Motor rotor with surface treatment

A motor rotor comprising:

• a magnet that is disposed around a rotation shaft, wherein the magnet has a cylindrical shape that extends continuously in a circumferential direction of the rotation shaft;
• a protective layer that is disposed around the magnet without contacting the magnet, wherein the protective layer has a cylindrical shape that extends continuously in the circumferential direction;
• and
• a middle resin portion to bond the magnet with the protective layer, wherein the middle resin portion has a cylindrical shape that extends continuously in the circumferential direction between the magnet and the protective layer.

A method for manufacturing a motor rotor comprising:

• disposing a cylindrical magnet disposed around an inner sleeve to form a first gap between the inner sleeve and the magnet;
• disposing a cylindrical protective layer around the magnet to form a second gap between the protective layer and the magnet;
• injecting a resin by a first insert injection-molding to form an inner resin portion in the first gap, and to partially form an end resin portion to cover an end surface of the magnet in an axial direction of the inner sleeve;
• and
• injecting a resin by a second insert injection-molding to form a middle resin portion in the second gap, and to form a remaining part of the end resin portion.