Patent Publication Number: US-2007114857-A1

Title: Rotor device

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention is related to a rotor device and particularly to a rotor assembly, which can remove heat generated from running of the rotor.  
      2. Brief Description of the Related Art  
      Referring to  FIGS. 1 , a conventional fan rotor device with heat dissipation structure includes a hub  11  and a case member  12 , which is disposed in the hub  12 . The hub  11  has a closed end  111  and an open end  112  and a lateral wall  113  connects with the closed end  111  and the open end  112 . The closed end  111  provides at least an opening  114  with an inner wall along the axial direction and the case member  12  is closely next to the inner side of the lateral wall  113  and provides a top wall  121  closely next to the closed end Ill of the hub  11 . The top wall  121  provides a through hole  122  with an inner wall extending along an axial direction corresponding to the opening  114  of the hub  11  and a spindle  13  is disposed at the inner side of the top wall  121 . Referring to  FIG. 2 , another conventional fan rotor device with heat dissipation structure almost the same as the fan rotor shown in  FIG. 1  and the difference of the fan rotor shown in  FIG. 2  is in that the hub  21  has a lateral wall  213  and the lateral wall  213  provides a shoulder part  211  extending toward the center of the hub  21  at an end thereof next to the top wall  121 . The shoulder part  211  are arranged not to exceed the through hole  122  of the case member, that is, the hub  21  has a hollow space  212  next to the top wall  121  of the case member  12  to expose the top wall  121  and the through hole  122 . Referring to  FIG. 3 , a further conventional fan rotor device with heat dissipation structure almost the same as the fan rotor shown in  FIG. 1  and the difference of the fan rotor shown in  FIG. 3  is in that the case member  22  provides a lip part  221  toward the center of the case member  22  next to the closed end  111  of the hub  11  and lip part is arranged not to exceed the opening  114  of the closed end  111  with the spindle  23  is disposed at the closed end  111  of the hub  11 .  
      However, a common problem resided in the preceding three conventional rotor devices is explained hereinafter. When the hub ( 11 ,  21 ) and the case member ( 12 ,  22 ) rotate, fluid in the hub ( 11 ,  21 ) and the case member ( 12 ,  22 ) is induced to flow centrifugally such that radial pressure of the fluid increases and fluid in the case member ( 12 ,  22 ) near the lateral wall ( 113 ,  213 ) of the hub ( 11 ,  21 ) increases intensity thereof. Once the density of the fluid is greater than fluid outside the opening  114  and the through hole  121 , the fluid with higher density is capable of moving outward via the opening  113  and the through hole  121 , that is, the fluid changes flow path due to radial pressure thereof increasing. When the fluid passes through the opening  114  and the through hole  121 , the radial pressure has to change to axial pressure during the fluid passing through the opening  114  and the through hole  121  due to the opening  114  and the through hole  121  providing the inner walls thereof being along the axial direction. As a result, impedance is formed to lower velocity of the fluid while the fluid and a lower heat convection efficiency is obtained to degrade heat dissipation effect.  
      Further, US Patent Publication No. 2004/0075356 entitled “FAN ROTOR”, Taiwanese Patent Gazette No. 566751 entitled “ROTOR ASSEMBLY” and Taiwanese Patent Gazette No. 568508 entitled “GOOD SELF HEAT DISSIPATION FAN” disclose a hub or a case member or a hub with a case member provides openings in order to remove heat generated by the rotor and the stator. The inner walls of the these openings are along the axial direction and it is the same as the preceding three conventional rotor device so that heat is unable to flow outward smoothly too.  
     SUMMARY OF THE INVENTION  
      An object of the present invention is to provide a rotor device capable of dissipating heat and resisting foreign objects in which the hub holes offset the through holes in the shield case for preventing the foreign objects from entering the rotor device and for the fluid moving in and out for attaining purposed of heat dissipation.  
      Another object of the present invention is to provide a rotor device in which the hub provides a first opening at the outer surface thereof with a first lateral side corresponding to or exceeding a fourth lateral side of a second opening at the inner surface thereof along X-axis for preventing from foreign objects falling into the hub and allowing fluid passing through the first opening, the second opening and a flow passage communicating with the first and second openings.  
