Abstract: An inexpensive and high efficiency power transmission method and device with a simple structure for converting a rotational motion into a linear motion in accordance with a load is provided. A feed screw (21) and a female screw (22) having a larger diameter than the feed screw are engaged in an eccentric manner. A counterforce from a work is detected by a helical spring (28). Then, rotation restraint of the female screw (22) engaged in an eccentric manner is released, and the female screw (22) is rotated. The feed screw (21) and the female screw (22) rotate in a differential manner so that traveling speed is decreased and that pressing force is increased.

Abstract: An inexpensive and high efficiency power transmission method and device with a simple structure for converting a rotational motion into a linear motion in accordance with a load is provided. A feed screw (21) and a female screw (22) having a larger diameter than the feed screw are engaged in an eccentric manner. A counterforce from a work is detected by a helical spring (28). Then, rotation restraint of the female screw (22) engaged in an eccentric manner is released, and the female screw (22) is rotated. The feed screw (21) and the female screw (22) rotate in a differential manner so that traveling speed is decreased and that pressing force is increased.