Abstract: An electric fan includes a fan base (10), a bearing (40) and a rotor assembly (20). The fan base forms a central tube (11) receiving the bearing therein. The rotor assembly includes a fan hub (22), and a pivot axle (23) joined to the fan hub. The pivot axle pivotably extends into the bearing. A first and second locking rings (50, 70) are received in the central tube. Each of the first and second locking rings defines a central bore (52) therein. The pivot axle is engaged in the central bores of the first and second locking rings. The first locking ring is located at a top of the bearing and the second locking ring is located at a bottom of the bearing to prevent the rotor assembly from escaping from the bearing when the fan is operated.

Abstract: An electric fan includes a fan base (10), a bearing (40) and a rotor assembly (20). The fan base forms a center tube (11) receiving the bearing therein. The center tube has a wall and a baffle element (110) bending from a top end of the wall. The baffle element engages with a top of the bearing to prevent lubricant oil from leakaing from the top of the bearing. The rotor assembly includes a fan hub (22), and a pivot axle (23) joined to the fan hub. The pivot axle pivotably extends into the bearing. The bearing has a central bore (42) and at least one channel (43) defined in the bearing and located around the bore. As the fan is operated, the lubricating oil repeatedly flows through the at least one channel.

Abstract: An articulated joint for a foldable ladder includes an outer casing pair, an inner casing pair pivotally moving with respect to the outer casing pair, a lock device composed of a lock block and a locating pin. The locating pin has a ball end to be slightly squeezed in the locating hole such that the ball end is capable of retained in the locating hole and pivotally joined to the locating hole. The lock block provides triangular prism shaped projections at two opposite long edges of the bottom side of the lock block. Hence, the lock block can move along the guide slot of the outer casing shells steadily and be pivotally joined to fixing pin without loosening apart from each other.

Abstract: A mounting arrangement for mounting a cooling fan to a support member (30) includes a fan frame (10) having a mounting flange (14) for confronting with the support member, and a plurality of vibration isolation members (20) attached to the mounting flange. When the fan frame is secured to the support member, the vibration isolation members are pressingly sandwiched between the mounting flange and the support member.

Abstract: A heat dissipation fan includes a fan frame, a stator mounted to the frame, and a rotor rotatably disposed around the stator. The fan frame includes a bracket, a central tube for positioning the stator, and a supporting member. The supporting member is made of a material having a higher bending strength than a plastic material used to form the bracket and the central tube. The supporting member includes a main body connected to the central tube, a plurality of ribs extending radially outwardly from the main body, and a plurality of engaging units formed at free ends of the ribs, respectively. The engaging units are embedded in the bracket for integrally connecting the central tube to the bracket.

Abstract: A heat dissipation device includes a heat sink, a cooling fan having a frame arranged on the heat sink, and a fan holder disposed between the heat sink and the cooling fan. The fan holder includes a square shaped frame defining an opening therein. A pair of flexible fasteners extend upwardly from a pair of opposite sides of the frame and abut a pair of opposite side edges of the frame of the cooling fan. At least a clamping arm extends upwardly from one of the other pair of opposite sides of the frame of the fan holder and abuts one of the other pair of opposite sides of the frame of the cooling fan.

Abstract: A method of controlling a rotational speed of a fan motor for a heat generating electronic component includes the following steps: (1) obtaining an original PWM pulse in response to an internal die temperature of the electronic component, the original PWM pulse having a first duty cycle which corresponds to a first rotational speed for the fan motor; (2) obtaining an ambient temperature surrounding the electronic component; (3) generating a new PWM pulse based on the original PWM pulse and the ambient temperature, the new PWM pulse having a second duty cycle which corresponds to a second rotational speed for the fan motor; and (4) controlling the fan motor to operate at the second rotational speed. In this method, both the internal die temperature of the electronic component and the ambient temperature surrounding the electronic component are taken into consideration in determining the rotational speed of the fan motor.

Abstract: A fan blade set (10) for a cooling fan includes a hub (12) having a first wall and a second wall extending from the first wall. First blades (14) extend radially from the second wall. Second blades (16) formed on the first wall extend from a central portion of the first wall to a border thereof. Each second blade has a twisted shape such that an angle formed between the surface of the second blade and the first wall varies continuously along the extending direction of the second blade.

Abstract: A fan frame (10) for encircling an impeller (20) of a fan unit is disclosed. The fan frame includes a base (11) and a plurality of sidewalls (12) extending from the base. The base defines a hole (13) in a center so that an airflow passage is formed between the impeller and the sidewalls. The sidewalls extend upwardly from side edges of the base for encircling the impeller. Each of the sidewalls is bent inwardly to form a bent portion (121) with a groove (14) formed between the bent portion and an adjacent sidewall for providing extra access to airflow through the passage.

