ENERGY CONSUMPTION SAVING DESIGN METHODOLOGY OF BALL BEARING FOR SMALL ELECTRIC MOTORS

摘要

Based on the principle of tribology and theory of optimization design, multi-objective optimal design methodology of inner main parameters was carried out for deep-groove ball bearings used for the small electric motors. And their technical requirements related to bearing design were also analyzed. The objective functions of these bearings are as follow: (1) the minimizing friction torque, (2) the longest service lifetime, (3) lower vibration and noise, (4) seizure-free in operating. This principle was further enriched by the choice of outer load, the amount of torque has been reduced to about 20% on the basis of optimization by adopting the appropriate measure of lowering the applied preload, and this approach not only improves the torque function, but minimizes the side-effort on bearings followed by the change of their inner parameters. Two kinds of bearings before and after improvement design have been experimented on the friction torque tester YZC-Ⅱ, the results showed that the starting friction torque and running friction torque of the improved type bearings reduce by about 40% and 47% compared with the old ones respectively. Finally, the difference of theoretical calculations and experimental results was analyzed in the view of the tribology mechanism of bearing's friction torque origination. The total friction torque of the ball bearing consists of two parts: dissipation torque and conservative torque while the former can be calculated quantitatively, however, the latter originates from fabrication error and the theoretical method for its calculation remains to be determined.