Patent Publication Number: US-2007110592-A1

Title: Integrated liquid cooling system

Description:
FIELD OF THE INVENTION  
      The present invention relates generally to a liquid cooling system for dissipation of heat from heat-generating components, and more particularly to an integrated liquid cooling system suitable for removing heat from electronic components of computers.  
     DESCRIPTION OF RELATED ART  
      With continuing development of the computer technology, electronic packages such as central process units (CPUs) are generating more and more heat that is required to be dissipated immediately. The conventional heat dissipating devices such as combined heat sinks and fans are not competent for dissipating so much heat any more. Liquid cooling systems have thus been increasingly used in computer technology to cool these electronic packages.  
      A typical liquid cooling system generally comprises a heat-absorbing member, a heat-dissipating member and a pump. These individual components are connected together in series so as to form a heat transfer loop. In practice, the heat-absorbing member is maintained in thermal contact with a heat-generating component (e.g., a CPU) for absorbing heat generated by the CPU. The liquid cooling system employs a coolant circulating through the heat transfer loop so as to continuously bring the thermal energy absorbed by the heat-absorbing member to the heat-dissipating member where the heat is dissipated. The pump is used to drive the coolant, after being cooled in the heat-dissipating member, back to the heat-absorbing member.  
      In the typical liquid cooling system, the heat-absorbing member, the heat-dissipating member and the pump are connected together generally by a plurality of connecting tubes so as to form the heat transfer loop. However, the typical liquid cooling system has a big volume and occupies more room in a computer system, and is not adapted to a small room of a notebook PC. Furthermore, the liquid cooling system has many connecting tubes with a plurality of connections, which is prone to lead to a leakage of the coolant so that the system has a low reliability and a high cost. Moreover, the heat-absorbing member, the heat-dissipating member and the pump are to be located at different locations when mounted to the computer system. In this situation, mounting of the liquid cooling system to the computer system or demounting of the liquid cooling system from the computer system is a burdensome and time-consuming work.  
      Therefore, it is desirable to provide a liquid cooling system which overcomes the foregoing disadvantages.  
     SUMMARY OF THE INVENTION  
      An integrated liquid cooling system in accordance with an embodiment of the present invention for removing heat from a heat-generating electronic component includes a base, a pump mounted in the base and a heat-dissipating member communicating with the pump and coupling with the base. The pump includes a casing having a chamber. A rotor, a partition seat and a stator are in turn received in the chamber. A top cover is attached on the casing. The casing comprises a bottom plate having a bottom surface. The bottom surface of the bottom plate contacts the heat-generating electronic component for absorbing heat generated by the electronic component. The base, the pump and the heat-dissipating member are connected together in series to thereby form a heat transfer loop, without the necessity of using any connecting tube. Thus, these individual components of the liquid cooling system are assembled together without any connecting tubes. The integrated liquid cooling system is compact in structure and has a low cost, high reliability and increased heat-dissipating effect.  
      Other advantages and novel features of the present invention will become more apparent from the following detailed description of preferred embodiment when taken in conjunction with the accompanying drawings, in which: 
    
    
     BRIEF DESCRIPTION OF THE INVENTION  
       FIG. 1  is an assembled, isometric view of a liquid cooling system in accordance with a preferred embodiment of the present invention;  
       FIG. 2  is an exploded view of  FIG. 1 , but shown from another aspect;  
       FIG. 3  is an isometric view of a heat-dissipating member of the liquid cooling system of  FIG. 2 ;  
       FIG. 4  is an exploded view of a pump of the liquid cooling system of  FIG. 2 ;  
       FIG. 5  is a cross-sectional view of the pump of  FIG. 2 ;  
       FIG. 6  is an exploded view of a pump of a liquid cooling system in accordance with a second embodiment of the present invention;  
       FIG. 7  is an assembled, cross-sectional view of the pump of  FIG. 6 ;  
       FIG. 8  is an exploded view of a pump of a liquid cooling system in accordance with a third embodiment of the present invention;  
       FIG. 9  is an assembled, cross-sectional view of the pump of  FIG. 8 ;  
       FIG. 10  is an isometric view of a rotor of the liquid cooling system of  FIG. 8 ;  
       FIG. 11  is an isometric view of a rotor in accordance with an alternative embodiment of the present invention;  
       FIG. 12  is an exploded view of a pump and a base of a liquid cooling system in accordance with a fourth embodiment of the present invention;  
       FIG. 13  is an exploded view of a pump and a base of a liquid cooling system in accordance with a fifth embodiment of the present invention; and  
       FIG. 14  is an assembled, cross-sectional view of the pump and the base of  FIG. 13 . 
