transmission_technology_international_变速器技术2010-09_(2)

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1、Accelerating into the future24OEMintErviEw:FiatTransmission Technology International | September 2010Fiat may be steeped in the tradition of manual transmissions but that does not mean the Italian car makers sole focus is on conventional gearbox technology n Being the dedicated R&D engine and transm

2、ission division to one of Europes largest car making groups is no easy task, but thats exactly the role Fiat Powertrain Technologies (FPT) fulfills for Fiat Group. First, a few numbers to put everything into context: FPT delivers 2.9 million engines a year, makes 2.4 million transmissions, employs 2

3、0,000 people, and has a footprint across 10 countries all of which makes the Italian company a highly significant player in the global powertrain marketplace. And this does not include the development of new engine ideas, notions and concepts taking place on a daily basis. “Fiats transmission market

4、 is 50% European and 40% Latin American, with the remaining 10% in India and China,” outlines Sergio Cairola, FPT transmission platforms vice president and a Fiat veteran who has been developing engines and transmissions there for nearly 25 years. “Today we produce transmissions not only for our veh

5、icles but also for the likes of the Ford Ka, and Peugeot in Argentina.” As for the types of transmissions on the agenda, Cairola settles this argument very quickly: “Fiat transmissions were born manual,” he says. “Manual is the dominant technology and will remain dominant in our portfolio.”But thats

6、 not to say that FPT is focused exclusively on manual transmissions far from it, in fact. Not only has Fiat been manufacturing automatics for over a decade, the company also has a portfolio in the A, B and C class segments for AMTs. However, most noteworthy within Fiats recent transmission ventures

7、has been its entry into the DCT marketplace. “Even though it is likely automatic transmissions will remain dominant worldwide for now, we believe that the dual clutch has the highest potential growth,” confirms Cairola. “We had long and passionate discussions on the subject and made a thorough compa

8、rison analysis. Our view is that the DCT offers the optimal balance between fuel economy, comfort, sportiness and cost.”Fiats DCT is part of the new C635 family of transmissions being constructed at the FPT facility in Verrone, Italy. Available in a six-gear layout, the dry DCT can handle torque inp

9、uts of 350Nm, making it the highest-torque dry-clutch application in the world. Known as the Alfa TCT transmission, it weighs just 81kg complete with oil and transmission control unit, and is being debuted in the new Alfa Romeo MiTo.“The TCT consists of two gearboxes, each with its own clutch, which

10、 allows for the selection and engagement of the next gear, while the previous one is still engaged,” explains Cairola. “This kind of gear change OEM intErviEw: Fiatwords: Saul wordsworth25September 2010 | Transmission Technology International“Our view is that the DCT offers the optimal balance betwe

11、en fuel economy, comfort, sportiness and cost”Above: tipping the scales at just 81kg, the Alfa tCt consists of two gearboxes, each with its own clutchLeft: Sergio Cairola, FPt transmission platforms vP, says manuals will remain the dominant transmission for FiatBelow: tCt made its debut in the Alfa

12、Mito earlier this yearmeans continuous torque delivery and traction, the outcome of which is a greater level of comfort than a conventional automatic transmission, as well as a sportier feel.“The speed of the gear change and the ability to switch between manual and automatic, plus the near-zero powe

13、r loss during gear change, make it the most efficient automatic transmission in terms of fuel consumption levels.”The brand new TCT transmission boasts the largest number of interactions with a vehicles systems available today. These include the brake and accelerator controls, steering wheel and Alf

14、as stop/start system, all of which means the DCT contains 23 patents in the areas of gearbox control, mechanics and actuator.But despite Fiat, and a host of other car makers and suppliers championing the DCTs cause, Cairola believes that over the next ten years the manual transmission within Fiat wi

15、ll still remain predominant. “Of course we are interested in other kinds of transmissions, particularly DCTs which are planned to reach 25% of total FPT volumes,” he says. “However our focus will remain in our traditional market. This approach makes sense.” Unlike some of its competitors, FTP also i

16、ntends to keep things simple. “Although a few manufacturers continue to look at seven- and eight-speed transmissions, we see this as too many operations and too challenging for the operator,” he adds. “The challenge for us is therefore to achieve a continuous evolution and optimization of the six-sp

17、eed manufacturing footprint.”In the longer term Cairola predicts a steady rise in the volume of hybrid technology, particularly for customers with significant coast and stop time in other words, small, compact cars designed for congested, inner-city driving environments. “The challenge is to offer t

18、his technology at a fair market price,” he explains. “FPT is developing a new small DCCT to be the basis for a compact, low-weight and low-cost hybrid powertrain, in combination with the TwinAir turbo engine. The design concept will allow for an add-on option of the baseline powertrain, minimizing s

