Abstract: An axial fan, including: a wind deflector including a cavity; a motor; a plurality of blades circumferentially disposed on the motor; and a grid mesh disposed on one end face of the wind deflector. The motor and the plurality of blades are disposed in the cavity. The grid mesh includes a central part provided with a fixed platform. The motor is disposed on the fixed platform.

Abstract: A centrifugal impeller includes a base plate, a wheel cover, and a plurality of twisted blades disposed between the base plate and the wheel cover. Every two adjacent twisted blades form an air duct; and each air duct includes an air outlet along an outer edge of the base plate. Each of the plurality of twisted blades includes a leading edge, a trailing edge, an upper edge, and a lower edge. The upper edge and the lower edge are disposed between the leading edge and the trailing edge, and are opposite to each other. Defining an axis of the device as L1, and a plane passing through the axis L1 of the device as a meridional plane, when the twisted blades rotate around the axis L1, the leading edge intersects with the meridional plane to produce a plurality of intersection points on the meridional plane which form a first curve.