Abstract: Conventionally, a main shaft of the wind turbine apparatus has awkward such as heaviness or difficulties of assembling, since the length of the main shaft must be long to support a generator rotor. It is requested originally to light heaviness of a wind turbine apparatus, since it supports a wind wheel and a generator etc. on a tower at prescribed height. A hub 29 supported on the one side of the main shaft 10, a generator rotor 12 supported on the other side of the main shaft 10, the main shaft housing 40 and the generator housing 20 are combined, the generator rotor 12 having a backward opening is fixedly provided on the rear end of the main shaft 10, the main shaft 10 and the generator rotor 12 are detachably fixed through the opening, and a rotational fitting (rod bearing 33) for a pitch control shaft 37 is at least disposed at the rear space of the generator housing 20.

Abstract: Conventionally, a main shaft of the wind turbine apparatus has awkward such as heaviness or difficulties of assembling, since the length of the main shaft must be long to support a generator rotor. It is requested originally to light heaviness of a wind turbine apparatus, since it supports a wind wheel and a generator etc. on a tower at prescribed height. A hub 29 supported on the one side of the main shaft 10, a generator rotor 12 supported on the other side of the main shaft 10, the main shaft housing 40 and the generator housing 20 are combined, the generator rotor 12 having a backward opening is fixedly provided on the rear end of the main shaft 10, the main shaft 10 and the generator rotor 12 are detachably fixed through the opening, and a rotational fitting (rod bearing 33) for a pitch control shaft 37 is at least disposed at the rear space of the generator housing 20.