Patent ID: 8264112

Claim:
A motor comprising: a motor frame having an open end at one end thereof and an end plate portion at other end thereof, the motor frame being a magnetic material and being a magnetic constituent portion of the motor; a magnet disposed on an inner surface of the motor frame, wherein the magnet includes at least four poles and has an outer surface conforming to the motor frame and an inner surface forming a circular opening and wherein the width of the magnet between the inner and outer surface varies; a rotor having a shaft and rotatably disposed in the circular opening of the magnet; and an end cap attached to the open end of the motor frame, wherein the motor frame surrounds the magnet and includes four straight portions and at least four connecting portions, wherein each of the connecting portions is located between adjacent two of the four straight portions, wherein the motor frame includes the same number of connecting portions as the number of poles contained in the magnet, wherein each of the connecting portions is a segment of a circle concentric with a center of the shaft, and wherein an air gap provided between the inner surface of the magnet and the rotor has a constant distance.