Abstract:
A computer system and a method for cooling the system incorporate removable modules within a housing. The housing includes a parallelepiped structure with at least four walls. The four walls include at least two sets of opposing walls. Both walls of one set of opposing walls include opposing first and second openings substantially aligned with each other to allow passage of a cooling medium therethough. The module is receivable through a third opening in the parallelepiped structure and includes an electrical component region. The housing includes a first airflow path in-line with the third opening and a second airflow path between the first opening and the second opening. The first airflow path and the second airflow path are directed across the component region of the module when the module is received within the housing.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention generally relates to a free-standing or rack-mountable chassis with computer modules or blades slidably received therein, and more particularly to such a chassis that enables components associated with these modules to be cooled by at least two airflow paths.  
           [0003]    2. Description of the Prior Art  
           [0004]    Cooling computer systems has always been a problem. The form-factor of the chassis, “hot pluggable” components, and the demand for improved reliability of client/server network systems, with ever-increasing microprocessor power dissipation and system power consumption, have created additional problems with cooling system design, particularly with respect to temperature monitoring and control. High-end servers utilize newer high powered processors, as well as multiple processors, thereby creating even more heat within the system.  
           [0005]    Typically, microprocessors and associated electronic components are cooled by forced air. That is, fans are used to push or pull air from one side of a chassis housing electrical components, across the electrical components and out the other side of the chassis. By forcing air to flow over the electrical components, heat is dissipated, which prevents the electrical components from overheating and failing.  
           [0006]    Cooling electrical components with air is limited by the ability to channel or direct the airflow through the chassis and across the electrical components housed therein. Air follows the path of least resistance, and in many cases, the path of least resistance does not cross the electrical components that most need cooling. Thus, large volumes of air may be pulled through a chassis without ever cooling certain electrical components. The end result being that the electrical components overheat and the computer system fails.  
           [0007]    Existing systems include barriers throughout the chassis that direct airflow through the chassis. These barriers, however, are generally designed around certain configurations of electrical components within the chassis, that is, specific electrical components function as airflow barriers. The component configurations are often altered when particular components are added or removed. By removing or adding new components, the preferred airflow through the chassis is disturbed and air may stop flowing in particular areas of the chassis. These areas are commonly referred to as “dead spots”.  
           [0008]    A particular problem exists with respect to preventing dead spots around power supplies and disk drives on computer motherboards since airflow is generally designed to be directed across these components. Because of the arrangement and placement of the power supply and disk drives at the rear of a motherboard, the height of these assemblies, and conventional airflow paths, dead spots are created between the power supply, disk drives, and the front of the chassis.  
           [0009]    Unfortunately, this is precisely where high performance microprocessors are located in standard ATX form-factor motherboards. These processors dissipate a large amount of heat while being critical to the operation of the system. In addition, the power supply and disk drives generate relatively large amounts of heat, and may thus cause a particular module and/or component to fail.  
           [0010]    Because the failure of any electrical component, but most particularly the processor or processors, disrupts the operation of the computer system, it is essential that the computer chassis provide high efficiency cooling, cool all electrical components housed within the chassis, and minimize system down time with respect to different electrical component configurations, whether they be the standard ATX, Micro-ATX, ITX, Mini-ITX, or LPX form-factors or an open non-proprietary standard.  
         OBJECTS AND SUMMARY OF THE INVENTION  
         [0011]    It is an object of the present invention to provide a method, chassis, and module that promote efficient, effective, uniform, and thorough cooling of all components within a computer system.  
           [0012]    It is another object of the present invention to provide a method, chassis, and module that eliminate dead spots in conventional airflow paths commonly created around oversized or high profile components and assemblies, such as power supplies and disk drives, in computer systems.  
           [0013]    It is yet another object of the present invention to provide a method, chassis, and module that provide for dual airflow paths to cool all components mounted on removable modules within the chassis.  
           [0014]    It is still another object of the present invention to provide a method, chassis, and module that create an airflow path or chimney through a plurality of chassis stacked or cascaded in vertical alignment.  
