A motor includes a housing that has a bottom with a first bearing accommodation and a cylindrical side surface portion which extends from the bottom; a rotor assembly with a rotation shaft, and a rotor mounted on the rotation shaft and accommodated inside the housing; a stator assembly accommodated inside the housing and surrounding the rotor; a housing cover coupled to an upper end of the housing and having a second bearing accommodation; a flow guide on the housing cover; an impeller connected to the rotation shaft over the flow guide; an impeller cover; a first bearing accommodated in the first bearing accommodation and receiving the rotation shaft; and a second bearing accommodated in the second bearing accommodation and receiving the rotation shaft, the housing cover having a cover body with an opening, connection arms between the second bearing accommodation and the opening portion, and a guide rib.

A motor assembly includes an impeller inside a motor assembly housing, a motor including a rotor including a rotor shaft rotatable with the impeller and a pair of stators disposed facing each other across the rotor while electromagnetically interacting with the rotor to rotate the rotor shaft, and a motor housing inside the motor assembly housing that fixes the pair of stators relative to the rotor.

A fan motor is disclosed. The fan motor includes a heat dissipation fin. The heat dissipation fin includes an outer ring part, an inner ring part disposed inside the outer ring part, and a connection part connecting the outer ring part and the inner ring part. The inner ring part is elastically deformed to be inclined in parallel to a rotational shaft which is inclined when axial alignment between bearings is not made. Accordingly, the heat dissipation fin can reduce a temperature of the bearing while enclosing the bearing, and improve concentricity (axial alignment) of the bearing.

A blower for providing a supply of air at positive pressure in the range of approximately 2 cmH.sub.2O to 30 cmH.sub.20 includes a motor, at least one impeller, and a stationary component. The stationary component includes an inlet and an outlet. The motor, the impeller, the inlet and outlet are co-axial.

A disclosed fan system includes a housing having side walls, an inflow side, and an outflow side; a fan secured in the housing by a mounting; and a backflow blocker mounted to the side walls within the housing on the outflow side of the housing partially blocking a cross-sectional area of the outflow side. The backflow blocker is positioned approximately centrally in a flow path of the housing and is configured to block part of an airflow cross section such that, between side walls of the housing and side walls of the backflow blocker, an annular duct is formed as an air passage. Further, the backflow blocker has a thickness that is greater than 5% of a width of the housing, and is less than 20% of an axial design height of the fan system.

A blower for providing a supply of air at positive pressure in the range of approximately 2 cm H.sub.2O to 30 cm H.sub.2O includes a motor, at least one impeller, and a stationary component. The stationary component includes an inlet and an outlet. The motor, the impeller, the inlet and outlet are co-axial.

A blower includes a housing including an inlet and an outlet, a bearing-housing structure provided to the housing and adapted to rotatably support a rotor, a motor provided to the bearing-housing structure and adapted to drive the rotor, and an impeller provided to the rotor. The bearing-housing structure includes a bearing shaft having a bearing surface that rotatably supports the rotor. The bearing shaft provides only a single bearing of the non-ball bearing type for the rotor.

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 impeller of this disclosure includes a hub having a ring shape; and a plurality of blades that are provided on an outer periphery of the hub, wherein the blade has a trailing edge formed such that an inner side of a radial width of the blade is curved in a direction opposite to a rotation direction, in a plan view as viewed in a direction of a rotation axis.

A bladed wheel of a blower device has a main plate, a side plate and multiple fan blades between the main plate and the side plate. A fan casing of the blower device has a bell mouth portion and a guide wall portion, which extends in a radial-outward direction from an axial rear-side end of the bell mouth portion to an outer periphery of the side plate. An air reflecting space is formed in the fan casing at a radial-outside position of the guide wall portion and at an axial front-side position of the fan casing between an axial rear-side end of the guide wall portion and an axial front-end wall portion of the fan casing. Air blown out from the bladed wheel flows through an air blow-out passage, wherein sound wave of the air from the bladed wheel and sound wave of the air from the air reflecting space interfere with each other so that noise is decreased.