| 摘要 |
<p>PURPOSE:To provide the above high speed main shaft device which is capable of preventing lowering of rigidity in a low speed rotation range by making the fitting clearance of a bearing controllable with relatively simple construction even if the clearance is set to the fitting clearance that suits in a high speed rotation range. CONSTITUTION:In a main shaft device having a ball bearing 4 that supports a main shaft 1 freely rotatable, a main shaft housing 2 fitted with this bearing, and an outer ring spacer 4, a thin-walled ring-shaped member 7 in the form of recess is provided between the main shaft housing 2 and the outer ring spacer 4, a pressure chamber 8 is formed with the recessed part of this thin-walled ring-shaped member 7 and the main shaft housing 2, pressure fluid is forced to act on this pressure chamber 8 to perform elastic deformation of the thin- walled ring-shaped member 7 in a radial direction, thereby this device is made capable of adjusting the fitting clearance between the thin-walled ring-shaped member 7 and the outer ring 3a of the bearing.</p> |
