view of those similarities the embodiments of fig2 a 2d will only be described to highlight the differences among those embodiments features in fig2 a 2d are numbered with numbers corresponding to those used in fig1 a in fig2 a the shroud radius reduction segments 27a and 29a are rearward of the trailing edge of band 24a the inner radius of segment 29a is less than the outer radius of the trailing edge of band 24a in fig2 b shroud segment 29b has an inner radius slightly larger than the outer radius of the trailing edge of band 24b in fig2 c segment 29c has a radius approximately equal to that of the fan band segment 26c flares outwardly to optimize performance in some applications the thickness of the shroud may decrease with rearward extent so that the outer shroud diameter in this segment flares less or is generally cylindrical in fig2 d segment 29d is rounded to form a pocket 48d this geometry allows a large amount of flare to be used on an injection moldable part vanes 28d extend into the pocket fig3 a and 3b are sections of fan and housing combinations that are similar to the fan of fig1 a except in the configuration of shroud 26 39 and 26 34 upstream of the fan in both figures fan blade 22 terminates in a band 24 vanes 28 are positioned in the recirculation flow path motor supports 37 extend from a downstream extension of the shroud unlike the fan and housing depicted in fig1 a in fig3 a a restriction is not formed between the band 24 39 and shroud 26 39 in fig3 b the radius of shroud segment 26 34 is essentially constant.