Research On Design And Application Of Adjustable Damper

In the field of power machinery,vibration isolation systems are often used to reduce vibration and its transmission.For the powertrain system,its vibration characteristics are multiple excitation sources,strong coupling and broadband.In order to reduce the vibration transmission of the system and improve riding comfortability,the two-stage vibration isolation system is usually used in the system.With the development of lightweight and high-power powertrain systems,it is difficult to meet the increasingly stringent vibration control requirements with the traditional passive control of rubber isolation.In order to explore better vibration isolation methods,based on the parameter optimization study of the two-stage vibration isolation system,this paper has analyzed the required stiffness and damping parameters of the vibration isolation element,and proposed a new type of adjustable damper.The relevant experiments have verified that the new component can achieve better vibration isolation characteristics in wider frequency range.First of all,the basic theory of the structure,working principle,energy dissipation mechanism and fluid material properties of several conventional damper dampers was studied,and the damping characteristics of three selected conventional dampers were tested.According to the vibration isolation performance requirements of the powertrain two-stage vibration isolation system,the system damping parameters were matched and designed.On this basis,a new structure of adjustable damper was proposed,which combines the structural principle of the non-adjustable damper and the damping parameter requirements of the two-stage vibration isolation system.Then,in order to complete the manufacture and test of the new adjustable damper and verify its design method,its mathematical model was established.The influence of key parameters on the damping characteristics was analyzed by MATLAB simulation,and the structural parameters of the key components were obtained.On the other hand,the dynamic model of the two-stage vibration isolation system was established,and the influence laws of the number of dampers,installation position and different damping coefficients on the vibration isolation performance of the system were analyzed.Then,the vibration isolation effect of the new adjustable damper under typical operating conditions was verified.Finally,different types of conventional dampers and the new adjustable damper were respectively applied to the test bench of the two-stage vibration isolation system set up by the simulation powertrain to conduct the vibration characteristics test under full operating conditions,which showed that the new adjustable damper has better vibration isolation characteristics.Research results showed that the "large" and "small" damping states of new adjustable damper can be switched significantly,and the deviation of its damping force between simulation and test is less than 10%.It's indicating that the design of the component is correct and feasible.Through the simulation analysis of the dynamic model of the two-stage vibration isolation system,we can see that: the low-frequency resonance of the system can be effectively suppressed by increasing the damping,while the large damping reduces the high-frequency vibration isolation characteristics of the system.The results of simulation and test comparison analysis show that: under the typical operating conditions,the large damping can significantly suppress the low-frequency resonance,and the simulation is basically consistent with the test.And besides,the results of vibration tests using various types of dampers for two-stage vibration isolation indicate that: the low frequency unit vibration intensity of the spring + new adjustable “small” damper scheme and the spring + no-damping scheme is greater than 10mm/s,while the low frequency unit vibration intensity of the spring + new adjustable “large” damper scheme and other schemes is less than 10mm/s.These show that the new adjustable "large" damper scheme can suppress low-frequency resonances of the two-stage vibration isolation system.The spring + no-damping scheme have minimal high-frequency transmission force,and compared with other schemes,the spring + new adjustable “small” damper scheme has the lowest high-frequency transmission force.These show that the new adjustable "small" damper scheme has smaller high-frequency transmission force and has better vibration isolation characteristics of the two-stage vibration isolation system.Relevant conclusions can provide reference for the design and development of adjustable damper used in vibration isolation systems,and it also has guidance in the practical application of optimization research on the two-stage vibration isolation system,and introducing semi-actively controlled adjustable damper into vibration isolation system.