Fan system with integrated fan-shroud channel for reduced recirculation flow

摘要

The invention refers to a fan system (10) comprising a fan shroud (14) and a ring fan (12) having a hub (30), a plurality of fan blades (32), and a ring structure (34). The ring structure (34) has a ring member (46) and a flange member (48), the ring member (46) having a hollow cylindrical shape, the flange member (48) extending radially outwardly from the ring member (46). The fan shroud (14) has an annular shroud flange (54), a shroud body (56) and a plurality of shroud guide vanes (58), the shroud flange (54) extending radially outwardly from the shroud body (56) and being disposed along the rotary axis (A) between the flange member (48) and the shroud body (56), the shroud body (56) being disposed about the ring member (46) and having a first body portion (70), a second body portion (72) and a divergent nozzle (74). A recirculation throttle (88) is formed by the shroud body (56) and the ring member (46) at a location where the first and second body portions (70, 72) of the shroud body (56) intersect one another. The divergent nozzle (74) and a trailing end (50) of the ring member (46) cooperate to form a dynamic sealing feature (90).