| 摘要 |
Provided are a ball bearing for a spindle pivot section, adapted to be compatible with machine tools with recent tendency of having composite functions while keeping or improving functions of high accuracy (high rotational accuracy), high rigidity, low torque, and low heat generation, and a spindle pivot device of a machine tool, using the ball bearing. In the ball bearing, when it is a single-row ball bearing, the cross-sectional area ratio (B/H) between the cross-sectional width B in the axial direction and the cross-sectional height H in the radial direction is set to (B/H) < 0.63, and when it is a double-row ball bearing, the cross-sectional ratio (B2/H2) of the cross-sectional width B2 in the axial direction and the cross-sectional height H2 in the radial direction is set to(B2/H2) < 1.2. |
