Abstract: A worm wheel is installed inside a wheel accommodation chamber of a body casing; a motor is fastened by screws from the right side perpendicular to the axis line of the worm wheel, thus forming a motor fastening part; and a worm fixed to an output shaft of the motor is engaged with the worm wheel. A board accommodation chamber is formed so as to be adjacent to the right of the wheel accommodation chamber, and a control board is inserted inside the board accommodation chamber from below. The control board is disposed so as to be inclined in a direction in which the upper end of the control board is displaced toward the wheel accommodation chamber from an erect attitude perpendicular to the axis line of the output shaft of the motor, and thus the upper end is separated from the motor fastening part in the direction of the axis line of the output shaft.

Abstract: A worm wheel is installed inside a wheel accommodation chamber of a body casing; a motor is fastened by screws from the right side perpendicular to the axis line of the worm wheel, thus forming a motor fastening part; and a worm fixed to an output shaft of the motor is engaged with the worm wheel. A board accommodation chamber is formed so as to be adjacent to the right of the wheel accommodation chamber, and a control board is inserted inside the board accommodation chamber from below. The control board is disposed so as to be inclined in a direction in which the upper end of the control board is displaced toward the wheel accommodation chamber from an erect attitude perpendicular to the axis line of the output shaft of the motor, and thus the upper end is separated from the motor fastening part in the direction of the axis line of the output shaft.