采用一种自动轿车变速箱实现动力换档范围改变——一种开发概念研究

采用一种自动轿车变速箱实现动力换档范围改变──一种开发概念研究ＲｅａｌｉｚａｔｉｏｎｏｆＲａｎｇｅ－ＣｈａｎｇｅＰｏｗｅｒｓｈｉｆｔＵｓｉｎｇａｎＡｕｔｏｍａｔｉｃＣａｒＴｒａｎｓｍｉｓｓｉｏｎ－ＣｏｎｃｅｐｔＤｅｖｅｌｏｐｍｅｎｔＳｔｕｄｙ￥ＺＦＦ...     

ZF Ecotronic-CVT 节油无级自动变速箱──中型与豪华车用新型自动无级变速箱给驾驶者带来更多的福音

ＺＦＥｃｏｔｒｏｎｉｃ－ＣＶＴ节油无级自动变速箱ＦＵＥＬ┐ＳＡＶＩＮＧＺＦ┐ＥＣＯＴＲＯＮＩＣ┐ＣＶＴＡＵＴＯＭＡＴＩＣ中型与豪华车用新型自动无级变速箱给驾驶者带来更多的福音Ｎｅｗｃｏｎｔｉｎｕｏｕｓｌｙｖａｒｉａｂｌｅｔｒａｎｓｍｉｓｉｏｎｆｏｒｍ...     

ZF无级变速器（CVT）ECOTRONIC地开发与装置的优越性

现在对汽车一个非常重要的课题是要改善燃油消耗、安全性和舒适性。ＣＶＴ技术可起到十分重要的作用。本文介绍新开发的ＺＦ ＥＣＯＴＲＯＮＩＣ ＣＶＴ予示在中等轿车中安装自动变速器的时代将发生变化。采用无级变速ＺＦ ＥＣＯＹＴＲＯＮＩＣ变速器，你的德国将会更舒适、安全和更经济。ＺＦ ＥＣＯＴＲＯＮＩＣ是ＺＦ对现代金融和生态的回报。     

信息之窗

１　未来的发展目标——ＺＦ－ＥＥ驱动　　今天的城区环境保护要求未来的公共汽车要有所创新。图１　电驱动低底板公共汽车尽管近年来为减少传动系统对环境污染做了许多努力,如推行欧共体１与欧共体２废气排放规定,选用其他动力原料,但“消灭废气排放”的呼声日趋强烈。为此,在低底板公共汽车领域,继推出自动变速箱、门式驱动桥和独立悬挂前桥后,ＺＦ正在研制开发电驱动传动系统。新的驱动技术将使公交车辆更吸引公众（图２）。　　采用ＺＦＥＥ传动技术使公共汽车的离地间隙约为３２０ｍｍ,无需提高车厢底板（图３）。　　灵活多变…     

单片机在轴承温升检测系统中的应用

１问题的提出在为“桑塔纳”国产化西Ｚ套开发试制过程中，研究生产了一大批高附加值、高技术含量、市场需求量大的轴承产品，其中有差速器轴承、四挡变速箱轴承、悬挂减振器轴承、张紧轮轴承等。为了保证轴承的质量，在出厂前对每个轴承进行高低速运转温升测试，要求能够自动控制、自动显示以及自动打印试验结果。用一般的检验手段是不可能达到目的的。故研究一种用单片机对轴承温升检测控制的方法具有一定的实用价值，单片机轴承温升控制系统是为轿车张紧轮轴承温升试验机配置的温度检测与控制设备。其系统功能要求如下：（１）试验台有３…     

吉利首款自主自动挡车即将正式投放市场

近日，从吉利汽车获悉，我国首款完全具有自主知识产权的自动挡轿车将正式投放市场。吉利自动变速箱，是吉利为匹配1.0L、1．3L、1．5L轿车而自主研发的一系三型系列产品。去年5月，吉利自主研发的自动变速箱实现了产业化生产。     

FTIR定量分析润滑油中的ZDDP

根据Ｐ－Ｅ公司ＦＴＩＲ定量软件原理，设计分析方法进行润滑油中ＺＤＤＰ含量的测定，数据误差小于５％，与ＭＯＡ油料光谱仪再现性小于１５％。本方法对于润滑油中ＺＤＤＰ的定量分析有很大实际应用价值。     

轿车变速箱齿轮磨合次数对疲劳寿命影响的试验研究

为了使相同尺寸规格的变速箱满足不同型号车辆对变速箱强度的不同要求，也为了合理设置变速箱齿轮的磨合次数，以达到最佳强化效果，对某型轿车变速齿轮的磨合次数进行初步研究。在试验的基础上，给出该变速箱齿轮低载强化的最佳磨合次数，并总结出该齿轮在交变载荷下不同磨合次数的疲劳寿命增长规律。有助于提高轿车变速箱齿轮的疲劳寿命，也为进一步制定轿车变速箱齿轮的磨合规范提供技术依据。     

