Patent attributes
An electric power tool includes a housing, a motor disposed in the housing, a planetary gear reduction mechanism and an internal gear. The planetary gear reduction mechanism includes multi-stage planetary gears, multi-stage carriers each configured to carry a plurality of planetary gears, and a bearing assembled with a final-stage carrier from a rear side of the final-stage carrier to rotatably support the final-stage carrier. The internal gear is configured to be rotatable and axially slidable while allowing planetary motion of final-stage planetary gears supported by the final-stage carrier. A gear portion provided on the final-stage carrier is formed as a separate gear which is assembled with the final-stage carrier from the rear side of the final-stage carrier after assembling the bearing with the final-stage carrier.