外文翻譯--研究利用差動(dòng)齒輪系實(shí)現(xiàn)機(jī)械混合壓力

1、<p><b>　　中文4340字</b></p><p>　　出處：Science in China Series E: Technological Sciences February 2007, Volume 50, Issue 1, pp 69-80</p><p>　　Study of utilizing differe

2、ntial gear train to achieve hybrid mechanism of mechanical press</p><p>　　HE YuPeng1?, ZHAO ShengDun2, ZOU Jun2 & ZHANG ZhiYuan2</p><p>　　1 School of Mechanical Engineering, Nanjing Universi

3、ty of Science & Technology, Nanjing 210094, China;</p><p>　　2 School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049, China</p><p>　　The problems of hybrid input of mechan

4、ical press are studied in this paper, with differential gear train as transmission mechanism. It is proposed that “adjustable-speed amplitude” or “differential-speed ratio” is the important parameters for the hybrid inpu

5、t mechanism. It not only defines the amplitude of the adjustable</p><p>　　speed, but also determines the ratio of the power of the servomotor to the power of the conventional motor. The calculating equations

6、 of the ratio of transmission in all axes, the power of two motors, and the working load distribution are deduced. The two kinds of driving schemes are put forward that the servomotor and the conventional motor simultane

7、ously drive and the servomotor and the conventional motor separately drive. The calculating results demonstrate that the latter scheme can use much</p><p>　　mechanical press, hybrid mechanism, differential g

8、ear train, adjustable-speed</p><p>　　1 Introduction</p><p>　　At present there are many research papers about the hybrid mechanism of mechanical press, and it</p><p>　　has become a h

9、ot research topic. The hybrid mechanism is a mechanism with 2-degree-of freedom</p><p>　　(also called differential speed mechanism), and when two independent motions are input at the</p><p>　　sa

10、me time, the output that can satisfy some motion requirements is obtained through the motion</p><p>　　composition of the mechanism. The hybrid mechanism is also called controllable mechanism, or</p>&

11、lt;p>　　hybrid machine. The purpose of research on hybrid mechanism of mechanical press is using conventional motor with big power carrying flywheel to finish stamping work pieces; and uses ser —vomotor with low power

12、to adjust the slider speed. The advantages of the hybrid mechanism applied in the mechanical press are that it not only can reduce much lower manufacturing cost than servo press, but also has a flexible working velocity

13、of slider[1]. So the mechanical press of hybrid mechanism arouses many</p><p>　　The concepts of the adjustable-speed amplitude and differential-speed ratio are not mentioned in their works, and the relations

14、hip between the velocity variation and the power of the two motors were not clearly given[5―8]. But these concepts are very important and absolutely necessary for the hybrid mechanism to select the two motors’ power and

15、determine the working load distribution between conventional motor and the servomotor. In refs. [1―3] they used linkage mechanism to implement the hybrid</p><p>　　2 The principle of the hybrid mechanism</

16、p><p>　　The working principle of the hybrid mechanism of the mechanical press with differential gear train is illustrated in Figure 1. The system consists of conventional motor (also called AC machine with cons

17、tant speed), servomotor, reducing unit I, reducing unit II, differential gear train, and crank slide mechanism. The output axis of the differential gear train is connected with the crankshaft of the crank slide mechanism

18、. One of the two input axes links the conventional motor through the reducing </p><p>　　Figure 1 Working principle of hybrid mechanism of differential gear train.</p><p>　　3 The velocity charact

19、eristics of the mechanical press slide</p><p>　　The work of the mechanical press presents the regularity of the periodic change[12]. The displacement and velocity changes of the mechanical press slide in an

20、ideal work circulation are</p><p>　　illustrated in the Figure 2. The slide starts to move from top dead center to the working start point at high velocity (called quick feeding stage). When the slide of mech

21、anical press approaches the</p><p>　　working point, its high velocity is shifted to slow velocity and then it begins to stamp work piece at low velocity (called low working stage). The low velocity of the sl

22、ide is to avoid great impact on the die, and benefit the plastic shaping of the work piece. After the slide finishes the stamping work and reaches the bottom dead center, the slide comes back at high velocity and stops a

23、t the top dead center (called quick back stage). Hence, the motion velocity of the mechanical press slide can </p><p>　　4 The nomenclatures and equations of the hybrid mechanism</p><p>　　4.1 The

