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研究生:孫國峰
研究生(外文):Guo-Feng Sun
論文名稱:捲揚式防墜器的離心鎖定機構設計
論文名稱(外文):Design of Centrifugal Locking Mechanism for Self Retracting Lifeline
指導教授:陳達仁陳達仁引用關係
指導教授(外文):Dar-Zen Chen
口試委員:林柏廷吳宗明
口試委員(外文):Po-Ting LinTzong-Ming Wu
口試日期:2019-07-31
學位類別:碩士
校院名稱:國立臺灣大學
系所名稱:機械工程學研究所
學門:工程學門
學類:機械工程學類
論文種類:學術論文
論文出版年:2019
畢業學年度:107
語文別:英文
論文頁數:66
中文關鍵詞:捲揚式防墜器離心力鎖定機構分離旋轉運動鎖定準則設計準則
DOI:10.6342/NTU201903470
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本論文提出了將捲揚式防墜器(Self Retracting Lifeline)的離心力鎖定機構(Centrifugal Locking Mechanism)中的卷線筒和轉盤分開配置成不同轉速的設計。以美國專利US9121462作為例子,推導出離心力鎖定機構的鎖定準則(Locking Criterion):當離心力作用於棘爪上所產生的力矩大於棘爪上預設的阻力時,離心力鎖定機構會被鎖定。
如美國專利US9121462中所述,離心力鎖定機構中的卷線筒與轉盤是以相同的角速度旋轉,且該角速度為繩索捲繞半徑的函數。由於離心力為角速度的二次函數,當繩索捲繞半徑增加時,離心力會急劇的下降,導致鎖定準則愈來愈難被滿足。離心力也為棘爪安裝位置的一次函數,當繩索捲繞半徑增加後,為了要滿足鎖定準則,棘爪的安裝位置必須沿著轉盤的徑向急劇的向外移動,其導致轉盤的半徑增加。
在不改變棘爪的安裝位置的前提下,提出了另一個能夠滿足鎖定準則的方法:將原先同等速旋轉的卷線筒與轉盤分離成不同轉速的配置,並讓兩者之間產生速比關係,目的在於當卷線筒轉速減少時能夠增加轉盤的轉速來滿足鎖定準則。根據上述概念,提出配置此離心力鎖定機構的設計準則(Design Specifications)、需求與與限制。
提出以齒輪機構、連桿機構以及齒輪連桿機構達成將卷線筒與轉盤分離成不同轉速的配置的實例。接著在棘爪、彈簧、彈簧變形量等參數保持一樣的情況下去比較離心力鎖定機構在分離和不分離的配置之間鎖定表現和整體所佔面積的差異。在比較的結果上,分離配置下的離心力鎖定機構擁有和不分離配置一樣的表現,且其所佔面積也相對的比較小。
In this paper, design of centrifugal locking mechanism (CLM) for self retracting lifeline (SRL) with separated rotation of drum and rotor is presented. The following takes patent US9121462 as example, and the locking criterion is determined: when the torque on the pawl caused by centrifugal force is larger than predetermined constraint on the pawl, CLM is locked.
As described in patent, angular velocity of drum and rotor are the same and are function of outer radius of wound cable. When outer radius of wound cable increases, the centrifugal force decreases seriously because it is quadratic function of angular velocity. As a result, there is more difficult to satisfy locking criterion. To satisfy locking criterion after outer radius of wound cable increases, pawl is moved outward seriously in radial of rotor to enhance centrifugal force, because centrifugal force is linear function of pawl position. As a result, radius of rotor will get larger.
Under the premise that pawl positon remains the same, there proposes another method can satisfy locking criterion: separating rotation of rotor from drum and produces a speed ratio between them, so as to increase the angular velocity of rotor to satisfy the locking criterion when angular velocity of drum decreases. Design specifications, requirements, and constraints of CLM with separated rotation of drum and rotor are proposed.
The Embodiments can use gear mechanism, linkage and geared linkage to reach separated rotation are proposed. The comparison of locking performance and occupied area between CLM with and without separated rotation are done which is under the premise that parameters of pawl, spring, and deformation of spring are the same in both of them. As the result, the CLM with separated rotation can reach the same locking performance as and has the smaller occupied area than the CLM without separated rotation.
