A motor comprising: a stator and a rotor comprising a hole in which a shaft is disposed; wherein the rotor further comprising a rotor core ; a plurality of magnets arranged on a radially outer circumferential surface of the rotor core ; and a cover disposed on a radially outer circumferential surface of the plurality of magnets , wherein the rotor core comprises a plurality of guide protrusions disposed on the radially outer circumferential surface of the rotor core between the plurality of magnets , and wherein a distance from a center of the rotor core to a radially outer circumferential surface of the cover through a center of the guide protrusion is smaller than a distance from the center of the rotor core to the radially outer circumferential surface of the magnet through a center of one of the plurality of magnets , wherein the cover is a can member, wherein the can member comprises a separate first can and a separate second can , each one disposed along an axial direction of the shaft respectively at one end side of the rotor core , characterized in that the first can and the second can are arranged such that a bottom end of a groove portion of the first can which bottom end concavely formed on the outer circumferential surface of the rotor core and disposed between the magnets , comes into contact with a bottom end of a groove portion of the second can which bottom end concavely formed on the outer circumferential surface of the rotor core and disposed between the magnets , and in that the first can and the second can comprise a first weld bead disposed through the bottom end of said groove portion of the first can and the bottom end of said groove portion of the second can . a stator and a rotor comprising a hole in which a shaft is disposed; wherein the rotor further comprising a rotor core ; a plurality of magnets arranged on a radially outer circumferential surface of the rotor core ; and a cover disposed on a radially outer circumferential surface of the plurality of magnets , a rotor core ; a plurality of magnets arranged on a radially outer circumferential surface of the rotor core ; and a cover disposed on a radially outer circumferential surface of the plurality of magnets , wherein the rotor core comprises a plurality of guide protrusions disposed on the radially outer circumferential surface of the rotor core between the plurality of magnets , and wherein a distance from a center of the rotor core to a radially outer circumferential surface of the cover through a center of the guide protrusion is smaller than a distance from the center of the rotor core to the radially outer circumferential surface of the magnet through a center of one of the plurality of magnets , wherein the cover is a can member, wherein the can member comprises a separate first can and a separate second can , each one disposed along an axial direction of the shaft respectively at one end side of the rotor core , characterized in that the first can and the second can are arranged such that a bottom end of a groove portion of the first can which bottom end concavely formed on the outer circumferential surface of the rotor core and disposed between the magnets , comes into contact with a bottom end of a groove portion of the second can which bottom end concavely formed on the outer circumferential surface of the rotor core and disposed between the magnets , and in that the first can and the second can comprise a first weld bead disposed through the bottom end of said groove portion of the first can and the bottom end of said groove portion of the second can . <EOS>