Mixed flow fan

摘要

A mixed-flow fan features a housing (42); an impeller (43) journaled rotatably with respect to the housing, and equipped with fan blades (54); a generally cylindrical air conduit (50) defined between the fan housing and the impeller, the fan blades extending into the air conduit in order, during operation, to transport air; an external-rotor motor (75) having an internal stator (100) and an external rotor (81) which includes a tubular ferromagnetic yoke (63) partly embedded in material of the impeller. A cup-shaped yoke (72) fits into a central cavity (68) of the tubular yoke (63) and accommodates a permanent magnet arrangement (66) which interacts with the stator. The tubular yoke (63) and the cup-shaped yoke (72) together serve as a magnetic return path for the external-rotor motor. The structure minimizes damage during final assembly, and simplifies insertion of balancing weights.

主权项

1. A mixed flow fan, comprising:
a fan housing (42); an impeller (43) that is equipped with fan blades (54) and is journaled rotatably relative to the fan housing (42); an air conduit (50) that extends between the fan housing (42) and impeller (43), having an inlet side (44) and an outlet side (52), and into which the fan blades (54) extend, in order, during operation, to transport air through said air conduit (50); an external-rotor motor (75) having an internal stator (100) and an external rotor (81), which latter comprises a tubular ferromagnetic yoke (63) that is embedded with part of its longitudinal extension into a central part of the impeller (43) on the latter's inlet side (44) and defines a central cavity (68) in the impeller (43); a cup-shaped magnetic yoke (72) having an approximately cylindrical rim (73) and a bottom (77), which cup-shaped yoke (72) is arranged in the central cavity (68) defined by the tubular ferromagnetic yoke (63), and on whose inner side a permanent magnet arrangement (66) of the external-rotor motor (75) is mounted in such a way that said permanent magnet arrangement interacts with the internal stator (100), the tubular ferromagnetic yoke (63) forming, together with the generally cylindrical rim (73) of the cup-shaped magnetic yoke (72), a ferromagnetic return path for the external-rotor motor (75).