    
    
     DETAILED DESCRIPTION  
       FIG. 1  and  FIG. 2  illustrate a liquid cooling system in accordance with a preferred embodiment of the present invention. The liquid cooling system includes a base  10 , a pump  20  mounted in the base  10 , and a heat-dissipating member  30  communicating with the pump  20  and coupling with the base  10 . The base  10 , the pump  20  and the heat-dissipating member  30  are connected together in series without any connecting tubes. A heat transfer loop is formed by the base  10 , the pump  20  and the heat dissipating member  30 . A coolant such as water is filled into the pump  20  and is circulated through the heat transfer loop under a drive of the pump  20 .  
      The base  10  is made from Polyethylene (PE) or Acrylonitrile Butadiene Styrene (ABS), and has a rectangular configuration. The base  10  defines an opening  100  in a central portion thereof for receiving and securing the pump  20  therein. The base  10  forms a pair of ears  12  extending from left and right sides thereof, wherein a pair of mounting holes  120  is defined in each ear  12  for receiving screws  40  with springs  42  therein. Annular rings  44  are used to snap in recesses (not labeled) defined in lower portions of the screws  40  thereby to attach the screws  40  and the springs  42  to the base  10  before the liquid cooling system is mounted on a supporting member (not shown), for example, a printed circuit board on which a heat-generating electronic component is mounted. A pair of rectangular slots  102 ,  104  is symmetrically defined at two opposite sides of the base  10  beside the opening  100 . A pair of rectangular channels  106 ,  108  is respectively defined between the opening  100  and the slots  102 ,  104 . The channels  106 ,  108  communicate the opening  100  with the slots  102 ,  104 .  
      With reference also to  FIGS. 4-5 , the pump  20  comprises a hollow casing  21 , a magnetic rotor  22 , a partition seat  23 , a stator  24  and a top cover  25  hermetically attached to a top end of the casing  21 .  
      The casing  21  is made of metal material with good heat conductivity, and defines a chamber  212  for in series receiving the rotor  22 , the partition seat  23  and the stator  24  therein. The casing  21  comprises a bottom plate  214  having a blind hole  213  defined in a central portion thereof. The bottom plate  214  serves as a heat-absorbing plate to contact with the heat-generating electronic component and absorb heat generated by the electronic component. An annular step  216  is formed on a top of a ring of the casing  21 . The step  216  is declined inwardly. An inlet  26  corresponding to the channel  106  of the base  10  and an outlet  27  corresponding to the channel  108  of the base  10  are formed at two opposite sides of an outer surface of the casing  21 , so that the coolant is capable of entering into casing  21  via the inlet  26  and escaping the casing  21  via the outlet  27 .  
      The magnetic rotor  22  is mounted in the chamber  212  of the casing  21 , and includes an annular impeller  220  having an inner surface and an outer surface, and a magnetic ring  222  securely abutting against the inner surface of the impeller  220 . The impeller  220  forms a plurality of plate-shaped vanes  224  extending radially and outwardly from the outer surface thereof. When the rotor  22  rotates, the plate-shaped vanes  224  agitate the coolant in the chamber  212  of the casing  21 , for providing a pressure to the coolant and to thereby circulating the coolant in the liquid cooling system.  
