US Patent 9525313 Coil tooth assembly

A stator back-iron or rotor back-iron of an electric motor, for receiving coil windings comprises a support (2) with a plurality of teeth (3) radially distributed about the support. The teeth are arranged to receive wire windings and are integrally formed with the support. The teeth and support are formed of laminations. The support further comprises a plurality of engagement means (5) formed between the teeth arranged to receive additional teeth (6) having wire windings mounted thereon. Preferably the engagement means are provided between adjacent teeth. The support and integral teeth provide a rigid structure while the spacing provided by using additional teeth makes it easier to wind coils.