Abstract: [Objective] Aiming at the existing problems such as intensive vibration and big impact of the modified Salix psammophila chipper, the vibration measurement has been carried out to provide technical references for investigating the vibration effects on the chipping qualities and utilizing the Salix psammophila chipper efficiently and reasonably in the future.[Method] The multi-point vibration measurement systems for its main working parts such as the cutting and feeding mechanism under the unloaded and working conditions have been constructed.[Result] As shown from the measured dada analysis in the time and frequency domain, the vibration accelerations of the cutting and feeding mechanism decrease at first and then increase when the rotation speed of the knife roll increases. Their auto-power spectrums of the vibration accelerations keep stationary for the whole low-frequency band. Secondly, the accelerations in the up-and-down direction of the cutting mechanism increase remarkably when the rotation speed of the feeding roll increases. The accelerations in other two directions of the cutting mechanism and the accelerations in the up-and-down and left-and-right directions of the feeding mechanism increase at first and then decrease. Especially, when the rotation speed of the feeding roll comes up to 80 r·min^-1, the main working parts such as the cutting and feeding mechanism vibrated dramatically. Thirdly, the feeding quantities have great influences on the vibration accelerations in the up-and-down direction of the cutting mechanism and the vibration accelerations in the up-and-down and left-and-right directions of the feeding mechanism. When the feeding quantity increases, the maximum vibration accelerations of the main working parts also increase. Especially at the frequency of 157 Hz, the auto-power spectrum in the up-and-down direction of the feeding mechanism increases at first and then decreases. Furthermore,when the moisture content of the Salix psammophila increases, the maximum vibration acceleration at each direction of the cutting and feeding mechanism decreases, and their auto-power spectrums at the whole low-frequency band of the main working parts still decrease. Finally, the vibration acceleration at each direction of the cutting and feeding mechanism increases with the increasing of the root diameter of the Salix psammophila.[Conclusion] The vibration accelerations of the cutting and feeding mechanism under the working condition are obviously higher than those under the unloaded condition and more affected by the rotation speed of the knife and feeding roll, feeding quantity, moisture content and the root diameter of the Salix psammophila.

Key words: Salix psammophila chipper, vibration characteristics, cutting mechanism, feeding mechanism, auto-power spectrum