Due to particular structural design, the error of manufacturing and other factors, the tool system will have more or less residual imbalance. The spindle-tool system’s vibration signals and its frequency response structure were made as reference under the testing of machine raising speed idle running, firstly the tool system’s amount of imbalance was adjusted with the aid of the special balancing ring, then the spindle-tool system’s vibration characteristic was obtained under various amount of imbalanced in idle running condition, finally making use of frequency spectrum analysis the influence of unbalanced quantity to spindle-tool system’s vibration characteristics was studied and compared, the results and the researching approach can help to find the rules about the influence of tool system imbalance to its vibration characteristics in higher speed condition.
