Abstract: A cooling device for a bearing, including a bearing support for supporting a bearing in position and having a hollow annular chamber therewithin and extending along substantially the entire dimension of the bearing support parallel to the bearing, a refrigerant type fluid substantially filling the hollow chamber and having a vaporization temperature in the range of the temperature to which the bearing is heated during use, a heat radiator spaced from the bearing support, and a vapor pipe extending from the top of the hollow chamber to the heat radiator and a liquid pipe extending from the heat radiator to the bottom of the hollow chamber.