外文翻譯---網(wǎng)狀工藝制造下循環(huán)型諧波傳動柔性齒輪的發(fā)展

1、<p>　　Development of the composite flexspline for a cycloid-type harmonic drive using net shape manufacturing method</p><p>　　The flexspline for a harmonic drive must be flexible in the radial direction

2、 for the elastic deformation, but must be stiff in the torsional direction for accurate transmission of rotational motion. Since these requirements cannot be satisfied simultaneously with conventional metals such as stee

3、l or aluminium, in this work the carbon fiber epoxy composite material was employed for the flexspline material in order to increase the torsional stiffness by tailoring the stacking sequence and to impro</p><

4、p>　　The toothed composite flexspline was manufactured with the elastomeric cascade tooling that is composed of the steel tooth die, the silicon rubber mandrel and the cone-shaped steel core. Also, the steel flexspline

5、 with the same dimensions of the composite flexspline was manufactured by CNC wire cutting method.</p><p>　　The static and dynamic performances of the composite flexspline and the steel flexspline were exper

6、imentally tested. From the test results, it was found that the developed composite flexspline had better flexibility in the radial direction and high damping capacity at the fundamental natural frequency.</p><

7、p>　　INTRODUCTION</p><p>　　The harmonic drive is a special gear-drive speed reduction system whose operation principle is based on the elastic deformation rather than the rigid body motion of general geari

8、ng system. It has many advantages, such as high speed reduction ratio, high rotational accuracy, high torque transfer per weight, high efficiency, little backlash and very compact size. Therefore, the harmonic drive is w

9、idely accepted in industrial robots and precision mechanisms. </p><p>　　The three basic components of the harmonic drive are the circular spline, flexspline and elliptical wave generator as shown in Fig. 1.&

10、lt;/p><p>　　The circular spline which has usually two or four more teeth than the flexspline operates in rigid body motion. The flexspline is usually designed as a thin walled cup-type shape. The flexspline is

11、composed of tooth, tube and boss sections as shown in Fig. 2.</p><p>　　Figure 3 shows the principle of motion of the harmonic drive.</p><p>　　As the ball-bearing mounted on the elliptical wave g

12、enerator deforms the flexspline as shown in Fig. 3, the teeth of the flexspline on the major axis of the elliptical wave generator engage the teeth of the circular spline and the teeth of the flexspline on the minor axis

13、 disengage the teeth of the circular spline. If the rigid circular spline is fixed, the clockwise rotating of the wave generator produces the counterclockwise rotation of the flexspline. If the circular spline has 102 te

14、eth and </p><p>　　The flexspline of the harmonic drive that is the key element for the torque transmission has the contradictory dual role that must be flexible in the radial direction but must be stiff in t

15、he torsional direction to accurately transmit rotational motion. The conventional flexspline that is made of isotropic materials such as steel or aluminium can not satisfy perfectly the contradictory dual role. Also, the

16、 motion of the harmonic drive is not perfectly smooth but has a ripple which has the same f</p><p>　　However, if the flexspline is manufactured using the carbon fiber epoxy composite material, many drawbacks

17、 of the harmonic drive can be eliminated, because the carbon fiber epoxy composite material has high specific stiffness, high specific strength and high material damping capacity. Therefore, in this work, the flexspline

18、was designed and manufactured with the high strength carbon fiber epoxy material. The torsional stiffness was increased without increasing the radial stiffness by tailoring t</p><p>　　The initial study on th

19、e development of the composite flexspline with carbon fiber epoxy composite materials for the harmonic drive was carried out by Oh6 and Jeong.7 They manufactured the composite flexspline by adhesively joining the separat

20、ely manufactured parts such as the boss, tube and tooth sections. Since the previous manufacturing methods required several labor intensive operations, in this work, a new net shape manufacturing method for the composite

21、 flexspline was developed to increase</p><p>　　Since the involute tooth profile that is used in the conventional steel flexspline has a small curvature at the dedendum, the stress concentration at the root o

22、f the teeth is large when the flexspline is elliptically deformed, which shortens the life of the flexspline.。However, the cycloid tooth profile has less stress concentration at the root section of the tooth because the

