| 摘要 |
PURPOSE:To prevent the lifetime of a bearing from shortening by machining a rotational shaft to increase the surface area, thereby suppressing the temperature rise of the bearing engaged with the shaft. CONSTITUTION:A penetrating hole 7a made along the axial direction is formed in a rotational shaft 7. Since the heat generated in a rotor 5 is dissipated also from the cooling hole 7a formed in the shaft 7, its heat sink is accelerated to reduce the heat transmitted to a bearing 6. |
