Stator assembly for a brushless motor in a power tool

Abstract

A power tool includes a brushless DC motor having a stator and a rotor pivotably arranged inside the stator, the stator including a first winding, a second winding, and a third winding. Each winding is arranged at at least two opposite poles connected together. The stator windings may be connected in a delta configuration by electrically coupling adjacent terminals of the first and second windings, second and third windings, and third and first windings at three connection points. A baffle may be provided in parallel and adjacent to the stator, the baffle including at least one conductive routing or stamping to facilitate electrically coupling the first, second, and third windings in at least one of a delta or a wye configuration.

1 . A power tool comprising:
 a housing;   a brushless DC motor housed inside the housing, the motor comprising a stator and a rotor pivotably arranged inside the stator, the stator comprising a first winding, a second winding, and a third winding, each said winding arranged at at least two opposite poles connected together around the stator, wherein the at least three stator windings are connected in a delta configuration by electrically coupling adjacent terminals of the first and second windings, second and third windings, and third and first windings at three connection points.   
     
     
         2 . The power tool of  claim 1 , wherein each of the first, second, and third windings are associated with a first and second terminals on the stator, the first terminal of each winding being located adjacent to the second terminal of another winding. 
     
     
         3 . The power tool of  claim 1 , further comprising a baffle arranged adjacent the stator. 
     
     
         4 . The power tool of  claim 3 , wherein the baffle comprises a plurality of metal routings or stampings to facilitate the electric couplings of the adjacent terminals of the first and second windings, second and third windings, and third and first windings at the three connection points. 
     
     
         5 . The power tool of  claim 1 , wherein the motor further comprises a bus bar having a plurality of input terminals adapted to be coupled to a power source. 
     
     
         6 . The power tool of  claim 5 , wherein the plurality of input terminals is coupled to the three connection points. 
     
     
         7 . The power tool of  claim 5 , wherein the bus bar comprises a plurality of conductive plates corresponding to the plurality of input terminals separated by a plurality of insulating channels. 
     
     
         8 . The power tool of  claim 7 , wherein each conductive plate includes a first hook for facilitating a connection to one of the connection points of the windings and a second hook for facilitating a connection to the power source. 
     
     
         9 . The power tool of  claim 5 , wherein the bus bar is arranged on a periphery of the stator. 
     
     
         10 . The power tool of  claim 1 , wherein the pole designation of at least one of the first, second, or third windings is swapped to facilitate connecting adjacent terminals of the first and second windings, second and third windings, and third and first windings at the three connection points in the delta configuration.