23、curvature is larger than the involute curve. The disadvantage of the cycloid tooth is the difficulty of machining. Howev</p><p>　　For the manufacturing method of the toothed flexspline, an elastomeric cascad

24、e tooling that is composed of the steel tooth die, the silicon rubber die and the cone-shaped steel core was used. The tooth profile of the steel die was manufactured by a CNC wire cutting machine. Also, the steel flexsp

25、line with the same dimensions of the composite flexspline was made by CNC wire cutting machine to compare the performances. Finally the static and dynamic tests were performed to compare the mechanical p</p><p

26、>　　DESIGN OF THE CYCLOID-TYPE HARMONIC DRIVE</p><p>　　The cycloid drive whose operational principle is similar to that of the harmonic drive operates in the rigid body motion. The cycloid drive is compose

27、d of the rigid internal gear which has many pins, the rigid planetary gear which has the epitrochoid tooth profile and the ball bearing mounted on the rigid ring as shown in Fig. 4.</p><p>　　The rigid ring i

28、s usually assembled in the eccentric input shaft. When the internal gear is fixed, the eccentric rotation of the rigid ring around the input shaft produces a motion of the planetary gear. </p><p>　　Since the

29、 pin-type tooth profile is used in the internal gear and the epitrochoid tooth profile which is made from sinusoidal functions is used in the planetary gear of the conventional cycloid drive, in this work, the pin-type t

30、ooth profile was used in the tooth profile of the circular spline and the epitrochoid tooth profile was used in the tooth profile of the flexspline. The behavior of the designed tooth profile was checked through the comp

31、uter simulation to avoid the tooth interference dur</p><p>　　Figure 5 shows the configuration of the developed circular spline and the flexspline of the cycloid-type harmonic drive.</p><p>　　Tab

32、le 1 shows the dimensions of the developed cycloid-type harmonic drive.</p><p>　　Figure 6 shows the assembled cross sections of the conventional involute type harmonic drive and the developed harmonic drive.

33、</p><p>　　Figure 7 shows a computer graphic simulation of the engagement of the involute and developed flexsplines. From Fig. 7, it was found that the interference of the tooth of the developed cycloid-type

34、flexspline did not occur during the flexspline translation.</p><p>　　NET SHAPE MANUFACTURING OF THE FLEXSPLINE</p><p>　　In order to manufacture the composite flexspline with net shape manufactur

35、ing method, the elastomeric cascade tooling which is composed of the tooth die, the tube die, the silicon rubber mandrel, the steel core and the vises, was used in the this work. Figure 8 shows the die assembly for the m

36、anufacturing of the composite flexspline. </p><p>　　In this method, the teeth of the composite flexspline were molded using the tooth die which has the shape of the internal gear. The teeth of the tooth die

37、were machined by a CNC wire cutting machine. The tooth machining was carried out in two stages such as rough cutting with O-3 mm diameter wire and precise cutting with 0.1 mm diameter wire. The tooth die as shown in Fig.

38、 9 was composed of four parts to make demolding of the composite flexspline easy. Before wire-cutting the tooth profile, the </p><p>　　For the consolidation of the composite material during cure, the tapered

39、 hollow silicon rubber mandrel was used. In order to compress the silicon mandrel, the steel core with 5” taper was inserted and pushed down using the clamping nuts and bolts. By adjusting the clamping length, the pressu

40、re of the silicon mandrel was controlled. The tube die which was used to manufacture the tube section of the tlexspline was also divided into two parts to make the demolding of the flexspline easy. In order t</p>

41、<p>　　The composite flexspline was manufactured by the following processes. The carbon fiber epoxy prepreg was wrapped on the silicon mandrel.The part of the prepreg to which the boss of the flexspline as shown in F

42、ig. 2 was joined by cocure was heated a little to make the prepreg flexible and was joined to the boss part. Then, the tube section of the silicon mandrel wrapped with prepreg was covered by the tube die. The silicon rub