           [0015]    A computer system formed in accordance with one form of the present invention, which incorporates some of the preferred features, includes a housing and a module. The housing includes a parallelepiped structure with at least four walls. The four walls include at least two sets of opposing walls. Both walls of one set of opposing walls include opposing first and second openings substantially aligned with each other to allow passage of a cooling medium therethough.  
           [0016]    The module is receivable through a third opening in the parallelepiped structure, and includes a component region adapted for positioning at least one electrical component therein. The housing includes a first airflow path in-line with the third opening, and a second airflow path between the first opening and the second opening. The first airflow path and the second airflow path are directed across the component region of the module when the module is received within the housing.  
           [0017]    A method of cooling a computer system formed in accordance with one form of the present invention, which incorporates some of the preferred features, includes the steps of forming a housing including a parallelepiped structure with at least four walls including at least two sets of opposing walls, and forming opposing openings substantially aligned with each other on both walls of one set of opposing walls for passage of a cooling medium therethrough.  
           [0018]    The method further includes the steps of providing a module receivable through a third opening in the parallelepiped structure, providing a component region on the module adapted for positioning at least one electrical component therein, providing a first airflow path substantially in-line with the third opening, and providing a second airflow path substantially between the first opening and the second opening. The first airflow path and the second airflow path are directed across the component region of the module when the module is received within the housing.  
           [0019]    These and other objects, features, and advantages of this invention will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]    [0020]FIG. 1 is a front pictorial view of a computer system including a chassis and removable modules formed in accordance with the present invention.  
         [0021]    [0021]FIG. 2 is a rear pictorial view of the computer chassis formed in accordance with the present invention.  
         [0022]    [0022]FIG. 3 is an exploded view of the chassis formed in accordance with the present invention.  
         [0023]    [0023]FIG. 4 is a top isometric view of a computer motherboard module formed in accordance with the present invention.  
         [0024]    [0024]FIG. 5 is an exploded view of a first embodiment of the computer module formed in accordance with the present invention.  
         [0025]    [0025]FIG. 6 is an exploded view of a second embodiment of the computer module formed in accordance with the present invention.  
         [0026]    [0026]FIG. 7 is an exploded view of a third embodiment of the computer module formed in accordance with the present invention.  
         [0027]    [0027]FIG. 8 is an exploded view of a fourth embodiment of the computer module formed in accordance with the present invention.  
         [0028]    [0028]FIG. 9 is a front isometric view of the chassis formed in accordance with the present invention.  
         [0029]    [0029]FIG. 10 is a top isometric view of a first embodiment of a top-mounted fan assembly formed in accordance with the present invention.  
         [0030]    [0030]FIG. 11 is a bottom isometric view of a second embodiment of the top-mounted fan assembly formed in accordance with the present invention.  
         [0031]    [0031]FIG. 12 is an isometric view of a plurality of chassis stacked in vertical alignment.  
         [0032]    [0032]FIGS. 13A, 13B, and  13 C show three embodiments of the chassis and module formed in accordance with the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0033]    [0033]FIG. 1 is a front pictorial view of a computer system  10 , which includes a computer chassis or housing  12  and modules  14  formed in accordance with the present invention. The modules  14  are preferably slidably removable from the chassis  12 . The modules  14  or blades are preferably provided in various configurations, such as:  
         [0034]    1. a computer blade module, which supports a standard ATX/Micro ATX mother board, two (2) standard 3½ inch form-factor hard disk drives, and single or dual high-speed processors;  
         [0035]    2. a storage blade module, which supports six (6) standard 3½ inch form-factor hard disk drives;  
         [0036]    3. a communication blade module, which supports multiple communication devices; and  
         [0037]    4. a control blade module, which supports multiple industrial controller devices.  
         [0038]    Each of the modules  14  preferably includes the following features:  
         [0039]    1. tool-less thumbscrew module locking within the chassis;  
         [0040]    2. front-accessible power switching;  
         [0041]    3. front-accessible power connectors, which enable rapid power source disconnection;  
         [0042]    4. front-accessible input/output (I/O) connectors, which include video, local area network (LAN), keyboard, mouse, serial, universal serial bus (USB), small computer system interface (SCSI), integrated drive electronics (IDE), fibre channel, and advanced technology attachment (ATA) ports;  
         [0043]    5. front-accessible peripheral component interconnect (PCI) expansion slots; and  
         [0044]    6. a self-contained power supply.  
