Research On Modeling And Load Characteristics Of Vibration Isolator With Metal Spring

Ultra-precision manufacturing machines and measurement equipment usually need to protect the platform from the impact of ground vibration and environmental interference.Steel springs are used in the vibration isolation system because of their simple structure,precise mathematical modeling,no additional power supply and long life.The horizontal stiffness of metal springs is an important factor for the vibration isolation system.In this paper,the effect of load position on passive vibration isolation system of metal spring is discussed,the horizontal stiffness characteristics of a single metal spring,the theoretical modeling of the vibration isolation system and the influence of the load position on the stability and vibration transmission of the vibration isolation system are studied.The vertical stiffness of the metal spring used in the vibration isolator can be regarded as a constant,but its horizontal stiffness characteristics are more complicated.In this paper,the metal spring is equivalent to an cantilever beam with equal cross section,derived the deformation of the metal spring’s free end with the vertical load and horizontal load.And the horizontal stiffness of the circular spring and rectangular cross section metal spring is obtained,Then the impact of the parameters on the horizontal stiffness of the spring is analyzed.This paper first modelling the vibration isolation system under load,Taking into account the metal spring horizontal stiffness with its vertical load changes,First,the vertical load of each vibration isolation unit under load is analyzed to get different horizontal stiffness of each unit.On this basis,the mass matrix and stiffness matrix of the vibration isolation system are obtained according to the knowledge of rigid body kinematics and the system frequency response matrix is obtained by modal analysis theory.The influence of the position of the load on the stability and vibration transmission of the vibration isolation system is also analyzed.According to the principle of stable balance of the mechanical system in the equilibrium position,The stability domains are obtained by analyzing the energy change of the vibration isolation system,The vibration transmission in the horizontal and vertical directions of the vibration isolation system is analyzed separately for the different positions of the load.And the finite element software is used to simulate the vibration transmission in all directions of the vibration isolation system when the load is applied to different positions of the vibration isolator.And finally compare with the theoretical results to verify the correctness of the analysis results.Finally,the vibration of the vibration isolation system is tested in the different positions of the load,and the correctness of the analysis result is verified.