Patent attributes
A motor stator includes a stator core (500) and a stator coil. The stator core includes a central cylinder (501) and a plurality of posts (503) extending from the central cylinder. Each post is connected with a magnetic pole (505). The post has a smaller height than the central cylinder and the magnetic pole whereby a recess (507) is formed above the post between the central cylinder and the magnetic pole. The stator coil is received in the recess and wound around the post. The stator core is integrally made from ferromagnetic powder by powder metallurgy technique. Each particle of the powder includes an inner core (12) made of magnetic material and an outer shell (14) surrounding the inner core. The shell has a higher electrical resistance than the inner core.
