懸浮均載行星齒輪減速器結(jié)構(gòu)設(shè)計【工程牽引車懸浮均載行星減速器】

懸浮均載行星齒輪減速器結(jié)構(gòu)設(shè)計【工程牽引車懸浮均載行星減速器】,工程牽引車懸浮均載行星減速器,懸浮均載行星齒輪減速器結(jié)構(gòu)設(shè)計【工程牽引車懸浮均載行星減速器】,懸浮,行星,齒輪,減速器,結(jié)構(gòu)設(shè)計,工程,牽引車,行星減速器 科技譯文英文原文MICRO PLANETARY REDUCTION GEAR USING SURFACE-MICROMACHININGAbstractA micro planetary gear mechanism featuring a high gear reduction ratio with compactness in size ispresented in this paper. SUMMiT V is employed for the fabrication method so that the redundancy of assembling parts is eliminated. The design rules of which has also been checked. To make full use of the benefits of the surface- micro - machining, the planetary reduction gear is designed toward using the on-chip micro- engine. The expected gearreduction ratio is calculated and compared with the conventional chain gear mechanism. The microplanetary gear mechanism presented in this paper is expected to have 162:1 reduction ratio utilizing less space consumption. This is an order of magnitude higher than the previously reported design in a single reduction gear train.Keywords:MEMS, planetary gear, reduction gear surface-micromachining, SUMMiT V processNomenclaturea sun gearb planet gearsc internal gear (fixed)d internal gear (rotary)n the number of units of gear trainD diameter of the pitch circleN number of teethP number of planets angular velocityIntroductionThe gear mechanisms in microelectro mechanical systems(MEMS) are commonly expected to generate high torque in the confined micro-size systems. However, it is generally difficult for the micro-scale systems to have such a high torque without having multiple reduction systems.The design of the reduction gear drive based on a planetary paradox gear mechanism can increase the torque within a compact area, since the microplanetary gear system has an advantage of high reduction ratio per unit volume 1. However its mechanism is so complicated that relatively few attempts have been made to miniaturize the gear systems 2-3. Suzumori et al. 2 used the mechanical paradox planetary gear mechanism to drive a robot for 1-in pipes forward or backward. They employed a single motor to drive the gear mechanisms with high reduction ratio. Precise gear fabrication was enabled by micro wire electrical discharge machining (micro-EDM). These parts, however, should be assembled before the drive motor is attached to the gearbox. Takeuchi et. al. 3 also used micro-EDM to fabricate the micro planetary gears. They suggested special cermets or High Carbon Steel for possible materials. While the design can achieve a reduction ratio of 200, the gears should also be assembled and motor driven.To enable the driving of the planetary gear by onchip means, Sandia Ultra- planar Multi-level MEMS Technology (SUMMiT-V) process 4 for planetary gear fabrication is adopted in this study. The SUMMiT-V process is the only foundry process available which utilizes four layers of releasable