Chapter 1 Introduction 1
1.1 Background 1
1.2 Overview and related works 4
1.2.1 Metamorphic mechanism 4
1.2.2 Operation space of joint 6
1.2.3 Methodologies for mechanism design 7
1.3 Motivation and preview 9
Chapter 2 Locking criteria of CLM 12
2.1 The forces apply on pawl to cause torques 13
2.2 Reaction force applies on pawl after locking 18
2.3 Locking time range and critical condition of outer radius of cable for CLM 20
2.4 Separation of rotation of lock unit and drive unit 23
Chapter 3 Design specifications of CLM with separated rotation 26
3.1 Requirements and constraints for separated rotation kinematic structure 26
3.1.1 Search of admissible kinematic structures of IC 34
3.1.2 Search of compatible kinematic structures of IC 35
3.1.3 Search of feasible mechanisms of IC 36
3.2 Joint compatibility with orientation of the joints 38
3.3 Constraints for locking and feasible mechanism of differential type CLM 41
Chapter 4 Comparison of locking performance and occupied area between CLM with and without separated rotation 47
4.1 Locking performance and demand occupied area of CLM 48
4.1.1 Co-rotation type CLM 48
4.1.2 Differential type CLM with gear mechanism 49
4.1.3 Differential type CLM with linkage 51
4.1.4 Differential type CLM with geared linkage 55
4.2 Advantage of differential type CLM and performance comparison between each differential type CLM 59
Chapter 5 Conclusion and future work 61
5.1 Conclusion 61
5.2 Future work 62
References 64
[1]DB industries, “Safety device with retractable lifeline,” US Patent US4877110, 1988
[2]DB industries, “Self-retracting lifeline,” US Patent US7281620, 2004
[3]3M Innovative Properties Company, “Centrifugally-operated apparatus,” US Patent US 8256574, 2010
[4]Crouse, Jr.; Benjamin F., “Safety harness for stairs,” US Patent US 5899298, 1987
[5]Eddy current limited partnership, “Tuning of a kinematic relationship between members,” US Patent US10110089, 2015
[6]DB industries, “Retrieval assembly,” US Patent US7780146, 2008
[7]DB industries, “Brake assembly for a self-retracting lifeline assembly,” US Patent US8567562, 2010
[8]Eddy Current Limited Partnership, “Line dispensing device with eddy current braking for use with climbing and evacuation,” US Patent US8490751, 2010
[9]Inland Steel, “Safety reel,” US Patent US2791397, 1954
[10]Autoliv Development AB, “Seatbelt system,” US Patent US6412875, 2002
[11]John, S., Ian, M., “Fall arrest device,” US Patent US4923037, 1989
[12]Zhang, L., Wang, D., & Dai, J. S., 2008, “Biological modeling and evolution based synthesis of metamorphic mechanisms,” Journal of Mechanical Design, 130(7), pp. 072303.
[13]DB industries, “Self-retracting lifeline,” US Patent US9121462, 2012
[14]Shieh, W. B., Sun, F., & Chen, D. Z., 2011. “On the operation space and motion compatibility of variable topology mechanisms,” Journal of Mechanisms and Robotics, 3(2), 021007.
[15]Freudenstein, F., and Maki, E. R., 1979, “The creation of mechanisms according to kinematic structure and function,” Environment and Planning B Planning and Design, 6(4), pp. 375–391.
[16]Chen, D. Z., & Pai, W. M., 2005. “A methodology for conceptual design of mechanisms by parsing design specifications,” Journal of Mechanical Design, 127(6), pp. 1039-1044.
[17]The Fall Protection Code, “Safety Requirements for Self-Retracting Devices or Personal Fall Arrest and Rescue Systems,” ANSI/ASSE Z359.14-2012
[18]Yao, K. L., & Chen, D. Z., 2000, “Topological synthesis of fractionated geared differential mechanisms," ASME Journal of Mechanical Design, 122(4), pp. 472-478.
[19]Tsai, L. W., 2000, “Mechanism design: enumeration of kinematic structures according to function,” CRC press.
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