Analysis of coupled vibration characteristics of PMS grinding motorized spindle

Field-path-kinetic coupling and the multi-body dynamics models were established and the finite element method (FEM) was used to study the coupled vibrations of motorized spindle. The results show that the frequency is mainly 1f(r)at low speeds, fractional-octave and 1f(r)at high-speed only the bearing force. The orbit of bearing transitions is from a more pronounced circle to an approximately circular shape, while the rotor changes from a rule to a random pattern. The front bearing is more obvious than the rear and the orbits are always round; the radius of the orbit at the front bearing gradually increases as the speed increases. The result is the vibration displacement changes more significantly close to the spindle end and the amplitude increases accordingly. The experimental results show that operating conditions are closer to the normal, the influence of unbalanced magnetic pull can be neglected, the bearing selection and assembly are reasonable.