Abstract: The dynamic performance of high speed dynamic balancing machine directly affects the accuracy and safety of the dynamic balance test. The three-dimensional finite element method is adopted to numerically study the dynamic stiffness of a 250 t high speed dynamic balancing machine, which is compared with the experimental results. The dynamic stiffness characteristics of four improved models are evaluated, aiming to investigate how the stiffness of the main stiffness rod influences the dynamic performance of the machine. The results show that the calculated dynamic stiffness curves agree well with the experimental results. The dynamic stiffness of the machine increases with the increment of the structure size and material elastic modulus of the main stiffness rod; a suitable structure and material for the main stiffness rod enables the machine to meet the dynamic balance test requirements of the large-mass rotors. Improving the main stiffness rod cannot lead to a flat dynamic stiffness curve.

Key words: Dynamic stiffness, Finite element method, High speed dynamic balancing machine, Optimization