Abstract: A heat dissipation module includes a housing, and a fan including an outer frame, a first rotor, a base, a second rotor and a driving device. The first rotor includes a shaft, a first hub and a plurality of first rotor blades disposed around the first hub. The base is disposed in the outer frame. The second rotor includes a plurality of second rotor blades, and is coupled to the shaft of the first rotor and disposed next to the first rotor. The driving device is supported by the base for driving the first rotor and the second rotor simultaneously.

Abstract: A heat dissipation fan includes a housing, a first rotor, a second rotor, a base and a plurality of static blades. The first rotor has a shaft and a plurality of rotor blades. The second rotor is coupled to the first rotor and has a plurality of rotor blades. The base is disposed in the housing for supporting the first and second rotors. The static blades are disposed between the housing and the base, wherein a rear portion of each static blade extends along an axial line of the heat dissipation fan for improving the working efficiency of the second rotor.

Abstract: A heat dissipating fan includes a frame, a first rotor having a shaft and a hub, a base disposed in the frame, a second rotor disposed at one side of the first rotor and coupled to the first rotor, and a driving element supported by the base for driving the first and second rotors to rotate. The hubs of the first and second rotors include a plurality of heat dissipating holes formed on the surface thereof. Airflow passes through the plurality of heat dissipating holes to generate a forced convection effect on the driving element.

Abstract: A fan includes an impeller and a motor. The impeller includes a hub and a plurality of blades. The hub has a top portion, a connection portion, and at least one airflow-guiding portion. The top portion is connected to the connection portion. The blades are disposed around the connection portion. The motor is disposed corresponding to the impeller and used to drive the impeller to rotate. The airflow-guiding portion is disposed between two adjacent blades.

Abstract: A heat dissipation apparatus. A fan frame includes an air inlet, an air outlet, a passage, and a curved expansion portion. The air inlet is opposite the air outlet. The passage is between the air inlet and the air outlet, guiding airflow from the air inlet to the air outlet. The curved expansion portion is radially and outwardly extended from an inner peripheral wall of the passage at the air inlet or air outlet. An impeller is disposed in the fan frame and includes a plurality of blades. Each blade is disposed in the passage and includes an extension end extending to the curved expansion portion.

Abstract: A centrifugal fan, comprising a frame and a first guide portion. The frame comprises a bottom portion and a curved wall connected thereto. The curved wall comprises an airflow inlet. The first guide portion disposed along the curved wall at the bottom portion comprises a beginning area, a middle area, and an ending area. The middle area connects the beginning and the ending areas, and the beginning area extends from the airflow inlet. The beginning area has a width less than that of the ending area, and the beginning area has a height greater than that of the ending area.

Abstract: A centrifugal fan, comprising a frame and a first guide portion. The frame comprises a bottom portion and a curved wall connected thereto. The curved wall comprises an airflow inlet. The first guide portion disposed along the curved wall at the bottom portion comprises a beginning area, a middle area, and an ending area. The middle area connects the beginning and the ending areas, and the beginning area extends from the airflow inlet. The beginning area has a width less than that of the ending area, and the beginning area has a height greater than that of the ending area.

Abstract: The invention provides a magnetic-positioning motor having a magnetic element or magnet disposed at the interior center of a rotor, so that attractive force between the magnetic element and a metallic stator can maintain a rotor at a predetermined position during fan rotation. Additionally, a magnetic element or magnet can be placed on a stator, so that attractive force between the magnetic element and a metallic rotor can maintain a rotor at a predetermined position during fan rotation to reduce vibration, flotation and friction between the shaft and bearing under high speed operation.

Abstract: A heat-dissipating device and a housing thereof. The housing includes a passage for guiding an air stream flowing from an opening to another opening, wherein an inner wall of the passage at at least one of the opening sides extends radially outwards with a rotational axis of the heat-dissipating device or the passage so as to enlarge intake or discharge area for the air streams. Accordingly, the intake airflow rate may be greatly increased and the heat-dissipating efficiency of the heat-dissipating device may be greatly enhanced without changing assembling conditions with other elements.

Abstract: A heat dissipation apparatus. A fan frame accommodates an impeller therein and includes an air inlet, an air outlet, and a passage for guiding airflow from the air inlet to the air outlet. An inner peripheral wall of the passage radially and outwardly extends a smooth curved expansion portion at the air outlet. The curved expansion portion includes a recess in which the airflow forms an airflow layer, stopping subsequent airflow from directly contacting the inner peripheral wall of the passage.

Abstract: A heat-dissipating device and a housing thereof. The housing includes a passage for guiding an air stream flowing from an opening to another opening, wherein an inner wall of the passage at at least one of the opening sides extends radially outwards with a rotational axis of the heat-dissipating device or the passage so as to enlarge intake or discharge area for the air streams. Accordingly, the intake airflow rate may be greatly increased and the heat-dissipating efficiency of the heat-dissipating device may be greatly enhanced without changing assembling conditions with other elements.

Abstract: An axial flow fan. The axial flow fan includes an impeller, an annular structure, and a plurality of connecting elements. The impeller has a plurality of blades, arranged radially. Each blade has an outer periphery. The outer periphery has a top portion. The annular structure is attached to the top portion of the outer periphery of each blade. Each connecting element respectively connects each blade to the annular structure.

Abstract: A cooling fan with high heat-dissipating performance includes a plurality of blades; and a frame for receiving the blades therein, wherein the frame has a reduced height for exposing the blades to outside of the frame so as to allow air to enter into the frame via a top portion and a peripheral portion of the blades to improve air introduction and heat dissipating efficiency of the cooling fan. A cover may be mounted to a top surface of the frame, and formed with a plurality of openings for allowing air to enter into the frame through the openings; such an arrangement cam effectively enhance air intake and working efficiency of the cooling fan.

Abstract: A cooling fan with high heat-dissipating performance includes a plurality of blades; and a frame for receiving the blades therein, wherein the frame has a reduced height for exposing the blades to outside of the frame so as to allow air to enter into the frame via a top portion and a peripheral portion of the blades to improve air introduction and heat dissipating efficiency of the cooling fan. A cover may be mounted to a top surface of the frame, and formed with a plurality of openings for allowing air to enter into the frame through the openings; such an arrangement cam effectively enhance air intake and working efficiency of the cooling fan.

Abstract: A fan motor speed control circuit includes a driving circuit, a voltage division circuit, and a speed modulator. The voltage division circuit has a first transistor and a plurality of resistors and is connected between a voltage source and the driving circuit. The speed modulator has a second transistor and a plurality of parallel resistors and is connected between the voltage division circuit and the driving circuit. The current of the fan motor speed control circuit flows through a first path under a first input voltage generated from the voltage source and through a second path under a second input voltage larger than the first one; the parallel resistors are in the second path such that the current value passing through the driving circuit varies according to the resulting resistance value of the parallel resistors.

Abstract: A centrifugal fan, comprising a frame and a first guide portion. The frame comprises a bottom portion and a curved wall connected thereto. The curved wall comprises an airflow inlet. The first guide portion disposed along the curved wall at the bottom portion comprises a beginning area, a middle area, and an ending area. The middle area connects the beginning and the ending areas, and the beginning area extends from the airflow inlet. The beginning area has a width less than that of the ending area, and the beginning area has a height greater than that of the ending area.