19、pecific investments and R&D costs.” The transmission world waits with baited breath. TTiHome improvementsFTPs plant in Verrone, near Turin, might date back to 1974, but in every other way, this facility is very modern. Not only has it been showered with awards, including those for quality and cost c

20、ontrol, its grounds also encompass part of a local nature reserve called Le Baragge. So, when it came to selecting a new production line for the creation of the C635 family of transmissions, there was little debate as to where it was to be built.The new facility at Verrone cost the best part of US$6

21、50 million, most of which was spent on equipment and R&D. Boasting a floor space of 35,000m2, the area is divided between processing and assembly units and houses nearly 200 cutting-edge machine tools. “All the equipment has been selected from the worlds best suppliers to ensure optimal performance,

22、” says Cairola. “To guarantee every transmission is of the quality we expect, we carry out final inspections on all the products we manufacture.”The investment to date in technology should ensure a production of 400,000 transmissions per year. In the longer term this number is expected rise to 800,0

23、00 and will require the engagement of over 1,000 staff. The new division in Verrones facility, dedicated to the C635 transmissions, has also enjoyed the benefit of local subsidies from the Piedmont Region. This investment has contributed to providing training for all employees. In addition, both the

24、 Verrone municipality and the Biella province have promised to carry out transportation and urban-planning infrastructure improvements. 26OEMintErviEw:FiatFtPhasworkedhardtobringtomarkettheMultiAirengine,whichismatedtoAlfastCt.theunitusesBorgwarnersDualtroniccontrolsystemandcanhandletorquelevelsupto

25、350nmtransmission technology international | September 2010FtPsverronebasehasanewdivisionthatsdedicatedtotheC635transmissionsGet the specs at WAM Unsurpassed stability in material strength, elasticity and sealing properties Dynamic property retention over a wide range of temperatures Custom formulat

26、ions to exceed your end of life requirements Resistance to aggressive lubrication fl uidsOur Extended Transmission Life (ETL) materials are engineered to last up to 3X longer against the next generation of automatic transmission fl uids at high temperatures.?n Functional features and performance of

27、automatic transmissions offer designs that fully emulate manual shift modes of driving to eight-speed concepts approaching the smoothness of CVTs. They have kept pace with powertrain technology advancements in meeting the demands for horsepower and torque management while providing significant benef

28、its with respect to fuel economy. Automatic transmissions comprise 55% of the market today and are estimated to reach 70% during the next decade. Significant reliability and extended life gains have been achieved through improved efficiency within fluid power transfer (torque converter assembly), po

29、wer flow control logic (servo based and electro-hydraulic modules), planetary gear design (tandem based gear ratio systems) and automatic transmission fluid (ATF) formulation changes. Prior to the early 1970s, ATFs relied on whale oil as the primary friction modifier and lubricant used in automatic

30、transmissions. As engine operating temperatures were increased to improve fuel economy and emissions, this lubricant was unable to maintain acceptable fluid service life. General Motors introduced the first advancements in lubricant chemistry with Dexron I (Type A and B) and Dexron II (Type C and D)

31、 as a replacement solution to retain viscosity and minimize lubricant breakdown at higher temperatures. The synthetic blends existing today (ATF+4, Mercon V, Dexron VI, ATF-Z1) support the Chrysler, Ford, GM and Honda automatic transmission system applications today. Dexron VI, as the next-generatio

32、n lubricant to Dexron III, significantly improves friction clutch wear (120%), oil film thickness Lifecycle optimization(20%), fluid oxidation (100%), shear stability (200%) and foam aeration (150%). These improvements extend transmission life significantly by keeping operating fluid temperatures wi

33、thin the 80C range with expected fluid service life of 100,000 miles. Heavy towing/grade conditions can bring these temperatures above 150C, which will destroy lubrication, compromise conventional sealing material thermal resistance, wear/friction properties and require a lubricant change after 1,50

34、0 miles under this loading condition.The technical improvements led by ATF formulations to reach vehicle long life targets have posed a new challenge in the area of gasket performance. The ATF developments have not stopped as new lubricants are pushing the envelope. Many sealing elastomer specificat

35、ions and associated validation key life tests are expecting 3,000 hours of acceptable performance. Achieving this using present ATF formulations combined with sealing materials formulated with less aggressive anti-oxidant and friction modifier additive resistance characteristics is not possible. Sea

36、l degradation occurs by either increased cross linking driven by the fluid as a cure catalyst that leads to hardening and embrittlement or softening/plasticizing the elastomer via polar solvent interaction via the ATF immersion at elevated temperatures.Introducing new fluids with incompatible sealin

37、g materials was first realized as a major hurdle for long life sealing when gasoline/alcohol blends became common fuels for petrol vehicles. Pure gasoline is a non-polar fluid. The electron charge distribution is distributed evenly throughout the molecular 28Casestudy:Wolverine AdvAnced MAteriAlsTra