24、 relationship of the angular velocity in all axes</p><p>　　There are three external axes in the differential gear train as illustrated in Figure 1. In order to</p><p>　　conveniently express the

25、relationship of the three axes, the axis connected with the conventional</p><p>　　motor is called axis 1, the axis connected with servomotor is called axis 2, and the axis connected</p><p>　　wit

26、h crankshaft is called axis 0. The angular velocities of the three axes are respectively expressed</p><p>　　as n1 , n2 and n0 . The torques of the three axes are respectively expressed as M1 , M2 and M0 .<

27、;/p><p>　　Because there are two freedoms in the differential gear train, only the third axis is fixed, such that</p><p>　　the drive ratio of the other two axes can be determined. So the relationshi

28、ps of drive ratio and</p><p>　　angular velocity of the three axes need to be expressed as the character with superscript and subscript.</p><p>　　Figure 2 Ideal displacement cure of the slide.<

29、;/p><p>　　4.1.1 The conventional motor’s influence on the output motion. </p><p>　　When the servomotor stops, n2 = 0 , only the angular velocity of the conventional motor affects the output angular

30、 velocity n0 .</p><p>　　4.1.2 The servomotor’s influence on the output motion. </p><p>　　When the conventional motor stops, n1 = 0 , only the angular velocity of the servomotor affects the outpu

31、t angular velocity n0 , where 1 n0 represents axis 0 angular velocity, and 1 i20 represents total drive ratio from axis 2 to axis 0 including differential gear train and reducing unit II when axis 1 (servomotor axis) is

32、fixed.</p><p>　　4.1.3 The conventional motor’s and servomotor’s influence on the output motion. </p><p>　　When the conventional motor and the servomotor run at the same time through the composit

33、ion of the differential gear train, the output velocity can be expressed as . Because the servomotor can run at arbitrary angular velocity between the zero and specific velocity in both positive and negative directions,

34、n2 can be expressed as .where K is the ratio of the actual angular velocity to the specific angular velocity of the servomotor; the value is arbitrary between ?1 and +1, including zero. n2e is</p><p>　　4.2 A

35、djustable-speed amplitude and differential-speed ratio</p><p>　　4.2.1 Adjustable-speed amplitude. </p><p>　　In order to correctly denote the variable velocity of the differential gear train of t

36、he hybrid mechanism, the concept of adjustable-speed amplitude is introduced. As shown in Figure 1, adjustable-speed amplitude is the ratio (or percentage) of absolute value of up and down adjustable amount to the base s

37、peed. In the differential gear train of the hybrid mechanism, the adjustable-speed amplitude equals the ratio value of axis 0 output speed of operating a single servomotor at the specific speed </p><p>　　4.2

38、.2 Differential-speed ratio.</p><p>　　The differential-speed ratio is usually used to express adjustable speed technology performance in the differential gear train. It is an important technology parameter o

39、f the differential effect in the differential system. The differential-speed ratio equals the reciprocal value of the adjustable-speed amplitude. It can be expressed as According to the fact that the angular velocity is

40、in inverse proportion to its torque and that the same load is driven by conventional motor and servomotor, an e</p><p>　　4.3 The working load power distribution</p><p>　　Supposing that the worki

41、ng load power of the mechanical press is P0 , the power relationship</p><p>　　between the conventional motor, the servomotor and working load can be expressed as below:</p><p>　　Figure 3 Physica

42、l sense of the adjustable-speed amplitude.</p><p>　　From eqs. (9)―(11), the output powers of the conventional motor and the servomotor are determined by the value of factor K, which is actually equal to the

43、change ratio of angular velocity of the servomotor. Hence when the output angular velocity runs in different working region, the ratio of bearing load of the two motors is different, too.</p><p>　　4.3.1 The

44、output axis running at the basic speed.</p><p>　　When the output angular velocity of the servomotor equals zero, that is, K = 0 , P2 = 0 , from</p><p>　　eq. (9), we have .Here the conventional m

45、otor bears all the loading power.</p><p>　　4.3.2 The output axis running in the increasing speed region.</p><p>　　The servomotor runs in the positive direction, 0≤K≤1 , and both P1 and P2 are po

46、sitive values, so both the conventional motor and the servomotor bear a part of the working load. </p><p>　　Thus the conventional motor bears 90.9%―100% working load and the servomotor bears only</p>

47、<p>　　0―9.1% working load. The value of the adjustable-speed and the differential-speed ratio deter-mine the load distribution between the two motors.</p><p>　　4.3.3 The output axis running in the decre

48、asing speed region.</p><p>　　In the decreasing speed region, the servomotor runs in negative direction, and the range value of K is ?1≤K≤0 . By eqs. (9) and (10), the P1 is positive, and the P2 is negative.

