Ventilator for ventilation circuit of aircraft, has front and rear ball bearings interposed between shaft and support structure, where each bearing is mounted without grease and bearing parts or bearings are formed of ceramic material

The ventilator (10) has a wheel (16) carried by a shaft (26) coupled with an electric motor (24), and front and rear ball bearings (30, 32) interposed between the shaft and a support structure (20). Bearing elements i.e. balls (30C, 32C), or bearings are formed of ceramic material such as silicon nitride, where each bearing is mounted without grease. Maximum Hertz pressure applied to balls or the bearings is less than 1500 Pascal. The rear ball bearing is axially loaded by elastic washers placed around the shaft and applied between an external ring (32A) of the bearing and the structure. Le ventilateur comporte une structure de support (20), une roue (16) portée par un arbre (26) accouplé à un moteur d'entraînement (24) et au moins un roulement à billes (30, 32) interposé entre l'arbre (26) et la structure de support (20).Au moins les éléments de roulement du ou de chaque roulement sont formés en un matériau céramique, et le ou chaque roulement (30, 32) sont montés sans graisse.