Stator structure of motor and its forming method

A stator comprising:

• a ring;
• N pieces of unbent first salients spacedly connected to said ring and located on a first plane to serve as upper salients;
• and
• N pieces of second salients longer than said first salients and bent to form N pieces of lower salients and N pieces of waist posts, said N pieces of lower salients being spaced at intervals and located on a second plane, said N pieces of waist posts being arranged between said first and second planes for forming a magnetically conductive path, wherein one end of each of said waist posts is connected to said ring within an interval between two adjacent upper salients and the other end is connected to a corresponding one of said N pieces of lower salients located between said two adjacent upper salients, said upper and lower salients being separated by a distance along an axial direction of said waist posts sufficient to reduce magnetic leakage between said upper and lower salients;
• a pair of coils twining around said waist posts and positioned so that a line passing radially outward through said coils and perpendicular to said axial direction of said waist posts does not intersect said first or second salients;
• an insulator sheathed on said N pieces of upper and lower salients and said N pieces of waist posts for prohibiting the contact of said pair of coils with said stator structure;
• a circuit board positioned under said N pieces of lower salients;
• and
• a stator bracket engaged with said ring for securing said stator structure thereon;
• wherein N is an integer greater than 1.

A method for forming a stator structure comprising the steps of:

• (a) integrally forming a hollow cogged plate consisting of a first ring, N pieces of short, and N pieces of long salients alternately connected to said first ring;
• and
• (b) bending said N pieces of long salients to form said stator structure having N pieces of waist posts, N pieces of lower salients, and N pieces of upper unbent salients, wherein said lower and upper salients are separated by a distance along an axial direction of said waist posts sufficient to reduce magnetic leakage between said lower and upper salients;
• wherein N is an integer greater than 1.