Electronic component cooling apparatus

Abstract

An electronic component cooling apparatus comprises a so-called water-cooled heat sink, a radiator to be cooled by a motor-driven fan, first and second coolant paths for circulating a coolant between the heat sink and the radiator, and a motor-driven pump for giving a moving energy to the coolant. A plurality of engaging pieces of the motor-driven fan and a plurality of engaged portion of the radiator are engaged to connect the motor-driven fan and the radiator.

1 . A motor-driven pump used in an electronic component cooling apparatus, comprising: 
 a rotor having a rotating body, a plurality of rotary side magnetic poles and a shaft, the rotating body having a cylindrical peripheral wall portion and a closing wall portion integrally formed with the peripheral wall portion to close one end of an inner space enclosed by the peripheral wall portion, the rotary side magnetic poles being formed from permanent magnets and arranged on an inner peripheral surface of the peripheral wall portion, the shaft being fixed at one end thereof to a center of the closing wall portion and extending through a center of the peripheral wall portion;    a bearing rotatably supporting the shaft;    a cylindrical bearing holder in which the bearing is fitted and held;    a stator having a stator core mounted on an outer periphery of the bearing holder and arranged inside the rotating body and a plurality of excitation coils wound around the stator core;    an exciting current supply circuit for supplying an exciting current to the plurality of excitation coils;    a waterproof structure including a seal member for watertightly closing one of open ends of the bearing holder which does not face the closing wall portion of the rotating body, the waterproof structure being adapted to waterproof the stator and the exciting current supply circuit;    an impeller having a blade mounting portion arranged on at least the closing wall portion of the rotating body and a plurality of blades provided at the blade mounting portion; and    a housing having a liquid inlet and a liquid outlet and accommodating therein elements such as the rotor, the impeller and the stator,    wherein when the rotor, the impeller and the bearing are submerged in the coolant and the impeller is rotated, the housing draws in the liquid coolant through the liquid inlet and discharges it from the liquid outlet.    
   
   
       2 . The motor-driven pump as defined in  claim 1 , wherein the closing wall portion of the rotating body is formed with one or more through-holes extending therethrough in a thickness direction thereof to allow the coolant to flow through the closing wall portion.  
   
   
       3 . The motor-driven pump as defined in  claim 2 , wherein the blade mounting portion of the impeller has a portion that faces almost entirely the closing wall portion of the rotating body, and the portion is formed with one or more through-holes aligned with the one or more through-holes.  
   
   
       4 . The motor-driven pump as defined in  claim 1 , wherein the blade mounting portion of the impeller has a cylindrical extended mounting portion extending along the peripheral wall portion of the rotating body, and the plurality of blades are each shaped to extend continuously from over the blade mounting portion to over the cylindrical extended mounting portion.  
   
   
       5 . A motor-driven pump usable in an electronic component cooling apparatus, comprising: 
 a rotor having a rotating body, a plurality of rotary side magnetic poles and a shaft, the rotating body having a cylindrical peripheral wall portion and a closing wall portion integrally formed with the peripheral wall portion to close one end of an inner space enclosed by the peripheral wall portion, the rotary side magnetic poles being formed from permanent magnets and arranged on an inner peripheral surface of the peripheral wall portion, the shaft being fixed at one end thereof to a center of the closing wall portion and extending through a center of the peripheral wall portion;    two bearings spaced from each other in an axial direction of the shaft to rotatably support the shaft;    a cylindrical bearing holder in which the two bearings are fitted and held;    a retainer mechanism arranged between the other end of the shaft and one of the two bearings which is situated on an opposite side to the closing wall portion and adapted to prevent the shaft from coming off;    a stator having a stator core mounted on an outer periphery of the bearing holder and arranged inside the rotating body and a plurality of excitation coils wound around the stator core;    an exciting current supply circuit for supplying an exciting current to the plurality of excitation coils;    a waterproof structure including a seal member for watertightly closing one of open ends of the bearing holder which does not face the closing wall portion of the rotating body, the waterproof structure being adapted to waterproof the stator and the exciting current supply circuit;    an impeller having a blade mounting portion arranged on at least the closing wall portion of the rotating body and a plurality of blades provided at the blade mounting portion; and    a housing having a liquid inlet and a liquid outlet and accommodating therein elements such as the rotor, the impeller and the stator,    wherein when the rotor, the impeller and the two bearings are submerged in the coolant and the impeller is rotated, the housing draws in the liquid coolant through the liquid inlet and discharges it from the liquid outlet.    
   
   
       6 . The motor-driven pump as defined in  claim 5 , wherein at least one liquid path extending along the shaft is formed between an inner peripheral surface of the bearing holder and an outer peripheral surface of each of the two bearings.  
   
   
       7 . The motor-driven pump as defined in  claim 6 , wherein at least one groove extending along the shaft is formed in that portion of the inner peripheral surface of the bearing holder which faces the outer peripheral surface of the bearings, and the groove constitutes the liquid path.  
   
   
       8 . The motor-driven pump as defined in  claim 7 , wherein a plurality of the grooves are formed at equal intervals in a peripheral direction.  
   
   
       9 . The motor-driven pump as defined in  claim 7 , wherein the inner peripheral surface of the bearing holder is formed with one or more narrow elongate grooves that extend along the shaft and face the outer peripheral surfaces of the two bearings, respectively, and the one or more narrow elongate grooves constitute the liquid path.  
   
   
       10 . The motor-driven pump as defined in  claim 6 , wherein the bearings are ball bearings.