关键词: 结合面, 主轴, 双转子, 拉杆拉力, 刚度, 频率

Abstract: To reveal the influence of tool holder-spindle joint surface's contact condition on dynamic characteristics of high speed spindle system,a double-rotor dynamic model was established based on receptance coupling method by considering the dynamic changes of contact force and contact stiffness.Simulations of contact stiffness characteristics and frequency changes of double-rotor system were taken out under the influence of initial and/or dynamic drawbar force.The result showed that contact stiffness could be raised by increasing initial and dynamic drawbar force,and dynamic drawbar force was more efficient,but the contact characteristics in high speed condition disputed downward trend which determined by the difference value of centrifugal expansion of tool holder and spindle.The modal frequencies decreased remarkably when drawbar was considered,which meant the drawbar was a weak point.Small changes of draw force could not affect frequencies characteristics significantly,which indicated the force of this magnitude was big enough and the frequencies were not sensitive to the changes of contact stiffness.

Key words: contact surface, spindle, double rotor, drawbar force, stiffness, frequency