Contactless dynamic tests for analyzing effects of speed and temperature on the natural frequency of a machine tool spindle

This paper presents a contactless dynamic test for characterizing several effects on the dynamic stiffness, in particular the first mode frequency, in the radial direction of a rigidly preloaded spindle. The effects of the static load, spindle speed, and spindle outer race temperature on the frequency response function (FRF) are investigated independently in different measurement steps. The first mode frequency was estimated from the measured FRF to evaluate the effects. In the test measurement for a spindle with rigid preload, both thermal and speed effects on the first mode frequency were quantitatively evaluated and a simple prediction model based on the measured data is presented.