Electric blower and electric apparatus equipped therewith

Abstract

By arranging a power device or devices on the outer face of a partition wall such as a linking portion (flange portion) constituting a flow passage between the exhaust port of a centrifugal fan and a motor, the power device or devices can be efficiently cooled without disturbing the air flow in an air channel within a case and without increasing in pressure loss of the air channel. Moreover, the power device or devices are not affected by heat from the motor since they are positioned farther upstream than the motor, in the air flow from the centrifugal fan.

What is claimed is:  
     
         1 . An electric blower, comprising: 
 a motor having a rotation shaft;    a centrifugal fan fitted to the rotation shaft of the motor, the fan having an exhaust port;    a case for housing the motor and the centrifugal fan, the case including a partition wall constituting an air channel between the exhaust port of the centrifugal fan and the motor; and    a drive circuit including a power device for driving the motor,    wherein the power device is fixed on the outer surface of the partition wall.    
     
     
         2 . An electric blower according to  claim 1 , wherein the case comprises a motor case for housing the motor, and a fan cover covering the centrifugal fan, the fan cover having an outer circumferential wall greater in width than that of the motor case, the partition wall including a linking portion interposing between the outer circumferential wall of the motor case and the outer circumferential wall of the fan cover, wherein the power device is fixed on the linking portion of the partition wall.  
     
     
         3 . An electric blower according to  claim 2 , wherein the motor case includes a cylindrical wall and a flange formed at the edge of the cylindrical wall, the flange acting as the linking portion.  
     
     
         4 . An electric blower according to  claim 2 , wherein the linking portion includes an outer ring shaped plate portion on which the power device is fixed and an inner disk shaped plate portion integrally extending from the inner edge of the outer ring shaped plate portion, the inner disk shaped plate portion having an opening through which air from the exhaust port of the centrifugal fan flows to the motor case.  
     
     
         5 . An electric blower according to  claim 1  further comprising a diffuser located between the centrifugal fan and the motor for rectifying an air flow from the exhaust port of the centrifugal fan toward the motor, the diffuser being opposite to the partition wall, wherein the power device is fixed on a portion of the partition wall opposite to the diffuser.  
     
     
         6 . An electric blower according to  claim 1 , wherein a cooling opening is formed on the case in the vicinity of the power device.  
     
     
         7 . An electric blower according to  claim 1 , wherein the motor is a brushless motor and the drive circuit includes a plurality of the power devices on the partition wall arranged radially on substantially the same circle around the rotation shaft.  
     
     
         8 . An electric apparatus for causing air flow, comprising: 
 an electric blower including;    a motor having a rotation shaft;    a centrifugal fan fitted to the rotation shaft of the motor, the fan having an exhaust port;    a case for housing the motor and the centrifugal fan, the case including a partition wall constituting an air channel between the exhaust port of the centrifugal fan and the motor; and    a drive circuit including a power device for driving the motor,    wherein the power device is fixed on the outer surface of the partition wall.    
     
     
         9 . An electric apparatus comprising: 
 an electric blower including;    a motor having a rotation shaft;    a centrifugal fan fitted to the rotation shaft of the motor,    a case for housing the motor and the centrifugal fan, the case having a fan cover for covering the fan, a motor case for housing the motor, and a partition wall being located between the fan cover and the motor case for constituting an air channel from the fan to the motor, the fan cover having an outer circumferential wall greater in width than that of the motor case;    a drive circuit including a power device for driving the motor;    a blower chamber having a wall for housing the electric blower; and    a supporter located between the wall of the blower chamber and the outer circumferential wall of the fan cover for supporting the electric blower,    wherein the power device is fixed on the outer surface of the partition wall.    
     
     
         10 . An electric apparatus according to  claim 9 , wherein the supporter is made of a vibration absorbing material.  
     
     
         11 . An electric apparatus according to  claim 9 , wherein the supporter is made of thermally insulating material.  
     
     
         12 . An electric apparatus according to  claim 9 , wherein the supporter is made of a heat resisting material.