Sub-Combination Tones of a Rotating Shaft due to Ball Bearings

抄録

When a vertical rotating shaft is supported by single-row deep groove ball bearings, there appear symmetrical nonlinear spring characteristics in the elastic restoring force of the shaft due to the "angular clearance" of the bearings, provided that both bearing center lines at the upper and the lower bearings are aligned well. In such a system, two exciting forces with ω₁ (ω₁ : angular velocity of the precessional revolution of the balls) and 2ω₁ appear due to the coexistence of irregularities of balls and angular clearances of bearings. As the result of this, sub-combination tones of the angular velocity (3/2)ω₁ occur. In this paper, this kind of nonlinear forced oscillations is treated experimentally and theoretically.