         [0045]    The chassis  12  preferably supports ten (10) independently operated pluggable blade modules  14 , and preferably includes perforated vent panels  16  that can be removed from both the top and bottom of the chassis  12 . The chassis  12  is preferably configured as a stand-alone unit or mounted in vertical alignment as shown in FIG. 12 within, for instance, a rack (not shown) using rear ear brackets  18 . Handles  20 ,  22  are preferably mounted on both the modules  14  and the chassis  12  to aid in their handling and relocation.  
         [0046]    [0046]FIG. 2 shows a rear pictorial view of the chassis  12 . The chassis  12  preferably includes six (6) rear-mounted heat exhausting fans  24 , which provide about 72 CFM. The fans  24  preferably draw air from a front region of the chassis  12 , into which the modules are inserted, towards a rear portion of the chassis  12 , from which the hot air is exhausted.  
         [0047]    The chassis  12  and modules  14  formed in accordance with the present invention support at least two independent airflow paths. A first or horizontal airflow path, which is indicated in FIGS. 1 and 2 by arrow A, is preferably directed through a front vent  26 , which is preferably located on each of the modules  14 , across the modules  14 , out a rear vent of the modules  14 , and exits the chassis  12  through the rear-mount fans  24 .  
         [0048]    A second or vertical airflow path, which is indicated in FIGS. 1 and 2 by arrow B, is preferably directed from the vent panel at the bottom of the chassis  12 , through a lateral vent  28  of the modules  14  across the modules  14 , out an opposing lateral vent  28  of the modules  14 , and exits a top region of the chassis  12  at the vent panel  16 . Thus, the chassis  12  and removable modules  14  formed in accordance with the present invention provide at least two independent airflow paths to cool components on each of the modules while substantially eliminating dead spots created by oversized and/or high profile components and assemblies.  
         [0049]    [0049]FIG. 3 is an exploded view of the chassis  12  formed in accordance with the present invention. The chassis  12  preferably includes a bottom portion  30 , which forms the bottom surface, left side, and right side of the chassis  12 . The chassis also preferably includes a top cover  32 , which mounts on top of the bottom portion  30 , and a rear cover  34 , which covers the rear portion of the chassis  12  and provides a mounting surface for the fans  24  shown in FIG. 2.  
         [0050]    A pair of rear ear brackets  18  preferably mounts to each of the right and left sides of the chassis  12 . Upper and lower housing slots  36  preferably mount to top and bottom internal surfaces of the chassis  12  and function to guide the modules as they are inserted and removed from the chassis  12 . The bottom portion  30  and the top cover  32  both preferably include vents  38 , which are preferably covered by perforated vent plates  16 .  
         [0051]    Stabilization bars  40  preferably mount to the front portions of the top cover  32  and the bottom portion  30  to add rigidity to the front of the chassis  12 . Front ear brackets  42  and center mount ear brackets  44  preferably mount to the right and left sides of the chassis  12  to add further rigidity to the chassis  12  and to enable the chassis  12  to be mounted within a rack (not shown).  
         [0052]    [0052]FIG. 4 shows a top isometric view of a standard ATX computer motherboard module  14  formed in accordance with the present invention. The module  14  preferably includes an external enclosure  46  to house electrical and/or electronic components mounted within the module, such as a power supply  48 , disk drives  50 , and microprocessors  52 , while permitting electrical access to and cooling of these components.  
         [0053]    The external enclosure  46  also preferably includes friction-reducing material  47 , such as silicone and/or Teflon® tape, affixed to one or both sides of an external surface to enable the module  14  to slide freely when being removed or inserted into the chassis  12 . Alternatively, or in addition, friction-reducing material  47  may be affixed to an internal surface of the chassis, such as on the upper and lower housing slots  36  for a similar purpose.  
