| 摘要 |
1534884 Axial flow fans PAPST MOTOREN KG 18 Nov 1975 [18 Nov 19741 47500/76 Heading F1C An axial flow fan driven electrically by a motor 62, Fig. 2, of the external rotor type comprises blades 12-16 within a flow channel 5 having inlet 7 and outlet 8 and which converges to and diverges from a waisted portion extending close the periphery of the fan blades, the rotor shaft 36 being mounted with axial clearance in bearings 20, 21 and engaged on the inlet side by a bearing formed of a molybdenum disulphide impregnated plastics disc 222 and a felt disc 122 saturated with lubricant, both mounted in a flanged disc 23 fixed to the casing 1 by spokes 24-27, Fig. 1 inclined forwardly in the direction of fan rotation relative to the suction side edges of the fan blades thus facilitating noise reduction. Convergent section 35 and divergent section 34 of the flow channel 5 form inlet and outlet ducts of non-circular cross-section having outwardly projecting corner areas e.g. 95- 98.
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