43、ber mandrel with the tube die was inserted in the vise 2 and the vise 3</p><p>　　Since the circular spline of the cycloid-type harmonic drive has the pin type tooth, it is very difficult to make the tooth wi

44、th machining. The tooth profile might be manufactured by CNC wire cutting, however, the manufacturing time and the cost will be large. Therefore, in this work, the composite circular spline was manufactured with steel pi

45、ns and carbon fiber epoxy composite material. The manufactured composite tooth was adhesively bonded to the steel body of the circular spline. Figure 11 s</p><p>　　Table 2 shows the measured properties of th

46、e uni-directional carbon fiber composite material, and Table 3 shows the measured properties of the adhesive used in this work. </p><p>　　The SNCM 439 steel flexspline with the same dimensions of the composi

47、te flexspline was manufactured by CNC wire cutting to compare the performances of the two flexsplines. Figure 13 shows the photograph of the manufactured steel flexspline.</p><p>　　EXPERIMENTS AND DISCUSSION

48、S</p><p>　　Since the weights of the composite flexsplines and the steel flexspline were 1.20 N and 2.00 N, respectively, it was found that the weight of the composite flexspline was decreased about 40% compa

49、red with that of the steel flexspline.</p><p>　　In order to measure the radial compliance of the flexspline, the displacement measuring device as shown in Fig. 14 was manufactured. After a reference initial

50、displacement was set using a gauge block, the weight on the flexspline was increased and the resulting displacement was measured. </p><p>　　Figure 15 shows the relationship between the applied weight and the

51、 resulting displacement.When the applied weight on the flexspline was 20 N, the radial displacement of the composite flexspline and the steel flexspline were 560 um and 410 ,um, respectively. In this case, the radial com

52、pliances of the composite flexspline and the steel flexspline were 28.0um/N and 20.5 um/N, respectively. Accordingly, it was found that the radial compliance of the composite flexspline was increased 36.6% compare</p&

53、gt;<p>　　The vibration characteristics of the flexsplines were measured through impulse-frequency response tests. The apparatus for measurement was a dual channel fast Fourier transform analyzer (B&K 2032), a

54、charge amplifier (B&K 2635), an impulse hammer (B&K 8202) an accelerometer (B&K 4374) a force transducer (B&K 8200) and a personal computer for data acquisition. Impulses were given to the flexsplines in

55、the radial and torsional directions as shown in Fig. 16. Figure 16(a) shows the test method in t</p><p>　　CONCLUSIONS</p><p>　　In order to increase the torsional stiffness and manufacturing prod

56、uctivity, a new composite flexspline was designed and manufactured with the carbon fiber epoxy composite material for the cycloid-type harmonic drive using elastomeric cascade tooling. The static and dynamic performances

57、 of the composite flexspline were compared with those of the steel flexspline which was manufactured by CNC wire cutting method. From the tests on the flexsplines, the following conclusions were drawn:</p><p&g

58、t;　　1.the mass of the composite flexspline was decreased by about 40% compared with that of the steel flexspline;</p><p>　　2.the radial compliance of the composite flexspline was increased by about 40% compa

59、red with that of the steel flexspline; </p><p>　　3.the natural frequencies in the radial and torsional modes of the composite flexspline were increased by about 40% and 30%,respectively, compared with those

60、of the steel flexspline; </p><p>　　4.the damping capacities in the radial and torsional modes of the composite flexspline was increased by about 140% and 160%, respectively, compared with those of the steel

61、flexspline.</p><p>　　網(wǎng)狀工藝制造下循環(huán)型諧波傳動柔性齒輪的發(fā)展</p><p>　　諧波傳動柔性齒輪在徑向上必須表現(xiàn)出其彈性和柔軟性，而在精確的扭轉(zhuǎn)傳輸過程中又必須體現(xiàn)出一定的韌性和強度?？墒?，一般的常規(guī)物質(zhì)材料，例如鋼和鋁是不可能同時達到以上所說的要求。因此，引進碳纖維環(huán)氧合成材料以增強諧波傳動柔性齒輪在扭轉(zhuǎn)傳輸過程中的韌性及強度，同時，以模制澆鑄工藝替代加工生產(chǎn)

