Patent ID: 8421282
Filing Date: 2013-04-16
Classification: H02K

Abstract:
1. A power tool comprising a brushless motor, the power tool performing a predetermined operation by rotationally driving a tool bit by the brushless motor, wherein the brushless motor includes a rotor having a permanent magnet, a cylindrical stator, and three-phase stator windings which are installed on an inner circumferential side of the stator and rotationally drive the rotor, a plurality of slots are formed in an inside surface of the stator at predetermined intervals in a circumferential direction and each of the three-phase stator windings is formed by a plurality of coils wound through the slots of the stator and connected to each other, the number of turns of the coils is adjusted to control the output characteristic of the brushless motor, and the number of turns of the coils is adjusted such that the total number of turns of the coils wound through the slots in each phase is the same in the three phases and not a multiple of the number of the slots in each phase.