The temperature control performance of a developed temperature feedback control system was experimentally investigated. The control system was based on a real-time temperature control of a cooling fluid. In particular, this study focused on the temperature control performance of a built-in motor spindle that used the developed temperature fedback control system. The built-in motor used in the study had water cooling jackets. The temperature of the built-in motor spindle was measured and feedback into the developed temperature feedback control system. Temperature control accuracy of the built-in motor spindle under steady state was then assessed. Furthermore, the effects of the time-variant changes in spindle rotation and ambient temperature on the performance of the temperature control system was investigated. The results of the experiments show that the temperature control accuracy of the built-in motor spindle under steady state condition was ±0.03°C. The temperature control performance of the built-in motor spindle under changes in the rotational speed of the spindle was examined. The experimental results show that the temperature change of the spindle could be suppressed to a maximum of approximately 0.3°C under transient state during sudden change in spindle speed. In addition, the effects of the changes in ambient and cooling water temperatures, which simulated actual environmental operating conditions, on the spindle temperature were investigated. The results show that the change in the spindle temperature could be suppressed by approximately less than ±0.1°C. These experimental results indicate that the developed temperature feedback control system achieved high temperature control accuracy and high response for the built-in motor spindle. In particular, the developed control system successfully controlled the time-variant change in the generated heat, thereby improving the thermal stability of the machine tool spindle.

1. [1] T. Kawai, K. Ebihara, and A. Yamamoto, “5-axis ultra precision nano machine tool by means of linear motor drive,” J. of Japan Society for Precision Engineering, Vol.72, No.4, pp. 435-439, 2006 (in Japanese).
2. [2] J. Mayr, J. Jedrzejewski, E. Uhlman, M. Alkan Donmez, W. Knapp, F. Härtig, K. Wendt, T. Moriwaki, P. Shore, R. Schmitt, C. Brecher, T. Würz, and K. Wegener, “Thermal issues in machine tools,” CIRP Annals, Vol.61, No.2, pp. 771-791, 2012. https://doi.org/10.1016/j.cirp.2012.05.008
3. [3] S. Nakamura, Y. Kakino, A. Muramatsu, and K. Urano, “An analysis on influence of motor heat generation and effect of shaft-bore cooling for motor integrated spindle,” J. of Japan Society for Precision Engineering, Vol.60, No.7, pp. 979-983, 1994 (in Japanese). https://doi.org/10.2493/jjspe.60.979
4. [4] S. Xiang, H. Lu, and J. Yang, “Thermal error prediction method for spindles in machine tools based on a hybrid model,” Proc. IMechE, Part B, J. of Engineering Manufacture, Vol.229, No.1, pp. 130-140, 2015. https://doi.org/10.1177/0954405414525
5. [5] K. Nagashima, T. Ueta, and T. Momochi, “Analysis and compensation of main spindle displacement derived from temperature rise and centrifugal force in CNC machine tools,” Trans. of the Japan Society for Mechanical Engineers, Ser. C, Vol.65, No.636, pp. 3438-3443, 1999 (in Japanese).
