An energy generating device for generating energy from a flowing fluid, especially from a wind flow and/or from a water flow, comprises: a rotation body, the rotation body extending along an axis of rotation between a first point and a second point and the rotation body being adapted to rotate about the axis of rotation and the rotation body being formed from at least a first, a second, and a third rotation segment, wherein the rotation segments are joined together and arranged along the axis of rotation, and they form a region at least partly surrounded by fluid, wherein the second rotation segment is situated between the first and the third rotation segment and has a different diameter than the first and third rotation segment; and a generator device mechanically connected to the rotation body, wherein the generator device is adapted to generate energy which is produced from the rotation of the rotation body.

A method of refurbishing a facility for converting hydraulic energy into electrical energy including the following steps: providing a first cover plate, a second cover plate, a first opening located at an inner head cover, a second opening located at a hub, a third opening located at a runner; connecting the first cover plate to the inner head cover; connecting the second cover plate to the hub, wherein the first cover plate and the second cover plate surround an axis, and a part of an outer surface of the inner head cover, a part of an outer surface of the hub, an inner surface of the first cover plate, and an inner surface of the second cover plate are confining an annular shaped space.

A water-fed turbine includes a shaft and a Kaplan runner having a plurality of blades and a hub, the hub located at an end of the shaft and bearing the blades. Means are provided for generating dry air, as well as a means for supplying the turbine with a flow of the dry air. Means are also provided for evacuating air out of the turbine after the flow of dry air has flowed at least through the hub.