62、來提高生產(chǎn)效率。</p><p>　　鋸齒狀合成柔性齒輪的制造需要借助人造橡膠加工工藝，包括齒輪鋼模、硅橡膠心軸和錐形鋼芯。同時，與合成柔性齒輪尺寸相同的鋼材料柔性齒輪的制造是要通過CNC金屬絲切割工藝。</p><p>　　通過實驗證明，相對于鋼材料柔性齒輪，高質(zhì)的合成柔性齒輪無論是在靜態(tài)還是動態(tài)情況，在徑向上都表現(xiàn)出良好的柔性，同時在基本的固有頻率下體現(xiàn)了高減幅能力。</p>

63、;<p><b>　　前言</b></p><p>　　諧波傳動是一種特殊的齒輪傳動減速系統(tǒng)，它的運作是基于彈性變形而非一般傳動裝置系統(tǒng)的剛性運作。它集眾多優(yōu)點于一身，例如，高比率減速，高正確率轉(zhuǎn)動，單位質(zhì)量高扭矩傳輸，高效，低后沖和尺寸統(tǒng)一適當(dāng)?shù)葍?yōu)點。因此，諧波傳動廣泛應(yīng)用于工業(yè)機器人和機密機械制造業(yè)上。</p><p>　　諧波傳動的三大基本組件是剛

64、性齒輪、柔性齒輪和橢圓波發(fā)生器。（見圖1）</p><p>　　當(dāng)剛性機械運作中剛輪通常要比柔性齒輪多出兩個到四個鋸齒。柔性齒輪通常設(shè)計為薄壁杯狀形態(tài)，如圖2所示它包括鋸齒、電子管和主元件。</p><p>　　圖3顯示的則是諧波傳動的運作機理。</p><p>　　橢圓波發(fā)生器上的滾珠軸承使柔性齒輪變形，橢圓波發(fā)生器主軸上的柔性齒輪就會和剛性齒輪相咬合，而次軸上的

65、柔性齒輪與剛性齒輪脫離。如果剛性齒輪是固定的，那么順時針轉(zhuǎn)動的波發(fā)生器則會引起柔性齒輪的逆時針轉(zhuǎn)動。如果剛性齒輪有102個鋸齒，同時柔性齒輪有100個鋸齒，那么波發(fā)生器的順時針轉(zhuǎn)動一周會使柔性齒輪相對于2個鋸齒的角度產(chǎn)生逆時針旋轉(zhuǎn)。在這種情況下，轉(zhuǎn)動速率之比為50：1。</p><p>　　諧波傳動的柔性齒輪在扭矩傳輸中最重要的特點是具有相矛盾的雙重特性，即在精確傳輸轉(zhuǎn)動運作時徑向上表現(xiàn)出柔性而在扭轉(zhuǎn)方向上表現(xiàn)出

66、剛性。但是，以鋼或鋁等等方性材料往往不能很好的表現(xiàn)出柔性齒輪的雙重特性，而且，諧波傳動的運作往往不是很平穩(wěn)，會和波發(fā)生器產(chǎn)生同頻波動，導(dǎo)致抖動和噪音。</p><p>　　但是，如果利用碳纖維環(huán)氧合成材料制造柔性齒輪側(cè)可以避免諧波傳動的許多缺點，因為碳纖維環(huán)氧合成材料具有特殊的高韌性、高強度和高減幅能力。所以此處所說的柔性齒輪都是以碳纖維環(huán)氧合成材料設(shè)計并制造的，增強扭轉(zhuǎn)硬度的同時不改變徑向硬度。</p&g

67、t;<p>　　最初以碳纖維環(huán)氧合成材料制造諧波傳動柔性齒輪的理論由兩位韓國人所提出。他們將分離的鋸齒、電子管和主元件結(jié)合到一起制造柔性齒輪。之前柔性齒輪的制造需要經(jīng)過多道精密的工序，而新的網(wǎng)狀制造工藝可大大提高制造效率。以此工藝技術(shù)，除了主元件以外，柔性齒輪的所有部件都是利用碳纖維環(huán)氧合成材料制造。</p><p>　　通常情況下，鋼制柔性齒輪都會有著復(fù)雜的鋸齒刨面使之齒根處有著較低的曲率，壓力都