6. [6] M. Mareš, O. Horejš, and J. Hornych, “Thermal Error Minimization of a Turning-Milling Center with Respect to its Multi-Functionality,” Int. J. Automation Technol., Vol.14, No.3, pp. 475-483, 2020. https://doi.org/10.20965/ijat.2020.p0475
7. [7] Y. Ishino, H. Tachiya, and Y. Kaneko, “Compensation for Thermal Deformation of a Compact Lathe in Cutting Operations Using a Coolant Fluid with Temperature Measurement at a Few Specific Points,” Int. J. Automation Technol., Vol.13, No.4, pp. 527-538, 2019. https://doi.org/10.20965/ijat.2019.p0527
8. [8] R. Kondo, D. Kono, and A. Matsubara, “Evaluation of Machine Tool Spindle Using Carbon Fiber Composite,” Int. J. Automation Technol., Vol.14, No.2, pp. 294-303, 2020. https://doi.org/10.20965/ijat.2020.p0294
9. [9] C. Brecher and A. Wissmann, “Compensation of Thermo-Dependent Machine Tool Deformations Due to Spindle Load Based on Reduced Modeling Effort,” Int. J. Automation Technol., Vol.5, No.5, pp. 679-687, 2011. https://doi.org/10.20965/ijat.2011.p0679
10. [10] S. Yagyu, S. Shimizu, and N. Imai, “Mechanism of Thermal Deviation Characteristic in Spindle System of Machine Tools,” Int. J. Automation Technol., Vol.2, No.3, pp. 191-198, 2008. https://doi.org/10.20965/ijat.2008.p0191
11. [11] C. Hong and S. Ibaraki, “Observation of Thermal Influence on Error Motions of Rotary Axes on a Five-Axis Machine Tool by Static R-Test,” Int. J. Automation Technol., Vol.6, No.2, pp. 196-204, 2012. https://doi.org/10.20965/ijat.2012.p0196
12. [12] E. Uhlmann and J. Hu, “Thermal modeling of a high speed motor spindle,” Procedia CIRP, Vol.1, pp. 313-318, 2012. https://doi.org/10.1016/j.procir.2012.04.056
13. [13] Y. Nakao, K. Suzuki, K. Yamada, and K. Nagasaka, “Feasibility Study on Design of Spindle Supported by High-Stiffness Water Hydrostatic Thrust Bearing,” Int. J. Automation Technol., Vol.8, No.4, pp. 530-538, 2014. https://doi.org/10.20965/ijat.2014.p0530
14. [14] Y. Nakao, R. Kirigaya, D. Fedorynenko, A. Hayashi, and K. Suzuki, “Thermal Characteristics of Spindle Supported with Water-Lubricated Hydrostatic Bearing,” Int. J. Automation Technol., Vol.13, No.5, pp. 602-609, 2019. https://doi.org/10.20965/ijat.2019.p0602
15. [15] B. Bossmanns and J. F. Tu, “A Power Flow Model for High Speed Motorized Spindles–Heat Generation Characterization,” Trans. of the ASME, J. of Manufacturing Science and Engineering, Vol.123, No.3, pp. 494-505, 2001. https://doi.org/10.1115/1.1349555
16. [16] B. Denkena, B. Bergmann, and H. Klemme, “Cooling of motor spindles–a review,” The Int. J. of Advanced Manufacturing Technology, Vol.110, No.11, pp. 3272-3294, 2020. https://doi.org/10.1007/s00170-020-06069-0
17. [17] S. Kodaka, B. Kawase, J. Kusuyama, and Y. Nakao, “Development of temperature feedback control system for machine tools and fundamental evaluation of control performance,” J. of the Japan Society for Abrasive Technology, Vol.64, No.4, pp. 208-213, 2020 (in Japanese). https://doi.org/10.11420/jsat.64.208
18. [18] J. Kusuyama, K. Komatsu, T. Hashimoto, Y. Tanada, and Y. Nakao, “Study of optimum cooling conditions of built-in motor spindle 1st report: Thermal simulation of built-in motor spindle,” J. of the Japan Society for Abrasive Technology, Vol.64, No.5, pp. 254-259, 2020 (in Japanese). https://doi.org/10.11420/jsat.64.254
19. [19] K. Wegener, J. Mayr, M. Merklein, B. A. Beherens, T. Aoyama, M. Sulitka, J. Fleischer, P. Groche, B. Kaftanoglu, N. Jochum, and H. C. Möhring, “Fluid elements in machine tools,” CIRP Annals – Manufacturing Technology, Vol.66, No.2, pp. 611-634, 2017. https://doi.org/10.1016/j.cirp.2017.05.008
20. [20] Y. Zhang, L. Wang, Y. Zhang, and Y. Zhang, “Design and thermal characteristic analysis of motorized spindle cooling system,” Advances in Mechanical Engineering, Vol.13, No.5, 2021. https://doi.org/10.1177/16878140211020878