Wall-mounted ventilation fan - has external-rotor motor with blades held by radial spokes in smooth tubular housing with outward mounting eyes

摘要

The wall-mounted (21) ventilation fan comprises a motor (8) with an external rotor (27) serving as the hub of a bladed (11) impeller. The fan is completely contained within a tubular housing (1) provided with outward mounting eyes (at 2) and a radially inward spider (4) carrying the central motor stator (via 7). The spider is arranged on the outlet side of the fan and the housing is an internally and externally smooth cylinder, except for the mounting eyes. The spider may consist of three radial spokes whilst the fan has five blades. The internal housing diameter (23) is pref 73mm plus/minus 10% and around 2.25 times the external hub dia (22).