68、會集中于齒根，柔性齒輪受力變形就會大大減短其壽命然而，環(huán)狀鋸齒齒根會有相對較小的壓力集中，因為其曲率較前者要小的多?？墒?，這種環(huán)狀鋸齒的缺點就在于它的制造難度比較高，但如果有了這種鋸齒的模型，那么在制造方面兩者的難易程度便會相同。所以，通常在諧波傳動上采用外旋輪線型鋸齒以改變其強度。</p><p>　　同時，利用碳纖維環(huán)氧合成材料和鋼插腳制造與柔性齒輪相配合使用剛性齒輪。鋸齒狀合成柔性齒輪的制造需要借助人造橡膠

69、加工工藝，包括齒輪鋼模、硅橡膠心軸和錐形鋼芯。同時，與合成柔性齒輪尺寸相同的鋼材料柔性齒輪的制造是要通過CNC金屬絲切割工藝。最后分別通過靜態(tài)和動態(tài)實驗，將結(jié)果與高質(zhì)合成柔性齒輪的機械性能進行比較。</p><p>　　循環(huán)型諧波傳動設(shè)計構(gòu)思</p><p>　　循環(huán)型諧波傳動運作機理與剛性齒輪構(gòu)件的諧波傳動基本相同。循環(huán)型諧波傳動內(nèi)部剛性齒輪具有外旋輪型齒輪，同時滾珠軸承牢固安裝在剛環(huán)中

70、。（見圖4）</p><p>　　剛環(huán)一般安裝在輸入桿內(nèi)部，當(dāng)內(nèi)齒輪固定，剛環(huán)的旋轉(zhuǎn)就會帶動行星齒輪的運動。</p><p>　　內(nèi)齒輪通常是針式齒輪外型，而常規(guī)循環(huán)型傳動具有外旋輪型齒輪外型。前者往往應(yīng)用于剛性齒輪，后者則應(yīng)用于柔性齒輪。通過電腦模擬器對相應(yīng)外型齒輪的表現(xiàn)進行檢測以規(guī)避可能帶來的內(nèi)部齒輪沖突。</p><p>　　圖5表現(xiàn)的是諧波傳動的高質(zhì)剛性齒輪

71、和柔性齒輪構(gòu)造。</p><p>　　表1體現(xiàn)的是循環(huán)型諧波傳動參數(shù)尺寸。</p><p>　　圖6是復(fù)雜型和發(fā)展型諧波傳動的交叉部件。</p><p>　　圖7是復(fù)雜型和發(fā)展型柔性齒輪咬合的電腦模擬圖解。從圖7可以看出發(fā)展型的循環(huán)柔性齒輪在傳輸過程中不會出現(xiàn)內(nèi)部沖突。</p><p>　　柔性齒輪的網(wǎng)狀制造工藝</p><

72、;p>　　為利用網(wǎng)狀工藝生產(chǎn)合成柔性齒輪，需要采用彈性體層疊加工：鋸齒模型、管模型、硅橡膠心軸和鋼芯等等。圖8顯示的即為生產(chǎn)柔性齒輪的模具。</p><p>　　在此工藝下，合成柔性齒輪是根據(jù)鋸齒模具以內(nèi)齒輪的形式澆鑄而成的，其模具是采用CNC線割機器制造，主要分兩個階段：0-3mm直徑的粗糙線割和0.1直徑的精密線割。圖9所示為使合成柔性齒輪澆鑄更加簡單易行鋸齒模型的四個主要部分。在線割以前，原始模型材料

73、可分為四部分。當(dāng)表面打磨完畢后，原始材料的四部分才真正組合到一起，然后進行CNC線割。圖9（a）、（b）分別表現(xiàn)出模具組合前后的形式。</p><p>　　在制造過程中為加固柔性齒輪需要用到錐形空洞的硅橡膠心軸。為壓縮硅心軸，需要通過夾具的各種零件將錐形鋼芯推如并嵌如其中。通過調(diào)整夾具的長度來控制硅心軸的壓力。管模具也可以分成兩個部分以降低澆鑄的難度。通過調(diào)整管模具的錐型角度以減小在齒輪根部的集中壓力。</