49、The negative value of the servomotor power shows that the servomotor power is already the working resistance. Hence the conventional motor is not only doing work to the working load, but also doing work to the servomotor

50、 power, When the angular speed is in the region 0―n2e, the load of the conventional motor is Thus when</p><p>　　consuming the servomotor input power. In order to save energy, the output angular speed should&

51、lt;/p><p>　　avoid or reduce running in the decreasing region.</p><p>　　4.4 The two drive schemes of the hybrid mechanism of the mechanical press</p><p>　　According to eq. (3), the outp

52、ut angular velocity of the hybrid mechanism is equal to the reduced</p><p>　　value of their sum of the angular velocities of both the conventional motor and the servomotor. As</p><p>　　shown in

53、Figure 1, the output angular velocity of the differential gear train is connected with the</p><p>　　crank axis of the mechanical press, so the two axes have the same angular velocity. When either of</p>

54、;<p>　　the conventional motor or the servomotor is driven, or when both of them are driven, the different</p><p>　　angular velocity of the crankshaft of the mechanical press can be obtained. Therefore

55、, two kinds of the schemes of the hybrid mechanism of the mechanical press are proposed: (i) the conventional motor and the servomotor are simultaneously driven; and (ii) the conventional motor and the servomotor are sep

56、arately driven.</p><p>　　4.4.1 The conventional motor and the servomotor being simultaneously driven.</p><p>　　This scheme shows that the angular velocity of the crankshaft of the mechanical pre

57、ss is composed of the angular velocity of the conventional motor as the basic speed and the angular velocity of the servomotor as the adjustable speed (Figure 3). The angular velocity and the powers can be calculated by

58、using eqs. (1)―(18).</p><p>　　4.4.2 The conventional motor and the servomotor being separately driven. </p><p>　　This scheme shows that only one motor is driven in the hybrid input course and at

59、 the same time another motor is braked, i.e. when the crankshaft is in differential running stage, the conventional motor and the servomotor are separately operated; thus the different angular velocity of the crankshaft

60、can be obtained. The flexible low speed operation .When the conventional motor is braked and the servomotor is operated, n1 = 0，the below equation can be obtained from eq. (5)</p><p>　　Because ?1≤K≤+1 , the

61、output angular velocity of the crankshaft is adjustable and the</p><p>　　crankshaft has two rotating directions; therefore it is flexible. A big value of the drive ratio 1</p><p>　　i20 can be de

62、signed, so a very small output angular velocity 1 n0 can be achieved. Hence in this course the output angular velocity is flexible and low. When the servomotor is braked and the conventional motor is operated, n2 = 0 , f

63、rom eq. (5), we have. Crankshaft has two rotating directions; therefore it is flexible. </p><p>　　Figure 4 Physical sense of the comparison of the two output angular speed.</p><p>　　Because driv

64、e ratios 2 i10 and 1 i20 are independent of each other, and the operation and the servomotor operation of the conventional motors are independent of each other too, the values of the two drive ratios can be assigned a ve

65、ry different value (one is very small, and the other is very big), so the two output angular velocities may differ greatly. So doing can satisfy the motion requirements of the mechanical press slide in different stages.

