Heat pipe and method of making the same

Abstract

A heat pipe includes a casing, a main wick structure received in the casing and attached to an inner surface of the casing, a multi-layered auxiliary wick structure received in the main wick structure and a working fluid contained in the casing and saturating the main wick structure and the auxiliary wick structure. An inner peripheral surface of the main wick structure and an outer peripheral surface of the auxiliary wick structure cooperatively define a vapor channel therebetween. The auxiliary wick structure extends along a longitudinal direction of the casing and defines a liquid channel therein. The auxiliary wick structure is formed by a plurality of layers radially stacked on each other, such that each outer layer is attached around an adjacent inner layer.

1 . A heat pipe comprising:
 a casing;   a main wick structure received in the casing and attached to an inner surface of the casing;   a multi-layered auxiliary wick structure received in the main wick structure, an inner peripheral surface of the main wick structure and an outer peripheral surface of the auxiliary wick structure cooperatively defining a vapor channel therebetween, the auxiliary wick structure extending along a longitudinal direction of the casing and defining a liquid channel therein; and   a working fluid contained in the casing and saturated in the main wick structure and the auxiliary wick structure;   wherein the auxiliary wick structure is formed by a plurality of layers radially disposed on each other in which each outer layer is attached immediately around an adjacent inner layer.   
   
   
       2 . The heat pipe as claimed in  claim 1 , wherein the auxiliary wick structure comprises a first inner layer and a second outer layer attached around the first layer, an inner surface of the first inner layer defining the liquid channel, the inner surface of the main wick structure and an outer peripheral surface of the auxiliary wick structure defining the vapor channel. 
   
   
       3 . The heat pipe as claimed in  claim 1 , wherein each layer of the auxiliary wick structure is formed by weaving a plurality of wires. 
   
   
       4 . The heat pipe as claimed in  claim 3 , wherein the wires of an inner layer have a greater wire diameter than that of the wires of an adjacent outer layer of the auxiliary wick structure. 
   
   
       5 . The heat pipe as claimed in  claim 1 , wherein an outer diameter of the auxiliary wick structure is smaller than a bore diameter of the main wick structure. 
   
   
       6 . The heat pipe as claimed in  claim 1 , wherein the casing is round. 
   
   
       7 . The heat pipe as claimed in  claim 1 , wherein the casing is flattened. 
   
   
       8 . A method for manufacturing a heat pipe comprising the steps of:
 providing an elongated pole, weaving a plurality of first wires on an outer peripheral surface of the pole to form a first layer;   weaving a plurality of second wires on an outer peripheral surface of the first layer to form a second layer;   removing the pole from the first layer to form an auxiliary wick structure, the auxiliary wick structure defining a liquid channel therein;   providing a casing having a main wick structure, the main wick structure attached to an inner surface of the casing, inserting the auxiliary wick structure into the casing;   vacuuming the casing and filling a working fluid into the casing; and   sealing the casing.   
   
   
       9 . The method as claimed in  claim 8 , wherein the plurality of first wires of the first layer has a greater wire diameter than that of the plurality of second wires of the second layer.