Design and Development of Viscous brake Device for Power Measurement of Dental Handpiece

高速牙醫手持鑽機(簡稱牙醫手機)，近十幾年來已被廣泛的應用於口腔醫療產業。針對牙醫手機性能的量測技術，則是世界各國製造廠商在研究追求高穩定、高性能的牙醫手機時，不可缺少的重要關鍵。 本論文之目標為設計開發針對牙醫手機之特性，即時擷取其動態扭力矩與轉速等性能之檢測裝置。量測系統以接觸式液體黏滯力為原理，此量測原理避免了一般摩擦煞車式扭矩量測中易出現的滑跳現象與剛性接觸之振動。藉由控制溫度變化與主軸浸入液體深度，調整作用於牙醫手機主軸上之煞車扭矩，增長高速牙醫手機之煞停時間。如此於牙醫手機之動力量測過程中，可穩定記錄其動力變化，確實了解牙醫手機在不同操作情況下的性能表現。 系統之量測目標為現有牙醫手機筒匣。由建構黏滯理論開始，導入模組化之概念，逐步完成實體設計。並藉由理論分析與有限元素法模擬，探討設計和操作參數對產生之黏滯煞車力矩之影響，進一步找出適當之設計參數。 完成之牙醫手機動力量測平台，黏滯式煞車單元扭矩傳遞效率平均可達80%；煞車力矩量測單元部分，透過像散式讀取頭之微米級位移量測，可實現量測微小扭力矩之目標。其量測範圍為0~8.54 Nmm，解析度可達0.187 Nmm，敏感度為1.0265 Nmm/V，線性誤差為2.19 %。The performance measuring technology for high-speed dental handpiece, has become an essential solution for worldwide manufacturer pursuing more stable and high performance products. The aim of this thesis is to design and develop a measuring system, which focus on the characteristic of high-speed dental handpiece, and can acquire its dynamic torque as well as its rotational speed simultaneously. With the principle of contact viscous force of fluid, the stick-slip phenomenon and vibration which are often occur on the fiction-brake type of measurement system can be avoided. Through controlling the liquid medium temperature and the shaft immersion depth, we can regulate the braking torque value along with its acting time on the spindle of dental handpiece cartridge. The power output of dental handpiece could be recorded continuously throughout its measuring process, and its performance can be practically analysis with diverse operating condition. To measure the dental handpiece cartridge, this thesis begins with deriving the theoretical background of viscous theory. With the modular concept, the structural design of measuring system had been constructed. The appropriate design parameter had been obtained through the optimization by simulation with FEA, CFD and theoretical analysis. The average transmitting efficiency of viscous braking unit of the novel measuring platform for dental handpiece, can reach to 80%. By applying the astigmatic DVD pickup head, the braking torque measuring unit can achieve its objective of measuring micro-torque, with the total measuring range from 0 to 8.54 Nmm, the resolution of 0.187 Nmm, the sensitivity of 1.0265 Nmm/V, and linear error of 2.19 %.致謝 III 中文摘要 IV 英文摘要 V 目錄 VI 表目錄 IX 圖目錄 X 符號表 XIII 第一章 緒論 1 1.1研究背景與動機 1 1.2文獻回顧 2 1.3研究目標及論文內容摘要 7 第二章 牙醫高速手機與性能量測方法 8 2. 1牙醫手機簡介 8 2. 2扭力矩特性與量測方法 9 2. 3轉速特性及量測方法 11 2.4黏滯式煞車動力量測原理 13 2.4.1黏滯式煞車原理 13 2.4.2 像散式扭力量測原理 14 第三章 黏滯式煞車理論與分析 16 3.1液體黏滯性 16 3.1.1剪應力與液體黏滯性之關係 16 3.1.2溫度對黏滯係數之關係 17 3.1.3液體黏滯係數之量測原理 17 3.2 黏滯式煞車 19 3.2.1黏滯式煞車之理論 19 3.2.2黏滯式煞車單元之設計 21 3.2.3黏滯式煞車單元之模擬分析 23 第四章 黏滯式煞車動力量測平台之設計開發 26 4.1待測物夾持及驅動單元 28 4.2黏滯式煞車單元 28 4.3煞車力矩量測單元 29 4.4轉速量測單元 33 4.5間隙調整單元 34 4.6致冷單元 34 4.7人機介面 36 第五章 黏滯式煞車動力量測平台之性能測試 38 5.1 黏滯式煞車動力量測平台校正實驗 38 5.2高速牙醫手機筒匣動態量測實驗 43 5.3影響動力量測精度探討與改善方案 47 第六章 結論與未來展望 48 參考文獻 49 附錄 5