         [0054]    The external enclosure  46  includes front vents  54 , rear vents  56 , and lateral vents  58 . As described above, the first airflow path, indicated by arrow A, preferably flows into the front vents  54 , across the components housed in the enclosure  46 , and exits the module  14  through the rear vents  56 . The second airflow path, indicated by arrow B, preferably flows into one of the lateral vents  58 , across the components housed within the enclosure  46 , and exits the opposing lateral vent  58  of the module  14 . The first and second airflow paths are preferably perpendicular with respect to each other, but are not required to be so while remaining within the scope of the present invention.  
         [0055]    In a conventional chassis and module, the microprocessors  52  are located in a dead spot within the first airflow path A, which is created by oversized or high profile components and assemblies, such as the power supply  48  and disk drives  50  blocking the flow of air. However, presence of the second airflow path B advantageously provides an independent cooling mechanism for the high-performance microprocessors  52 , as well as other components in this area, that eliminates dead spots in the first airflow path A.  
         [0056]    [0056]FIGS. 5-8 show exploded views of different embodiments of the external enclosure  46  of the module formed in accordance with the present invention. In a first embodiment, shown in FIG. 5, the lateral vents  58  are formed as rectangular cut-outs in the right and left side portions of the enclosure  46 . FIG. 6 shows a second embodiment of the enclosure  46  wherein the lateral vents  58  are provided as substantially circular, triangular, or elliptical perforations.  
         [0057]    In a third embodiment of the enclosure  46  shown in FIG. 7, the lateral vents  58  of the enclosure  46  are formed by removing an oblong portion of both the right and left sides of the enclosure  46 . In a fourth embodiment of the enclosure  46  shown in FIG. 8, the lateral vents  58  are shown as substantially linear perforations in the sides of the enclosure  46 .  
         [0058]    [0058]FIGS. 5-8 are merely intended to provide examples of various embodiments of the lateral vents  58 , which apply equally to other vents in the module  14  and chassis  12 , such as the front vents  54 , rear vents  56 , and vent plates  16 , without in any way limiting the scope of the present invention. For instance, any of the vents formed in accordance with the present invention may include substantially circular, rectangular, elliptical, linear, and/or triangular perforations and/or cutouts while remaining within the scope of the present invention.  
         [0059]    As shown in each of FIGS. 5-8, the enclosures  46  preferably include a rear panel  60 , which covers the rear portion of the enclosure  46 . One of two ATX I/O shields  62  is preferably affixed to the front portion of the enclosure  46  to provide a mounting surface for various electrical connectors as well as providing a grid for the front vent  54 . A PCI expansion bracket  64  and a handlebar  20  are also preferably mounted to the front portion of the enclosure  46 .  
         [0060]    A case holder  66  is preferably mounted from side to side within the enclosure  46  to provide further structural integrity. Power supply brackets  68  are preferably mounted within the enclosure  46  to mount the power supply  48  shown in FIG. 4 to the enclosure  46 . Hard disk drive trays  70  are also preferably mounted to the inside bottom portion of the enclosure  46  to affix the disk drives  50  shown in FIG. 4 to the enclosure  46 .  
         [0061]    [0061]FIG. 9 shows a front isometric view of the chassis  12  formed in accordance with the present invention having the bottom and top vent panels  16  removed. The first airflow path preferably enters the front region of the enclosure  12 , flows across the modules (not shown) in the chassis  12 , and exits the rear of the chassis  12  by operation of the rear-mount fans  24  shown in FIG. 2. The second airflow path B preferably enters the bottom vent  38  of the enclosure  12 , flows across the modules (not shown) in the chassis  12 , and exits the top vent  38  of the enclosure  12 .  
         [0062]    [0062]FIG. 10 shows a top isometric view of a first embodiment of a top-mounted fan assembly  72  formed in accordance with the present invention. The top-mounted fan assembly  72  is preferably mounted to the top surface of the chassis  12  after the vent panel  16  has been removed. The top-mounted fan assembly  72  preferably includes three fans  74 , pressurized air blower units, and/or alternative devices for displacing air that are well known in the art, which direct air from the chassis  12  beneath the fan assembly  72 , through the fans  74 , and exhaust the air upwards from the fan assembly  72 , as shown by arrows C.  
