A fan blade (1) has a front leading edge (2) and a rear trailing edge (3). The fan blade (1) has a leading edge (4), at least some portions, that are undulated. The edge forms a wave (W) with a specific three-dimensional waveform.

A motor assembly includes an impeller, a first diffuser at a downstream side of the impeller, a second diffuser at a downstream side of the first diffuser, an impeller cover coupled to the second diffuser and accommodating the impeller and the first diffuser, and a motor provided at the downstream side of the second diffuser to drive the impeller. The second diffuser includes a hub, an outer wall concentrically disposed outside the hub, and a plurality of blades having one side connected to the hub and the other side connected to the outer wall. The impeller cover is coupled to the outer wall of the second diffuser. A communicating portion for allowing fluid communication between inside and outside of the hub of the second diffuser is provided at the hub of the second diffuser.

A motor assembly includes an impeller, a first diffuser at a downstream side of the impeller, a second diffuser at a downstream side of the first diffuser, an impeller cover coupled to the second diffuser and accommodating the impeller and the first diffuser, and a motor provided at the downstream side of the second diffuser to drive the impeller. The second diffuser includes a hub, an outer wall concentrically disposed outside the hub, and a plurality of blades having one side connected to the hub and the other side connected to the outer wall. The impeller cover is coupled to the outer wall of the second diffuser. A communicating portion for allowing fluid communication between inside and outside of the hub of the second diffuser is provided at the hub of the second diffuser.

An impeller for use in a fan system includes a hub extending along an axis of rotation and having a hub outer surface. There also are a plurality of blades extending radially outwardly of the hub outer surface. The blades have a unique cross-section at several different locations that result in relatively thin blades. A fan system and method are also disclosed.

An electrical fan and an electric appliance are provided. The fans has a driving structure, an impeller, a wind hood and a diffuser. The impeller has a cover plate installed on the driving structure. The wind hood is covered on the impeller and has an air inlet and an air outlet communicated to each other. The diffuser is located at one end of the impeller facing the air outlet. The diffuser has a first protrusion connected to the driving structure. The first protrusion protrudes in a direction of the wind hood. The diameter of an end of the first protrusion adjacent the cover plate is smaller than the diameter of an end away from the cover plate. The diffuser has an inner ring arm connected to the first protrusion and an outer ring arm sleeved outside the inner ring arm.

An integral fan and airflow guide including a hub having a frusto-conical outer surface, and a plurality of fan blades circumferentially spaced apart about the hub and radiating outwardly from the hub. The frusto-conical outer surface having a plurality of circumferentially spaced apart slots that separate inclined segments of the outer surface to define respective airflow guide surfaces. The plurality of fan blades are integral with the respective airflow guide surfaces. The inclined airflow guide surfaces cooperate with the fan blades to direct impelled air axially and radially outwardly for improving the cooling of a machine component, such as a hydrostatic transmission, that is obstructed from airflow by a pulley or other obstacle.

A blower assembly includes a housing including an inner shell and an outer shell that define a flow passage therebetween. The inner shell also at least partially defines a cavity. The blower assembly also includes a fan coupled within the housing such that the fan also at least partially defines the cavity. The blower assembly further includes a motor configured to rotate about an axis. The motor is coupled to the inner shell and is positioned within the cavity radially inward of the flow passage.

A blower assembly includes a housing including an inner shell and an outer shell that define a flow passage therebetween. The inner shell also at least partially defines a cavity. The blower assembly also includes a fan coupled within the housing such that the fan also at least partially defines the cavity. The blower assembly further includes a motor configured to rotate about an axis. The motor is coupled to the inner shell and is positioned within the cavity radially inward of the flow passage.

A fan assembly includes an internal housing having an outer internal housing, and an inner internal housing partially disposed within the outer internal housing. The inner internal housing defines an internal cavity, and has a curved exterior surface. Stator blades extend between the inner internal housing and the outer internal housing.

A diagonal fan having an electric motor and a diagonal impeller which can be driven about an axis of rotation (RA) by means of the electric motor. The diagonal impeller determines an air inlet and an air outlet and has a hub and impeller vanes which are distributed in the circumferential direction, extend radially outwards from the hub and are surrounded radially externally by a slinger ring. A flow angle αD formed by the slinger ring relative to the axis of rotation (RA) increases from the air inlet to the air outlet, and a flow angle αN formed by the hub relative to the axis of rotation (RA) decreases from the air inlet to the air outlet.