Patent 7942779 was granted and assigned to Nabtesco Corporation on May, 2011 by the United States Patent and Trademark Office.
To facilitate an integrating operation and to make fabricating cost inexpensive. An idle gear for transmitting rotation of an input gear of a drive motor to a cylindrical gear is rotatably supported by an input side end portion of a specific one crank pin, and therefore, the idle gear may simply be supported by the crank pin, further, a length in an axial direction of the cylindrical gear brought in mesh with both of the idle gear the input gear is sufficiently to a degree of being more or less longer than a distance between remote side ends of the two gears.