Turning drive apparatus for model, and slip gear apparatus

A turning drive apparatus for a model for turning a movable portion of the model by transmitting power from a drive source to the movable portion, comprising:

• a gear train for transmitting power to the movable portion, said gear train comprising:
• a pair of gears;
• and
• a friction transmitting portion being interposed between the pair of gears, the friction transmitting portion using friction force to transmit the power, wherein
• the pair or gears are concentrically coupled with each other through a common slip plate;
• any one of the pair of gears has a hollow portion at a center side of gear, an outer circumference of the slip plate is engaged with an inner periphery of the hollow portion;
• and
• the other gear is combined to the slip plate so that the other gear makes a slip motion in a circumferential direction, thereby the friction transmitting portion is interposed between the other gear and the slip plate;
• wherein
• a radially deformable spring portion disposed on a center side of the slip plate, an inner circumference of the spring portion is engaged with an outer circumference of an axis of the other gear by forming so that a radius of the outer circumference of the axis of the other gear is slightly longer than a radius of the inner circumference of the spring portion.