| 摘要 |
PURPOSE:To ensure detection of a supersonic vibration generated by rotating members such as a tool holder without being affected by the bearing between the main spindle and the main body, by forming a thin oil film between the main spindle and an annular member put on the end portion of the main spindle with a predetermined gap provided therebetween. CONSTITUTION:A machine main spindle 2 is rotatably borne by a fixed portion 1 through a bearing 3, and a tool holder 5 is removably fitted in a fitting hole 4 bored in the front end of the main spindle 2. An annular member 8 put on the main spindle 2 is fixed to a bearing keep 7 by fixing bolts 9, and a predetermined gap is provided between the circumferential surface of the main spindle 2 and the annular member 8. Seal members 13 are fitted to the main spindle 2 on both sides of the above gap and a seal ring is inserted in a gap 11, and thus an annular gap 15 is formed, and an oil inlet 16 and an oil outlet 17 communicating with the gap 15 are provided. By adapting a thin oil film 20 to be formed in the gap 15, part of the noise produced is transmitted to the annular member 8 through the oil film 20 to be damped thereby. |
