Patent ID: 7148601

Claim:
A built-up stator assembly, comprising: four magnetic guide members, each of magnetic guide members being formed of a plurality of magnetic sheet plates; wherein, each of the magnetic guide members further comprises: a frame arm extending inward a rib from the center of the inner side thereof with an inner end the rib having an arc shaped magnetic pole part; an end plate, providing a shape similar to the magnetic sheet plates and being attached to two opposite lateral sides of the frame arm respectively; and a coil, being wound to surround the rib and the respective end plate; characterized in that an end of the respective magnetic guide member has first bent joining part, which has a circular projection head with a hook part extending outward to embrace the projection head and another end of the respective magnetic guide member has second bent joining part, which has a circular recess with a hook groove part at two opposite sides of the circular recess corresponding to the projection head and the hook part, such that the four magnetic guide members are capable of being joined to each other as a square shaped stator assembly by way of both the circular projection and the hook part of the first bent joining part engaging with the circular recess and the hook groove part.