polysilicon, for a total of five layers (including a ground plane) 5. Due to this fact, it is frequently used in complicated gear mechanisms being driven by on-chip electrostatic actuators 5.However, in many cases, the microengines may not produce enough torque to drive the desired mechanical load, since their electrostatic comb drives typically only generate a few tens of micronewtons of force. Fortunately, these engines can easily be driven at tens of thousands of revolutions per minutes. This makes it very feasible to trade speed for torque 7.Rodgers et al. 7 proposed two dual level gears with an overall gear reduction ratio of 12:1. Thus six of these modular transmission assemblies can have a 2,985,984:1 reduction ratio at the cost of the huge space.With the desire for size compactness and at the same time, high reduction ratios, the planetary gear system is presented in this paper. It will be the first planetary gear mechanism using surface micromachining,to the authors knowledge. The principles of operations of the planetary gear mechanism, fabrication, and the expected performance of the planetary gear systems are described in this paper.Principles of operationAn alternative way of using gears to transmit torque is to make one or more gears, i.e., planetary gears, rotate outside of one gear, i.e. sun gear. Most planetary reduction gears, at conventional size, are used as well-known compact mechanical power transmission systems 1. The schematic of the planetary gear system employed is shown in FigureSince SUMMiT V designs are laid out using AutoCAD 2000, the Figure 1 is generated automatically from the lay out masks (Appendix 1). One unit of the planetary gear system is composed of six gears: one sun gear, a, three planetary gears, b, one fixed ring gear, c, one rotating ring gear, d, and one output gear. The number of teeth for each gear is different from one another except among the planetary gears. An input gear is the sun gear, a, driven by the arm connected to the micro-engine. The rotating ring gear, d, is served as an output gear. For example, if the arm drives the sun gear in the clockwise direction, the planetary gears, b, will rotate counter-clockwise at their own axis and at the same time, those will rotate about the sun gear in clockwise direction resulting in planetary motion. Due to the relative motion between the planetary gears, b, and the fixed ring gear, c, the rotating ring gear, d, will rotate counterclockwise direction. This is so called a 3K mechanical paradox planetary gear 1.Fabrication procedure and test structuresThe features of the SUMMiT V process offer four levels of structural polysilicon layers and an electrical poly level, and also employ traditional integrated circuit processing techniques 4. The SUMMiT V technology is especially suitable for the gear mechanism. The planetary gear mechanism can be driven by the on-chip