ENDOSCOPE

摘要

An endoscope, comprising a speed reduction mechanism part (30) having a sun gear (31) formed of a spur gear, three planetary gears (32), a fixed gear (33), and a movable gear (34). The movable gear (34) further comprises internal teeth (34a) formed on the inner peripheral surface thereof and external teeth (34b) formed on the outer peripheral surface thereof. The fixed gear (33) further comprises internal teeth (33a) formed on the inner peripheral surface thereof and engagement grooves (33b) formed on the outer peripheral surface thereof. The number of the internal teeth (33a) of the fixed gear (33) is different a specified quantity from the number of the internal teeth (34a) of the movable gear (34). The fixed gear (33) functions as the fixed gear (33) when en engagement parts (51a) are engaged with the engagement grooves (33b). The external teeth (32a) of the planetary gears (32) are meshed with the external teeth (31a) of the sun gear (31) and the internal gears (33a) and (34a) of the fixed gear (33) and the movable gear (34).