Patent ID: 6975050

Claim:
A cordless power tool, comprising; a power module for supplying electrical energy to the brushless DC motor; a brushless DC motor for converting electrical energy to mechanical energy, including; a rotor assembly having a rotatable shaft and a permanent magnet affixed to the shaft, said permanent magnet for generating a magnetic field; a winding form enclosing the rotor assembly; a plurality of coils wound upon the winding form for producing a magnetic field for applying a torque to the rotor assembly, said coils including end turns that enclose the rotor assembly such that the rotor assembly is not removable, said end turns arranged to minimize any gap between respective ends of the rotor assembly and the end turns adjacent the respective ends of the rotor assembly, wherein said coils are connected in a three phase delta configuration; a stator stack made of a stator magnetic material for providing a magnetic flux return path for the permanent magnet magnetic field; a position sensor system for sensing the positional relationship between the permanent magnet and the plurality of coils; and a controller, responsive to said position sensor, for controlling the supply of power to the brushless DC motor; and a tool interface for interfacing the DC motor with a tool; and a housing for enclosing the power module, controller and DC motor.