| 摘要 |
PROBLEM TO BE SOLVED: To provide a combined bearing device which can improve the impact resistance of a bearing to which a large load is applied, and a spindle device for a machine tool.SOLUTION: Ball diameters d1, d4 of balls 43, 73 of outside-row bearings 40, 70, out of front-side bearings 40, 50, 60 and 70 are set larger than ball diameters d2, d3 of balls 53, 63 of inside-row bearings 50, 60. Ball pitch circle diameters PCD1, PCD4 of the outside-row bearings 40, 70 are set larger than ball pitch circle diameters PCD2, PCD3 of the inside-row bearing 50, 60. Contact angles α1, α4 of the outside-row bearings 40, 70 are set larger than contact angles α2, α3 of the inside-row bearings 50, 60.SELECTED DRAWING: Figure 2 |
