Handiwork instrument using coreless brushless motor

Abstract

The present invention locates the gravity of a handiwork instrument at the front part by deposing a rotation device right after a tool of the instrument, so that its size is reduced, its operation becomes easier, and its handling is firmed.

1 . A handiwork instrument using a coreless brushless motor, comprising: 
 (a) a handle unit;    (b) a transmission device, said transmission device deposing at an end of said handle unit, said transmission device having a shell fixed to said handle unit, said shell having an axle movably deposed at center of said shell, a coreless wired stator deposing on said axle, said coreless wired stator connecting to a power supply unit to obtain an outside power, said shell having two collar plate inside said shell corresponding to two end surfaces of said coreless wired stator, a permanent magnet deposing on at least one collar plate, said permanent magnet corresponding to said coreless wired stator;    (c) a sensing unit, said sensing unit sensing a pole of said coreless wired stator, said pole corresponding to a pole of said permanent magnet; and    (d) a chuck seat, said chuck seat connecting to said axle of said transmission device, a working unit deposing on said chuck seat.    
   
   
       2 . The instrument according to  claim 1 , 
 wherein said handle unit is ‘L’ shaped.    
   
   
       3 . The instrument according to  claim 1 , 
 wherein said handle unit is cylinder shaped having a concaves part at a place for hand-holding.    
   
   
       4 . The instrument according to  claim 1 , 
 wherein said handle unit is cylinder shaped having a cross handle at an end of said handle unit.    
   
   
       5 . The instrument according to  claim 1 , 
 wherein said handle unit is cylinder shaped having a grasp handle at a side of said handle unit.    
   
   
       6 . The instrument according to  claim 1 , 
 wherein said sensing unit connects to an inverter deposed in said handle unit to recieve a pole of said coreless wired stator sensed by said sensing unit; and    wherein said sensing unit controls a phase change of said coreless wired stator.    
   
   
       7 . The instrument according to  claim 6 , 
 wherein said inverter has a detecting unit inside said inverter to receive a counter-electromotive force (CEMF).    
   
   
       8 . The instrument according to  claim 1 , 
 wherein said sensing unit is a Hall element; and    wherein said Hall element is deposed in said shell at a place corresponding to said coreless wired stator.    
   
   
       9 . The instrument according to  claim 1 , 
 wherein said sensing unit processes a phase change of said coreless wired stator according to a CEMF of a coil of said coreless wired stator.    
   
   
       10 . The instrument according to  claim 1 , 
 wherein said transmission device connects to a control unit deposed on said handle unit;    wherein a circuit is obtained through said control unit and said transmission device to control a rotation speed of said transmission device.    
   
   
       11 . The instrument according to  claim 10 , 
 wherein said control unit comprises a plurality of switches controlling rotation speeds of said transmission device; and    wherein an open loop is obtained through said transmission device and said control unit.    
   
   
       12 . The instrument according to  claim 10 , 
 wherein said control unit comprises a tachometer, connecting to said axle of said transmission device, and a differential amplifier, connecting to said tachometer and said inverter.