Excavator Engine Vibration Analysis And Vibration Isolation

As the main vibration sources of hydraulic excavator, engine vibration has an important effect on excavator overall performance. In order to reduce the vibration transfer to excavator and improve the excavator operation comfort properties, it is general use power-train mounting system to cut down the engine vibration at present. Based on the background of engineering application, combined with the state 863 projects, used vibration related theory, the following several aspects will be researched:Summarize power-train mounting system vibration isolator's material, structure and layout position, etc. Review this paper power-train isolation analysis research situation. Clear up the content and meaning of this paper.Discuss the main vibration source of small hydraulic excavator; calculation the vibration force and vibration frequency of three cylinder engine. Analysis the evaluation indexes of vibration damping performance engine-mount system. Research the main parameters of rubber isolator, static and dynamic characteristics and test the rubber isolator's stiffness under various hardness. Establish twelve freedom dynamic models of body & power-train engine-mount system. Get the vibration differential equation by application the Lagrange equation, and solve the system's natural frequencies and vibration mode.Build power-train engine-mount system twelve freedom simulation model. Take research about system'vibration isolation performance under different engine speed from three aspects of modal parameter time-domain vibration response and frequency response.Take excavator power-train mount system vibration experiment to test engine accessories'vibration acceleration and amplitude and both engine side and body side of vibration isolator'vibration acceleration in different engine speed. Compute system vibration isolation transfer rate to validate the accuracy of power-train mount system simulation model.Based on system inherent frequency and modal decoupling rate and vibration transmissibility for target function, vibration isolators'stiffness coefficient as design variables, the simulation model is optimized to get the vibration isolators stiffness value which can satisfy isolation requirements so as to improve the performance of vibration isolation system.This paper study based on machine's power-train mount system design method, and apply this method can effectively improve the performance of vibration isolation engine-mount system.