Abstract: A cooling fan includes a base plate and a central tube connected to a center of the base plate. The central tube is made of metal by injection molding, and is a hollow cylinder with both ends open. An outer circumferential surface of one end adjacent to the base plate is connected to the base plate by laser welding, thereby forming a melted layer at a connecting portion between the outer circumferential surface of the end and the base plate.

Abstract: A method for making graphene comprises providing and stacking alternately a plurality of polyimide films and a plurality of carbon papers to form a laminate and conducting carbonization treatment to the laminate to form a intermediate product. The intermediate product is subjected to graphitization treatment to form a polyimide artificial graphite which can be stripped to achieve a graphene.

Abstract: A magnet case for a rotor includes a hollow cylindrical supporting body for accommodating two magnetic bands, an annular flange extending outwardly from a top end of the supporting body, and a positioning plate extending inwardly from a bottom end of the supporting body. The annular flange of the magnet case has two spaced notches defined in an outer periphery thereof, and the two spaced notches are configured to reduce vibration of a cooling fan associated with the rotor during operation of the cooling fan. A rotor incorporating the magnet case is also provided.

Abstract: A heat dissipating assembly of a mold includes an angular pin, a heat pipe, and a liquid passage passing through the angular pin. The angular pin defines a receiving chamber therein. The liquid passage passes through a lower portion of the receiving chamber of the angular pin. The heat pipe includes a condensing section, an evaporation section, and a connecting section interconnecting the condensing section and the evaporation section. The evaporation section is embedded in an upper portion of the receiving chamber opposite to the lower portion. The condensing section is located in the lower portion of the receiving chamber. A mold having the heat dissipating assembly is also provided.

Abstract: A cooling fan includes a hub and an impeller. The hub includes a circular wall and an annular wall. The annular wall has a position end opposite to the circular wall. The impeller includes a blade ring and a plurality of blades integrally extending outwards from an outer circumferential surface of the blade ring. The blade ring receives the hub and has a first mounting end and a second mounting end opposite to the first mounting end. When the position end abuts the second mounting end of the blade ring, the blades extend aslant from the blade ring toward a counterclockwise direction relative to the circular wall. When the position end abuts the first mounting end of the blade ring, the blades extend aslant from the blade ring toward a clockwise direction relative to the circular wall.

Abstract: A bearing device includes a body, a circular cover, and a through hole commonly defined through both the body and the cover. The body is an injection molded piece made from metal powder and molten binder. The cover is an injection molded piece made from metal powder and molten binder. Two passages are defined between the body and the cover, and each passage communicates the through hole with an exterior of the bearing device, whereby lubricant can flow from the through hole to the passages. A bearing assembly having the bearing device is also provided, and a method of manufacturing the bearing device is further provided.

Abstract: A method for manufacturing a casing of a heat pipe includes steps: providing a hollow mold; injecting a feedstock of powder and molten binder into the mold under pressure, thus forming a desired body of a first shell and a desired body of a second shell; separating the binder from the body of the first shell and the body of the second; sintering the body of the first shell and the body of the second shell, thereby forming the first shell and the second shell; and mounting the second shell on the first shell and sintering the first shell and the second shell together, thereby forming the casing of the heat pipe.

Abstract: An exemplary method for manufacturing a fan rotor includes the following steps. First, a discoid-shaped metal sheet is provided. Second, the metal sheet is stamped such that the stamped metal sheet includes a hub at a middle thereof, a blade-portion spaced from and surrounding the hub, and supporting bars interconnecting the hub and the blade-portion. The blade-portion includes outer peripheral blades adjacent to each other. Third, a free end of each blade is curled up by force applied along a direction substantially perpendicular to a plane of the blade-portion. Finally, each blade is bent downward about an axis coinciding with a portion of one side of the blade that connects with an inner periphery of the blade-portion.

Abstract: An exemplary injection molding apparatus includes a first mold defining a passage therein, a second mold engaging with the first mold, working fluid received in the passage of the first mold, and a thermal conductive member engaged in the first mold and thermally interconnecting the first mold and the working fluid. The first mold and the second mold cooperatively define a molding chamber therebetween adapted to receive injected molten material therein. The thermal conductive member transfers heat from the first and second molds to the working fluid when the first and second molds are hotter than the working fluid, and transfers heat from the working fluid to the first and second molds when the working fluid is hotter than the first and second molds.