自动变速箱系统的对比

本文论述了在轿车和商用车辆中具有重要应用的各种不同的自动变速箱(普通自动变速箱、自动化变速箱、双离合器式变速箱和无级变速箱),并根据它们的基本准则(起动性能、效率、发动机-变速箱匹配、噪音、尺寸/重量)进行了对比性的评估。最后,对各种变速箱未来的应用前景进行了预测。     

ZF传动技术(苏州)有限公司--ZF目标瞄准公共汽车/客车市场

ＺＦ传动技术（苏州）有限公司是德国最大的商用车辆传动系统产品供应厂商所建立的独资公司。ＺＦ目睹这日益明显的发展趋势：中国需要在与欧洲公共汽车与客车制造厂合作生产的底盘的基础上生产功率更大,速度更快的公共汽车和客车。ＺＦ决定为此建立一家独资公司,装配和销售完整的传动系统产品。其产品包括ＺＦＳｅｒｖｏｃｏｍ动力转向系统、６档同步手动（以后发展为全自动ＺＦＥｃｏｍａｔ）变速箱、客车用独立悬挂前轮圈与后从动桥、ＺＦ　　ＺＦＤｒｉｖｅｔｅｃｈ（Ｓｕｚｈｏｕ）Ｃｏ．Ｌｔｄ．ｉｓａｗｈｏｌｌｙｆｏｒ－ｅｉｇｎ…     

新型自动变速箱对润滑油的额外要求

减少二氧化碳排放是防止地球大气层受到对气候有影响的微量气体之影响的一种努力。所有的消费市场都必须增加效率和最经济地使用化石能源。为了尽可能利用所有的节油措施，同时继续提供对重要的安全和舒适性标准，汽车工业早已不对发动机消耗抱有希望。他们的努力集中在改善整车效率上。新变速器采用智能化的电控系统以优化发动机和变速器的互相作用，它能显著改善排放。常规的有级自动变速器现正被新型的无级自动变速器（ＣＶＴ）所     

Evaluating lifetime performance of limited slip differentials

Extensive research has been performed regarding wet clutch function and performance. Although wet clutches are used in both automatic transmissions and limited slip differentials in cars, most research has been performed for wet clutches incorporated in automatic transmissions. The operating conditions of wet clutches in automatic transmissions differ from the operating conditions of the wet clutches used in limited slip differentials. Therefore, a method and a test bench to use in the investigation of the degradation of limited slip differentials were developed in this work. The typical operating conditions of the limited slip differential and the differences compared with wet clutches incorporated in automatic transmissions were also addressed. Tests performed showed that the developed test bench and method can be used to address differences in frictional response over time for different types of operating conditions. Copyright © 2013 John Wiley & Sons, Ltd.     

ZF6档自动变速器:燃油经济性和对环保的贡献

随着ZF于2001年首先在后轮驱动轿车中引入6档自动变速器后,在自动变速器的燃油经济性和环保方面迈进了一大步.与5档自动变速器相比,新的6档自动变速器至少能节约5%的燃油.另外新的齿轮组件、低粘度润滑油和滑差控制锁止离合器等新技术也随之被开发.新6档自动变速器比5档自动变速器更小,长度短10-15%.变速器的零部件数减少了30%.由于将TCU集成在机电一体化模块中,将线束减至最少.采用新的负载控制策略后减少了内部元件的尺寸.由于具有这些优点,6档自动变速器正成为中级和豪华轿车的现代化配置.ZF正在用全新的3款变速器替代5档变速器.在2005年,ZF6档变速器的产量最佳90%以上.     

Future helicopter transmission oils

For many years helicopter transmissions have shown low reliability relative to planned overhaul lives and to other comparable lubricated systems. Reasons for this include the extremely wide range of conditions encountered by the lubricant in helicopter transmissions and also the requirement that, in many cases, the oil be common to both transmission and gas turbine engines. Recently acquired understanding of lubrication mechanisms shows that potential exists both for improved performance and for the ability to cater for higher temperatures by the development of new helicopter transmission oils based on synthetic lubricants. This paper discusses the particular lubricating problems associated with helicopter transmission lubrication and describes test methods and formulation approaches to improving such lubricants.     

Frictional Behavior of a Wet Clutch Using Blends of Automatic Transmission Fluid (ATF) and Biolubricant (Jatropha Oil) in a Pin-on-Disk Tester

Nowadays, biolubricants are being used to replace mineral lubricants totally or partially and it is of great importance due to interest in environmental protection. Jatropha oil is a good alternative as lubricant feedstock and combustible. Its production is cheap in comparison to other vegetable oils. In México, Jatropha curcas L. is widely distributed in more than 15 states, which makes a sustainable supply of this natural resource possible. The aim of this work was to investigate the frictional behavior of blends of automatic transmission fluid with vegetable oil tested in a pin-on-disk rig simulating the wet clutch operation. Two different friction materials were separately tested and used as pins against actual steel disks from a wet clutch. The frictional behavior results demonstrated that the mixtures presented antishudder characteristics. Thus, Jatropha oil could be potentially used as part of automatic transmission fluid (ATF) formulations to enhance their antishudder properties and increase the efficiency of the torque transferred of wet clutches with a controlled lock-up clutch system, which improves the full economy of vehicles.     

