Floating ball fixing assembly, top cover drainage system and hydro-generator

The invention provides a floating ball fixing assembly, a top cover drainage system and a hydro-generator, the floating ball fixing assembly is used for being installed in a gap between a turbine pit wall and a water guide bearing, and the floating ball fixing assembly comprises a support, at least one floating ball adjusting piece and at least one floating ball assembly; the bracket is fixedly connected with the machine pit wall and is arranged along the axial direction of the machine pit wall; the floating ball adjusting piece comprises a fixing part which is arranged at the end, away from the support, of the floating ball adjusting piece. The floating ball assembly comprises a floating ball and a cable, and the cable penetrates through the fixing part and then is connected with the floating ball. The support is arranged, the floating ball adjusting piece is arranged on the support, the fixing part is arranged at the end, away from the support, of the floating ball adjusting piece, and the cable connected w