| 摘要 |
A device in a tool holding assembly for moving in the axial direction a rotatable shaft (1) that carries means arranged in a first end (4) for performing work during rotation of said shaft, comprising an electric motor (3) for said rotation and at least one bearing (5,6), which radially support the shaft (1) and permit movement of the shaft in the axial direction. According to the invention the shaft (1) has a free second end (7) and electro-magnetic means is arranged to affect said second end and draw said shaft in the axial direction from the first end (4) to the second end (7) against the effect of an pressure acting against said second end in the opposite axial direction. <??>Means (15) is arranged to controll said electro-magnetic means in order to achieve said axial movement of the shaft (1) during rotation of the shaft. <IMAGE> |
