2021-06-04

1.      Background

Bearing Type7017AD/7015C

Bearing ArrangementDBT/DB (<>> / <>)

Rotating Speed5000 RPM

PhenomenonNoise was found at 4000RPM during running-in test.

 

2.          Investigation and Research

Before

From FFT diagram at 4000RPM, vibration was mainly come from 2 times, 3 times and 4 times frequencies, which lead to the noise occurrence. As shown in Fig. 1 and 2.

 

NoteFTF: Fundamental Train Frequency, BSF: Ball Spin Frequency, BPFO: Ball Pass Frequency Outer, BPFI: Ball Pass Frequency Inner.





proimages/Engineering/blog/21-KD05-BL02_7017改善前.jpg

Fig. 1 7017AD side FFT diagram 

proimages/Engineering/blog/21-KD05-BL02_7015改善前.jpg

Fig. 2 7015C side FFT diagram

After

Amplitude at 2 times, 3 times and 4 times frequencies was obviously lowered and so did the noise level. As shown in Fig. 3 and 4.

proimages/Engineering/blog/21-KD05-BL02_7017改善後_EN.jpg

Fig. 3 7017AD side FFT diagram

proimages/Engineering/blog/21-KD05-BL02_7015改善後_EN.jpg

Fig. 4 7015C side FFT diagram

3.          Conclusion

From FFT diagram, the vibration and noise were caused by 2 times, 3 times and 4 times frequencies, which might be related to bearing looseness. After investigation, bearing inner ring and the spindle shaft has no interference was found out. Hence, a new spindle was selected for appropriate interference and the vibration and noise were obviously reduced.

top

This website uses cookies:

We use cookies to ensure our website work normally and provide you with the best user experience. By using this website, you agree to the current setting.

I agree