Abstract: A performance testing apparatus for a heat pipe includes an immovable portion having a cooling structure defined therein for cooling the heat pipe requiring test. A movable portion is capable of moving relative to the immovable portion and has a cooling structure defined therein for cooling the heat pipe. A receiving structure is located between the immovable portion and the movable portion for receiving the heat pipe therein. A positioning structure extends from at least one of the immovable portion and the movable portion for avoiding the movable portion from deviating from the immovable portion during movement of the movable portion relative the immovable portion to ensure the receiving structure being capable of precisely receiving the heat pipe. At least a temperature sensor is attached to at least one of the immovable portion and the movable portion for detecting temperature of the heat pipe.

Abstract: A performance testing apparatus for a heat pipe includes an immovable portion having a heating member located therein for heating a heat pipe requiring test. A movable portion is capable of moving relative to the immovable portion. A receiving structure is defined between the immovable portion and the movable portion for receiving the heat pipe therein. At least one temperature sensor is telescopically mounted in at least one of the immovable portion and the movable portion. The least one temperature sensor has a detecting section exposed in the receiving structure for thermally contacting the heat pipe in the receiving structure to detect a temperature of the heat pipe.

Abstract: A performance testing apparatus for a heat pipe includes an immovable portion having a cooling structure defined therein for cooling a heat pipe needing to be tested. A movable portion is capable of moving relative to the immovable portion. A receiving structure is defined between the immovable portion and the movable portion for receiving the heat pipe therein. At least a temperature sensor is attached to at least one of the immovable portion and the movable portion. The least a temperature sensor has a detecting section exposed in the receiving structure for thermally contacting the heat pipe in the receiving structure to detect a temperature of the heat pipe.

Abstract: A performance testing apparatus for a heat pipe includes an immovable portion having a cooling structure defined therein for cooling a heat pipe requiring test. A movable portion is capable of moving relative to the immovable portion. A receiving structure is defined between the immovable portion and the movable portion for receiving the heat pipe therein. A concavo-convex cooperating structure is defined in the immovable portion and the movable portion for avoiding the movable portion from deviating from the immovable portion to ensure the receiving structure being capable of precisely receiving the heat pipe. At least a temperature sensor is attached to at least one of the immovable portion and the movable portion for thermally contacting the heat pipe in the receiving structure to detect a temperature of the heat pipe.

Abstract: A method (100) of producing a heat pipe includes the following steps: (1) inserting a mandrel (10) into a hollow metal casing (20) with a space formed between the hollow metal casing and the mandrel; (2) filling into the space with a slurry (40) comprised of powders; (3) solidifying the slurry in the space; (4) drawing the mandrel out of the hollow metal casing after the slurry is solidified; and (5) sintering the powders contained in the slurry to form the heat pipe (60) with a sintered powder wick (61) arranged therein. In the sintering step of the method, no mandrel is required. Thus, the problem that the mandrel is difficult to be drawn out of the hollow metal casing as suffered in the conventional art is effectively solved.

Abstract: A performance testing apparatus for a heat pipe includes an immovable portion having a cooling structure defined therein for cooling the heat pipe. A movable portion is capable of moving relative to the immovable portion. A receiving structure is defined between the immovable portion and the movable portion for receiving the heat pipe therein. A concavo-convex cooperating structure is defined in the immovable portion and the movable portion for ensuring the receiving structure being capable of precisely receiving the heat pipe. Temperature sensors are attached to the immovable portion and the movable portion to detect a temperature of the heat pipe. An enclosure encloses the immovable portion and the movable portions therein to provide a thermally stable environment for the heat pipe during test.

Abstract: A heat pipe includes a casing (100) containing a working fluid therein and a capillary wick (200) arranged in an inner wall of the casing. The casing includes an evaporating section (400) at one end thereof and a condensing section (600) at an opposite end thereof, and a central section (500) located between the evaporating section and the condensing section. The thickness of the capillary wick formed at the condensing section is smaller than that of the capillary wick formed at the central section in a radial direction of the casing. The capillary wick is capable of reducing the thermal resistance between the working fluid and the casing at the condensing section.

Abstract: A powder feeding apparatus of manufacturing a heat pipe includes a vibration tray having a supporting board and a plurality of pipes positioned in the supporting board of the tray. A mandrel is coaxially inserted in each of the pipes. A feeder is located corresponding to an end of each pipe for feeding powder into the pipe. A vibration source is located under the tray to drive the tray to vibrate with substantially a same amplitude in a vibration direction when feeding the powder into the pipes from the feeder.

Abstract: A performance testing apparatus for a heat pipe includes an immovable portion having a cooling structure defined therein for cooling a heat pipe requiring to be tested. A movable portion is capable of moving relative to the immovable portion and has a cooling structure therein for cooling the heat pipe. A receiving structure is located between the immovable portion and the movable portion for receiving the heat pipe therein. At least one temperature sensor is attached to at least one of the immovable portion and the movable portion. The least one temperature sensor has a detecting section exposed in the receiving structure for thermally contacting the heat pipe in the receiving structure to detect a temperature of the heat pipe.

Abstract: A particle (10) of ferromagnetic powder for use in preparation of soft magnetic core components has a core-shell structure. The particle includes a central core (12) and a shell (14) coated on the central core. The central core is made of magnetic material and is used for providing the necessary magnetic property for the magnetic core components made from the ferromagnetic powder. The shell has a higher electrical resistance than the central core so as to reduce an eddy current loss of the magnetic core component. The shell also functions to provide an excellent bonding strength between particles of the powder.

