SQUARE TRAJECTORY FORMATION DEVICE AND RECTANGLE TRAJECTORY FORMATION DEVICE

PROBLEM TO BE SOLVED: To provide a square trajectory formation device and a rectangular trajectory formation device that can constitute a mechanism capable of actuating at an extremely high turning speed an object to be actuated, for example, that has to be turned on almost a rectangular moving trajectory. SOLUTION: The square trajectory formation device rotates around an axis of an inner gear 3 by a rotary drive source in a state of being engaged with the inner gear 3. The device comprises a planetary gear 7 that revolves along the inner gear 3 while rotating; and an actuation output shaft 14 arranged at a region that is eccentric relative to an axis c2 of the planetary gear 7. The planetary gear 7 is rotated at a rotational speed three times the speed of the revolution, and turned and moved on almost the square trajectory of the actuation input shaft 14. The rectangular trajectory formation device is constituted by combining at least three sets of the first and second square trajectory formation devices 31, 32 of which the actuation output shafts 38, 41 are turned and moved on almost square trajectories each having sides different in lengths. COPYRIGHT: (C)2004,JPO