Patent ID: 7112910

Claim:
A brushless DC electric motor comprising a housing, a magnetic rotor and a stator comprising at least one circuit board, wherein: (i) said magnetic rotor comprises a disk installed perpendicularly to a shaft and has circumferentially arrayed magnetic poles; (ii) said circuit board comprises a controlling device and is located parallel to said disk and serves as a part of said housing; (iii) said circuit board on each side comprises one layer of circumferentially arrayed coil windings; (iv) said coil windings of each said layer arranged in pairs, each pair a comprising a spiral formed by a start coil winding and an end coil winding, said spiral extending from a center of a start coil winding to a center of an end coil winding, each spiral having the same turn direction relative to each of said centers; (v) said layers being the same in transparent view with the pairs of coil windings and shifted angularly in such a way that the centers of said start coil windings on one side of said circuit board coincide and are electrically connected by vias with said centers of said end coil windings on the other side of said circuit board; (vi) said magnetic poles having the same magnetic polarity and equal to the number of said pairs of coil windings on the one side of said circuit board; (vii) said rotor comprises at least one ferrous metal plate placed parallel to said rotor disk so that said circuit board is located between the disk and the ferrous metal plate.