Abstract: An electric heating device includes an electric heater (10) and at least one heat radiator (30, 40) thermally attached to the electric heater. The electric heater includes a pair of electrode plates (12, 14) parallel to each other and a plurality of PTC (Positive Temperature Coefficient) heating elements (16) sandwiched between and electrically connecting the electrode plates. The heating elements are alternately arranged with a plurality of insulation sheets (18). An electrically-insulating and heat-conductive insulation frame (19) encloses the electrode plates therein for electrically insulating the electric heater from the heat radiator.

Abstract: A electrical fan includes a frame (10) having a central tube (11), a bearing (30) received in the central tube, a stator (50) mounted around the central tube, and a rotor (70) being rotatably supported by a bearing in the stator. The frame defines an air inlet (19) and an air outlet (17) at two different sides thereof. The stator and the rotor expand radially along a direction from the air inlet to the air outlet. Fan blades (75) extend radially from the rotor. A hub (71) of the rotor has a streamline shaped outer surface. A stator core (511) of the stator is made by powder sintering technology.

Abstract: A heat pipe (50) and a method (100) of producing the heat pipe are disclosed. The method includes the following steps: (1) inserting a mandrel (10) into a hollow metal casing (20) with a porous structure (30) combined to an outer surface of the mandrel; (2) filling powders (40) into a space formed between the hollow metal casing and the porous structure; (3) sintering the filled powders; (4) drawing the mandrel out of the hollow metal casing; and (5) sealing the hollow metal casing with a working fluid filled therein. The heat pipe produced by this method includes a composite wick structure (60) arranged in the hollow metal casing. By using this method, the mandrel can be easily drawn out of the hollow metal casing after the filled powders are sintered.

Abstract: A method for sealing a heat pipe, includes the steps of: providing a metallic pipe with an end sealed and an opposite open portion; pressing the open portion of the pipe to form a two layer portion by using two pairs of pressing molds; welding an end part of the two layer portion to form a sealing structure, during which at least one pair of pressing molds continues pressing the two layer portion; and moving the at least one pair of pressing molds away from the sealing structure.

Abstract: A performance testing apparatus for a heat pipe includes an immovable portion having a cooling structure defined therein for cooling a heat pipe requiring test. A movable portion is capable of moving relative to the immovable portion. A receiving structure is defined between the immovable portion and the movable portion for receiving the heat pipe therein. A positioning structure extends from at least one of the immovable portion and the movable portion and avoids the movable portion from deviating from the immovable portion to ensure that the receiving structure is capable of precisely receiving the heat pipe therein. At least a temperature sensor is attached to at least one of the immovable portion and the movable portion for thermally contacting the heat pipe in the receiving structure to detect a temperature of the heat pipe.

Abstract: A heat pipe includes a metal casing (100) filled with a working fluid therein, a capillary wick (200) provided inside of the metal casing and a tube (300) contacting with a surface of the capillary wick. The capillary wick extends in an axial direction of the casing. A plurality of spaced vapor passages (700) is formed by the capillary wick in the casing and a liquid channel (800) is defined by the capillary wick. The working fluid in vapor state flows along the vapor passages and the working fluid in liquid state flows along the liquid channel. The tube separates the vapor from the liquid at a place where the tube is located.

Abstract: A performance testing apparatus for a heat pipe includes an immovable portion having a first heating member located therein for heating an evaporating section of the heat pipe. A movable portion is capable of moving relative to the immovable portion and has a second heating member located therein for heating the evaporating section. A receiving structure is defined between the immovable portion and the movable portion for receiving the evaporating section of the heat pipe therein. A concavo-convex cooperating structure is defined in the immovable portion and the movable portion to ensure the receiving structure being capable of receiving the heat pipe precisely. Temperature sensors are attached to the immovable portion and the movable portion for detecting temperature of the heat pipe. An enclosure encloses the immovable portion and the movable portions therein.

Abstract: An electric fan includes a frame (10) having a central tube (12) extending therefrom, a bearing (30) received in the central tube, a stator (50) mounted around the central tube, and a rotor (70) being rotatably supported by the bearing. The frame defines an air inlet (19) and an air outlet (17) at two different sides thereof. The stator includes a stator core (52) having a central cylinder (520). A plurality of radial posts (522) extends from the central cylinder. A plurality of magnetic poles (524) is formed at free ends of the posts. A plurality of stator coils (54) is wound around the posts. Each magnetic pole includes a lower portion (700) adjacent to the air outlet and an upper portion (60) adjacent to the air inlet. The upper portions expand radially along a direction from the air inlet to the air outlet.

Abstract: A performance testing apparatus for a heat pipe includes an immovable portion having a heating member located therein for heating an evaporating section of the heat pipe requiring test. A movable portion is capable of moving relative to the immovable portion. A receiving structure is defined between the immovable portion and the movable portion for receiving the evaporating section of the heat pipe therein. At least one temperature sensor is attached to at least one of the immovable portion and the movable portion to detect the temperature of the evaporating section of the heat pipe. An enclosure encloses the immovable portion and the movable portion therein and has sidewalls thereof slidably contacting at least one of the immovable portion and the movable portion.

Abstract: A motor stator includes a stator core (500) and a stator coil. The stator core includes a central cylinder (501) and a plurality of posts (503) extending from the central cylinder. Each post is connected with a magnetic pole (505). The post has a smaller height than the central cylinder and the magnetic pole whereby a recess (507) is formed above the post between the central cylinder and the magnetic pole. The stator coil is received in the recess and wound around the post. The stator core is integrally made from ferromagnetic powder by powder metallurgy technique. Each particle of the powder includes an inner core (12) made of magnetic material and an outer shell (14) surrounding the inner core. The shell has a higher electrical resistance than the inner core.