Abstract: A bearing includes an axial hole and a plurality of first grooves. The first grooves are formed on the inner wall of the bearing, and extends through the top surface and to the outer wall of the bearing. The lubricant oil originally held in the bearing can be guided to flow around the whole bearing effectively.

Abstract: An embodiment of a test structure in accordance with the present invention comprises a pair of interdigitated comb portions of a metallization layer present in a recess of an inter-layer dielectric (ILD) formed over a polysilicon heater element. A third portion of the metallization layer comprises a serpentine metal line interposed between the comb portions. Application of force voltages, and detection of sense voltages, at various nodes of the metallization portions allows identification of the following: (1) electromigration of metal in the metallization portions; (2) extrusion of metal from one metallization portion to contact another; (3) breakdown voltage (Vbd) and time dependent dielectric breakdown (TDDB) of the ILD; (4) contamination in the metallization portions with mobile ions; and (5) k valve and drift in k value of the ILD. A bias voltage may be applied to the polysilicon heater to accomplish temperature control during testing.

Abstract: A frame for a centrifugal fan. The frame includes an air inlet and an air outlet. A first barricade is formed on one side of the air inlet and extends outwardly, preventing impurities from entering the air inlet. A second barricade is formed on part of the periphery of the air outlet and extends outwardly and axially, contacting a guide plate of a system and reducing reflow of air.

Abstract: A fan includes a frame, a stator and a rotor. The stator is disposed in the frame, and the rotor is disposed in the frame and coupled with the stator. The rotor includes a connecting element, an impeller and a shaft. The connecting element has a flange. The impeller is disposed on a periphery of the connecting element. The flange is embedded with the impeller. One end of the shaft is connected to the connecting element and the impeller is rotated when the shaft rotates.

Abstract: A fan comprises an impeller and a motor. The impeller has a hub, a plurality of blades and a plurality of reinforced elements. The blades are disposed around the hub. At least one reinforced element is disposed on the active surfaces of two adjacent blades. The blades and the reinforced elements are integrally formed as a single piece. The motor connects to the impeller for driving it to rotate.

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 controller of a brushless DC electric machine having a rotor and at least a stator winding powered by a driving voltage is provided. The controller includes a position sensor, an advance angle control circuit, and a driving circuit. The position sensor is moved along a reverse rotating direction of the rotor by a prepositioned angle for outputting a position signal. The advance angle control circuit receives the position signal and a driving voltage reproduction signal reproduced from the driving voltage and outputs a commutation control signal lagging the position signal by a first delay time. The driving circuit receives the commutation control signal for outputting a driving signal for controlling a commutation of the brushless DC electric machine.

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 method for testing a motor having a rotor and a winding is provided. The method includes steps of (a) providing a power to rotate the rotor to a predetermined speed, (b) removing the power, (c) measuring a terminal voltage of the winding while a current within the winding is zero, (d) obtaining a back electromotive force in the winding by compensating the terminal voltage with a performance of the rotor, (e) selecting a characteristic of the back electromotive force and (f) determining a magnetization of the motor by comparing the characteristic with a predetermined parameter.

Abstract: A permanent magnet motor is provided. The permanent magnet motor includes a stator having a stator shaft having an outer surface, K salient teeth formed upon the outer surface, and K winding slots formed among the K salient teeth, and a rotor having a first inner surface facing the outer surface, and P pairs of permanent magnets formed on the first inner surface, each of which has a second inner surface facing the outer surface and at least a groove formed on the second inner surface to reduce a cogging torque.

Abstract: A rotary structure of a permanent magnet electric machine including a stator and a rotor is provided. The stator has K salient teeth peripherally spaced with equal intervals for forming K winding slots, wherein K is a natural number greater than 1. The rotor has an annular inner surface and has P pairs of permanent magnets peripherally spaced with equal intervals along the inner surface for rotating around the stator, wherein P is a natural number. Each permanent magnet having two sides along a peripheral direction of the rotor includes a pair of inclined surfaces on the two sides, the pair of inclined surfaces is symmetric with respect to a radial plane of the each permanent magnet, and an inclined angle ? between the inclined surface and the radial plane is selected from a range of 90(1?1/(4P))<?<90(1+1/(4P)).

