【正文】 eing simultaneously driven, the power of the two motors has to be assigned high value in order to satisfy the velocity requirements of the mechanical press. So doing increases the manufacturing cost and the operation cost of the mechanical press, and therefore is valueless in practical application. (3) With the scheme of the conventional motor and the servomotor being separately driven, the power of the servomotor can be assigned low value in order to satisfy the velocity requirements of the mechanical press. So doing decreases the manufacturing cost and the operation cost of the mechanical press. Therefore, this scheme proposes a feasible way in practical industrial engineering. 研究利用差動(dòng)齒輪系實(shí)現(xiàn)機(jī)械混合壓力 本文對(duì)機(jī)械壓力混合輸入的問(wèn)題進(jìn)行了研究，用差動(dòng)輪系作為傳動(dòng)機(jī)構(gòu)。 and uses ser — vomotor with low power 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 of slider[1]. So the mechanical press of hybrid mechanism arouses many researchers’ interest in working on it。 2 School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049, China The problems of hybrid input of mechanical press are studied in this paper, with differential gear train as transmission mechanism. It is proposed that “adjustablespeed amplitude” or “differentialspeed ratio” is the important parameters for the hybrid input mechanism. It not only defines the amplitude of the adjustable speed, but also determines the ratio of the power of the servomotor to the power of the conventional motor. The calculating equations 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 simultaneously drive and the servomotor and the conventional motor separately drive. The calculating results demonstrate that the latter scheme can use much lower power of the servomotor, so this scheme makes manufacture and use cost much lower. The latter scheme proposes a feasible way to apply the hybrid mechanism of mechanical press in practice engineering. mechanical press, hybrid mechanism, differential gear train, adjustablespeed 1 Introduction At present there are many research papers about the hybrid mechanism of mechanical press, and it has bee a hot research topic. The hybrid mechanism is a mechanism with 2degreeof freedom (also called differential speed mechanism), and when two independent motions are input at the same time, the output that can satisfy some motion requirements is obtained through the motion position of the mechanism. The hybrid mechanism is also called controllable mechanism, or 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。 therefore it is flexible. A big value of the drive ratio 1 i20 can be designed, 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 , from eq. (5), we have. Crankshaft has two rotating directions。 機(jī)械壓力，混合機(jī)制，差動(dòng)輪系，調(diào)速 引言 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。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。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)。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(lái)控制。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。 混合機(jī)械的術(shù)語(yǔ)和方程 所有軸的角速度的關(guān)系 如圖 1所示在差動(dòng)齒輪輪系中有三個(gè)外部軸。 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。 差速齒輪速度比 差速齒輪速度比通常用來(lái)表達(dá)在差速 齒輪系中的調(diào)速技術(shù)體現(xiàn)。這就是常規(guī)電機(jī)所承受的載荷功率。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。 常規(guī)電機(jī)和伺服電機(jī)同時(shí)驅(qū)動(dòng) 這種方案表明機(jī)械壓力機(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(lái)計(jì)算。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。所以減少了制造成本和機(jī)械壓力機(jī)的運(yùn)行成本。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。因此在這個(gè)過(guò)程中輸出角速度是很小的而且還很靈活。 混合機(jī)械壓力機(jī)的兩種驅(qū)動(dòng)方案 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 的減少值相等。 輸出軸在增速區(qū)域運(yùn)行。 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. 工作載荷功率分配 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。如圖 1 所示，調(diào)速振幅是最大和最小的絕對(duì)值之比。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軸的傳動(dòng)比。在滑塊完成沖壓工件并達(dá)到工件死角中心的底部時(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）?；旌蟿?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。 混合型機(jī)械的主要原則 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(shuō)明。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是絕對(duì)必要的。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。 and the servomotor provides its adjustable speed. Therefore, in this way, it not only makes the output motion of the crankshaft of the mechanical press flexible, but also avoids using high power servomotor. Hence it could save