38、nsmission Technology International | September 2010Leftandabove:theaCMpolymerelastomerprovidesextendedlifepropertiesforpowertraincomponentsInroads made in extended transmission-life sealing are helping to ensure new automatic gearboxes systems are lasting longerchain. Water is highly polar with a de

39、finite positive and negative charge collection at each end of the molecule. They dont mix because “like dissolves like” is the governing rule. The closer two materials are to equal polarity, the greater their interaction including solubility. In the case of the gasoline/alcohol blends the alcohol co

40、mponent is highly polar and fairly close to acrylonitrile-butadiene. This is the base polymer of NBR and HNBR. At low temperatures or engine startups there is phase separation of the alcohol with the gasoline. In a non-dissolved state, the alcohol is free to cross link with nitrile molecules and for

41、m a bridging structure. For both NBR and HNBR this leads to unacceptable high hardness levels and compromises seal over time. Certain fluorine polymers (FKM) also have a highly polar vinylidene fluoride molecule that has greater affinity to the alcohol than its own molecular chain. This type of reac

42、tion breaks down the molecular chain, softens the material and leads to elastomer swelling and lower temperature resistance. Higher concentration of tetraflouroethylene monomer within the FKM can reduce this effect. Unfortunately, the cost becomes significantly higher and low temperature sealing fun

43、ction is sacrificed. Engine oils, power steering fluids, long life coolants, A/C refrigerants/lubricants and ATFs all have the potential for either breaking down via repolymerization or increasing the molecular crosslink structure of the sealing elastomer. Higher thermal conditions accelerate the pr

44、ocess. The two major additives to present ATF formulations that effect elastomer resistance and life are incorporating friction modifiers as well as the type and amount of antioxidants. Friction modifiers adhere to metal surfaces and avoid premature wear when lubricating film thickness decreases at

45、lower viscosities and higher pressures. They also assist in maintaining a viscous barrier, increase torque transfer efficiency and have minimal localized heating related to lubricant shear. Antioxidants protect against lubricant viscosity breakdown and oxidation at higher temperatures. These additiv

46、es have a negative effect in plasticizing (softening) and/or generating increased cross linking via existence of fatty acid derivatives or amines. The amines are highly polar and will easily interact with NBR, HNBR and FKM. Sealing becomes the weak link in achieving extended life of the transmission

47、.In development of an elastomer formulation that would significantly minimize ATF influence on sealing life and performance, a base alkyl acrylate polymer (ACM) was selected as a starting point in development. The application was sealing the valve body channel plate used for guiding hydraulic flow a

48、nd maintaining proper shift characteristics. Initial screening was performed on the base ACM as compared to peroxide and sulfur The reduction of heat induced breakdown on modified ATF fluids was discussed previously through both antioxidant and friction modifier additives. In heavy-duty service cond

49、itions, the transmission during towing can reach (110C) and rise up to (160C) during high ambient mountain terrain driving. This pushes beyond the stable 150C limit of NBR thermal stability. ACM thermal resistance extends this to approximately 35-50C higher before molecular breakdown due to thermal

50、resistance in intermolecular cross link strength. Thermo-gravimetric analysis (TGA) indicate at 95% mass retention that ACM elastomers require significantly higher temperature to achieve 5% organic mass loss (50C increase) in comparison to NBR.Ability to seal for the life of the transmission has to

51、consider that seal degradation is continuously progressive with respect to maintaining acceptable compressive load ranges. ACM and NBR were tested for physical characteristics after 72 hours of Dexron VI immersion at 150C. Below 500psi in clamp load, the higher elongation/elastic seal retention char

52、acteristics were apparent in maintaining significantly lower leak rates at low clamp loads with ACM.In developing an optimal ACM formulation, the elastomer had to achieve comparable spring stiffness characteristics to the existing NBR gasket application as well as exhibit no material extrusion under

53、 maximum torque conditions. This also established the maximum stress that the material could withstand and how much compressive load was generated as a function of thickness. Two factors controlled this: state of cure and reinforcing filler. Successive development formulations were refined with resp

54、ect to curing agents/catalysts as well as reinforcing filler type and loading levels to optimize compressibility/recovery, shear/elastic modulus, tensile/shear strength, elongation and creep. Nonlinear FEA contact analysis along with Fuji pressure distribution tests were also conducted to validate m

55、inimum contact pressures that achieved compressive sealing above the 1,000psi design target with highly uniform distribution of pressure and compressive deformation. The ACM polymer elastomer with optimal cure state and reinforced filler formulation provides significant extended life gasket properti

56、es for automatic transmission sealing in maintaining higher strength levels, elongation, volume stability and elasticity. The product exhibits excellent performance under all types of extreme conditions including high internal pressures, operating temperature levels, compressive seal maximum pressur

