Optimal design of the high-speed spindle’s bearings to minimize the non-repeatable runout 2019-01-0825
The production with high-quality at the lowest production time can be a key means to success in the competitive environment of the manufacturing companies. Therefore, in recent years, the need for the extra precise and high-speed machine tools has been impressively increased in the manufacturing applications. One of the main sources of errors in the motion of the high-speed spindles is the occurrence of non-repetitive runouts (NRRO) in the bearing. The NRRO can be caused by some factors such as the form of balls, the waveness of rings, the number of balls, and the permutation of one or two balls in the ball bearing. In this paper, a Taguchi-based approach is proposed for the optimal design of the high-speed spindle’s bearings by minimizing NRRO in the machine tools compatible with corresponding standards. First, the problem of optimal design of the effective parameters of the bearings for minimizing NRRO in the high-speed the spindle is formulated. In order to reach this aim, a 2D model for formulating the NRRO in the ball bearings of the spindle is presented based on the Hertzian contact theory. Subsequently, the objective function, the constraints, are formulated in terms of the design parameters for the simulations and the optimization processes. To find the effective parameters with significant impact, above 95% confidence level, the sensitivity analysis is carried out based on the Plackett-Burman design. Finally, the optimal robust design of the high-speed spindle’s bearings for minimizing NRRO is carried out through the Taguchi optimization method. For validation, the obtained optimal results are compared with experimental results and discussed.
S. Khodaygan, M. R. Farahani
Sharif Univ. of Technology, Sharif University of Technology