         [0063]    [0063]FIG. 11 shows a bottom isometric view of a second embodiment of the top-mounted fan assembly  76 . The top-mounted fan assembly  76  is also preferably mounted to the top surface of the chassis  12  after the vent panel  16  has been removed. The second embodiment of the fan assembly  76  preferably includes three lateral exhaust fans  78  with baffles or cowls  80  to direct heated air from inside the chassis  12  up through the fan assembly  76  and out the rear of the fan assembly  76 , as shown by arrows D.  
         [0064]    [0064]FIG. 12 shows an isometric view of a plurality of chassis  12  stacked in substantially vertical alignment. As shown, the topmost chassis  12 A preferably includes the top-mounted fan assembly  76  mounted to the top surface of the chassis  12 A. The top-mounted fan assembly  76  preferably directs air from the second airflow path B through each of the upper and lower vents  38  of the vertically aligned chassis  12  and out the rear of the top-mounted fan assembly  76  towards the rear of the chassis  12 A, as shown by arrows D. The first airflow path A, as described above is preferably directed from the front of each of the chassis  12 ,  12 A to the rear of each of the chassis  12 ,  12 A.  
         [0065]    Thus, the chassis  12  and modules  14  formed in accordance with the present invention are preferably cascadable to provide a channel or chimney directed along the second airflow path B through each of the chassis  12 ,  12 A for efficient cooling of the electrical components mounted within the modules  14 . This chimney effect may be enhanced by positioning a gasket  77  between adjacent chassis  12  to seal the second airflow path B as it passes vertically from chassis to chassis.  
         [0066]    [0066]FIG. 13A shows a first embodiment of the chassis  12  and module  14  formed in accordance with the present invention, as described above, in which the first airflow path A preferably flows from the front of the chassis  14  to the rear of the chassis  12 , and the second airflow path B preferably flows from the bottom of the chassis  12  to the top of the chassis  12 . The modules  14  are shown as preferably inserted into the front of the chassis  12  substantially parallel to the sides of the chassis  12 . The chassis vents  38  are preferably on the top and bottom of the chassis  12  in the first embodiment.  
         [0067]    [0067]FIG. 13B shows a second embodiment of the chassis  12  and module  14  formed in accordance with the present invention, in which the first airflow path A preferably again flows from the front of the chassis  14  to the rear of the chassis  12 , and the second airflow path B preferably flows from the left side of the chassis  12  to the right side of the chassis  12 . The modules  14  are shown as preferably inserted into the front of the chassis  12  substantially parallel to the top and bottom of the chassis  12 . The chassis vents are preferably on the right and left sides of the chassis  12  in the second embodiment.  
         [0068]    [0068]FIG. 13C shows a third embodiment of the chassis  12  and module  14  formed in accordance with the present invention, in which the first airflow path A preferably flows from the right side of the chassis  14  to the left side of the chassis  12 , and the second airflow path B preferably flows from the bottom of the chassis  12  to the top of the chassis  12 . The modules  14  are shown as preferably inserted into the right side of the chassis  12  substantially parallel to the rear of the chassis  12 . The chassis vents  38  are preferably on the top and bottom of the chassis  12  in the third embodiment.  
         [0069]    It is to be understood that the direction with respect to any of the airflow paths described above may be reversed, which may or may not involve relocating the associated fans, while remaining within the scope of the present invention.  
         [0070]    Thus, the method, chassis, and module formed in accordance with the present invention promote efficient, effective, uniform, and thorough cooling of all components within a computer system, while eliminating dead spots in conventional airflow paths commonly created around oversized or high profile components and assemblies, such as power supplies and disk drives, in computer systems.  
         [0071]    The method, chassis, and module formed in accordance with the present invention also provide dual airflow paths to cool all components mounted within the modules while creating an airflow path or chimney through a plurality of chassis stacked or cascaded in vertical alignment.  
         [0072]    Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention.