Study On The Influence Of Unbalance On The Jumpiness Of Grinding Wheel

In precision/ultra precision grinding, grinding vibration is a key problem to the grinding quality and efficiency. To obtain precise dimensions and fine surface quality, the grinding vibration should be greatly well controlled. One of factors on grinding vibration is the balance of grinding wheel, which is evaluated in term of the amount of unbalance. It causes wheel vibrate during grinding, which is assessed by the term of jumpiness of wheel. Thus, to study of the relationship between the amount of unbalance of grinding wheel and the jumpiness of wheel is vital important for the control of grinding process.In this work, the jumpiness of wheel during grinding is measured by a laser ranging sensor. With changing the rotation speed of wheel without cut, influences of the unbalance on the jumpiness of grinding wheel were experimentally studied. A signal process program was designed by Labview software to efficiently analyze relations among wheel rotational speed, wheel vibration (jumpiness) and the unbalance of wheel. The main results of this paper can be summarized as follows:1. Based on the features of the grinding vibration, it is confirmed that then signal collected is generated by the vibration caused by the amount of unbalance of wheel. It also reveals that the measure system and the signal process program established work well for collecting and analyzing the jumpiness of wheel.2. The spectrum analysis results of the vibration signal of wheel reveal that under the same value of unbalance, the amplitude value of the mail spectrum increases with the increase of rotational speed. At the same rotational speed, the amplitude value of the mail spectrum increases with the increase of the unbalance.3. With the increase of the rotational speed, the jumpiness of wheel changes slightly when the amount of unbalance is less than 0.4g and strongly when the amount of unbalance is more than 0.8g.4. The jumpiness of wheel increases with the increase of the rotational speed of wheel. The jumpiness varies slightly when the rotation speed is lower than 20m/s. It changes a lot when the rotation speed is over 30m/s and the amount of unbalance is more than 0.83g. For the wheel with aluminum as basal body, The jumpiness varies slightly when the rotation speed is lower than 30m/s and changes a lot when the rotation speed is over 40m/s and the amount of unbalance is 0.39g.5. The jumpiness of wheel with aluminum as basal body is 0.05μm less than that of wheel with steel as basal body.