Bearing Support Systems for Rotary Tables

Bearing Support Systems for Rotary Tables Schaeffler Group Industrial has developed a bearing support system for rotary tables that helps to achieve a combination of high static rigidity and good vibration damping. This makes it possible to achieve both good surface qualities of the workpieces as well as precise and dimensionally stable machining results. Schaeffler Group Industrial will present this theme for the EMO 2007 in the form of a real comparison. Rotary tables are mainly equipped with ready-to-fit rolling bearing supports. This type of bearing support permits very high rigidity of the assembly so that workpieces can be precisely machined and are dimensionally stable even with greater machining forces. However, due to their extremely rigid construction, such bearing supports have low vibration damping properties. The newly developed bearing support system from Schaeffler Group Industrial complements the ready-to-fit rolling bearing arrangement with a damping element. To this end, the bearing outer ring is connected to an additional washer. In this way, a defined narrow gap forms between this disc and the rotating face plate of the rotary table. This gap is filled with oil. Due to the occurring vibration the gap dimension changes with the vibration frequency. Thus the oil is continuously driven out of the narrow gap and drawn in again. The energy required for this serves to reduce or dampen the machining vibration. Calculation results and measurements that were determined by means of a prototype incorporated in a rotary table have shown that impressive damping values can be achieved despite the extremely rigid rolling bearing support.