Abstract: A fan guard includes a frame, a bracket connected with the frame and a bearing seat connected with the bracket. A detachable interlocking device is formed between at least one of the combinations of the frame and the bracket, and of the bracket and the bearing seat.

Abstract: A bearing assembly includes a sleeve bearing (2) having a mating portion (22) and a center bore (20), a shaft (1) disposed in the center bore, and a rotary block (3) mounted on the shaft and being rotatable therewith. A gap exists between the inner circumferential surface of the bearing and the outer circumferential surface of the shaft to allow the shaft to be capable of rotate in the bore without scrapping the bearing. The rotary block includes a mounting portion (30) engaging with the mating portion of the bearing, whereby the rotary block is rotatably supported on the bearing.

Abstract: An articulated joint for a foldable ladder includes an outer casing pair, an inner casing pair pivotally moving with respect to the outer casing pair, a lock device composed of a lock block and a locating pin and a trigger for pressing the lock block apart from the locating recesses at the inner pair. The locating pin has a ball end and the lock block has a locating hole at a side thereof corresponding to the ball end for the ball end fitting with the locating hole to allow the lock block integrally joined to the locating pin as a single piece. The lock block provides the side joining with the locating pin with projections at two opposite edges thereof for preventing the lock block, the locating pin and the spring from loosening apart.

Abstract: A mounting arrangement for mounting a cooling fan to a support member (30) includes a fan frame (10) having a mounting flange (14) for confronting with the support member, and a plurality of vibration isolation members (20) attached to the mounting flange.

Abstract: A heat dissipation device assembly comprises a heat sink having a columniform conductive core and a plurality of fins arranged radially around the conductive core, a columnar fan cover housing the heat sink and defining a first open end and a second open end, and a fan located at the second open end of the fan cover. Pluralities of channels are formed between the radiation fins. A plurality of elongated slot surrounding the heat sink is defined in the fan cover and extends from the first open end of the fan cover to the second open end. The airflow provided by the fan travels through the channels and the slots to outside of the fan cover.

Abstract: An electric fan includes a stationary assembly and a rotor (40) being rotatable with respect to the stationary assembly. The stationary assembly includes a support member (16) located at a center portion thereof, and a stator (20) mounted around the support member. The rotor includes a blade set (41) having a rotary shaft (412) extending from the blade set toward the stationary assembly and pivotably supported by the support member. A rail assembly consisting of a lower rail (18) and an upper rail (49) is attached to the stationary assembly and the blade set to movably support the rotor on the stationary assembly.

Abstract: A cooling fan includes a frame (30), a stator (20) and a rotor (10). The frame includes a base (32) having a central tube (34). A bearing (22) is received in the central tube. The rotor includes a hub (11) having a shaft (15) extending from the hub into the bearing. An oil retaining ring (40) is mounted on the hub around the shaft and near a top of the central hub.

Abstract: A stator (1) includes a stator core (10), an insulating member (14) attached to the stator core, and a printed circuit board (18) attached to the insulating member. The stator core includes a center portion (102). Pole members (104) extend outwardly from the center portion. The insulating member includes a center section (142) corresponding to the center portion of the stator core. Extensions (14) extend outwardly from the center portion of the insulating member, corresponding to the pole members. The insulating member defines an outer periphery. Joint portions of the insulating member and the printed circuit board are located within the outer periphery of the insulating member and spaced from the extensions a distance along an axial direction of the stator.

Abstract: A frame (10) for an electrical fan includes a bracket (20) and a bearing support (30) located at the center of the bracket. The bearing support includes a metal tube (50) and a plastic body (40) connecting with the metal tube. The metal tube defines at least one connecting hole (52) in a wall thereof. The plastic body includes an inner portion (42) located inside the metal tube, an outer portion (44) located outside the metal tube, and a connecting portion (46) located in the connecting hole and integrally connecting the inner and the outer portions of the plastic body. The inner portion is used for engaging with two bearings (60) for rotatably connecting with a rotor shaft of the electrical fan.

Abstract: A heat dissipation fan includes a rotor (1) having a hub (10) with a permanent magnet (104) attached to an inner surface thereof, a stator (2) and a fan frame (3) having a bearing seat (36). The bearing seat (36) includes a base (361) and a central tube (362) around which the stator is mounted. Slots (102) are defined through the top wall of the hub facing to the magnet ring. The base defines slots (360), corresponding to the slots of the hub.

Abstract: A stator (1) includes a stator core (10) and an insulating member (12) attached to the stator core. The stator core includes a first engaging structure. The insulating member includes portions to cover the stator core, thereby insulating the stator core from stator coils, and a first engaging structure other than said portions. The first engaging structure engages with the second engaging structure to interconnect the stator core and the insulating member. According to a preferred embodiment, the first engaging structure includes a plurality of mounting holes (108), and the second engaging structure includes a plurality of mounting protrusions (124) engaged in the mounting holes respectively.