Research On The Relationship Between Preload Of Angular Contact Ball Bearing And System Natural Frequency

Precise determination of bearing preload directly affects bearing stiffness, rotating precision and service life. It is also the precision guarantor of bearing supporting system in special occasions. Suitable preload can increase stiffness, rotating precision and service life, which reduces vibration and noise. During use process, if the actual preload is more than the designing preload, stiffness can't meet requirements. Unload and clearance would appear at high acceleration. If the actual preload is less than the designing preload, high stiffness and anti-offloading capacity can be got. But at the same time, friction moment increases, and a dead point appears easily. It rises temperature and reduces their operating life. Conventional methods have the shortcomings of low efficiency, big worker labor intensity, complicated process. They need workers debug repeatedly,depend on their working skills and technical levels. This paper mainly embarks from the practical application angle for resolving the problem of measuring preload.Based on the theory of preload, stiffness and system natural frequency, this paper studied on the relationship among preload,system natural frequency and span. The new formula was advanced. The preload was measured and showed on PC through a self-made data collection board. Then the actual preload and natural frequency data were tested by the test rig of bearing preload system, which verified computed results. The results showed that the theoretical and experimental results agreed well, which provided a new method for measuring bearing preload.According to the analysis, it was found that at the same span, natural frequency increased with the increase of preload; under the same preload, natural frequency increased with the increase of span.