Brushless motor

Abstract

A brushless motor comprising a housing; a drive shaft rotatably held by the housing; a stator disposed on said housing and having a plurality of coils which are arranged to surround the drive shaft; a yoke secured to the drive shaft to rotate therewith; a plurality of magnets that are held by the yoke in a manner to surround the stator keeping a given space therebetween; an electric parts protecting case on which the housing is mounted; a drive circuit installed in the case for energizing the coils of the stator, the drive circuit including a plurality of switching elements each changing the direction of electric current flowing in the corresponding coil of the stator; a control circuit installed in the case for controlling operation of the switching elements to adjust a rotation speed of the drive shaft; electric connectors for connecting the drive and control circuits; and a heat sink held by the case, the heat sink including a hidden portion exposed to an interior of the case and a plurality of heat radiation fins exposed to the outside of the case, the hidden portion having the switching elements attached thereto. The drive circuit and control circuit are arranged on respective substitutes which are arranged at different positions in the electric parts protecting case. The drive and control circuits are connected through electric connectors.