Journal of Advanced Mechanical Design, Systems, and Manufacturing (Jan 2015)
Influence of nonlinear spring behavior of friction on dynamic characteristics of a rolling guideway
Abstract
The friction of rolling guideways in the prerolling region displays hysteretic behavior known as nonlinear spring behavior (NSB). NSB deteriorates motion accuracy and causes vibration in the feed direction. Therefore, the influences of NSB on the dynamic characteristics of rolling guideways should be clarified. This paper describes the influence of NSB on the dynamic characteristics of a rolling guideway. A simple friction model is constructed based on the Masing rule. Because the proposed friction model is described with only three parameters, the factor that inherently affects the dynamic characteristics can be clearly identified. To clarify the influence of NSB, the impulse response, frequency response, and steady state motion are analyzed by numerical analysis. According to the results, the dynamic characteristics in the feed direction depend only on the change rate of friction in the prerolling region, which is introduced to the friction model as the shape factor, n. The stiffness and damping are high when the change rate of friction is high in the prerolling region. The frequency response function is force- dependent, and its tendency is varied by n. The frequency response function includes harmonic and super harmonic resonances. When the carriage is excited with a frequency lower than that of the super harmonic resonance, a displacement spike (quadrant glitch) is observed. Additionally, the nonlinearity cannot be ignored when the carriage is excited with a frequency lower than the harmonic resonance. Finally, an experiment with a roller guideway is conducted to prove the validity of the analysis. The resonance frequency and compliance at the harmonic resonance measured by the experiment accurately conform to the analytical results.
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