57、e clamping loads, low clamp load seal integrity, recovery and compression stability for the life of the transmission unit, thermal shock resistance and unsurpassed micro-seal characteristics. TTiCase study: Wolverine AdvAnced MAteriAls29September 2010 | Transmission Technology Internationalcured NBR

58、/HNBR, silicone rubber and FKM. ASTM D412 was used as the screening test to assess tensile strength percent change as well as elongation percent change. Dexron VI immersions at 72 hours (125C and 150C) as well as 1,008 hours (125C and 150C) were conducted. Based on the most severe test case of 1008

59、hours at 150C, ACM performed the best of all candidates maintaining 95% of tensile strength and 30% elongation. In order to fully understand the specific aging/degradation characteristics of elastomer visco-elasticity due to ATF fluid effects as a function of time, the ASTM D412 test protocol was th

60、en conducted at 72 hours, 150 hours, 500 hours, 1,008 hours and 1,500 hours. Type A and E fluids were added to this test as well.Several conclusions were derived from these results. Dexron VI, which has one of the highest antioxidant additive amine levels, is also the most aggressive in crosslink ba

61、sed hardening and loss of visco-elastic properties for NBR. The ACM resistance to carbon group affinity in amine bridging leads to much higher elongation levels than NBR. The NBR elastomer reaches total loss of elongation at approximately 500 hours. ACM maintains 25% of its elongation at 1500 hours.

62、aCM achieves comparable stiffness to existing NBR gasketstransmission valve body channel plates benefit from aCMaCM sealing has very high temperature resistance levelsn Increasing mobility around the world is having a direct influence on CO2 emission levels. As a result, car makers and suppliers are

63、 having to develop cleaner and more efficient engines, and its here where friction-optimized anti-friction bearings can help. To approach this challenge in a target-oriented way, the response and behavior of a bearing component has to be analyzed when a vehicle is in motion and these dynamic resista

64、nces act out during rolling resistance, air drag, climbing resistance and inertia.Knowing what engine power is needed to maintain a certain driving condition, SKFs innovative VEPS software translates the corresponding bearing power loss into CO2 emissions data output. Since the bearings saving poten

65、tial depends on its position in the car driveline, the first step in this process is to identify the most promising position for the bearing component.The potential of the bearing is high when these components are mainly axially loaded and run with high rotational speed, as on the pinion shaft of a

66、rear wheel-driven vehicle. At a speed of 130km/h, a maximum power loss of 750W on the pinion-head bearing is calculated. Together, all four tapered roller bearings generate a power loss of up to 1,300W.In general, rising bearing loads and increasing speed levels result in enhanced power loss from th

67、e vehicle drivetrain. However, due to different internal geometry, a ball bearing and a roller bearing show different friction behavior. For example, the ball bearing is preferable at moderate specific loadings, and the roller bearing behaves far better at high specific load levels. As a consequence

68、, two basic strategies have been applied for the development of SKFs energy efficient-bearing portfolio: the first is the optimization of the internal geometry of tapered roller bearings; the second focuses on the substitution of tapered roller bearings by driveline angular-contact ball bearings. It

69、s important to note that all the above fundamentally depend on application Bearing breakthroughFriction-optimized anti-friction bearings are enabling crucial CO2 emissions savings30Casestudy:SKFTransmission Technology International | September 2010requirements and which way they will be ranked in te

70、rms of importance and favorability. For example, important bearing functions, such as stiffness levels and service life cannot be sacrificed for the sake of a minimized power loss.As a result of all of this, the SKF energy efficient-bearing portfolio consists of the following bearing types: energy-e

71、fficient tapered roller bearing, driveline angular-contact ball bearing, ball-pinion unit and the hybrid-pinion unit. All of these advanced technologies from SKF can be utilized in any bearing position of gearboxes and axle drives, thus helping the powertrain to become more efficient in terms of emi

72、ssions output. TTithetechnologiesinsKFsenergyefficient-bearingportfoliocanbeutilizedinany bearingpositionofgearboxesandaxledrivesBe part of this exciting opportunityTo find out more about the roles that we are recruiting for visit: Were recruiting research & development experts from across the Autom

73、otive industry to help us improve engine efficiency and emissions, discover new powertrain andtransmission technologies and to investigate electric and hybrid vehicle trends.From Chief Engineer to Engineer, were putting together a team of over 150 specialists forour transmission and engine departmen

74、ts to help us achieve our objectives. Its a uniqueopportunity to work in a research focused environment with like minded colleagues,supported by a leading automotive manufacturer.To apply please contact our Recruitment Partner: Steve Doyle at Consilium Group Ltd - UK Office Tel: +44 (0) 1386 835 910

75、. Alternatively send your CV to: 4One of Chinas biggest car manufacturers42009 sales 7.2bn4Annual sales growth rateover 40% 41bn 5 year R&D budget44.5% of sales invested in R&D?25-27 October 2011The Rock Financial Showplace, Novi, MI, USAFor more information contact Tim Sandford on +44 1306 743744 o