Abstract: This is related to a fan including a casing, a first impeller structure, a second impeller structure, and at least one driving device. The casing has an outlet and an air-containing portion having an entrance and an exit provided inside the casing. The first impeller structure and the second impeller structure are installed inside the casing, and include a first blade set and a second blade set, respectively. The first blade set is located corresponding to the entrance of the air-containing portion. The second blade set is located corresponding to the exit of the air-containing portion. The driving device drives the first and second impeller structures.

Abstract: A driving apparatus for fan motors, electrically connected between a pulse width modulation (PWM) signal generator and a controller, includes a converter electrically connected to the PWM signal generator, generating a first reference voltage according to the duty cycle of a PWM signal generated by the PWM signal generator; a reference voltage generator electrically connected to an external power source, generating a second reference voltage according to the external power source; and a comparator having a first and second input terminal and an output terminal; wherein the first input terminal is electrically connected to the converter, the second input terminal is connected to the reference voltage generator and the output terminal is connected to the controller, and when the first reference voltage is greater than the second reference voltage, a driving signal is output from the output terminal to the controller to control the rotation speed of the fan motor.

Abstract: A heat dissipation system includes at least one fan, at least two controllers, a signal generator, and a signal converter. The controllers are electrically connected to the fan and generate an enable signal according to a feedback signal of the fan. The signal generator is electrically connected to the controllers and generates a control signal according to the enable signal. The signal converter is electrically connected to the signal generator and the fan, converts the control signal to a drive signal to the fan, thereby controlling rotation speed of the fan.

Abstract: A fan assembly comprises a frame and a securing element. The frame has a first end portion, a second end portion and a middle portion. The foam securing element comprises a positioning hole having a first hole having a shape corresponding to the first end portion, a second hole having a shape corresponding to the second end portion, and a third hole having a cross section larger than that of the second hole. When the second end portion is inserted into the first hole, the second end portion and the middle portion pass through the first hole and the first end portion urges against the periphery of the second hole to receive the second end portion in the third hole. The second end portion of the frame is stopped by a periphery of the positioning hole after rotating at a predetermined angle so that the frame is positioned.

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 includes a housing, an impeller and a motor. The housing has a main body, a motor base and at least one supporting member disposed between the main body and the motor base. The impeller is disposed on the motor base and has a hub and a plurality of blades disposed around the hub. The motor is connected to the impeller for driving the impeller to rotate. Each of the blades is connected to the hub at a predetermined angle ranging from 22.5 degrees to 36 degrees.

Abstract: A heat dissipating device includes an outer frame, a first rotor, a base, a second rotor and a driving device. The first rotor comprises 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 comprises a plurality of second rotor blades, 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.

Abstract: A terminal element, a motor winding structure and a manufacturing method are disclosed. The terminal element includes a fixing portion, a positioning portion and a buffering portion. The fixing portion is disposed at one end of the terminal element and has a serrate fixing pattern. The fixing portion is connected with a connecting position of the motor winding bobbin. The positioning portion is disposed adjacent to the fixing portion and urged against the motor winding structure for positioning the fixing portion while it is connected with the connecting position. The buffering portion has a first bending and a second bending, and the first bending is connected to positioning portion. The buffering portion absorbs the force applied to the terminal element.

Abstract: A PWM buffer circuit includes a duty cycle converting circuit and a frequency-fixed PWM signal generating circuit. The duty cycle converting circuit is used for receiving a first PWM signal and then generating a duty cycle reference voltage on the basis of the first PWM signal. The duty cycle reference voltage is a one-to-one mapping function of the first duty cycle. The frequency-fixed PWM signal generating circuit is used for receiving the duty cycle reference voltage and then outputting a second PWM signal with a fixed frequency. The second PWM signal has a second duty cycle, which is determined in accordance with the duty cycle reference voltage. In addition, the second duty cycle is a one-to-one mapping function of the duty cycle reference voltage.