Patent ID: 8042415

Claim:
A motion converting drive mechanism that converts a rotary motion into a linear reciprocating motion, comprising: a motor having an output shaft; a housing case in which the output shaft of the motor is rotatably mounted; a reduction gear mechanism including a first pinion that is a gear wheel having two to four teeth, that is rotatably supported by the housing case therein, and that includes a shaft that is connected to the output shaft of the motor such that an axis of rotation of the first pinion is coaxial with an axis of rotation of the motor, a second pinion that meshes with the first pinion, and that is rotatably supported by the housing case therein such that an axis of rotation of the second pinion is parallel to the axis of rotation of the first pinion; and a screw mechanism having an internal threaded portion and a lead screw with an external threaded portion, one of the internal threaded portion and the external threaded portion being integrally and coaxially formed with the second pinion and including an axis of rotation that is parallel to the axis of rotation of the motor, the other of the internal threaded portion and the external threaded portion being configured to linearly and axially reciprocate in synchronization with rotation of the one of the internal threaded portion and the external threaded portion, the other of the internal threaded portion and the external threaded portion remaining parallel to the axis of rotation of the motor throughout an entire range of motion of the other of the internal threaded portion and the external threaded portion; wherein the lead screw is arranged in a condition where a projected area of the lead screw overlaps a projected area of the motor in a direction parallel to the axis of rotation of the motor.