76、r email | www.engine- Americas exciting, new, dedicated international trade fair for automotive powertrain design, production, components, and technology. 2011BOOK NOWFOR 2011!www.engine- then The goal of achieving increased fuel economy in an economic and timely manner is one of the prime driving

77、forces of automotive developments today. This is especially true of the automatic transmission (AT), which has offered high levels of passenger comfort at the expense of fuel economy. Rapid advances in recent years have closed the gap between AT and manual transmission (MT) solutions and with the ad

78、vent of the dual-clutch system (DCT), it may finally be possible to offer AT comfort with fuel economy superior to the averagely driven MT passenger car.When designing a new transmission, an engineering team is faced with a multitude of design decisions, which are often contradictory and nearly alwa

79、ys dependant on one another. Key to this process is the numerous machine elements present to facilitate rotation, location, and fluid flow. Even a simple requirement for example concerning the torque rating of a shaft, is dependant on a secondary component, in this case the seal ring, for the simple

80、 reason that torque loss and wear of the seal are influenced by the shafts diameter.Good transmission design and energy efficiency really are governed by the sum of Seal ring successSeals that are based on a unique type of polymer are ensuring that advantages such as lower torque losses, improved re

81、finement and increased system-pressure usage are all being realizedthe parts. Each rotating element contributes to energy loss through a combination of factors, such as contact friction, fluid friction, or even simply the acceleration and deceleration of rotating mass. Crucial to the development of

82、the most energy-efficient transmissions is the identification of areas of power loss where gains may be made rapidly and economically. The seal ring is one of these areas.Hydraulic pressure is used within the transmission for the actuation of various components, such as pistons. The rotating couplin

83、g enables this hydraulic pressure to pass through a rotating shaft or housing and on into a static part of the system. The seal functions by providing accurate mating surfaces that conform to one another and prevent the oil from flowing between them. Elastomeric lip seals are the most commonly used

84、sealing element for rotating shafts. Under the high speed and pressure environment found in the rotating coupling, however, such seals are rapidly destroyed. Therefore, a rigid seal ring is used that combines the sealing function of the face seal with the economics of a mass produced part. Unlike el

85、astomeric seals, the rigid seal relies on the oil pressure to force the conforming surfaces together and make the seal. Two consequences of needing a rigid component follow. The first is that a rigid material demands a gap that enables it to be opened and installed in the groove, then to close again

86、. This joint enables some oil to escape through to the non-pressurized side. The second is that since there is motion between the shaft containing the seal and the housing, one of the seal surfaces is sliding, and due to the sealing requirement, is also in contact. The result is friction and energy

87、is lost as heat.32Casestudy:LS PoLymer TechnoLogyTransmission Technology International | September 2010atypicalrotatingcouplingfoundinat,dCtandCVtunits.FrictionisgeneratedinthecontactareasleadingtodragtorquesOptimizedsealshavelow,stableleakageratesthatcanbeonefifththatofastandarddesign.thisleadstoim

88、provedrefinementlevelsandmorepredictableperformanceDetailed functional analysis of the rotating coupling, combined with measurements in advanced seal test facilities operating under real transmission conditions, confirm that the sealing elements in the multiple rotating connections found in ATs can

89、contribute more than 30% of the observed power loss. In addition, the high interfacial temperatures found in poorly designed seals may lead to oil degradation with all of the implicit problems for transmission life that this poses. Oversized seals increase axial length unnecessarily and the variabil

90、ity of the leakage through the gap contributes to poor refinement in the transmission and necessitates the use of over-sized oil pumps. Therefore, many opportunities for optimization are lost through poor seal design.All of these errors can be avoided by using advanced seal designs and involving the

91、 designer early on in the development process, at which point key benefits can be built in and their advantages enjoyed over the life of the transmission. Foremost of these improvements are reductions in the drag torque and low, stable-leakage values.The rotating coupling has many sources of power l

92、oss, from turbulent flow of the oil to viscous shear and also friction from sliding contact. All of these aspects can be improved by using system optimization calculations. In particular, LS Polymer Technology focuses on designs that reduce the friction losses resulting from the sliding contact of t

93、he sealing surfaces. Evaluation of these designs over the typical transmission-operating conditions demonstrates that optimized low-drag seals have friction losses that are half of those found in standard types. Robust design methodologies ensure that these benefits are maintained over the life of t

94、he transmission. Additional advantages, such as reduced thermal degradation of the transmission fluid, are present but more difficult to quantify. The high rotational speeds and system pressures found in modern transmissions generate severe frictional heating, as the thermal model shows. This fricti

