Wind-powered device for use at flat roof, has housing whose front wall protecting rotor blade, which moves against wind direction, where distance of two rotational axes amounts about certain percentages of length of blade against direction

摘要

The device has a housing whose front wall protecting a rotor blade, which moves against a wind direction, and whose side walls exhibits a round form. The housing is provided with both openings whose total surfaces lying on a back side is smaller than total surfaces of the openings lying in a front side. A distance of two rotational axes amounts about 100 to 250 percentages of a rotor blade length against the wind direction.