A
stator punched plate of a single-phase
direct current brushless motor comprises a
stator punched plate body and is characterized in that the inner arc of the
stator punched plate body is in a step tooth shape, an asymmetrical continuous arc shape or an eccentric circular arc shape, the circular arc of the inner arc is transited by an offset circular arc, the offset direction is directed to a corresponding stator tooth portion, the
radius of the offset circular arc is R, the
radius of the stator inner arc before offset is R0, the center of a circle offset circle
radius of the offset circular arc is r, the circle center offset angle of the offset circular arc with a central axis serving as a basic reference is alpha, the
offset distance of the intersection point between the offset circular arc and the stator tooth central axis of the stator punched plate is e, the relations among the R, the R0, the r, the alpha and the e conform to a cosine law, and the radius of the offset circular arc can be determined. According to the stator punched plate of the single-phase
direct current brushless motor, an optimized stator
punching inner arc structure is utilized, the
flux density distribution in air gaps of the
punching structure which is a step tooth shape and a continuous arc shape tooth is rearranged, the flux density transition tends to be even, the starting torque is improved by about 14.48%, the average output torque is improved by 0.6%, the torque pulsation is decreased by 2.1%, the
electromagnetic noise and vibration of a motor are improved, and the efficiency of the motor is increased.