Abstract: There is provided a rotation device comprising a rotor, a stator, a target component, and a sealing device. The rotor is arranged to rotate along a rotation axis relative to the stator. The stator is arranged radial outward of the rotor to form a gap between the rotor and the stator. The sealing device is attached to the rotor to hydrodynamically seal the g against a fluid. The sealing device is adapted to direct the fluid to the target component to exchange heat between the target component and the fluid, and/or to lubricate the target component with the fluid.