Electric rotating machine with stator having core back portions with welding portions

An electric rotating machine with stator having-core back portions with welding portions comprising:

• a housing;
• a stator iron core that includes two or more stacked electromagnetic steel plates and has a core-back portion and tooth portions each extending from the core-back portion toward a radially inside thereof;
• and
• a rotor that is disposed at the radially inside of the stator iron core and is pivotably supported by a stator having the stator iron core,
• wherein the stator iron core is fixed to the housing through shrink-fitting or press-fitting,
• wherein the core-back portion has a welding portion that extends from a stacking-direction end portion along the stacking direction so as to ride on the two or more electromagnetic steel plates,
• wherein the welding portion is provided partly between the both stacking-direction end portions of the core-back portion,
• wherein the welding portion includes:
• a first welding portion formed from one end portion of the core-back portion in the stacking-direction to partway toward the center in the stacking-direction, and
• a second welding portion formed from other end portion of the core-back portion in the stacking-direction to partway toward the center in the stacking-direction,
• wherein the first welding portion being formed such that the welding width gradually decreases as it approaches the center in the stacking-direction from the one end portion, and
• wherein the second welding portion being formed such that the welding width gradually decreases as it approaches the center in the stacking-direction from the other end portion.