95、onal heating is localized in the sliding surface of the seal and leads to high temperatures despite the presence of transmission fluid.In practice, poor materials with high coefficients of friction can generate temperatures in excess of 240C, and most polymers will fail through melting, distortion o

96、r excessive wear. Switching back to metal seals provides no solution either, as higher oil pressures lead to metal-on-metal contact and rapid seal failure due to adhesive wear. For example, a cast iron seal ring will fail at modest engine speeds when oil pressures are only 1.5MPa. Therefore, materia

97、ls must be selected that survive the compressive and shear loads under the maximum conditions experienced by the seal. friction performance is advantageous in that lower values are observed as the pressure and speed environment become more severe. This unique behavior makes PAI the material of choic

98、e where conditions are demanding or a high degree of design-safety is required. Finally, the material can be injection molded and form the intricate joint designs that minimize leakage.As mentioned, high sliding speeds demand the use of a rigid seal and, as a consequence of assembly requirements, th

99、is must have a joint that enables the seal to open around the shaft and close again. It is this joint that provides a leakage path for the transmission fluid.The degree of leakage is governed by a combination of the oil viscosity, oil pressure and the size of the various leakage paths around and thr

100、ough the seal. When system pressures and speeds in transmissions were low, as in early three- to five-speed ATs, this leakage was not a serious issue and many simple joints were used to provide the gap, such as angled cuts or machined flat ends. Leakage values could easily exceed 500ml/min at maximu

101、m pressures and velocities.Single-step and multi-step joints were developed in an attempt to reduce leakage rates and to improve the uniformity of the leakage value. In recent years, LS Polymer Technology has pioneered the use of the 2T joint, named after the end-on profiles of the gap. This design

102、provides significant benefits by reducing not only the overall volume of oil flow through the joint, but also the rate of change of flow with speed and pressure.Using state-of-the-art testing, it is possible to evaluate this leakage at every combination of pressure and speed found in the transmissio

103、n. Such testing confirms the performance advantages of the 2T seal.As a result of such inroads, adopting optimized seal rings from the very beginning of the transmission development enables the design team to gain many significant advantages. These include lower torque losses, improved refinement th

104、rough leakage uniformity, and increased system-pressure usage. TTiCase study: LS PoLymer TechnoLogy33September 2010 | Transmission Technology InternationalPolymers such as PEEK may be used where conditions are not demanding, although the inclusion of potentially abrasive fibres or fillers is require

105、d. Over 20 years of experience with many seal designs and applications has led LS Polymer Technology to base their main developments on polyamide-imide (PAI), an ultra-performance plastic sold by Solvay Advanced Polymers under the Torlon trade name. This material has a long history of use in transmi

106、ssions and other severe friction and wear environments. Seals based on Torlon PAI have a unique combination of flexibility, wear resistance and strength at temperature, all of which are achieved without the use of abrasive materials that could wear softer surfaces, such as unhardened steel or alumin

107、um. In addition, thermal modelling of the friction zone reveals severe temperature gradients (above). a cross-section of an optimized seal showing the concept of drag torque reduction levels through hydrostatic relief (below)drag torque measurements under typical transmission conditions demonstrate

108、torque reductions of up to 50%. these benefits are especially significant at higher system pressuresn IBS Filtran specializes in the field of automatic transmission filtration for the automotive sector. In response to the rising demands on the transmissions regarding performance, comfort and environ

109、mental compatibilities, manufacturers are continuously developing new materials, innovative designs, and more complex control units, as well as advanced transmission types.Filter experts have to identify any changing conditions in order to refine the transmission requirements to generate supporting

110、filtration concepts. The key challenge in the development of filter systems is to find the best compromise between the interacting key factors, such as pressure drop, filtration efficiency and dirt hold capacity.The actual interaction is related to the nature of filter media. For example, the higher

111、 the efficiency, the higher the pressure drop will be. Likewise, the lower the pressure drop, the lower the dirt hold capacity will be. To optimize all three factors, new filter media types must be developed. The pressure drop of a filter consists of pressure differential related to the filter media

112、 and the filter geometry (housing). The optimization of the pressure drop in the filter geometry can be realized without many consequences to the other factors.The optimization of the sub-item pressure drop of filter geometry could be considered as a typical application area for CFD simulations. Bec

113、ause of the existence of a filter media inside the filter housing, the CFD software has to work not only with solid or liquid cells, but it also has to deal with porous cells related to the filter media.Since 2001, IBS Filtran has been working with the CFD program SuFiS, which was developed by Fraun

114、hofer-Institut fr Techno-und Wirtschaftsmathematik (ITWM) in Kaiserslautern, Germany, in collaboration with IBS Filtran. The algorithms of this system enabled the calculation of the pressure drop and velocity distribution inside real filter applications. Consequently, the resulting figures could be

