磁悬浮铣削电主轴时变质量系统动力学模型 与切削稳定性分析.

Aiming at the problem that the time varying unbalanced centrifugal force due to the time varying chip mass caused the regenerated chatter on the machined surface during the milling of magnetic levitation electric spindle, the stability of the milling system was predicted by constructing the stability lobe diagram. Firstly, by analyzing and establishing the mathematical models of dynamic milling force, time varying unbalanced centrifugal force and active magnetic bearing electromagnetic force, the dynamic model of magnetic levitation electric spindle milling system was established. Then, the stability profile of milling system was obtained by full discretization method. Finally, the cutting stability of the system was analyzed using MATLAB numerical calculation platform, and the influence of time varying mass characteristics and magnetic bearing electromagnetic force on the cutting stability of the system was obtained. The research results indicate that the limit axial cutting depth of the time varying system is respectively decreased by 0. 005 mm, 0. 010 mm, 0. 022 mm and 0. 033 mm, comparing with the constant system at lobe 1, lobe 2, lobe 3 and lobe 4, indicating that the time varying unbalanced centrifugal force can reduce the cutting stability of the system, and the higher the spindle speed, the greater the effect. When the force displacement stiffness of the magnetic levitation bearings is kq = - 2 × 10 5 N/ m, kq = - 2 × 10 6 N/ m, kq = - 2 × 10 7 N/ m, the ultimate axial cutting depth of the system is respectively 0. 37 mm, 0. 55 mm, 1. 45 mm, indicating that increasing the force displacement stiffness of the magnetic bearing can enhance the cutting stability of the system [ABSTRACT FROM AUTHOR]