engine and thus is another reason of using the SUMMiT V process.Since the Sandia process is such a well-known procedure 5-7, only brief explanation is presented. Figure 2 represents the cross-sectional view of Figure 1, and also was generated from the AutoCAD layout masks (Appendix 1). The discontinuity in the cross-section is for the etch holes. The poly1 (gray) is used for the hubs and also patterned to make the fixed ring gear, i.e., c, the sun gear, i.e., a, the rotating ring gear, i.e., c, and the output gear is patterned in the poly2. Since the planetary gear needs to contact both the fixed ring and rotating ring gear, poly2 is added to poly3, where the gear teeth are actually formed. The poly4 layer is used for the arm that drives the sun gear. After the release etch, the planetary gears will fall down so that those will engage both the ring gears.The figures for the test structures are presented in Appendix 2. Since the aim of this paper is to suggest a gear reduction mechanism, the planetary gear system is decomposed to several gear units to verify its performance. The first test structure is about the arm, which rotates the sun gear, connected to the on-chip engine. The angular velocity of the arm depends on the engine output speed. The second test structure describes the point at which the sun gear and planetary gears are engaged to the fixed ring gear. Because of the fact that the ring gear is fixed, the planetary gear is just transmitting the torque from the sun gear to the fixed ring gear without planet motion, e.g., rotating its own axis not around the sun gear. When the rotating ring gear is mounted on top of the fixed ring gear, i.e., the third test structure, the planetary gears begin to rotate around the sun gear so that the planet motion are enabled. Therefore, once one output gear is attached to the rotating ring gear, i.e., the final test structure, the whole reduction unit is completed. Dismantling the planetary gear into three test structures allows the pinpointing of possible errors in the gear system.Solutions procedure and expected performanceThe reduction ratio is defined as the ratio between the angular velocity of the driver gear and that of the driven gear. High reduction ratios indicate trading speed for torque. For example, a 10:1 gear reduction unit could increase torque an order of magnitude. Since the gears in the planetary system should be meshed to one another , the design of gear module should follow a restriction. For example, the number of teeth for the sun gear plus either that of the fixed ring gear or that of the rotating ring gear should be the multiple of the number of planets, P (equation 1). Equation 2, which represent the reduction ratio, should observe the equation 1 first. The N is the number of the teeth for corresponding gear.Gears, a, b, c, d in the planetary gear system have a tooth module of 4 m, which is