A motor comprising: a shaft ; a rotor to which the shaft is coupled; a stator disposed on an outer side of the rotor , wherein the stator includes a stator core having a plurality of teeth , and a coil wound around each of the teeth, wherein each of the teeth includes a body part around which the coil is wound, a protrusion disposed on an end portion of the body part , and two grooves formed on an inner surface of the protrusion , wherein, in a circumferential direction of the stator core , respective ends of the protrusions of adjacent teeth of the stator core have a distance (W21) therebetween, and each groove has a width (W22) in a range of 1.05 to 1.1 times the distance (W21), wherein the protrusion has a side surface including a first surface extending from the body part and a second surface extending from the first surface , wherein the first surface has a first inclination (θ1) with respect to a side surface of the body part , and the second surface has a second inclination (θ2) with respect to the first surface , wherein the first inclination (θ1) is an obtuse angle of an outer side between the side surface and the first surface of the body part , and the second inclination (θ2) is an obtuse angle of an inner side between the first surface and the second surface , and wherein the grooves are symmetrically disposed based on a reference line (CL) passing through a center of a width of the protrusion in a circumferential direction and a center of the body part , characterized in that a first distance (L21) between the grooves is equal to a second distance (L22) from one end of the protrusion to the groove , wherein a depth (D) of each groove is 0.175 to 0.325 times the distance (W21), wherein the length (L20) of the second surface in a radial direction from an inner edge of the first surface to an edge of the inner surface is 1/4 of the distance (W21), wherein the first inclination (θ1) is in a range of 145° to 155°. a shaft ; a rotor to which the shaft is coupled; a stator disposed on an outer side of the rotor , wherein the stator includes a stator core having a plurality of teeth , and a coil wound around each of the teeth, wherein each of the teeth includes a body part around which the coil is wound, a protrusion disposed on an end portion of the body part , and two grooves formed on an inner surface of the protrusion , wherein, in a circumferential direction of the stator core , respective ends of the protrusions of adjacent teeth of the stator core have a distance (W21) therebetween, and each groove has a width (W22) in a range of 1.05 to 1.1 times the distance (W21), wherein the protrusion has a side surface including a first surface extending from the body part and a second surface extending from the first surface , wherein the first surface has a first inclination (θ1) with respect to a side surface of the body part , and the second surface has a second inclination (θ2) with respect to the first surface , wherein the first inclination (θ1) is an obtuse angle of an outer side between the side surface and the first surface of the body part , and the second inclination (θ2) is an obtuse angle of an inner side between the first surface and the second surface , and wherein the grooves are symmetrically disposed based on a reference line (CL) passing through a center of a width of the protrusion in a circumferential direction and a center of the body part , characterized in that a first distance (L21) between the grooves is equal to a second distance (L22) from one end of the protrusion to the groove , wherein a depth (D) of each groove is 0.175 to 0.325 times the distance (W21), wherein the length (L20) of the second surface in a radial direction from an inner edge of the first surface to an edge of the inner surface is 1/4 of the distance (W21), wherein the first inclination (θ1) is in a range of 145° to 155°. <EOS>