Abstract: A centrifugal fan includes a plurality of blades, a casing and a tongue. The casing includes a base plate perpendicular to a rotation axis of the blades and a sidewall extending upwardly from the base plate. The base plate and the sidewall cooperatively define a space for receiving the blades therein. The sidewall defines an opening in one side for functioning as an air outlet. An air channel is defined between outmost ends of the blades and the sidewall. The tongue is detachably mounted to one end of the sidewall adjacent to the air outlet. The tongue includes a guiding surface protruding towards the outmost ends of the blades. The tongues is provided for lowering a noise level of the centrifugal fan during operation.

Abstract: A notebook computer (1000) includes a base (100), a cover (300), a computer printed circuit board (PCB) (200) and a centrifugal fan (40). The cover covers the base, and cooperates with the base to form a receiving space (500) therebetween. The computer PCB is received in the receiving space and mounted on the base. The centrifugal fan is received in the receiving space, and includes a stator (401) and an impeller (402), rotatable with respect to the stator. The stator includes a motor (415) and a fan PCB (405) directly attached to the base. The motor electrically connects to the fan PCB. When the impeller rotates, airflow enters the receiving space through top and bottom air inlets (304, 104). The fan PCB is integrally formed with the computer PCB and has a height less than the computer PCB.

Abstract: An electronic device includes a casing and a centrifugal blower. The casing includes a bottom cover and a top cover. A sidewall extends from the bottom cover towards the top cover. The centrifugal blower is surrounded by the sidewall and includes a supporting member mounted to the bottom cover, and an impeller rotatablely supported by the supporting member. The impeller includes a hub and a plurality of blades extending outwardly from the hub. Outer portions of the blades extend beyond the supporting member along a radial direction of the hub. Inner portions of the blades have a height gradually increasing along an outward direction. The outer portions have a height equal to a maximum height of the inner portions. Bottom faces of the outer portions of the blades are located below a top surface of a base plate of the supporting member.

Abstract: A centrifugal blower includes a housing, a stator and a rotor. The housing includes a base plate defining an air inlet therein and a sidewall extending upwardly from a periphery of the base plate. The sidewall defines an air outlet therein. The base plate includes a supporting portion disposed in the air inlet. The supporting portion protrudes downwardly beyond a bottom surface of the base plate and connects with the base plate via a plurality of ribs extending radially outwardly and upwardly from a periphery of the supporting portion toward the base plate. The stator is mounted on the supporting portion and the rotor is rotatably disposed around the stator.

Abstract: A notebook computer (1000) includes a base (100), a cover (300), a computer printed circuit board (PCB) (200) and a centrifugal fan (40). The cover covers the base, and cooperates with the base to form a receiving space (500) therebetween. The computer PCB is received in the receiving space and mounted on the base. The centrifugal fan is received in the receiving space, and includes a stator (401) and an impeller (402), rotatable with respect to the stator. The stator includes a motor (415) and a fan PCB (405) directly attached to the base. The motor electrically connects to the fan PCB. When the impeller rotates, airflow enters the receiving space through top and bottom air inlets (304,104). The fan PCB is integrally formed with the computer PCB and has a height less than the computer PCB.

Abstract: A portable electronic device includes a casing, an electronic component disposed in the casing, and a thermal module for dissipating heat of the electronic component. The thermal module includes a heat pipe, a fin unit, and a transverse fan. The heat pipe includes an evaporating section thermally attached to the electronic component, and a condensing section thermally attached to the fin unit. The transverse fan is arranged in the casing for generating an airflow through the electronic component and the fin unit. The transverse fan includes a rotor, and a sidewall on a floor of the casing and surrounding the rotor. The sidewall defines an air inlet and an air outlet therein. The air outlet faces to the fin unit. The air inlet faces to the electronic component.

Abstract: An impeller of a centrifugal fan includes a hub and a plurality of blades arranged on and around the hub. Each of the blades includes a root portion and a tip portion. The tip portion of each of the blades has a concave surface and a convex surface in rear and front sides thereof respectively. In a rotational direction of the impeller, the tip portion of a rear blade protrudes towards a front blade.

Abstract: A cooling fan (10) includes a bottom plate (12) a top cover (14) covering the bottom plate, a sidewall (13) disposed between the bottom plate and the top cover, and an impeller (16) enclosed in a space formed between the bottom plate, the top cover and the sidewall. The impeller includes a hub (162), and a plurality of blades (164) radially and outwardly extending from the hub. Each of the blades includes a windward surface (164a) and a leeward surface (164b) opposite to the windward surface. The leeward surface of each blade defines three indents (171, 172, 173) therein. Two protrusions (174) are formed between adjacent indents. The uneven leeward surface is provided for lowering the noise level generated by the cooling fan during an operation thereof.