66、The physical sense of comparison of the two outp</p><p>　　5 Conclusion</p><p>　　According to the velocity characteristics of the mechanical press, the differential gear train is applied in the h

67、ybrid mechanism of the mechanical press. Through the above analysis and calculation, the following conclusions can be reached:</p><p>　　(1) The adjustable-speed amplitude and differential-speed ratio are imp

68、ortant parameters of the</p><p>　　hybrid mechanism. They are not only the ratio of the adjustable speed to the basic speed, but also</p><p>　　the ratio of the power of the servomotor to the powe

69、r of the conventional motor.</p><p>　　(2) With the scheme of the conventional motor and the servomotor being simultaneously driven,</p><p>　　the power of the two motors has to be assigned high v

70、alue in order to satisfy the velocity requirements of the mechanical press. So doing increases the manufacturing cost and the operation</p><p>　　cost of the mechanical press, and therefore is valueless in pr

71、actical application.</p><p>　　(3) With the scheme of the conventional motor and the servomotor being separately driven, the</p><p>　　power of the servomotor can be assigned low value in order to

72、 satisfy the velocity requirements of</p><p>　　the mechanical press. So doing decreases the manufacturing cost and the operation cost of the</p><p>　　mechanical press. Therefore, this scheme pro

73、poses a feasible way in practical industrial engineering.</p><p>　　研究利用差動(dòng)齒輪系實(shí)現(xiàn)機(jī)械混合壓力</p><p>　　本文對(duì)機(jī)械壓力混合輸入的問題進(jìn)行了研究，用差動(dòng)輪系作為傳動(dòng)機(jī)構(gòu)。它建議將“調(diào)速幅度”或“差動(dòng)速比”作為重要參數(shù)混合投入機(jī)械研究中。它不僅規(guī)定了可調(diào)節(jié)幅度速度，而且還決定了伺服電動(dòng)機(jī)功率比的傳統(tǒng)電機(jī)。所

74、有傳動(dòng)軸計(jì)算的傳輸功率，兩個(gè)電機(jī)的功率和工作負(fù)載的分布得到了推斷結(jié)果。它提出了伺服電機(jī)和傳統(tǒng)電機(jī)同時(shí)驅(qū)動(dòng)，伺服電機(jī)和傳統(tǒng)電機(jī)單獨(dú)驅(qū)動(dòng)兩種驅(qū)動(dòng)方案。計(jì)算結(jié)果表明后者的方案能比伺服電機(jī)使用更低的功率，因此這種方案能使得制造和使用成本低得多。后一個(gè)方案提出了一個(gè)可行的途徑在實(shí)際工程中來使用混合機(jī)械壓力。</p><p>　　機(jī)械壓力，混合機(jī)制，差動(dòng)輪系，調(diào)速</p><p><b>　

75、　1、引言</b></p><p>　　目前有許多關(guān)于機(jī)械壓力的混合機(jī)制的研究報(bào)道，并且已經(jīng)成為一個(gè)熱門的研究話題?；旌蟿?dòng)力機(jī)制是一種有2個(gè)自由度的機(jī)制（也稱為差速機(jī)制），當(dāng)兩個(gè)獨(dú)立的運(yùn)動(dòng)同時(shí)輸入時(shí)，輸出的運(yùn)動(dòng)能夠滿足一些運(yùn)動(dòng)要求，這些要求通過機(jī)械的運(yùn)動(dòng)組成來獲得的?；旌蟿?dòng)力機(jī)制也可稱為可控機(jī)制，或者稱作混合機(jī)器。研究機(jī)械壓力機(jī)的混合機(jī)械的目的是使用大功率常規(guī)電機(jī)利用飛輪來完成工件的沖壓；并使用低功率

76、的伺服電機(jī)來調(diào)整滑塊速度。應(yīng)用在機(jī)械壓力中的混合機(jī)制的優(yōu)勢(shì)在于它不僅可以比伺服壓力機(jī)降低更多的制造成本，而且還有一個(gè)靈活的工作速度滑塊。所以混合動(dòng)力機(jī)械壓力機(jī)在機(jī)制上的工作引起了許多研究者的興趣；并且這些研究主要集中在多桿混合機(jī)械中。杜和郭已經(jīng)全面討論了七桿的機(jī)械壓力機(jī)的混合機(jī)制，包括組成連桿機(jī)構(gòu)的可行條件，滑塊機(jī)構(gòu)的動(dòng)力分析，和兩臺(tái)電機(jī)之間轉(zhuǎn)矩和功率的分配以及它們之間的優(yōu)化設(shè)計(jì)?；诙囗?xiàng)式的軌跡規(guī)劃也需要調(diào)查，且計(jì)算機(jī)模擬表明結(jié)果的確