      A rotor device according to the present invention includes a hub and a case member disposed in the hub. The hub has a closed end and an open end with the outer surface of the closed end providing a first opening and the inner surface of closed end providing a second opening. The characteristics are a slant flow passage is disposed between the first opening and the second opening and communicates with the first opening for increasing fluid flow and preventing from foreign objects entering the hub and the case member via the flow passage and the second opening. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The detail structure, the applied principle, the function and the effectiveness of the present invention can be more fully understood with reference to the following description and accompanying drawings, in which:  
       FIG. 1  is a sectional view of the a conventional rotor;  
       FIG. 2  is a sectional view of another conventional rotor;  
       FIG. 3  is a sectional of a further conventional rotor;  
       FIG. 4  is an exploded perspective view of the first embodiment of a rotor according to the present invention;  
       FIG. 5  is a perspective view of the first embodiment of a rotor according to the present invention;  
       FIG. 6  is a sectional view of the first embodiment of a rotor according to the present invention;  
       FIG. 7  is a fragmentary sectional view of illustrating the opening and the through hole shown in  FIG. 6 ;  
       FIG. 8  is a sectional view illustrating the first embodiment of a rotor according to the present invention being applied to a fan motor;  
       FIG. 9  is a sectional view illustrating another type of the first embodiment of a rotor according to the present invention;  
       FIG. 10  is a fragmentary sectional view of illustrating the opening and the through hole shown in  FIG. 9 ;  
       FIG. 11  is a sectional view of the second embodiment of a rotor according to the present invention; and  
       FIG. 12  is a top view of the third embodiment of a rotor according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Referring to  FIGS. 4 and 5 , the first preferred embodiment of a rotor device is illustrated. The rotor device shown in  FIGS. 4 and 5  includes a hub  31  and a case member  32 . The hub  31  has a closed end  311 , an open end  312  and a lateral wall  313  between the closed end  311  and the open end  312  is integrally joined the closed end  311 . The closed end  311  provides at least a first opening  314  at the outer surface thereof and at least a second opening  315  at the inner surface of the closed end. A flow passage  316  is disposed between the first opening  314  and the second opening  315  to communicate both of the openings  314 ,  315 . The flow passage  316  has an oblique shaped passage wall. The respective first opening  314 , the respective second opening  315  and the flow passage  316  are disposed along the circumferential direction and the passage wall of the flow passage  316  is slant outward. It is noted that the flow passage  316  slanting outward is one of the examples and it can be slant in any directions. The case member  32  is next to the hub  31  with a top wall  321  adjoining the closed end  311  and provides at least a through hole  322  corresponding to the second opening  315 . The inner wall of the through hole  322  is slant outward as the flow passage  316  does and a spindle  33  is disposed at the center of the top wall  321  of the case member  32 .  
      Referring to  FIGS. 6 and 7  with reference  FIGS. 4 and 5  again, the first opening  314  has a first lateral side  3141  facing the center of the hub  31  and has a second lateral side  3142  near the periphery of the hub  31 . The second opening  315  has a fourth lateral side  3   152  facing the center of the hub  31  and has a third lateral side  3151  near the periphery of the hub  31 . The first lateral side  3141  is disposed at least corresponding to the third lateral side  3151  or exceeding the third lateral side  3151  along X-axis of the cross section shown in  FIG. 7 . That is, it is impossible to see the inner surface of the second opening  315  from outer surface of the first opening  314  such that the foreign objects is incapable of falling into the hub  31  and the case member  32  directly via the first opening  314  and the second opening  315 .  
      Referring to  FIGS. 7 and 8  in company with  FIG. 4 , a fan frame  34  has a support base  341  therein and the support base  341  has a hollow barrel  342  with a bearing  343  and a retaining ring  344  inside and fitting with a stator  35  outside. A rotor  36  is disposed inside the case member  32  and a plurality of fan blades  37  extending outward from the hub  31 . The spindle  33  passes through the bearing  343  and the retaining ring  344  catches the spindle  33  before the hub  31  and the case member  32  being movably joined to the support base  341  in the fan frame  34  such that the stator  35  is capable of magnetically connecting with the rotor  36 . Once the stator  35  and the rotor  36  are magnetized to drive the hub  31  and the case member  32 , the fan blades  37  rotates to induce fluid moving and relative rotation between the stator  35  and the rotor  36  physically changes from magnetic action to kinetic energy and then changes to heat energy. Under this circumference, it results in fluid in the hub  31  and the case member  32  increases temperature and radial pressure thereof and moves toward periphery of the case member  32  centrifugally. The fluid with greater radial pressure is capable of passes through the first opening  314 , the second opening  315 , the flow passage  316  and the through hole  322  to flow outward smoothly due to the flow passage  316  communicating with the first opening  314  and the second opening  315  and the inner wall of the through hole  314  being slant for promoting flow velocity and enhancing efficiency of convection. In addition, the temperature risen fluid is capable of lowering temperature thereof largely to promote heat dissipation effect thereof such that deficiency resulting from the openings and the through hole being along the axial direction and the fluid being unable to pass through the openings and the through hole smoothly and rapidly can be overcome completely. Further, the first lateral side  3141  of the first opening  314  being disposed at least corresponding to the third lateral side  3151  or exceeding the third lateral side  3151  along X-axis of the cross section prevents the foreign objects falling into the hub  31  and the case member  32  directly via the first opening  314  and the second opening  315  for avoiding running between the stator  35  and the rotor  36 .  
      Referring to  FIGS. 9 and 10 , the inner wall of the through hole  322  in the case member  32  can be arranged to be non-slant and the same effect can be achieved as well.  
      Referring to  FIG. 11 , the second embodiment of a rotor device according to the present invention is illustrated. The second embodiment is almost the same as the first embodiment in structure, function and implement and the identical parts are designated with the same reference number and no details will be described further. The difference of the present embodiment is in that the case member  42  provides a projection  4211  extends toward the center thereof but not exceeds the opening  314  and the spindle  43  is attached to the closed end of the hub  31 .  
      Referring to  FIG. 12 , the third embodiment of a rotor device according to the present invention is illustrated. The second embodiment is almost the same as the first embodiment in structure, function and implement and the identical parts are designated with the same reference number and no details will be described further. The difference of the present embodiment is in that the openings  514  at the closed end  311  of the hub  31  are disposed along radial direction.  
      In addition, the openings at the closed end  311  of the hub  31  can be arranged in a direction other than the opening  314 , which is along circumferential direction, and the opening  514 , which is along radial direction, to achieve the preceding functions and effects as well.  
      While the invention has been described with referencing to preferred embodiments thereof, it is to be understood that modifications or variations may be easily made without departing from the spirit of this invention, which is defined by the appended claims.