Study On The Influent Of Micro-Vibration On Forming Accuracy Of The Optical Aspherical Surface During Ultraprecise Grinding

This paper presents the influence of the jumpiness of the grinding spindle and the mainshaft in ultraprecise numerical control grinding machine on the surface precision during the aspheric surface grounding, which is based on the generalization and analyses of the development of the aspheric surface ultraprecise grounding home and abroad. The 3D models of the grinding spindle, bearing and the mainshaft are established by Solidworks, and the simulation of the natural frequency of these 3D models are proceed by ANSYS, in the meantime, the mathematical model of the influence on the surface precision resulted by radial jumpiness and the axial jumpiness is established, which presents the concrete influence on the machining precision of the grinder. The measuring accuracy of the laser non-contact measuring device with high precision we designed to measure the jumpiness of the grinding spindle and the mainshaft is 0.02μm. Furthermore, the influence on the radial jumpiness and the axial jumpiness resulted by the rotation speed of the grinding spindle and the oil pressure of the hydrostatic bearings are also studied. Then we find that the jumpiness decreased while the rotation speed increasing.The rotation speed and the oil pressure of the grinding spindle are recorded when the integrative micro-vibratory magnitude of the grinding spindle is minimal, and in the same time, the rotation speed and the oil pressure of the main shaft of the grinding machine are also recorded when the micro-vibratory magnitude of the main shaft is minimal. And the aspheric surface with the medium size whose surface shape precision is less than 4μm is processed under these conditions mentioned above, Which reaches the design requirements of the aspheric surface NC grinding machine.