| 摘要 |
<p>Loads acting on all bearings (131, 132, 133) which axially support a spindle (12) according to changes in the state of the spindle have been derived, and further the raceway surface/contact surface pressure of each of the bearings has been analyzed, thus making it possible to accurately grasp the state of each of the bearings. Meanwhile, when the raceway surface/contact surface pressure exceeds a threshold value, the raceway surface/contact surface pressure is controlled so as not to exceed the threshold value by changing working conditions, and further when the raceway surface/contact surface pressure exceeds the threshold value even if the working conditions are changed, the spindle is controlled so as to be stopped, thus making it possible to prevent the seizing of each of the bearings. As a result, the spindle can be controlled with high accuracy to improve the working accuracy.</p> |
