人工髖關(guān)節(jié)模擬試驗機(jī)機(jī)械傳動部分的研制（上置式 ）,人工髖關(guān)節(jié)模擬試驗機(jī)機(jī)械傳動部分的研制（上置式,人工,髖關(guān)節(jié),模擬,摹擬,試驗,實驗,機(jī)械傳動,部分,部份,研制,上置式 翻譯 Current driveline concepts 1. Engine developments Gasoline and Diesel engines are the dominant drive units of today. Hybrid concepts and fuel cells have so far only conquered market niches or have not yet developed beyond the design stage. New injection technologies, such as pump nozzle and common rail, are now common for Diesel engines. This resulted in significant fuel savings and improved driving dynamics due to raised torque and performance. Presently, multi-point injection is the dominant method for gas engine concepts. Increasingly stringent emission laws, the requirements of the European Parliament and the voluntary commitment of the European automobile industry to reduce the average CO2 emission of newly registered passenger cars by 25% by the year 2008 compared to the year 1995, will require significant reductions in fleet consumption and emissions within the next few years. this will result in a diversification of drive concepts for gas engines .DI versions will share the market with displacementreduced, supercharged engines , electromechanical and mechanical valve-gear systems and their combinations .The future-oriented concepts of complete de-throttling of the gas engine by means of charge stratification or volumetric efficiency control and shifting of the load cycle into the efficiency-optimal range of the engine graph will decisively contribute to the technology of the gas engine in the coming decades . Downsizing and supercharging will significantly raise specific maximum engine torque levels in the next few years. 2. Transmission types The Manual Transmission/MT and the Automatic Transmission/AT are the transmissions presently firmly established in the market . For some years the market has seen the appearance of the Automated Manual Transmission/AMT and the Continuously Variable Transmission/CVT, whose shares in the market are still very small. Manual transmissions are cheap , of relatively small size ,and their spur gears provide good efficiency , Consumption largely depends on the driver’s shifting style and the vehicle concept. The comfort of an automatic transmission is approached through automated shifting and cluthing . More gears snd the concomitant enhanced spacing also increase comfort . High efficiency ,favorable weight and low cost are factors that ate retained. Traction interruption , associated with automated shifting and regarded as impairing comfort , will be reduced in future AMTs by an optimized gearshift process . The powershifting double-clutch transmission with two separate transmission input shafts is part of this development . Gears are preselected in the load-free section of the transmission ,gear steps ate changed under full load through controlled trolled torque transfer from the first to the second clutch. Ats have undergone a continuous development process in recent years an have become even more comfortable ,lighter and economical . New gear set comfortable , lighter and economical .New gear set concepts and more gear steps will continue this trend . Their very high level of comfort ,how ever , is associated with a complex design and a relatively high weight and limited efficiency . Comfortable shifting with the CVT is principlerelated . Acceleration ideally follows the traction hyperbola , The initial engine speed increase fllowed by comtinuos transmission ratio variation , how ever ,is new .There is a delay between the initiation of acceleration and the following response . The hydraulically produced frictional connection in the variator , which transfers the torque to the output ,suggests increased consumption . Wide spacing , however ,lowers this for vehicles with manual transmissions. 