Abstract
Helium Turbine is used in High Temperature Reactor-helium Gas Turbine (HTR-GT) system, by which the direct helium circulation between the reactor and turbine generator system will come true. Between helium turbine and generator, there is gearbox device which reduces the turbine rotation speed to normal speed of the generator. Three optional gearbox schemes are discussed. (1) Single reduction cylindrical gearbox, which consists of one high speed gear and one low speed gear. Its advantage is simple structure, easy to manufacture, and high reliability, while disadvantage is large volume and misalignment of input and output axle. (2) Planetary gear mechanism with static planet carrier. (3) Planetary gear mechanism with static internal gear. The latter two gearbox devices have similar structure. Their advantage is small volume and high reduction gear ratio, while disadvantage are complicated structure, many gears, low reliability and low mechanical efficiency.