77、吸引人。此外，孟也調(diào)查了七桿機(jī)構(gòu)的運(yùn)動(dòng)學(xué)分析，基于最低功率的伺服電機(jī)的優(yōu)化設(shè)計(jì)已經(jīng)完成，然后孟建議混合機(jī)制是機(jī)械壓力機(jī)的研究方向。Tokuz 首次提出了混合機(jī)構(gòu)并且使用差動(dòng)齒輪系分析了合成速度。他</p><p>　　調(diào)速幅度和差速比的概念在他們的作品中沒有提到，并且兩電機(jī)的速度變化和功率之間的關(guān)系也沒有清楚的給出。但是這些概念對(duì)混合動(dòng)力機(jī)械選擇兩個(gè)電機(jī)的功率、決定傳統(tǒng)電機(jī)和伺服電機(jī)之間的工作負(fù)載分配非常重要而且

78、是絕對(duì)必要的。在參考文獻(xiàn)[1-3]中他們使用連桿機(jī)構(gòu)來實(shí)施機(jī)械壓力機(jī)的混合輸入。這種方法相當(dāng)復(fù)雜，因?yàn)檫B桿機(jī)構(gòu)每根連桿的長(zhǎng)度和位置的改變會(huì)對(duì)機(jī)械壓力機(jī)的滑塊運(yùn)動(dòng)產(chǎn)生影響。所以一些主要的問題在混合機(jī)械的課程研究中常常被忽略，而且研究結(jié)果不總是和實(shí)際工程條件相符合。差動(dòng)齒輪系有兩個(gè)自由度，并且任意兩軸之間的傳動(dòng)比是一個(gè)常數(shù)。為了簡(jiǎn)化機(jī)械模型并使得問題更加透明，在這篇文章中差速齒輪系常作為傳動(dòng)機(jī)構(gòu)來研究機(jī)械壓力機(jī)的混合問題。這篇文章討論了兩電

79、機(jī)調(diào)速幅度和功率之間的關(guān)系，兩電機(jī)之間的工作負(fù)載分配，并且提出了傳統(tǒng)電機(jī)和伺服電機(jī)同時(shí)工作、分開工作的兩種驅(qū)動(dòng)方案。隨著200噸的機(jī)械壓力機(jī)作為工程背景，機(jī)械壓力機(jī)的混合動(dòng)力驅(qū)動(dòng)系統(tǒng)已設(shè)計(jì)出來，并且在機(jī)械壓力機(jī)中的兩種驅(qū)動(dòng)方案的可行性也已得到了分析。</p><p>　　2、混合型機(jī)械的主要原則</p><p>　　帶有差動(dòng)齒輪系的混合機(jī)械壓力機(jī)的工作準(zhǔn)則在圖1中得到了說明。系統(tǒng)由傳統(tǒng)電機(jī)

80、（也叫作恒定速度的AC機(jī)器），伺服電機(jī)，減速器1，減速器2，差動(dòng)輪系和曲柄滑塊機(jī)構(gòu)組成。差動(dòng)輪系的輸出軸由曲柄滑塊機(jī)構(gòu)的曲柄軸連接而成。兩根輸入軸中的一根軸通過減速器1和傳統(tǒng)電機(jī)相連；另外一根輸入軸通過減速器2和伺服電機(jī)相連。因此曲柄軸的運(yùn)動(dòng)完全由傳統(tǒng)電機(jī)和伺服電機(jī)的運(yùn)動(dòng)來控制。減速器1和減速器2以串行方式安裝在兩個(gè)電機(jī)和差速齒輪系單元之間目的是為了承擔(dān)所有傳動(dòng)系統(tǒng)的一部分減速任務(wù)，因?yàn)樘蟮牟顒?dòng)齒輪系傳動(dòng)比會(huì)使得傳動(dòng)效率下降。傳統(tǒng)電機(jī)

81、的角速度是一個(gè)常數(shù)，所以它的價(jià)格更便宜。伺服電機(jī)的角速度是可調(diào)的，所以它的價(jià)格昂貴。混合動(dòng)力機(jī)構(gòu)系統(tǒng)中的輸出軸的恒定轉(zhuǎn)速由大功率的傳統(tǒng)電機(jī)提供；而伺服電機(jī)提供可調(diào)的速度。因此，用這種方式，不僅使得機(jī)械壓力機(jī)的曲柄軸的輸出運(yùn)動(dòng)靈活可變，而且還避免使用大功率的伺服電機(jī)。因此它既可以節(jié)約機(jī)器制造代價(jià)又可以節(jié)約機(jī)器運(yùn)轉(zhuǎn)成本。</p><p>　　圖1 差速齒輪系的混合機(jī)構(gòu)工作準(zhǔn)則</p><p>

