| 摘要 |
The invention relates to a diagonal fan (30; 130) comprising a fan housing (36) and a fan wheel (80) rotatable about a rotational axis (168), an electronically commutated electric motor (73) being associated with said fan wheel. The electric motor comprises an internal stator (64) and an external rotor (152), the latter being connected to the fan wheel (80) which, on rotation thereof, serves to convey air in a main conveying direction (40) from the air intake side (178) to an air exhaust side (180). On the exterior of the fan wheel (80) fan blades (82) are provided which, in relation to the direction of rotation (84) of the fan wheel (80) in operation, have a front face (114) and a rear face (112), wherein in the region of the rear face (112) of each blade (82) a negative pressure zone (110) occurs at the fan wheel (80) during operation, which negative pressure zone is connected via an opening (90) in the fan wheel (80) to the interior (81) thereof in order to extract cooling air from said interior to the exterior. A seal arrangement (174), which in operation counteracts a pressure equalisation between the pressure (P2) on the air exhaust side (180) and the pressure (P3) in the interior (81) of the fan wheel (80), is arranged between said interior (81) and the air exhaust side (180) of the fan. At least one intake opening (154) is provided in the region of the air intake side (178) of the fan wheel (80), through which opening cooling air is able to flow into the electric motor (73); after emerging from the electric motor (73) the cooling air is extracted through the at least one opening (90) in the fan wheel (80) to the exterior of the fan wheel (80) in order to maintain a constant cooling air flow (158) in a uniform direction in operation through the electric motor (73). |
