[Objective] The driving wheel is a challenge during the reconstruction of Su Song's astronomical clock-tower. Two approaches, the “flip-scoop” and “fixed-scoop” methods, have been identified based on whether the scoop can turn independently. Recent research reports that both options are inevitably inconsistent with the original text, indicating that conformity with the original text is no longer the only criterion for evaluating the merits of these approaches. Therefore, future models should not solely follow these options. New schemes can be designed by learning from their advantages while addressing their shortcomings and components that do not match the original text. Additionally, for museum exhibitions, long-term model stability is crucial. The force data of key components exactly determine the overall stability of the whole model. Therefore, in this study, the force data of some key components in the two schemes are obtained by constructing models in the software and calculations, which will provide valuable references for the reconstruction process. [Methods] This study establishes two models in the software based on the “flip-scoop” and “fixed-scoop” methods according to the original size in Song Dynasty. The force data between the forward upper lock and the driving wheel are calculated using the laws of a rigid body in rotational motion. Subsequently, the pressure between the forward upper lock and the driving wheel is analyzed. [Results] The results revealed that the force between the forward upper lock and the driving wheel was nearly three times higher in the “flip-scoop” model compared with the “fixed-scoop” model. The reason for this disparity was the different structural characteristics between the two schemes. The “fixed-scoop” model incorporated buffering components that reduced the rotation speed of the driving wheel and thus weaken the force between the forward upper lock and the driving wheel. However, the “flip-scoop” model lacked components to help achieve similar effects. More critically, while the driving wheel periodically struck the forward upper lock, it was also subjected to the reaction force of the forward upper lock. In the “fixed-scoop” model, the forward upper lock struck the bottom of the scoop, while in the “flip-scoop” model, the forward upper lock struck the edge of the spoke on the side of the driving wheel. This results in a much smaller spoke impacted contact area in the “flip-scoop” model than in the “fixed-scoop” model, leading to higher pressure on the driving wheel in the “flip-scoop” model than that in the “fixed-scoop” model. Furthermore, this increased pressure exacerbated the potential risk of deformation and damage to the spokes. Additionally, once the pivot wheel was damaged, the influence on the stability of the entire model would be irreversible. [Conclusions] In summary, the differences in the buffering components and the contact areas between the driving wheel and forward upper lock make the driving wheel and forward upper lock in the “fixed-scoop” model suffer less impact and render its operational stability. Future reconstruction models can be designed based on this advantage.
Key words
Su Songs astronomical clock-tower /
driving wheel /
reconstruction /
force analysis
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References
[1]刘仙洲. 中国在计时器方面的发明[J]. 清华大学学报(自然科学版), 1957, 3(2):57-70. LIU X Z. On Chinese invention of time-keeping apparatus[J]. Journal of Tsinghua University (Science and Technology), 1957, 3(2):57-70. (in Chinese)
[2]高宣. 水运仪象台工作原理的研究与复原试验工作[C]//机械技术史(3):第三届中日机械技术史国际学术会议论文集. 昆明, 中国:中国机械工程学会机械史分会, 2002:274-279. GAO X. Work of principle research and reconstruction experiment on the astronomical clock tower[C]//History Mechanical Technology (3):Proceedings of the Third China-Japan International Conference on History of Mechanical Technology. Kunming, China:Chinese Mechanical Engineering Society Mechanical History Branch, 2002:274-279. (in Chinese)
[3]刘蔷. 关于宋代水运仪象台的古文献综考[C]//机械技术史(3):第三届中日机械技术史国际学术会议论文集. 昆明, 中国:中国机械工程学会机械史分会, 2002:265-273. LIU Q. Research on the ancient documents of the astronomical clock tower of Song Dynasty[C]//History of Mechanical Technology (3):Proceedings of the Third China-Japan International Conference on History of Mechanical Technology. Kunming, China:Chinese Mechanical Engineering Society Mechanical History Branch, 2002:265-273. (in Chinese)
[4]高瑄, 陆震, 王春洁, 等. 利用仿真技术对古代水力机械的复原实验[J]. 清华大学学报(自然科学版), 2006, 46(11):1801-1804. GAO X, LU Z, WANG C J, et al. Simulations of the mechanics of ancient hydraulic machines[J]. Journal of Tsinghua University (Science and Technology), 2006, 46(11):1801-1804. (in Chinese)
[5]COMBRIDGE J H. The celestial balance:A practical reconstruction[J]. Horological Journal, 1962(104):82-86.
[6]COMBRIDGE J H. The Chinese water-balance escapement[J]. Nature, 1964, 204(4964):1175-1177.
[7]NEEDHAM J. Science and civilization in China[M]. Cambridge:Cambridge University Press, 1965.
[8]胡维佳. 《新仪象法要》中的"擒纵机构"和星图制法辨正[J]. 自然科学史研究, 1994, 13(3):244-253. HU W J. On the "escapement" and star-mapping in the Xin Yi Xiang Fa Yao[J]. Studies in the History of Natural Sciences, 1994, 13(3):244-253. (in Chinese)
[9]胡维佳. 宋代水运仪象台研究与复原中的两个问题[J]. 自然科学史研究, 2007, 26(3):449-454. HU W J. New problems in the study and reconstruction of the Song Dynasty water-powered armillary sphere and celestial globe tower[J]. Studies in the History of Natural Sciences, 2007, 26(3):449-454. (in Chinese)
[10]张柏春, 张久春. 水运仪象台复原之路:一项技术发明的辨识[J]. 自然辩证法通讯, 2019, 41(4):43-51. ZHANG B C, ZHANG J C. A review of the reconstruction of the Astronomical Clock-tower[J]. Journal of Dialectics of Nature, 2019, 41(4):43-51. (in Chinese)
[11]李志超. 水运仪象志[M]. 合肥:中国科学技术大学出版社, 1997. LI Z C. The astronomical clock tower summarization[M]. Hefei:University of Science and Technology of China Press, 1997. (in Chinese)
[12]唐乐为, 唐晓强, 李铁民, 等. 宋代水运仪象台天柱系统传动特性[J]. 清华大学学报(自然科学版), 2014, 54(11):1497-1501. TANG L W, TANG X Q, LI T M, et al. Driving characteristics of the transmission-shaft system in the Song Dynasty astronomical clock tower[J]. Journal of Tsinghua University (Science and Technology), 2014, 54(11):1497-1501. (in Chinese)
[13]徐思源, 王哲然. 水运仪象台两种复原方案探源[J]. 中国科技史杂志, 2023, 44(2):264-273. XU S Y, WANG Z R. Revisiting the two approaches for the reconstruction of the driving-wheel in Su Song's astronomical clock-tower[J]. The Chinese Journal for the History of Science and Technology, 2023, 44(2):264-273. (in Chinese)
[14]丘光明, 邱隆, 杨平. 中国科学技术史:度量衡卷[M]. 北京:科学出版社, 2001. QIU G M, QIU L, YANG P. The history of science and technology in China (metrology, weights and measures volume)[M]. Beijing:Science Press, 2001. (in Chinese)
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