| 摘要 |
PROBLEM TO BE SOLVED: To provide a ball bearing and a spindle device for a machine tool which are capable of suppressing cage noise.SOLUTION: A ball bearing 1 includes an outer ring 2, an inner ring 3, a plurality of rollers 4 rollably arranged between the outer ring 2 and the inner ring 3, and a cage 10 having a plurality of pockets 11 formed in a circumference direction with predetermined intervals provided therebetween and each holding the roller 4. A guide manner of the cage 10 is an outer ring guide or an inner ring guide. The roller 4 includes a crowning portion 5, 5 formed by gradually reducing diameters in both sides in the axis direction toward both sides around whole circumference, and a roller linear portion 6 formed by connecting the crowning portion 5, 5 with each other with a constant diameter dimension. In the pocket 11, a pocket linear potion 15 having a linear shape at a portion facing the roller linear portion 6 is formed. The length B of the pocket linear potion 15 is equal to or less than the length A of the roller linear portion 6. |