      The partition seat  23  is mounted between the rotor  22  and the stator  24  for isolating the coolant from the stator  24  to prevent the coolant entering the stator  24  to short circuit of the stator  24 . The partition seat  23  comprises a cylindrical body  231  having an inner space  230 , and an annular plate  233  extending outwardly from a top of the cylindrical body  231 . An upper shaft  236  extends upwardly from a center of a bottom portion  232  of the cylindrical body  231 . A lower shaft  238  extends downwardly from the center of the bottom portion  232  of the cylindrical body  231 , for engaging in the blind hole  213  of the bottom plate  214  of the casing  21 . The bottom portion  232  contacts with the bottom plate  214  of the casing  21 . An edge of the annular plate  233  hermetically contacts with the step  216  of the casing  21 .  
      The stator  24  is received in the space  230  of the partition seat  23 . The stator  24  comprises a cylindrical center portion  241  having a center hole  243  defined therein, six generally T-shaped pole members  240  extending radially and outwardly from the center portion  241 . The center hole  243  of the center portion  241  fittingly receives the upper shaft  236  of the partition seat  23 . Each pole member  240  of the stator  24  is surrounded by a coil  242 . A printed circuit board (not shown) is mounted on a top of the center portion  241  and electrically connects with the stator  24 .  
      The top cover  25  defines a center hole  250  therein, for providing passage of lead wires of the printed circuit board therethough. An edge of the top cover  25  hermetically contacts with the top of the casing  21 .  
      Referring to  FIG. 2  and  FIG. 3 , the heat-dissipating member  30  includes a plurality of metal fins  301 , a plurality of heat-dissipating channels  304 , and a pair of opposite fluid tanks  302 ,  303  connected to ends of the heat-dissipating channels  304 . The fluid tanks  302 ,  303  have openings  3020 ,  3030  corresponding to openings  1020 ,  1040  of the slots  102 ,  104  of the base  10 .  
      In assembly, the pump  20  is mounted in the center opening  100  of the base  10 , wherein the inlet  26  and the outlet  27  are respectively received in the channels  106 ,  108 , and a pair of blocks  110 ,  112  surrounding around the inlet  26  and the outlet  27  is clamped in the channels  106 ,  108 , for fixing the inlet  26  and the outlet  27  to the channels  106 ,  108 . The inlet  26  and the outlet  27  communicate with the slots  102 ,  104 , respectively. The heat-dissipating member  30  is mounted on the base  10 , wherein the openings  3020 ,  3030  of the fluid tanks  302 ,  303  are communicated with the openings  1020 ,  1040  of the slots  102 ,  104 , respectively, so that the fluid tanks  302 ,  303  of the heat-dissipating member  30  are in fluid communication with the slots  102 ,  104  of the base  10 . Thus, the base  10 , the pump  20  and the heat-dissipating member  30  are connected together without any connecting tubes, and the pump  20  is in fluid communication with both of the base  10  and the heat-dissipating member  30  so as to drive the coolant to circulate through the chamber  212  of the pump  20 , the slots  102 ,  104  of the base  10  and the fluid tanks  302 ,  303  and the channels  304  of the heat-dissipating member  30 . The combination of the base  10 , the pump  20  and the heat-dissipating member  30  is fixed to the printed circuit board such that the bottom plate  214  of the pump  20  intimately contacts with the electronic component on the printed circuit board.  
