Device in fluid pressure generators

An improved fluid pressure generator comprising an outer housing defining a through flow channel, an annular casing peripherally mounted for rotation in said outer housing, said annular casing having an inner face forming part of the wall of said through-flow channel, and a number of propeller blades provided on said annular casing, said blades projecting radially inwards into said fluid through-flow channel, and means for rotating said annular casing and said propeller blades about an axis extending through said through-flow channel the improvement comprising a shaft pin on each one of said propeller blades journaled within said annular casing, a regulating mechanism arranged to turn said propeller blades simultaneously about their individual shaft pin for changing the pitch thereof, said regulating mechanism being independent of the rotary drive of said annular casing, said annular casing having a substantiallv lesser length than the length of said of through-flow channel, said propeller blades tapering radially outwardly of said flow channel and defining their wider portion contiguous to said shaft pins, said shaft pins and said annular casing a substantially lesser length than the largest width of said propeller blades.