| 摘要 |
<p>The invention relates to a ventilation system comprising a fan propeller (1) and a drive motor (9) having an external rotor (9b), said propeller (1) comprising a central part (3) having a cylindrical wall (11) and defining a housing (13) for receiving said external rotor (9b), and also comprising a front wall (15) having an opening (17) in such a way that the proportion of the opening is greater than a predefined opening proportion.</p> |
