Stiffness Matching Method of Double-Layer Vibration Isolation System with Flexible Diesel Generator Set
In order to solve the problem of stiffness matching between the connecting sleeve and the vibration isola-tion system when a diesel engine is matched with different types and power generators,an energy decoupling method based on the work done by generalized elastic forces was proposed to quantify the effect of stiffness match-ing on the natural characteristics of the vibration isolation system.Based on the design of a double-layer vibration isolation system for an internal combustion powertrain,3 degree-of-freedom and 18 degree-of-freedom dynamics models were established for analysis.The study result shows that the 3 degree-of-freedom model can reflect the main coupling characteristics of the system.The influence of rigid body vibration on the elastic modal can be re-duced by improving the ratio of the elastic modal frequency of the powertrain to the low-order rigid body vibration modal frequency as it is greater than 2.96.Considering inertial coupling and elastic coupling of 18 degree-of-freedom dynamics models,the corresponding frequency ratio should be greater than 4.10 to significantly reduce the vibration coupling.The same type of diesel engine matched with various inertia parameters of generators can refer to the corresponding frequency ratio and stiffness ratio for vibration isolation of generators with small inertia pa-rameters to achieve stiffness matching.