Abstract: The present invention relates to a power drill which comprises a spindle and a rear bearing mounted on the rear portion of the spindle. A fixed gear wheel is connected to a gearbox and a movable gear wheel is connected to the spindle. An adjustment member is provided on the front portion of the spindle. The adjustment member comprises an adjustment cover, an adjustment fork connected to the adjustment cover and a sleeve connected to the adjustment fork and mounted on the front end of the spindle. On the sleeve is provided a groove. A stroke adjustment member on which is provided a protruding block is disposed between the movable gear wheel and the sleeve. A stopper whose radial dimension is greater than the spindle is disposed on the front portion of the spindle. A plane bearing is disposed between the front end of the sleeve and the rear end of the stopper and is provided with a retainer for receiving a rolling element.