| 摘要 |
PURPOSE:To enable the accuracy of machining to be improved with no thermal displacement being generated in a main spindle head further with no influence due to vibration being caused, by arranging a main spindle driving motor being isolated from a main spindle. CONSTITUTION:A main spindle head 18 mounts to its upper part a bracket 24, and this bracket 24, being arranged going across the upper of a column 14 or a cross rail 22 from the main spindle head 18, extends in a rearward direction of the main spindle head 18. The bracket 24 mounts to its end part, in an opposite side to the main spindle head 18, and main spindle driving motor in a manner being suspended. While the motor 26 transmits its rotation to be given to a main spindle 16 in the main spindle head 18 through a power transmission gear of belt device or the like housed in the bracket 24. Accordingly, the motor 26, being a heat generating and a vibrating source, comes to be isolated from the main spindle head 18 because the motor 26, for driving the main spindle, is mounted in a position very distant from the main spindle 16. |