115、calibrated and validated between calculated and experimental results. Simulation of filtration applicationsAdvanced CFD simulations for the design of efficient filters are playing a greater role, but exactly what advantages can this high-tech process realize? This is the most important aspect for th

116、e successful use of CFD programs. For example, the accuracy of a filter calculation is highly dependent on the applied porosity value of the filter medium. The porosity number for a filter medium can be identified by special laboratory tests, which should consider real boundary conditions. Another m

117、ethod to determine the porosity number is the micro structure analysis, which in turn is based on simulation. Nevertheless, the validation has to be done on the experimental side. Taking this into account, the implementation of CFD software in the filtration business will generate a relatively high

118、amount of laboratory effort. After successful implementation of the first SuFiS version, it was possible to simulate one of the three key factors describing a filter (pressure drop). To simulate an entire filter, it is necessary to implement the efficiency and loading of the porous media. IBS Filtra

119、n and ITWM decided to continue with the development of SuFiS. To do so, the behavior of the filter over time had to be determined. In other words, it is key to know the concentration and distribution of particles inside the oil volume and filtering media over 34Casestudy:IBS FIltranTransmission Tech

120、nology International | September 2010above:anall-newpressurefiltersystemwithfullplastichousingandadaptersubcomponentsthatarelightweightaboveandbelow:theautomotiveindustryisdemandingnewsmartmediafiltersaredevelopedthatcanfindtheoptimalbalancebetweenvariousfactors,suchaspressuredropsfiltrationefficien

121、cyanddirtholdcapacitya certain period of time. Because the loading and efficiency is velocity dependent, the flow field and pressure distribution also has to be recalculated over time. Having overcome several engineering hurdles, the two partners now have a stable working version of SuFiS.When deter

122、mining the validation and generation of input parameters, the effort is by far higher than for the pressure calculation only. For example, for calibration and the validation of the efficiency solver ISO 16889 and the Transmission Filtration Effectiveness Method (TFEM) is used. The results achieved b

123、y the new SuFiS version are very promising and for the first time it is possible to predict an ISO 16889 efficiency test or TFEM test in a real filter environment. Furthermore, one possibility of the new SuFiS is to compute the efficiency from combinations of filtering media inside a real filter hou

124、sing, which is more or less impossible without such a tool.Although the implementation of a CFD simulation tool causes extra charge related to the need of experimental studies, the benefit program. For example, the visualization tool of a CFD package enables the engineer to look into each corner of

125、a filter, which is often difficult or in some cases even impossible to realize. In addition, the possibility of choosing boundary conditions, which are not available for experimental testing (such as different porosity of filter media and different particle distribution and concentration of oil volu

126、me) expand the scope of filter development.Added visualization tools place the filter designer in a position to better understand the complex fluid dynamic situation. To get an idea what is possible some examples are shown in the illustrations above and below.Instead of this macroscopic view, other

127、manufacturers are developing microscopically analysis flow simulations or particle separation in porous media. It is possible that these parts will be able to integrate into the macroscopically structure of SuFiS. Another approach would be the connection of CFD and FEM analysis, which would be also

128、a helpful tool in filter design. TTiCase study: IBS FIltran35September 2010 | Transmission Technology Internationalat the end will be enormous, and especially at the time when all needed parameters are correctly determined.The decreasing lifecycle of products, and cost pressures based on increasing

129、competition, are aggravating circumstances in the automotive industry. The filter industry provides great development partners to help optimize operating efficiency and capabilities.But reducing time and cutting on costs are not the only benefits when using a CFD above: Velocity distribution of a sm

130、artMedia applicationabove: the pressure and velocity distribution inside a new smartMedia applicationabove: Vector field and retained mass inside dual layer porous for particle concentrationabove: Vector field and retained mass inside dual layer porous for particle concentrationn Shift quality for m

131、anual transmissions has become part of a vehicles DNA and even plays a role in a car makers brand image to the customer. Therefore it is necessary to engineer this characteristic from the early development phase of a drivetrain or vehicle application. Only a properly tuned vehicle, in terms of dynam

132、ic behavior, will lead to full satisfaction from the customers point-of-view.In public recognition, shift quality is a pure subjective attribute typically described as sporty, precise, easy-to-operate or of poor quality, particularly in cases where the shift quality is scratchy and tight. Within the

133、 typical development phases like target setting, down cascading to subsystems, development, verification and industrialization, shift quality development needs to be covered from the very first phase. But how can shift behavior be actually objectified? To answer this question, one needs to look at G

134、IF GSA system.Typical applications for the GIF GSA system are the measurement of load and stroke collectives at the human/machine interface, which for the drivetrain are the clutch pedal and gear lever.Loads and strokes are measured, visualized and then post processed in one tool. The basic idea dur

135、ing the system design was to implement the development experience of GIF to generate an easy to use system that offers lean and effective tools to objectify shift quality to the user.During the phase of target settings, GSA is used for vehicle benchmark analyses and then applied to system investigat