82、　　3、機(jī)械壓力機(jī)滑塊的速度特征</p><p>　　機(jī)械壓力機(jī)的運(yùn)轉(zhuǎn)體現(xiàn)了周期性的變化規(guī)律。機(jī)械壓力機(jī)的滑塊在理想的工作條件下的位置和速度變化如圖2所示?；瑝K以很大的速度（稱作快速進(jìn)給階段）從頂部死角中心移到工作起點(diǎn)。當(dāng)機(jī)械壓力機(jī)的滑塊接近工作起點(diǎn)時(shí)，它的速度會(huì)從高速變成低速，然后以低速（稱作低速進(jìn)給階段）沖壓工件。低速的滑塊是為了避免對(duì)模具產(chǎn)生重大的影響，有益于塑料工件的成型。在滑塊完成沖壓工件并達(dá)到工件死角

83、中心的底部時(shí)，滑塊會(huì)以高速返回并最終停在死角中心的頂部（稱作快速返回階段）。因此，機(jī)械壓力機(jī)的滑塊的移動(dòng)速度可以分為三種情況：快速下降速度V1，緩慢工作速度V2，和快速返回速度V3。速度V1和V3應(yīng)該盡可能一樣快，速度V2應(yīng)該緩慢、靈活，目的是為了確保機(jī)械壓力機(jī)每分鐘的工作次數(shù)并能滿足不同技術(shù)的要求。事實(shí)上機(jī)械壓力機(jī)在到達(dá)死角中心的底部之前僅以一個(gè)很短的行程工作，而在其他行程中對(duì)工件來說是不工作的。</p><p&g

84、t;　　4、混合機(jī)械的術(shù)語和方程</p><p>　　4.1所有軸的角速度的關(guān)系</p><p>　　如圖1所示在差動(dòng)齒輪輪系中有三個(gè)外部軸。為了方便的表達(dá)三個(gè)軸之間的關(guān)系，和常規(guī)電機(jī)連接的軸叫軸1，和伺服電機(jī)連接的軸叫軸2，和曲軸連接的軸叫軸0。三根軸的角速度分別為n1,n2和n3。三根軸的力矩分別為M1，M2和M0。因?yàn)樵诓顒?dòng)齒輪系中有兩個(gè)自由度，僅第三根軸是固定的，由此確定了其它兩根

85、軸的傳動(dòng)比。所以這三根軸的傳動(dòng)比和角速度的關(guān)系需要表達(dá)出上標(biāo)和下標(biāo)的特點(diǎn)。</p><p>　　圖2 滑塊的理想核心位置</p><p>　　4.1.1常規(guī)電機(jī)對(duì)輸出運(yùn)動(dòng)的影響</p><p>　　當(dāng)伺服電機(jī)停止運(yùn)動(dòng)時(shí)，n2=0，只有常規(guī)電機(jī)的角速度影響輸出的角速度n0。</p><p>　　4.1.2伺服電機(jī)輸出運(yùn)動(dòng)的影響</p>

86、;<p>　　當(dāng)常規(guī)電機(jī)停止時(shí)，n1=0,僅有伺服電機(jī)的角速度影響輸出角速度n0。</p><p>　　當(dāng)n10代表軸0的角速度，并且i20代表從軸2到軸0的總的驅(qū)動(dòng)旋轉(zhuǎn)，當(dāng)軸1（伺服電機(jī)的軸）修理時(shí)它包括差速齒輪和減速器2。</p><p>　　4.1.3常規(guī)電機(jī)和伺服電機(jī)對(duì)輸出運(yùn)動(dòng)的影響</p><p>　　當(dāng)常規(guī)電機(jī)和伺服電機(jī)同時(shí)以經(jīng)過差速齒輪系

