A light emitting diode (LED) bulb with a central axis bidirectional convection heat dissipation structure, the LED bulb comprising:
- a lower cover (11, 21) made of a non-thermally conductive or insulating material and provided with a bulb socket (110, 210) on the outer bottom side of the lower cover (11, 21), wherein the lower cover (11, 21) is provided therein with a driving circuit board (111, 211) near the bottom side thereof, two electrodes (1101, 1102, 2101, 2102) of the bulb socket (110, 210) are separately and electrically connected to the driving circuit board (111, 211), the outer periphery of the lower cover (11, 21) is provided with at least one ventilation hole (112, 212) so as to allow inside and outside of the lower cover (11, 21) to communicate with each other through the ventilation hole (112, 212), and the top side of the lower cover (11, 21) is formed with a first coupling opening (113, 213);
- a separating unit (12) having a bottom side provided within the lower cover (11, 21) at a position between the lower edge of the ventilation hole (112, 212) and the driving circuit board (111, 211), so as to confine the driving circuit board (111, 211) within the lower cover (11, 21) at a position near the bottom side of the lower cover (11, 21), wherein the separating unit (12) has a top side provided within the lower cover (11, 21) at a position between the upper edge of the ventilation hole (112, 212) and the first coupling opening (113, 213), and the separating unit (12) is formed with at least one convection pathway (121) which can communicate with the top side of the separating unit (12) and the ventilation hole (112, 212), respectively;
- a heat sink (13, 23) made of a thermally conductive material having a thermal conductivity coefficient higher than that of the non-thermally conductive or insulating material, wherein the bottom end of the heat sink (13, 23) is positioned on the top side of the separating unit (12) such that the heat sink (13, 23) can communicate with the ventilation hole (112, 212) through the convection pathway (121), at least one LED circuit board (131, 231) is attached to the outer side of the heat sink (13, 23), and the LED circuit board (131, 231) is electrically connected to the driving circuit board (111, 211) so as to drive at least one LED (1311, 2311) on the LED circuit board (131, 231) to emit light;
- and
- an upper cover (14, 24) made of a light permeable material, wherein the top side of the upper cover (14, 24) is formed with at least one convection hole (141, 241), the top end of the heat sink (13, 23) is positioned in the upper cover (14, 24) and corresponds in position to the convection hole (141, 241) such that the heat sink (13, 23) can communicate with the cold ambient air outside the bulb through the convection hole (141, 241), the upper cover (14, 24) is formed with a second coupling opening (143, 243) at the bottom side thereof, the second coupling opening (143, 243) can be coupled with the first coupling opening (113, 213) such that the upper cover (14, 24) and the lower cover (11, 21) are assembled together to form a receiving space (S) therebetween for accommodating the heat sink (13, 23), and the receiving space (S) can communicate with the cold ambient air outside the bulb through a central axis bidirectional convection heat dissipation pathway formed by the ventilation hole (112, 212), the convection pathway (121), the heat sink (13, 23) and the convection hole (141, 241).