Fan comprising an electronically commutated drive motor

Abstract

A fan having an electronically commutated drive motor ( 27 ) has a bearing tube ( 62 ) having an inner side and an outer side. The internal stator of the drive motor ( 27 ) is arranged in the region of the outer side. An external rotor ( 28 ) of said motor interacts during operation with the internal stator ( 72 ). Fan blades ( 26 ) of the fan ( 22 ) are arranged on the outer periphery of the external rotor ( 28 ). Bearing elements ( 52, 54 ), by means of which a shaft ( 46 ) connected to the external rotor ( 28 ) is journaled, are arranged on the inner side of the bearing tube ( 62 ). Conduits ( 90 ), which enable coolant to flow through the bearing tube ( 62 ) during operation of the fan ( 22 ), are provided in the bearing tube ( 62 ).

1 . A fan comprising
 an electronically commutated drive motor ( 27 ) having an internal stator ( 72 ) and an external rotor ( 28 ) cooperating therewith, said external rotor being supported by a central shaft ( 46 ) connected therewith;   a plurality of fan blades ( 26 ) being arranged on an outer periphery of said external rotor ( 28 ); and   a bearing tube ( 62 ) having an outer side ( 63 ) and an inner side ( 61 ), a plurality of bearings ( 52 , 54 ) being arranged on said inner side ( 61 ), journaling said central shaft ( 46 ) for rotation therein;   wherein   the bearing tube ( 62 ) includes, between said outer side ( 63 ) and said inner side ( 61 ), a wall formed with cooling conduits ( 90 ), enabling streaming of coolant through the wall,   said inner side ( 60 ,  66 ) of said bearing tube separating said cooling conduits ( 90 ) from said bearings ( 52 ,  54 ) arranged within said bearing tube ( 62 ).   
     
     
         2 . (canceled) 
     
     
         3 . (canceled) 
     
     
         4 . (canceled) 
     
     
         5 . (canceled) 
     
     
         6 . (canceled) 
     
     
         7 . (canceled) 
     
     
         8 . (canceled) 
     
     
         9 . (canceled) 
     
     
         10 . (canceled) 
     
     
         11 . (canceled) 
     
     
         12 . (canceled) 
     
     
         13 . The fan according to  claim 1 , wherein
 the bearing tube ( 62 ) is formed, at least in part, of plastic material.   
     
     
         14 . The fan according to  claim 1 , wherein
 said cooling conduits ( 90 ) in said bearing tube wall ( 59 ) are arranged in a pattern whose cross-section resembles a honeycomb.   
     
     
         15 . The fan according to  claim 1 , wherein said bearing tube ( 62 ) is arranged on a flange ( 70 ) oriented generally perpendicular to an axis of said bearing tube, and at least some of said cooling conduits ( 90 ) extend axially through said flange ( 70 ). 
     
     
         16 . The fan according to  claim 1 , wherein, in said wall ( 59 ) of said bearing tube ( 62 ), a plurality of carrier segments or ribs ( 92 ) are provided, each extending radially from said inner side ( 61 ) to said outer side ( 63 ). 
     
     
         17 . The fan according to  claim 16 , wherein, measured in a circumferential direction, an average angular extent of said cooling conduits ( 90 ) exceeds an average angular extent of said carrier segments ( 92 ) by a factor of 1.5 to 3. 
     
     
         18 . The fan according to  claim 1 , wherein
 bearing seats ( 64 ) for said bearings ( 52 ,  54 ) are formed on said inner side ( 61 ) of said bearing tube ( 62 ).   
     
     
         19 . The fan according to  claim 1 , wherein
 said fan, when operating, creates a pressure differential between a first longitudinal end of said cooling conduits ( 90 ) and a second longitudinal end thereof, thereby causing cooling air to stream ( 94 ) through said cooling conduits ( 90 ).   
     
     
         20 . The fan according to  claim 1 , wherein said external rotor ( 28 ) has a bell configuration, with an internal center, to which said central shaft ( 46 ) is attached. 
     
     
         21 . The fan according to  claim 20 , wherein the shaft ( 46 ) is cast into a recess formed on the inside of the rotor bell. 
     
     
         22 . The fan according to  claim 21 , wherein
 a radial fan wheel ( 48 ) is implemented from the material with which the shaft ( 46 ) is cast into the recess at the base of the bell, which fan wheel has the function of distributing, in the region of the base of the bell, coolant flowing out of the conduits ( 90 ) provided in the bearing tube ( 62 ).   
     
     
         23 . The fan according to  claim 20 , wherein, to facilitate the discharge of coolant from the fan ( 22 ), a gap ( 100 ) is provided, past which air moved ( 34 ) by said fan blades ( 26 ) passes, thereby creating an underpressure adjacent this gap ( 100 ). 
     
     
         24 . The fan according to  claim 23 , wherein said gap ( 100 ) is defined by a spacing between said flange ( 70 ) and a circumferential rim of said bell-shaped rotor ( 28 ), and passage of air from said fan blades ( 34 ) causes a Venturi effect, entraining coolant exiting ( 98 ) via said gap ( 100 ).