87、的組成來運(yùn)行時(shí)，輸出速度可以表達(dá)。當(dāng)K是伺服電機(jī)的實(shí)際角速度和特殊角速度之比時(shí)，數(shù)值相對(duì)的在1左右或+1，包括0.n20是伺服電機(jī)的特殊角速度。</p><p>　　4.2調(diào)速振幅和差速比</p><p><b>　　4.2.1調(diào)速振幅</b></p><p>　　為了正確的描述混合機(jī)械的差速齒輪系的變化速度，需要引入調(diào)速振幅的概念。如圖1所示

88、，調(diào)速振幅是最大和最小的絕對(duì)值之比。在混合機(jī)械的差速齒輪中，調(diào)速振幅等于運(yùn)行一個(gè)單獨(dú)伺服電機(jī)的軸0輸出速度和運(yùn)行一個(gè)單獨(dú)常規(guī)電機(jī)的軸0輸出速度之比。</p><p>　　在混合機(jī)械的差速齒輪中，調(diào)速振幅是最基本和最重要的技術(shù)參數(shù)。它不僅決定兩個(gè)輸出軸的速度匹配關(guān)系，還決定了伺服電機(jī)和常規(guī)電機(jī)安裝能力的匹配關(guān)系。</p><p>　　4.2.2差速齒輪速度比</p><p

89、>　　差速齒輪速度比通常用來表達(dá)在差速齒輪系中的調(diào)速技術(shù)體現(xiàn)。它是差速齒輪系統(tǒng)中的一項(xiàng)重要技術(shù)參數(shù)。差速齒輪比等于調(diào)速振幅的倒數(shù)值。</p><p>　　根據(jù)角速度和扭矩成反比，相同的載荷可以由常規(guī)電機(jī)和伺服電機(jī)來驅(qū)動(dòng)這一事實(shí)，一個(gè)代表兩個(gè)電機(jī)的功率的方程可以被推倒出來。</p><p>　　P是常規(guī)電機(jī)的功率，P=M1n1. P2是伺服電機(jī)的功率，P2=M2n2.</p&g

90、t;<p>　　4.3工作載荷功率分配</p><p>　　假設(shè)機(jī)械壓力機(jī)的工作載荷功率是P0，常規(guī)電機(jī)，伺服電機(jī)和工作載荷之間的功率關(guān)系可以表達(dá)如下。</p><p>　　圖3調(diào)速振幅的物理感應(yīng)</p><p>　　從（9）到（11），常規(guī)電機(jī)和伺服電機(jī)之間的輸出功率由K值決定，它等于伺服電機(jī)的角速度的變化之比。因此當(dāng)輸出角速度在不同的工作區(qū)域運(yùn)行時(shí)

91、，兩個(gè)電機(jī)載荷之比也不同。</p><p>　　4.3.1輸出軸以一個(gè)基本的速度運(yùn)行</p><p>　　當(dāng)伺服電機(jī)的輸出角速度等于0時(shí)，也就是，K=0，P2=0，從（9）中可以得到。這就是常規(guī)電機(jī)所承受的載荷功率。</p><p>　　4.3.2輸出軸在增速區(qū)域運(yùn)行</p><p>　　伺服電機(jī)在正方向運(yùn)行，0<K<1,P1和P

92、2都是正值，所以常規(guī)電機(jī)和伺服電機(jī)都承受一部分工作載荷。因此常規(guī)電機(jī)承受90.9%——100%的工作載荷，伺服電機(jī)僅承受0——9.1%的工作載荷。調(diào)速和差速比的數(shù)值決定了兩個(gè)電機(jī)之間的工作載荷分配。</p><p>　　4.3.3輸出軸在增速區(qū)域運(yùn)行。</p><p>　　在增速區(qū)域，伺服電機(jī)在負(fù)方向運(yùn)行，K值變化在0——1之間。根據(jù)方程（9）和（10），P1是負(fù)值。伺服電機(jī)的負(fù)值說明伺服

93、電機(jī)的功率已經(jīng)是工作阻力。因此常規(guī)電機(jī)不僅為工作載荷做功，還為伺服電機(jī)的功率做功。因此當(dāng)輸出角速度在減速區(qū)域，常規(guī)電機(jī)比其他領(lǐng)域消耗更多的能量。輸出速度的減小是以消耗伺服電機(jī)的輸入功率來衡量的。為了節(jié)約能量，輸出角速度應(yīng)當(dāng)避免或者減少在減速區(qū)域運(yùn)行。</p><p>　　4.4混合機(jī)械壓力機(jī)的兩種驅(qū)動(dòng)方案</p><p>　　根據(jù)方程（3），混合機(jī)械的輸出角速度和常規(guī)電機(jī)，伺服電機(jī)角速度和

