Design and Development of Magnetorheological Brake Device for Power Measurement of Dental Handpieces

• Main Authors: Wei-Cheng Chen, 陳偉程
• Other Authors: Kuang-Yuh Huang
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/32530582981130228032

碩士 === 國立臺灣大學 === 機械工程學研究所 === 104 === Dental handpieces are widely used in dental industry because of their operational advantages such as controllable cutting speed and cutting force. To achieve more stable operation and higher performance of dental handpieces, the development of performance measuring technology of high-speed dental handpieces is essential. In this thesis, the design and development of a dental handpiece measuring system of which can acquire its dynamic torque and its rotational speed, has been accomplished. With the principle of adaptable contact viscosity of magnetorheological fluid, the viscous force can be acted on the tested dental handpiece spindle as the breaking torque, and easily controlled by varying different magnet field intensity applied on the magnetorheological fluid. Due to the characteristic of magnetorheological fluid, the stick-slip phenomenon and vibration can be avoided compared to the traditional friction-brake type measurement system. To measure the performance of the dental handpieces, the research starts from deriving the viscous background theory of magnetorheological fluid. FEA (finite element analysis) and CFD (computational fluid dynamics) simulation have been approached to figure out the relationship between the design parameter and measuring system performances. Appropriated working range of applied magnet field intensity has also been studied by magnetic-electric field simulation software ANSYS Maxwell. Several experiments were implemented to verify the system performance. With the integrated DVD pickup head, the micro braking-torque measuring can be realized. The newly developed measuring platform of dental handpieces has its operational measurement range from 0.1 to 1.5 Nmm, the sensitivity of 4.4 Nmm/V, and linear error of 2.4%.