A Study on an Analysis and Design of the Internal Structure of Heumgyeonggak-nu

In this study, the internal structure of a Heumgyeonggak-nu (欽敬閣漏) was designed, and the power transmission mechanism\udwas analyzed. Heumgyeonggak-nu is an automated water clock from the Joseon Dynasty that was installed within Heumgyeonggak\ud(欽敬閣), and it was manufactured in the 20th year of the reign of King Sejong (1438). As descriptions of Heumgyeonggak-nu in\udancient literature have mostly focused on its external shape, the study of its internal mechanism has been difficult. A detailed\udanalysis of the literature record on Heumgyeonggak-nu (e.g., The Annals of the Joseon Dynasty) indicates that Heumgyeonggaknu\udhad a three-stage water clock, included a waterfall or tilting vessel (欹器) using the overflowed water, and displayed the\udtime using a ball. In this study, the Cheonhyeong apparatus, water wheel, scoop, and various mechanism wheels were designed\udso that 16 fixed-type scoops could operate at a constant speed for the water wheel with a diameter of 100 cm. As the scoop\udcan contain 1.25 l of water and the water wheel rotates 61 times a day, a total of 1,220 l of water is required. Also, the power\udgear wheel was designed as a 366-tooth gear, which supported the operation of the time signal gear wheel. To implement the\udmovement of stars on the celestial sphere, the rotation ratio of the celestial gear wheel to the diurnal motion gear ring was set\udto 366:365. In addition, to operate the sun movement apparatus on the ecliptic, a gear device was installed on the South Pole\udaxis. It is expected that the results of this study can be used for the manufacture and restoration of the operation model of\udHeumgyeonggak-nu