Eccentric rotor and vibration motor using such eccentric rotor

An eccentric rotor rotatable about a shaft comprising a commutator substrate having a plurality of commutator segments, armature coils on said substrate, a bearing receiving said shaft and having at least one cylindrical section having an outer diameter, a weight, an integral resin molded structure which integrally molds together said substrate, said armature coils, said bearing and said weight, said rotor having a first outer side and a second outer side, said weight having a first outer face defining a part of said first outer side and a second outer face defining a part of said second outer side, said substrate having an outer surface substantially coplanar with said second outer face of said weight;

• wherein said weight has an outer radial section and an inner radial section, said first and second outer faces of said weight being formed on said outer radial section, said outer radial section having a first axial thickness defined by the axial distance between said first and second outer faces of said weight, said inner radial section or said weight having a second axial thickness less than said first axial thickness;
• and
• wherein said inner radial section has a first side and a second side, said resin molded structure comprising a first structure part on said first side of said inner radial section and a second structure part on said second side of said inner radial section.