Abstract: A fan and a motor assembly. The motor assembly includes an electric motor with an output shaft defining a rotational axis, an impeller coupled to the output shaft for co-rotation therewith, an adapter positioned between the output shaft and the impeller, and an elastic member positioned between the adapter and the impeller. The elastic member is configured to be compressed by the impeller in response to installation of the impeller upon the adapter, from an undeformed state to an elastically deformed state, in which the elastic member is compressed in a direction of the rotational axis.