Effects of automatic variable preload device on performance of spindle

Abstract

To increase the machine accuracy by improving the stiffness of bearings, a preload was applied to bearings. A variable preload technology was necessary to perform machining processes in both low and high speed regions. An automatic variable preload device was fabricated using an eccentric mass. By installing the fabricated device on a spindle, the effect of the automatic variable preload device on the performance of the spindle was analyzed. In the results of the vibration measurement of the spindle, the vibration is increased by 20%–37% according to measurement points at the maximum rotation speed of 5 000 r/min. And, in the results of the noise measurement of the spindle, the spindle rotation speed is increased by about 1.9% and 1.5% at the front and side of the spindle, respectively. Based on the results of this analysis, an improved method that reduces such effects on the performance of the spindle is proposed.

Keywords

machine tool spindle / automatic variable preload device / vibration / noise

References

[1] MarshE. R.Precision spindle metrology [M], 2008, Lancaster, DEStech Publications: 127-146

[2] HARRIS T A. Bearing design in machinery [M]. Marcel Dekker, 2003: 236–599.

[3] DORNFELD D, LEE D E. Precision manufacturing [M]. Springer, 2008: 455–554.

[4] HarrisT. A.Rolling bearing analysis [M], 2007, London, Taylor & Francis

[5] HwangY. K., LeeC. M.. A review on the preload technology of the rolling bearing for the spindle of machine tools [J]. International Journal of Precision Engineering and Manufacture, 2010, 11(3): 497-504

[6] KIM J H. Development of piezoactuator using three dimensional bridge type hinge mechanism [D]. Korea Advanced Institute of Science and Technology, 2003.

[7] HarrisT. A., KotzalasM. N.Advanced concepts of bearing technology [M], 2007, London, Taylor & Francis: 209-258

[8] KimB. S., RoS. K., ParkJ. K.. Development of a 3-axis desktop milling machine and a CNC system using advanced modern control algorithms [J]. International Journal of Precision Engineering and Manufacture, 2010, 11(1): 39-47

[9] IBAG Switzerland AG. Hydraulic variable preload [EB/OL]. http://www.ibag.ch

[10] GMN Paul Müller Industrie GmbH & Co. Pneumatic variable preload [EB/OL]. KG. http://www.gmn.de

[11] TsutsuiS., AoyamaT., LnasakiI.. Development of a spindle system with an adjustable preload mechanism using a piezoelectric actuator [J]. The Japan Society of Mechanical Engineering, 1988, 31(3): 593-597

[12] ChenJ. S., ChenK. W.. Bearing load analysis and control of a motorized high speed spindle [J]. International Journal of Machine Tools and Manufacture, 2005, 45(12): 1487-1493

[13] NYE T W. Active control of bearing preload using piezoelectric translators [R]. NASA Technical Report N90-22098, 1990.

[14] TANIGUCHI K K. Preload control apparatus for bearings with shape memory alloy springs [P]. United States Patent 5094551, 1992-03-10.

[15] HwangY. K., LeeC. M.. Development of automatic variable preload device for spindle bearing by using centrifugal force [J]. International Journal of Machine Tools and Manufacture, 2009, 49(10): 781-787

[16] HwangY. K., LeeC. M.. Development of a newly structured variable preload control device for a spindle rolling bearing by using an electromagnet [J]. International Journal of Machine Tools and Manufacture, 2010, 50(3): 253-259

[17] GuoR., JangS. H., ChoiY. H.. Torsional vibration analysis of lathe spindle system with unbalanced workpiece [J]. Journal of Central South University of Technology, 2011, 18: 171-176

[18] KIM D H, LEE C M. Pre-load control device of bearing for machine tool [P]. Korea Patent 0125502, 2010-12-09.

[19] KIM D H, LEE C M. A basic study on the development of a variable preload device for a spindle bearing by using an eccentric mass [C]// Proc of KSPE Spring Conference. 2010: 341–342.

[20] KS B ISO 10816-1:2001. Mechanical vibration evaluation of machine vibration by measurements on non-rotating parts-Part 1: General guidelines [S].