Research on Thermally Induced Preload of Machine Tool Spindle Bearings Based on FBG Sensor.

Aiming at the difficult and inaccurate testing of the machine tool spindle bearing preloads, an online monitoring method was proposed herein based on FBG sensor. Firstly, the thermal analysis model of the spindle unit was established considering the heat generated by the spinning friction of the rolling elements, the contact thermal resistance between the inner/outer ring of the bearings and the spindle/housing. Secondly, a thermally induced preload test system for the spindle bearings was built. Through simulation and experimental comparison, the temperature distribution and thermally induced preloads of the key components of the spindle unit were analyzed at different speeds. The results show that the temperature measured by FBG sensor and thermal sensor is consistent with the simulation temperature prediction, which verifies the accuracy and reliability of the method proposed. [ABSTRACT FROM AUTHOR]