Abstract: A magnet case for a rotor includes a hollow cylindrical supporting body for accommodating two magnetic bands, an annular flange extending outwardly from a top end of the supporting body, and a positioning plate extending inwardly from a bottom end of the supporting body. The annular flange of the magnet case has two spaced notches defined in an outer periphery thereof, and the two spaced notches are configured to reduce vibration of a cooling fan associated with the rotor during operation of the cooling fan. A rotor incorporating the magnet case is also provided.

Abstract: A cooling fan includes a stator, a base supporting the stator, and a rotor positioned to rotate with respect to the stator. The base includes a bearing housing and a central hole defined in the bearing housing. The rotor includes a hub and a shaft extending from the hub. An end of the shaft is fixed in the hub, and another end of the shaft is extending in the central hole defined in the bearing housing. The bearing housing includes a main cylindrical portion and a protruding portion bent radially inward from a top end of the main portion, and the protruding portion thus serves as a lubricant retaining portion of the bearing housing.

Abstract: An exemplary heat sink includes a heat-conducting substrate and a heat-conducting film formed on an outer surface of the substrate. A heat resistance of the heat-conducting film is lower than that of the heat-conducting substrate. A heat conductivity coefficient of the heat-conducting film is higher than that of the heat-conducting film. The heat-conducting film is thinner than the heat-conducting substrate, and a thickness of the heat-conducting film is in a range from about 0.025 mm to about 0.05 mm.

Abstract: An exemplary heat sink assembly includes a base plate for thermally contacting an electronic component and fins protruded from the base plate to dissipate heat transferred from the base plate by nature convection and thermal radiation. A heat conductive film is formed on an outer surface of the heat sink. A thermal radiation wavelength region of a far and middle infrared ray is located in a thermal radiation wavelength region of the heat conductive film.

Abstract: An exemplary method for manufacturing a rotor is disclosed. A fixture is firstly made. The fixture includes a base, a column extending upwardly from the base, and an annular protrusion extending upwardly from the column. A slot is defined in the column. A shaft is inserted in the slot. A hub is made and disposed on a top face of the annular protrusion. The hub includes a cover and a sidewall extending downwardly from the cover. The shaft contacts a center of the cover. A laser beam is used to illuminate the center of the cover to thereby weld the shaft with the cover.

Abstract: An exemplary method for manufactured an impeller assembly of a cooling fan includes following steps: providing an impeller, the impeller comprising a plurality of blades and a hub, the blades formed on an outer periphery of the hub; testing a center of gravity of the impeller; providing a shaft and fixing one end of the shaft in the center of gravity of the impeller.

Abstract: A heat dissipating assembly of a mold includes an angular pin, a heat pipe, and a liquid passage passing through the angular pin. The angular pin defines a receiving chamber therein. The liquid passage passes through a lower portion of the receiving chamber of the angular pin. The heat pipe includes a condensing section, an evaporation section, and a connecting section interconnecting the condensing section and the evaporation section. The evaporation section is embedded in an upper portion of the receiving chamber opposite to the lower portion. The condensing section is located in the lower portion of the receiving chamber. A mold having the heat dissipating assembly is also provided.

Abstract: An exemplary injection molding apparatus includes a first mold defining a passage therein, a second mold engaging with the first mold, working fluid received in the passage of the first mold, and a thermal conductive member engaged in the first mold and thermally interconnecting the first mold and the working fluid. The first mold and the second mold cooperatively define a molding chamber therebetween adapted to receive injected molten material therein. The thermal conductive member transfers heat from the first and second molds to the working fluid when the first and second molds are hotter than the working fluid, and transfers heat from the working fluid to the first and second molds when the working fluid is hotter than the first and second molds.

Abstract: A cooling fan includes a hub and an impeller. The hub includes a circular wall and an annular wall. The annular wall has a position end opposite to the circular wall. The impeller includes a blade ring and a plurality of blades integrally extending outwards from an outer circumferential surface of the blade ring. The blade ring receives the hub and has a first mounting end and a second mounting end opposite to the first mounting end. When the position end abuts the second mounting end of the blade ring, the blades extend aslant from the blade ring toward a counterclockwise direction relative to the circular wall. When the position end abuts the first mounting end of the blade ring, the blades extend aslant from the blade ring toward a clockwise direction relative to the circular wall.

Abstract: A method of manufacturing a bearing includes, firstly, injecting a mixture of metal powder into a mold to form a semi-finished product. Then the semi-finished product is sintered. After that, the sintered semi-finished product is fine machined, and then washed, to form the bearing.