a comparable size of the current gear reduction units5, and the tooth numbers are 12, 29, 69, and 72 respectively. Therefore the overall reduction ratio is 162:1 from equation (2). Rodgers et al. 7 reported a 12:1 reduction unit using surface micromachining, which is less than order of magnitude for the gear reduction ratio of the planetary gear system. Although the reduction from Rodgers et al. 7 needs to be occupied in approximately 0.093 mm2, the planetary gear system only utilizes an area of approximately 0.076 mm2. Thus, this planetary reduction design can achieve an order of magnitude higher reduction ratio with less space. Since thereduction module is composed of several reduction units, the advantage of using a planetary gear system is self evident in Figure 3.Figure 3 shows the comparison of reduction ratios between the proposed planetary gear mechanism i.e. 162n, and the Sandia gear system 7, i.e. 12n, as a function of the number of units, i.e., n. The ordinate is drawn in log scale so that the orders of magnitude differences between two modules are evident. For example, in a module with five numbers of units, the reduction ratio difference between two is approximately six orders of magnitudes. Furthermore, the planetary gear system can save 8500 m2 in such a five unit reduction system.Conclusion and discussionsThe planetary gear reduction system using surface-micromachining, driven by an on-chip engine, first appears in this paper within the authors knowledge. The single reduction unit can achieve an order of magnitude higher reduction ratio than that of the previous design. However, due to the surface friction, and the backlash, which is inevitable for the gear manufacturing process, the overall reduction ratio may be less than 162:1 in the real situation. Even though some loss might be expected in the real application, the overall reduction ratio should be order of magnitude higher and the space consumption is less than the previous design 7.The authors learned a lot about the surfacemicromachining process during the project grant,and realized that a lot of the design needed to be revisited and corrected. This became prevalent when drawing the cross-sectional views of the design. Since the authors utilized the SUMMit V Advanced design Tools Software package and verified the design rules, the planetary gear layout is ready for fabrication. The authors hope that this planetary reduction unit will continue to be updated by successive researchers.AcknowledgementThe authors would acknowledge that discussions with Prof. Kris Pister, Prof. Arun Majumdar, Ms. Karen Cheung, and Mr. Elliot Hui contributed to this work tremendously.References1. Hori, K., and Sato, A., “Micro-planetary reduction gear” Proc. IEEE 2nd Int. Symp. Micro Machine and Human Sciences, pp. 53- 60 (1991).2. Suzumori, K., Miyagawa, T., Kimura, M., and Hasegawa, Y., “Micro Inspection Robot