摘要 |
PURPOSE:To control the variation of mutual positions between main spindles based on a difference between temperature increase, by a method wherein cooling is carried out evenly by connecting the piping of a cooling circuit of one side of the main spindle devices and the piping of a cooling circuit of the other side of the main spindle devices with each other. CONSTITUTION:A first main spindle device 1 and a second main spindle device 11 are formed between bearings 3 and 31 and bearing stands 4 and 41 and are provided with a cooling circuit consisting of annular and hollow chambers 7 and 71 into which hydraulic liquid is enclosed and radiators 8 and 81 to be connected through a pair of pipings 10, 11, 101 and 111 with the hollow chambers. The piping of the first main spindle device 1 and the piping of the second main spindle device 11 are connected through connecting pipes 12 and 13 with each other. As the connecting pipes are provided like this, even if differences are generated in increase of heating values and temperatures of both the main spindle devices 1 and 11, cooling is carried out so that the temperature is equalized. |