FLYWHEEL DEVICE

PURPOSE:To suppress a temperature rise due to heat generation of a stator and a bearing to a low degree, by both forming a member in the vessel bottom part supporting the stator and the bottom bearing of a dynamotor with a high heat conductive material and arranging a cooling member to the periphery of a vessel. CONSTITUTION:A cover member 6 and a supporter 10 in a bottom part are formed by high heat conductive metal of, for instance, copper, aluminum, etc., and generated heat (heat generation mainly caused by a stator 22) of a dynamotor 20 is positively emitted to the outside air. While generated heat of a pivot bearing 19 is also emitted similarly to the above, and lubricating oil immersing the bearing 19 is prevened from a temperature rise. Further plural cooling pipes 18, 18... are wound around the peripheral surface of a main unit 2 forming a completely sealed vessel 1, and water flows in through these pipes 18 to cool the main unit 2 and remove heat from the cover member 6 in the bottom part.