for 1-in Pipes”, IEEE/ASME Trans. On Mechatronics, Vol. 4., No. 3, pp. 286-292 (1999).3. Takeuchi, H., Nakamura, K., Shimizu, N., and Shibaike, N., “Optimization of Mechanical Interface for a Practical Micro-Reducer”, Proc. IEEE 13th Int. Symp. Micro Electro Mechanical Systems, pp. 170-175 (2000).4. Sandia National Laboratories, “Design Rules Design Rules”, MicroelectronicsDevelopment Laboratory, Version 0.8, (2000)5. Krygowask, T. W., Sniegowask, J. J., Rodgers, M. S., Montague, S., and Allen, J. J., “Infrastructure, Technology and Applications of Micro-Electro-Mechanical Systems (MEMS)”, Sensor Expo 1999 (1999).6. Sniegowski, J. J., Miller, S. L., LaVigne, G. F., Rodgers, M. S., and McWhorter, P. J., “Monolithic Geared-Mechanisms Driven by aPolysilicon Surface-Micromachined On-Chip Electrostatic Microengine”, Solid-State Sensor and Actuator Workshop, pp. 178-182, (1996).7. Rogers, M. S., Sniegowski, S. S., Miller, S., and LaVigne, G. F., “Designing and Operating Electrostatically Driven Microengines”, Proceedings of the 44th International Instrumentation Symposium, Reno, NV, May 3-7, pp. 56-65 (1998).Figure 3. The comparison of reduction ratios as a function of the number of units中文翻譯 采用表面微加工技術(shù)制造微型行星齒輪減速器摘要這篇文章論述了一種結(jié)構(gòu)緊湊、傳動比高的微型行星齒輪減速機構(gòu)。這種機構(gòu)的加工方法采用桑迪亞國家實驗室研發(fā)的過度平面的多極微機電系統(tǒng)技術(shù)去除整體結(jié)構(gòu)的冗余部分，而且這種設(shè)計原理已經(jīng)得到承認(rèn)。為了充分利用表面微加工技術(shù)，我們在設(shè)計加工這種行星減速齒輪時，需要使用安裝在芯片上的微電機。我們將計算這種齒輪預(yù)期的減速比，并把它與傳統(tǒng)的鏈傳動和齒輪傳動相比較。在這篇論文中演示的微行星輪占用較少的空間，消耗較少的材料，減速比卻有望達(dá)到162：1。這比以前的論文中設(shè)計的減速器的傳動比要高的多，簡直是一個神話。關(guān)鍵字：微機電 行星齒輪 減速器 表面微加工 過度平面的多極微機電系統(tǒng)的加工（簡稱為SUMMiT V）術(shù)語：a.太陽輪b.行星輪c.內(nèi)齒圈（固定）d.內(nèi)齒圈（旋轉(zhuǎn)）n.齒輪系組成單元的數(shù)目D.節(jié)圓的直徑N.齒數(shù)P.行星輪的數(shù)目.角速度介紹在微機電系統(tǒng)中的齒輪結(jié)構(gòu)通常希望用來在微小的體積內(nèi)產(chǎn)生較大的扭矩。但是沒有較大重量的減速器，往往是很難達(dá)到這樣的目的。研究發(fā)現(xiàn)擁有微行星齒輪的減速機構(gòu)能夠在狹小的空間內(nèi)增加扭矩，這好像有點自相矛盾。這是因為微行星齒輪系統(tǒng)能在每單位體積內(nèi)產(chǎn)生更大的傳動比。然而它的結(jié)構(gòu)是如此的復(fù)雜，以至于我們很少嘗試將齒輪系統(tǒng)微型化。Suzumori以及他的小組成員曾經(jīng)用類似的行星齒輪結(jié)構(gòu)來驅(qū)動一個機器人，并使它在直徑為一寸的鋼管里前后移動。他們利用一個馬達(dá)來驅(qū)動高傳動比的齒輪機構(gòu)，通過微電線的放電加工技術(shù)能夠?qū)崿F(xiàn)這種齒輪機構(gòu)的精確加工。但是這些部件應(yīng)該在裝配驅(qū)動馬達(dá)之前安裝在齒輪箱上。Takeuchi 等人也用這種技術(shù)制造了微行星齒輪。他們建議用特殊的含陶合金和高碳鋼作為最佳選擇材料。當(dāng)這種齒輪系統(tǒng)的傳動比達(dá)到200的時候，才可以安裝馬達(dá)并使之驅(qū)動。為了實現(xiàn)用芯片的方法來實現(xiàn)行星齒輪的驅(qū)動，在研究中我們采用SUMMiT V方法來加工微行星齒輪。SUMMiT V過程是唯一可以實現(xiàn)對于總數(shù)為五層(其中一層為地平面)的硅中釋放四層的鑄造過程由于這個原因，它經(jīng)常被用來通過安裝在芯片上的電子執(zhí)行器來驅(qū)動復(fù)雜的齒輪機構(gòu)。然而, 在許多情形,微電機不可能提供充足的轉(zhuǎn)力矩來驅(qū)動機械負(fù)荷,因為它們的靜電梳的典型驅(qū)動只產(chǎn)生幾十微牛頓的力。幸運的是,這些引擎能容易地達(dá)到每分鐘幾萬轉(zhuǎn)的速度。這就使將轉(zhuǎn)矩轉(zhuǎn)化為速度變成是可行的。羅杰等人設(shè)計了二個傳動比為12：1的雙重的水平齒輪。如此六個這樣的模組的傳輸集合在以占據(jù)極大的空間為代價的前提下可以達(dá)到2,985,984:1的傳動比。為了達(dá)到結(jié)構(gòu)緊湊，同時達(dá)到高傳動比的目的少比, 行星齒輪系統(tǒng)將被作為研究對象。根據(jù)作者的認(rèn)識，它將會是第一個使用表面微加工原理設(shè)計的行星齒輪結(jié)構(gòu)。我們還將闡述行星齒輪的操作規(guī)則，加工過程和希望達(dá)到的行星齒輪系統(tǒng)的性能。