Abstract: A centrifugal blower (10) includes a bottom housing (12), a top cover (14) covering the bottom housing, and an impeller (16) and a stator accommodated in a space formed between the bottom housing and the top cover. The bottom housing includes a base plate (121), and a sidewall (122) surrounding the base plate. The sidewall includes a tongue (126) extending from the sidewall towards an inner space enclosed by an inner surface of the sidewall. The tongue is slantingly arranged with respect to a top surface (121a) of the base plate and size of a transverse section of tongue is variable changing along a height direction of the tongue.

Abstract: A cooling fan (10) includes a bottom housing (12), a top cover (14) covering the bottom housing, and impeller (16) and stator accommodated in a space formed between the bottom housing and the top cover. The impeller includes a hub (162), and a plurality of blades (164) radially and outwardly extending from the hub. Each of the blades includes a windward surface (164a) and a leeward surface (164b) which has a different configuration with the windward surface. The windward surface has a tip portion selected from a group consisting of forward curved surface and planar surface. The leeward surface has a tip portion selected from a group consisting of planar surface and backward curved surface.

Abstract: An impeller (10) of a cooling fan includes a hub (11) and a plurality of blades (12) radially and outwardly extending from the hub. Each of the blades includes a windward surface (127) and a leeward surface (128). A groove (124) is defined in each of the blades for guiding airflow from the windward surface to the leeward surface.

Abstract: A centrifugal fan includes a fan frame (20), and a stator (30) and a rotor (40) received in the fan frame. The fan frame includes a bottom base (22), an opposite top cover (21) and a side wall (23) interconnecting the bottom base and the top cover. A first air inlet (24a) is defined in the top cover and a second air inlet (24b) is defined in the bottom base. The rotor includes a hub (41) and a plurality of blades (42) extending from an outer periphery of the hub. An air flow channel (48) is formed between an outer periphery of the blades and the side wall of the fan frame. A cylindrical wall (26, 26a) is formed around one of the first air inlet and the second air inlet to guide airflow from the first and second air inlets into the air flow channel and block the airflow in the air flow channel from flowing back towards the first and second air inlets.

Abstract: A cooling fan includes a frame (100) and an impeller (200) having a plurality of blades (240) disposed in the frame (100). The frame (100) has a cap (120) with an air inlet (122), a base (140) and a sidewall (160) extending from a periphery of the base (140) with an air outlet (180) defined therein. The cap (120) is mounted on the sidewall (160) with a chamber formed between the cap (120), the base (140) and the sidewall (160). A curved tongue portion (190) is formed on the sidewall (160) in vicinity of the air outlet (180). A protrusion (124) is formed on the cap (120) in vicinity of the curved tongue portion (190) and protrudes into the air inlet (122).

Abstract: A cooling fan includes a frame (100) and an impeller (200) with blades (240) disposed in the frame (100). The frame (100) has a base (140) and a sidewall (160) extending from a periphery of the base (140) with an air outlet (180) defined therein. The base (140) has an air inlet (142) and a vent hole (148) defined therein. The vent hole (148) is near the air outlet (180) and between tip portions of the blades (240) and the sidewall (160). In a preferred embodiment, the base (140) has a supporting portion (144) disposed in the air inlet (142). Two ribs (146) extend from a periphery of the supporting portion (144) towards the base (140). One of the ribs (146) is arranged adjacent to the air outlet (180) and has a changeable width which is gradually increased along a direction from the supporting portion (144) to the base (140).

Abstract: A cooling fan (100) includes a housing (50) and an impeller (20) rotatably received in the housing. The housing includes a bottom base (52) and a top cover board (59). The impeller includes a plurality of fan blades (25). A bump (58) extends upwardly from the base and surrounds a portion of an outer periphery of the impeller for blocking a portion of an airflow generated by the impeller and rebounded from the housing from entering the fan blades via a bottom of the fan blades.

Abstract: A centrifugal fan includes a fan frame (20) and a fan impeller (10) received in the fan frame. The fan impeller includes a hub (12) and a plurality of fan blades (14) extending radially from an outer periphery of the hub. Each of the fan blades has a leeward lateral surface (144a) and an opposite windward lateral surface (144b) as the fan impeller rotates. At least one of the fan blades has a rib (146) protruding longitudinally and outwardly from the leeward lateral surface of the fan blade. The rib is located adjacent to an outmost free end of the fan blade and adapted for blocking an airflow generated by the fan impeller to flow back towards the fan blades of the fan impeller.

Abstract: A centrifugal fan includes a fan frame (20) and an impeller (40) received in the fan frame. The impeller includes a hub (41) having a circular top wall (410) and a cylindrical side wall (412) extending downwardly from a rim of the circular top wall, a plurality of blades (42) extending radially from the side wall of the hub and a blade ring (44). The blade ring includes an annular top plate (441), a cylindrical sidewall (442) extending downwardly from an outer periphery of the top plate, and a flange (443) extending outwardly from a bottom of the cylindrical sidewall. The blade ring is arranged on top surfaces of the blades received in an air inlet (24a) defined in a top surface of the fan frame, and the top plate of the blade ring and the top surface of the fan frame are coplanar with each other.