Heat pipe and method for manufactureing the same

Abstract

An exemplary heat pipe includes a first pipe and a second pipe. The first pipe includes a condenser section and an evaporator section extending from the condenser section along a longitudinal direction thereof. The second pipe encloses the condenser section of the first pipe. The evaporator section is located at an outside of the second pipe. The second pipe includes a casing enclosing the condenser section, second wick structures and working fluid contained in the second wick structures. Opposite ends of each second wick structure are respectively adhered to an inner wall of the casing and an outer periphery of the condenser section.

What is claimed is: 
     
         1 . A heat pipe comprising:
 a first pipe comprising a condenser section and an evaporator section extending from the condenser section along a longitudinal direction thereof; and   a second pipe enclosing the condenser section of the first pipe, the evaporator section located at an outside of the second pipe, and the second pipe comprising a casing enclosing the condenser section, a plurality of second wick structures and working fluid contained in the casing.   
     
     
         2 . The heat pipe of  claim 1 , wherein opposite ends of each second wick structure attached to an inner wall of the casing and an outer wall of the condenser section. 
     
     
         3 . The heat pipe of  claim 2 , wherein the second wick structures are spaced from each other and a channel is defined between each two adjacent second wick structures to allow vaporized working fluid flowing therethrough. 
     
     
         4 . The heat pipe of  claim 3 , wherein the second wick structures are evenly distributed around the inner wall of the casing of the second pipe. 
     
     
         5 . The heat pipe of  claim 3 , wherein each second wick structure has a convex outer end attached to the inner wall of the casing, and a concave inner end opposite to the outer end and attached to the outer wall of the condenser section, and a width of each second wick structure decreases from the outer end to the inner end. 
     
     
         6 . The heat pipe of  claim 1 , wherein the second wick structures are made of sintered powder. 
     
     
         7 . The heat pipe of  claim 1 , wherein the first pipe comprises a casing, a first wick structure attached to an inner wall of the casing and working fluid contained in the casing. 
     
     
         8 . The heat pipe of  claim 7 , wherein the first wick structure selected from a porous structure such as grooves, sintered powder, screen mesh, or bundles of fiber. 
     
     
         9 . The heat pipe of  claim 7 , wherein an inner periphery of the first wick structure defines a chamber therein to allow vaporized working fluid flowing therethrough. 
     
     
         10 . The heat pipe of  claim 7 , wherein a length of the condenser section along a longitudinal direction of the casing of the first pipe is larger than that of the evaporator section. 
     
     
         11 . A method for manufacturing a heat pipe comprising following steps:
 providing a first pipe, the first pipe comprising a condenser section and an evaporator section extending from the condenser section along a longitudinal direction thereof;   providing a casing, the casing comprising a closed end and an open end opposite to the closed end along a longitudinal thereof;   providing a mandrel and inserting the mandrel in the casing from the open end to the closed end, the mandrel comprising a main body and a plurality of extending portions extending outwardly from an outer periphery of the main body and spaced from each other, the extending portions abutting an inner wall of the casing;   providing a plurality of metal powder and filling the metal powder in gaps between each two adjacent extending portions and sintering the metal powder to make the metal powder form a plurality of second wick structures;   tacking off the mandrel and inserting the condenser section of the first pipe in the casing and the second wick structures abutting an outer wall of the condenser section;   vacuuming and placing predetermined quantity of working fluid into the casing; and   sealing the open end of the casing.   
     
     
         12 . The method of  claim 11 , wherein the extending portions radially extend from the outer periphery of the maim body and evenly spaced from each other. 
     
     
         13 . The method of  claim 11 , wherein the main body is cylindrical. 
     
     
         14 . The method of  claim 11 , wherein each extending portion is an elongated strip and extends along a longitudinal direction of the main body. 
     
     
         15 . The method of  claim 11 , wherein the casing of the second heat pipe is a metallic, hollow tube having an annular transverse cross section and a uniform thickness along a longitudinal direction thereof. 
     
     
         16 . The method of  claim 11 , wherein the first pipe comprises a casing, a continuous first wick structure adhered to an inner wall of the casing and working fluid contained in the first wick structure. 
     
     
         17 . The method of  claim 16 , wherein the casing of the first pipe is a metallic, hollow, elongated tube having an annular transverse cross section and a uniform thickness along a longitudinal direction thereof. 
     
     
         18 . The method of  claim 11 , wherein a length of the condenser section along a longitudinal direction of the casing of the first pipe is larger than that of the evaporator section. 
     
     
         19 . A heat pipe comprising:
 a first pipe comprising a casing, and a first wick structure and working fluid received in the casing; and   a second pipe comprising a casing, and a second wick structures and working fluid received in the casing;   wherein the casing of the first heat pipe comprises one end of inserted into the casing of the second pipe, and another end adapted to thermally connect a heat generating component.