Modification of Boundary Lubrication by Oil-Soluble Friction Modifier Additives

The molecular-level function of model and commercial friction modifier additives in lubricants of the type used at the wet clutch interface in automatic transmissions has been studied using a surface forces apparatus (SFA) modified for oscillatory shear. The nanorheological properties of tetradecane with and without a model friction modifier additive (1-hexadecylamine) were examined in the boundary lubrication regime and compared to a fully-formulated automatic transmission fluid (ATF). 1-Hexadecylamine adsorbed as a single layer on the sliding surfaces, reduced the static frictional force and the limiting shear stress, and eliminated the stick–slip transition that exists in pure tetradecane. The ATF, which contains commercial-grade friction modifiers, showed nanorheological properties similar to those observed for tetradecane containing 0.1–0.2 wt% 1-hexadecylamine.     

Temperature—friction characteristics of cylinder lubrication in large,slow, cross‐head marine diesel engines under boundary lubrication conditions

In large, slow, cross‐head marine diesel engines research has increasingly shown that the lubrication regime between piston rings and cylinder liner at top dead centre is of the boundary lubrication type due to the high gas pressure, low sliding speed, and high temperature. This means that the tribological properties of piston ring, cylinder liner, and cylinder lubricant in these types of engine under boundary lubrication conditions should be considered simultaneously when friction and wear between the piston ring and cylinder liner are studied. Until now there has been no standard method to evaluate boundary lubrication performance. There are a few traditional methods used in lubricant research, but their results are not correlated with service conditions. It is important to find a suitable method to evaluate the boundary lubrication performance of lubricants at the laboratory testing stage or before the engine testing stage. The important parameters, such as sliding speed, normal load, materials of the contacting pairs, and lubricant, need all to be controlled. In this paper a systematic experimental procedure, the ‘five times heating and cooling test’, is introduced to assess lubricant properties under boundary lubrication conditions. Most of the parameters mentioned above are controlled. The model contact, of pin‐on‐plate form, is made from the actual piston and liner materials used in a large‐bore, slow, cross‐head marine diesel engine. The temperature characteristics of different blends of lubricants are investigated under boundary lubrication conditions using a pin‐on‐plate reciprocating test rig. These blends of lubricants have the same additives but different base fluids; they nevertheless fulfil the physical and chemical requirements of a real marine diesel engine. The test temperature range is from room temperature to the working temperature of the top piston ring. The experiments show that there are different temperature—friction characteristics for lubricants with different bases and the same additive package and there are also different temperature—friction characteristics during heating up and cooling down for each blend. Single‐base lubricants have more promising temperature—friction characteristics than those of a blend of a high‐viscosity base and a low‐viscosity base at high temperature.     

Biobased dry‐film metalworking lubricants

Metalworking lubricants must allow the manufacture of acceptable products at competitive cost without causing harm to operators or the environment. One way of attaining such a goal is through the use of biobased raw materials in lubricant formaulations. Biobased materials are generally non‐toxic, easily biodegradable, and abundantly available from renewable agricultural sources. However, successful application of biobased marterials in lubrication requires a thorough understanding of the tribochemical properties of these agricultural products. Recent studies have shown that biobased lubricants comprising starch and vegetable oils have promising lubrication properties. This paper discusses investigations into the effect of film thickness on the friction properties of dry‐film lubricants formulated from starch‐soybean oil composites.     

Slip control strategy for an automatic transmission vehicle

Modern automatic transmissions equip torque converters with lock-up clutches to reduce the energy loss of hydraulic systems. Instead of simply engaging the clutch disks, the new technology of clutch slip has been developed to improve the overall efficiency of power transmission. There are two major problems with the clutch slip system. The first is how to keep the slip between the two disks within a small range and the second is when to start or stop the slip. In this paper, the second problem is discussed in view of the vehicle economy. With a simple vehicle dynamic model, the fuel economy is calculated to determine the lock-up strategy. Then the lock-up strategy is developed for a slip schedule.     

A study on the tribological characteristics of graphite nano lubricants

Many researchers have tried to improve the tribological characteristics of lubricants to decrease friction coefficients and wear rates. One approach is simply the use of additives in the base lubricant to change its properties. Recently, nanoparticles have emerged as a new kind of additive because of their size, shape and other properties. A nano lubricant is a new kind of engineering lubricant made of nanoparticles, dispersant, and base lubricant. In this study, graphite nanoparticles were used to fabricate nano lubricants with enhanced tribological properties and lubrication characteristics. The base lubricant used was industrial gear oil, which has a kinematic viscosity of 220 cSt at 40°C. To investigate the physical and tribological properties of nano lubricants, friction coefficients and temperatures were measured by a disk-on-disk tribotester. The surfaces of the fixed plates were observed by a scanning electron microscope and an atomic force microscope to analyze the characteristics of the friction surfaces. The results show that when comparing fixed plates coated with raw and nano lubricants, the plate coated with a nano lubricant containing graphite nanoparticles had a lower friction coefficient and less wear. These results indicate that graphite nanoparticle additives improve the lubrication properties of regular lubricants.