3. Starting components Today ,there basic concepts are available for shifting and starting : . the dry clutch ; . the wet clutch ; . the torque converter; The dry clutch is known for . its very good efficiency; . its good controllability; . its drag torque –free feature: . its relatively small mass moment of inertia . The very good efficiency of the normally-closed dry clutch is due to the absence of auxiliary power .Other solutions always need pressure and thus additional power in the bridged or closed condition . Wet clutch advantage are : . little mass ; . very small mass moment of inertia; . very good controllability; . high power density and great torque capacity. The wet clutch is therefore optimally suited for vehicles with small installation space and very high torque levels. Due to its function as a hydrodynamic hydraulic transmission ,the torque converter with or without slip-controlled lockup clutch and torsionalvibration damper offers . . efficiency advantages in the non-bridged condition and . and a torque translated by the hydraulic transmission as well as . over load protection 目前的傳動系概念 1 發(fā)動機(jī)的發(fā)展 汽油和柴油發(fā)動機(jī)是目前主要的驅(qū)動元件，混合驅(qū)動和燃料電池仍處于設(shè)計開發(fā)階段尚未占領(lǐng)市場。新型的噴射技術(shù)，如共軌泵噴射，通常被應(yīng)用于柴油發(fā)動機(jī)。它大幅度降低了油耗并由于提高了發(fā)動機(jī)的轉(zhuǎn)矩和性能改善了動態(tài)傳動特性。 目前多點直接噴射廣泛應(yīng)用于汽油發(fā)動機(jī)。為了滿足苛刻的排放法規(guī)，歐洲議會和歐洲汽車工業(yè)協(xié)會要求在2008年將新注冊的轎車的CO2排放量在1995年水平上降低25%，這需要在近幾年內(nèi)明顯降低車輛的能耗和排放，這導(dǎo)致了汽油發(fā)動機(jī)用傳動系的多樣化。直接噴射系統(tǒng)將通過減少排量，發(fā)動機(jī)增壓、機(jī)電一體化或機(jī)械式閥門配氣機(jī)構(gòu)系統(tǒng)及他們的組合占領(lǐng)部分市場。采用分層進(jìn)氣或容積效率控制的汽油機(jī)多氣門技術(shù)和是發(fā)動機(jī)工作在高效率區(qū)的負(fù)荷循環(huán)換擋概念將是全分離節(jié)氣門汽油發(fā)動機(jī)今后幾十年的兩大主要技術(shù)。 小型化和發(fā)動機(jī)增壓技術(shù)在未來幾年內(nèi)將明顯提高發(fā)動機(jī)最大轉(zhuǎn)矩的水平。 2 變速器類型 手動變速器（MT）和自動變速器（AT）是目前變速器市場的主要產(chǎn)品，幾年前市場上開始出現(xiàn)機(jī)械自動變速器（AMT）和無級變速器（CVT），但它們僅占有極小的市場份額。 手動變速器便宜，體積較小、并且圓柱齒輪組的效率很高，能耗主要取決于駕駛員的換擋技術(shù)和車輛形式。 自動變速器的舒適性體現(xiàn)在自動換擋和離合器的自動工作上，教多的擋位及相應(yīng)增加的間距也改善了舒適性，效率高、重量合適和成本底是該類變速器生存的要點。 換擋時存在的牽引力中斷現(xiàn)象對舒適性有影響，將來的AMT可通過采用優(yōu)化換擋措施減少之。有兩根對立變速器輸入軸的雙離合器動力換擋變速器是AMT的一個發(fā)展方向，它在變速器的無負(fù)荷部分進(jìn)行預(yù)換擋，通過控制第一和第二離合器上的轉(zhuǎn)矩轉(zhuǎn)移實現(xiàn)所掛擋位的加載過程。 自動變速器經(jīng)過這些年的不斷發(fā)展，已變得更舒適、更輕和更經(jīng)濟(jì)。新型的齒輪組和更多的擋位將繼續(xù)是其發(fā)展趨勢。但是他們非常高的舒適性導(dǎo)致了復(fù)雜的設(shè)計相對較大的質(zhì)量和有限的效率。 從理論上講，CVT具有很高的換擋舒適性。其加速度與牽引力的雙曲線非常吻合。然而新問題是發(fā)動機(jī)起始轉(zhuǎn)速的增加與無級變速器速比變化有關(guān)。這里存在一個起始加速度和其響應(yīng)之間的滯后，將轉(zhuǎn)矩傳遞至輸出端時液力產(chǎn)生的摩擦連接會增加能耗。同時較寬的距離降低了它在手動變速器的車輛上的應(yīng)用。 3 起動元件 目前有三種不同的換擋和起動形式： 干式離合器 濕式離合器 變矩器 干式離合器具有如下特性： 非常高的效率 良好的控制性能 轉(zhuǎn)矩過載保護(hù)特性 轉(zhuǎn)動慣量相對較小 常閉干式離合器的高效率是由于不需要輔助動力的緣故。其他結(jié)構(gòu)的解決方法常常要在結(jié)合或閉合時壓力因而輔助動力。 濕式離合器的優(yōu)點是： 質(zhì)量小 非常小的轉(zhuǎn)動慣量 非常優(yōu)秀的控制性能 高的功率密度和大的傳扭能力 因此濕式離合器可很好的適用于那些安裝空間小并需傳遞大傳遞大轉(zhuǎn)矩的車輛。 變矩器的功能可看成一流體動力的液力變速器，帶或不帶滑差控制鎖止離合器和扭轉(zhuǎn)減振器的變矩器具有如下功能： 未結(jié)合時功效好 轉(zhuǎn)矩通過液力變速器傳遞 過載保護(hù)