74、p><p>　　合成柔性齒輪按以下過程進行制造：將碳纖維環(huán)氧料坯包在硅心軸外面。通過輕微加熱，碳纖維環(huán)氧料坯會與柔性齒輪的核心部分進行結(jié)合以保證柔性齒輪的柔韌性。然后將管模具包在硅心軸外面，并將此整體嵌如虎鉗中。通過此操作，預(yù)浸料坯將覆蓋整個齒輪模具。安置齒輪模具和虎鉗并將其旋緊。然后將安裝好的模具通過真空抽氣過程安置于高壓裝置中。圖10顯示的是制造完成的循環(huán)型合成柔性齒輪的圖樣。</p><p&

75、gt;　　由于循環(huán)型諧波剛性齒輪有制造工藝非常復(fù)雜的針式齒輪，而制造這樣的齒輪需要通過CNC線割，因此消耗大量的時間和金錢。所以，合成剛性齒輪是利用鋼針和碳纖維環(huán)氧合成材料。制造完成合成矩尺是完全結(jié)合在剛性齒輪的鋼體之上的。圖11顯示的是經(jīng)過CNC線割后的剛性齒輪。圖12是剛性齒輪的分體結(jié)構(gòu)和整體結(jié)構(gòu)。</p><p>　　表格2表示的是非單向的碳纖維合成材料的測量數(shù)據(jù)，表格3是組合型的測量數(shù)據(jù)。</p&g

76、t;<p>　　同時，對SNCM線割后的鋼材料柔性齒輪和合成材料齒輪的表現(xiàn)進行比較。圖13是鋼材料柔性齒輪。</p><p><b>　　實驗與討論</b></p><p>　　根據(jù)具體的測量，合成材料柔性齒輪和鋼材料柔性齒輪的質(zhì)量分別為1.20 和2.00 ，可以清晰的看出合成材料柔性齒輪的質(zhì)量相對減小40%。</p><p>

77、　　利用圖14所示的位置轉(zhuǎn)換工具對柔性齒輪的徑向拉伸性進行測量。首先利用測量尺對其進行原始固定和原始數(shù)據(jù)測量，然后根據(jù)重量的改變，進一步進行變化的測量。</p><p>　　圖15表示根據(jù)重量改變，柔性齒輪的具體數(shù)值變化。在柔性齒輪承重為20 時，合成柔性齒輪和鋼材料柔性齒輪的徑向改變分別為560 和410 ，即柔性比率分別為28.0 和20.5 。根據(jù)測量，合成柔性齒輪柔性比率相對于鋼材料柔性齒輪提高36.6%

78、。</p><p>　　柔性齒輪的擺動特征通過推動-頻率反饋測驗進行測量。測量工具是一個雙軌道傅立葉轉(zhuǎn)換分析器(B&K 2032)、電荷擴大器(B&K 2635)、推動錘(B&K 8202)、加速計(B&K 4374)、壓力轉(zhuǎn)換器和一臺電腦進行數(shù)據(jù)采集。根據(jù)圖16，推理按圖示分別從徑向和曲向給予柔性齒輪以推力。圖17顯示合成柔性齒輪和鋼材料柔性齒輪進行實驗后的反饋數(shù)據(jù)。</p

79、><p><b>　　結(jié)論</b></p><p>　　為了進一步提高齒輪的扭轉(zhuǎn)強度并且擴大制造生產(chǎn)力，一種利用碳纖維環(huán)氧合成材料的新型齒輪研發(fā)生產(chǎn)，并廣泛用于循環(huán)型諧波傳動。分別從靜態(tài)和動態(tài)兩方面對合成柔性齒輪和利用CNC線割的剛性齒輪進行綜合比較。實驗得出的結(jié)果如下：</p><p>　　1,成柔性齒輪的質(zhì)量相對于鋼材料柔性齒輪質(zhì)量降低40%；