Question

By how much is the rotor and the turbine runner and the hydraulic thrust requirements more than the dead weight of rotating masses?

(a) thrice

(b) twice

(c) by 4 times

(d) by 8 times

I had been asked this question in a national level competition.

The query is from Construction of Hydro-Generators in section Design of Synchronous Machines of Design of Electrical Machines

Answer 1

The correct option is (b) twice

To explain: In case of the vertical shaft generators special features have to be incorporated in the bearing set up. This is because the rotor and the turbine runner and the hydraulic thrust requirements is twice more than the dead weight of rotating masses.