      In operation, the coils  242  of the stator  24  are powered firstly to drive the magnetic ring  222  to rotate. The impeller  220  is driven to rotate with the magnetic ring  222 . The impeller  220  thus rotates with the plate-shaped vanes  224  to circulate the coolant in the liquid cooling system. Simultaneously, heat generated by the electronic component is absorbed by the bottom plate  214  of the pump  20  and then is transferred to the coolant contained in the chamber  212  of the casing  21  of the pump  20 . The rotatable impeller  220  quickly agitates the coolant via the plate-shaped vanes  224  thereof and increases the pressure of the coolant to circulate the coolant in the liquid cooling system. The coolant absorbing the heat has a higher temperature and is driven out of the casing  21  of the pump  20  via the outlet  27 , and flows to the heat-dissipating member  30  via the slot  104  of the base  10  and the fluid tank  303  of the heat-dissipating member  30 . Thereafter, the coolant flows to the fluid tank  302  through the channels  304  where the heat is dissipated to ambient environment via the fins  301 . After releasing the heat, the coolant having a lower temperature is brought back to the chamber  212  of the pump  20  via the inlet  26 , thus continuously taking the heat away from the electronic component.  
       FIGS. 6-7  show a pump  20  in accordance with a second embodiment of the present invention. The pump  20  of the second embodiment is similar with that of the preferred embodiment. However, a lower shaft  238 ′ replaces the lower shaft  238  of the previous preferred embodiment. The lower shaft  238 ′ has a longer length than that of the lower shaft  238  such that a gap  202  is thus defined between the bottom portion  232  of the cylindrical body  231  of the partition seat  23  and the bottom plate  214  of the casing  21 . In use, the coolant flows through the gap  202 , which is located adjacent to the central portion of the bottom plate  214  of the casing  21  of the pump  20 , whereby the heat absorbed by the bottom plate  214  from the electronic component can be more directly transferred to the coolant and effectively taken away by the coolant.  
       FIGS. 8-10  show a pump in accordance with a third embodiment of the present invention. The pump of the third embodiment is similar with that of the second embodiment. However, in the third embodiment, an agitator  223  is received in the chamber  212  of the casing  21 , for agitating the coolant of the chamber  212 . The agitator  223  is formed on the magnetic ring  222  of the rotor  22 . The agitator  223  comprises a plurality of agitating plates  225  extending radially and outwardly from a center of the rotor  22 . The agitating plates  225  connect with the inner surface of the magnetic ring  222 . A shape of the agitating plate  225  is linear (shown in  FIGS. 8 and 10 ). Please refer to  FIG. 11 , alternatively, the agitating plate  225  may have a curvilinear configuration.  
       FIG. 12  shows a pump  20  and a base  10 ′ in accordance with a fourth embodiment of the present invention. In the fourth embodiment, a base  10 ′ replaces the base  10  of the aforementioned embodiments. The base  10 ′ forms joint flanges  105 ,  107  at a top of the slots  102 ,  104  thereof, for hermetically engaging in the openings  3020 ,  3030  of the fluid tanks  302 ,  303  of the heat-dissipating member  30 .  
       FIG. 13  shows a pump  20 ′ and a base  10 ′ in accordance with a fifth embodiment of the present invention. In the fifth embodiment, a pump  20 ′ replaces the pump  20  of the aforementioned embodiments and the base  10 ′ is the same as the base  10 ′ of the fourth embodiment. Most parts of the pump  20 ′ of the fifth embodiment are the same as the aforementioned embodiments. A main difference is that in the fifth embodiment the pump  20 ′ comprises a casing  21 ′ having a plate shaped configuration, while in the aforementioned embodiments the casing  21  has a cylindrical chamber. The casing  21 ′ comprises a disk-like plate  214 ′ having atop surface and a bottom surface. The bottom surface contacts with the heat-generating electronic component and absorbs the heat generated by the electronic component. A protrusion portion  215 ′ extends upwardly from the top surface of the plate  214 ′, for extending into the base  10 ′ and hermetically engaging in the opening  100  of the base  10 ′. The protrusion portion  215 ′ defines a blind hole  216 ′ in a central portion thereof, for receiving the lower shaft  238  of the partition seat  23  therein. After the casing  21 ′ is mounted to a bottom of the base  10 ′ with the protrusion  215 ′ fitted in a lower part of the opening  100 , a chamber  212 ′ of the pump  20 ′ is defined by a part of the opening  100  above the casing  21 ′.  
      It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.