操作原則使用齒輪傳輸轉(zhuǎn)矩的其它可行的方法是將一個或者多個的齒輪,也就是, 行星齒輪,在另一個齒輪的外面旋轉(zhuǎn),也就是太陽輪。按照傳統(tǒng)的尺寸設(shè)計的行星齒輪減速器是使整體結(jié)構(gòu)緊湊的常用的傳輸系統(tǒng)。圖1是上述的行星齒輪的示意圖。自從用AutoCAD設(shè)計SUMMiT V以來,圖（1）可以通過軟件自動產(chǎn)生(附1)。一個完整的行星齒輪系統(tǒng)是由六個齒輪組成的: 一個太陽齒輪 a，三個行星齒輪 b，一個固定的內(nèi)齒圈 c,一個旋轉(zhuǎn)的內(nèi)齒圈 d,和一個輸出齒輪 e。除了行星齒輪之外,每個齒輪的齒數(shù)都不相同。 太陽齒輪 a是輸入齒輪，由與微引擎連接的機械手驅(qū)動。內(nèi)齒圈 d,被視為輸出齒輪。舉例來說,如果機械手驅(qū)動太陽輪按照順時針方向方向旋轉(zhuǎn), 那么行星輪 b, 將繞著它們自己的軸按照逆時針方向宣戰(zhàn)，同時也將繞著太陽輪按照順時針方向的方向旋轉(zhuǎn)，這樣就形成了行星運動。 由于多個行星齒輪b和固定內(nèi)齒圈c之間的運動相似，所以旋轉(zhuǎn)的內(nèi)齒圈d將按照逆時針方向旋轉(zhuǎn)。這也被叫做3K行星齒輪。加工過程和結(jié)構(gòu)測試SUMMiT V程序的特征體現(xiàn)了硅層結(jié)構(gòu)、電解聚乙烯, 以及傳統(tǒng)的集成電路處理等技術(shù)水平的四個層次。SUMMiT V技術(shù)尤其適應(yīng)于齒輪機構(gòu)。行星齒輪機構(gòu)由芯片上的微引擎驅(qū)動，而且這也是采用SUMMiT V技術(shù)的另一個理由。因為桑迪亞程序是一款眾所周知的程序 ,所以我們只簡要的作些解釋。圖2是圖 1的截面視圖,也是由AutoCAD按照附錄1設(shè)計產(chǎn)生的，其中截面中的不連續(xù)的部分是為了鉆孔而設(shè)置的。聚乙烯1(灰色)用來制造輪轂以及固定的內(nèi)齒圈c,太陽齒輪a,旋轉(zhuǎn)的內(nèi)齒圈 c,而輸出齒輪是由聚乙烯2制造的。圖 1.是由SUMMiT V設(shè)計軟件產(chǎn)生的行星齒輪機構(gòu)的視圖附錄 2是描述測試結(jié)構(gòu)的圖形。因為這篇文章的主旨是介紹一種齒輪減速機構(gòu),所以我們將整個行星齒輪系統(tǒng)分解成各個組成部分，以檢測它的性能。第一個測試結(jié)構(gòu)是驅(qū)動太陽齒輪的機械手,如前述，這個機械手是由芯片上的引擎驅(qū)動的，所以機械手的角速度是由引擎的輸出速度決定的。 第二個測試結(jié)構(gòu)描述的是太陽輪和行星輪與固定的內(nèi)齒圈嚙合的點。因為事實上內(nèi)齒圈是固定的, 所以行星輪將太陽輪輸入的轉(zhuǎn)矩傳到固定的內(nèi)齒圈，因此這個過程并沒有經(jīng)過行星運動。也就是說，行星輪只繞它自己的軸轉(zhuǎn)動，而沒有繞太陽輪轉(zhuǎn)動。第三個測試結(jié)構(gòu)是旋轉(zhuǎn)的內(nèi)齒圈，它安裝在固定的內(nèi)齒圈的頂端上，行星輪開始繞太陽輪旋轉(zhuǎn)，這樣就可以實現(xiàn)行星傳動。因此,一但輸出齒輪被安裝到旋轉(zhuǎn)的內(nèi)齒圈，也就是最后一個測試結(jié)構(gòu)，整個減速系統(tǒng)完成。將行星齒輪成拆解成三個測試結(jié)構(gòu)的過程中允許齒輪系統(tǒng)存在極微小的誤差。解決程序和預(yù)期的表現(xiàn)傳動比被定義為驅(qū)動輪和被驅(qū)動輪之間的角速度之比。高傳動比意味著將速度轉(zhuǎn)化為轉(zhuǎn)矩。舉例來說, 一個傳動比為10:1的齒輪可以按照一定的數(shù)量級增加轉(zhuǎn)矩。因為行星輪系的齒輪要保證相互之間嚙合，除了行星齒輪，所以齒輪模數(shù)的設(shè)計應(yīng)該遵從一定得限制。舉例來說，太陽輪的齒數(shù)加上固定的或者旋轉(zhuǎn)的內(nèi)齒圈的齒數(shù)應(yīng)該等于行星輪齒數(shù)的整數(shù)倍星， P(可以為1)。P代表著傳動比，如果P=2,應(yīng)該首先觀察P=1的情況 。 N 是對應(yīng)齒輪的齒數(shù)。 Ns + Nc (Nd ) = (1) (2) 行星輪系的齒輪a、b、c、d的齒型模數(shù)為4 um, 這是可以與現(xiàn)在的齒輪減速器相比較的模數(shù)，而齒數(shù)分別是12,29,69,和72。因此根據(jù)等式（2）可知，輪系的傳動比為162:1。根據(jù)羅杰等人的報告，他們設(shè)計出傳動比為12:1的減速器，但是要比行星輪系減速器的傳動比小一個數(shù)量級。雖然羅杰等人設(shè)計的減速器尺寸大約達(dá)到 0.093 mm 到2 mm之間, 但是本文的行星齒輪減速器設(shè)計大約可以達(dá)到0.076mm到 2mm的范圍. 因此, 行星齒輪減速器設(shè)計的傳動比能夠達(dá)成更高的數(shù)量級，同時占用更少的空間。因為減速器是由數(shù)個部分組成，所以圖3充分顯示了使用行星齒輪系統(tǒng)的優(yōu)點。 圖3利用數(shù)字的功能來顯示本文提議的行星齒輪機制，也就是, 與桑迪亞齒輪系統(tǒng)，也就是,之間的比較?？v坐標(biāo)以較大的比例單位作圖來顯示兩者之間的區(qū)別是很顯然的。 舉例來說, 在一個由5個部分構(gòu)成的組件中，兩組之間的區(qū)別大約達(dá)到。此外,在這個由五個部分組成的減速器因為采用了行星輪系，面積減少了8500。結(jié)論和討論我們首先討論了利用表面微加工技術(shù)制造的行星齒輪減速系統(tǒng)，它是由芯片上的引擎驅(qū)動的。這種減速器系統(tǒng)在傳動比方面比早先設(shè)計減速器提高了一個數(shù)量級。然而,由于表面的摩擦和反作用力在齒輪制造加工過程中是不可避免的。所以在實際情形中，減速器的傳動比可能比 162:1 要小。即使在實際情形中一些可能的損失被考慮,減速器的傳動比還是應(yīng)該比以前的設(shè)計提高一個數(shù)量級，而占據(jù)的空間會小很多。作者在設(shè)計過程中學(xué)習(xí)了許多關(guān)與微表面加工有關(guān)的知識，而且發(fā)現(xiàn)許多設(shè)計需要再研究和改正。當(dāng)畫這些設(shè)計得截面視圖時，這些知識已經(jīng)變得很熟悉了。因為我們利用了基于SUMMiT V的先進(jìn)的設(shè)計工具軟件包并確定了設(shè)計規(guī)則,行星齒輪的設(shè)計為制造加工做好了準(zhǔn)備。我們希望這種行星齒輪減速器能夠被研究人員繼續(xù)更新、完善。