94、的減少值相等。如圖1所示，差速齒輪系的輸出角速度和機(jī)械壓力機(jī)的曲柄軸有聯(lián)系，所以這兩個(gè)軸有相同的角速度。當(dāng)常規(guī)電機(jī)或伺服電機(jī)驅(qū)動(dòng)時(shí)，或同時(shí)驅(qū)動(dòng)它們時(shí)，機(jī)械壓力機(jī)的曲柄滑塊可以獲得差動(dòng)角速度。因此，混合機(jī)械壓力機(jī)有兩種建議方案：（i）常規(guī)電機(jī)和伺服電機(jī)同時(shí)驅(qū)動(dòng)；（ii）常規(guī)電機(jī)和伺服電機(jī)分開驅(qū)動(dòng)。</p><p>　　4.4.1常規(guī)電機(jī)和伺服電機(jī)同時(shí)驅(qū)動(dòng)</p><p>　　這種方案表明機(jī)械

95、壓力機(jī)曲柄軸的角速度由常規(guī)電機(jī)的角速度作為基本速度和伺服電機(jī)的角速度作為調(diào)速組成（圖3）.角速度和功率可由方程（1）——（18）來計(jì)算。</p><p>　　4.4.2常規(guī)電機(jī)和伺服電機(jī)分開驅(qū)動(dòng)</p><p>　　這種方案表明在混合輸入過程中只驅(qū)動(dòng)一臺(tái)電動(dòng)機(jī)，同時(shí)另一個(gè)電機(jī)制動(dòng)，即當(dāng)曲柄軸在不同的運(yùn)行階段，常規(guī)電機(jī)和伺服電機(jī)是分開運(yùn)行的；因此可以獲得不同的輸出角速度。靈活的低速運(yùn)行，當(dāng)常

96、規(guī)電機(jī)制動(dòng)，伺服電機(jī)運(yùn)行時(shí),n1=0。</p><p>　　因?yàn)?<K<+1,所以曲柄軸的輸出角速度是可以調(diào)節(jié)的而且能設(shè)計(jì)出來，且能獲得一個(gè)很小的輸出角速度n10。因此在這個(gè)過程中輸出角速度是很小的而且還很靈活。當(dāng)伺服電機(jī)止動(dòng)時(shí)常規(guī)電機(jī)運(yùn)行，n2=0，從方程（5）中我們可以得到。曲柄軸有兩個(gè)旋轉(zhuǎn)方向；因此它很靈活。</p><p>　　圖4兩種輸出角速度的物理感應(yīng)比較</

97、p><p>　　因?yàn)轵?qū)動(dòng)旋轉(zhuǎn)比i10和i20相互依賴，常規(guī)電機(jī)的運(yùn)行和伺服運(yùn)行也是相互依賴的，兩個(gè)驅(qū)動(dòng)比的數(shù)值可以設(shè)置不同的數(shù)值（一個(gè)很小，另一個(gè)很大），</p><p>　　所以這兩個(gè)輸出角速度可以不同。所以運(yùn)行可以滿足機(jī)械壓力機(jī)滑塊在不同時(shí)期的運(yùn)行需要。這兩個(gè)輸出角速度的物理感應(yīng)比較可以由圖4來說明。</p><p><b>　　5總結(jié)</b>

98、</p><p>　　根據(jù)機(jī)械壓力機(jī)的速度特征，差速齒輪系可以應(yīng)用在混合壓力機(jī)的混合機(jī)械中。通過以上的分析和計(jì)算，可以得到如下結(jié)論：</p><p>　　調(diào)速振幅和差速比是混合機(jī)械的兩個(gè)重要參數(shù)。它們不僅是可調(diào)速度和基本速度之比，也是伺服電機(jī)和常規(guī)電機(jī)的功率之比。</p><p>　　由于常規(guī)電機(jī)和伺服電機(jī)同時(shí)驅(qū)動(dòng)的這個(gè)方案，這兩種電機(jī)的功率可以設(shè)置成很大的數(shù)值，目