136、ions (transmission and/or external shift mechanism) on specific benches. Assessments and measurements are split into two main categories: static and dynamic shift behavior. In static shift behavior, criteria like shift and select strokes, friction and free plays, and load characteristics are objecti

137、fied. Since this behavior is prominent to the customer at any shift operation, it has a high priority during functional status descriptions and the following subsystem target process.The dynamic shift behavior is superposed to the static shift behavior and therefore is mainly driven by few additiona

138、l components in the transmission, which are from an engineering point-of-view the most complex ones. Gearshift optimizationShift quality is taking on a greater role, but how can this very subjective characteristic be objectified?Additionally, there are criteria like second-load behavior that are at

139、a certain percentage affected by drivetrain behavior, such as torsional stiffness and damping. Both static- and dynamic-shift behavior are assessed and analyzed in a wide temperature range varying typically from -20C up to 100C. Since the clutch actuation is directly related to a shift operation, th

140、e clutch pedal characteristic (similar to the gear engage load characteristic) and functional behavior (such as the disengagement stroke) needs to be assessed and analyzed in parallel with the GSA system. As soon as the system targets are defined, the responsible engineering team can start to develo

141、p the transmission-shift system.Beside the standard post-processing tools, this system offers the possibility to generate individual visualization charts. To improve the analysis of specific events, the system is open to measure and analyze various analogues and digital input signals, such as transm

142、ission speeds, temperatures or CAN signals.The system is flexible and can be used in any vehicle application. In the phase of target settings, GIF can develop such settings based on benchmark analyses combined with the companys drivetrain development experience. The verification of total system or s

143、ubsystem behavior is conducted on specific component test benches, or in the actual vehicle. Its equally important to note that the GIF GSA system is used at transmission production EOL quality tracking or by vehicle-plant quality teams.GIF develops transmissions from the first concept phase to seri

144、es production, and the definition and development of subsystem targets for the transmission and external-shift system cover all aspects, including packaging, durability, weight and cost. TTi36Casestudy:GIFTransmission Technology International | September 2010transmissionshiftbehaviorcanbeassessedobj

145、ectivelybyusingGIFsGsatechnologyduringearlydevelopmentGIFsGsasystemisusedforvehiclebenchmarkanalysesandcanthenbeappliedtocomplexsysteminvestigationsn Induction gear-spin hardening can be divided into two methods: through hardening and contour hardening. With the first method, which is used primarily

146、 for gears exposed to high wear, the tooth perimeter is hardened with a low specific power level. However, if the frequency is too low, there is the risk that being above the Curie temperature helps to induce eddy current flows mainly in the root circle, and the temperature lags behind in the teeth.

147、 Quenching is either by submersion or spraying, and is usually delayed to achieve a uniform temperature between the teeth and the root circle. Tempering after hardening is essential for crack prevention.Contour hardening is divided into single- and dual-frequency processes. With the former, a single

148、 generator feeds the inductor. Austenitizing is achieved either in a single heating, or by pre-heating the gear to between 550-750C, before further heating it to the hardening temperature. The purpose of pre-heating is to reach an adequately high austenitizing temperature in the root circle during f

149、inal heating, without overheating the teeth tips. Short heating times and a high specific power output are usually required Inductive spin hardening of gearsEasy integration into production flows has made the inductive spin hardening of gears very popularto achieve hardening profiles at an irregular

150、 distance to the tooth face. The dual-frequency process uses either separate or simultaneous frequencies. Using separate frequencies achieves hardening profiles similar to case hardening. This process applies two different frequencies, one after the other to the gear. The teeth are pre-heated, at a

151、low frequency, to 550-750C. The frequency should be such that pre-heating occurs in the root-circle area. After a short delay, use of a higher frequency achieves austenitizing. Accurate monitoring systems are key, as heating times are measured in tenths of seconds or seconds during the final heating

152、 phase. With the simultaneous dual-frequency method, a lower and a higher frequency feed into the inductor occurs at the same time. Hardening is achieved by heating the root circle with the lower frequency, and the tooth tips with the higher frequency, as shown in Figure 1. Unlike the separate dual-

153、frequency process, pre-heating is not always required when using the simultaneous dual-frequency process. However, the short heating times used with simultaneous frequencies place high demands on the generator and machine engineering. Figure 2 shows an example of a hardening profile achieved with th

154、is method. Correct quenching is critical for perfect spin hardening results, and should be performed as soon as possible after the final heating. The time gap between heating and quenching can be minimized by using a fast CNC axle to position the spray head, or by integrating a quench circuit into t

155、he inductor. During the quenching phase, gear speed is decreased to below 50rpm to avoid a shadow effect on the flank opposing the direction of rotation.Many factors influence spin-hardening outcomes. Due to short austenitizing times, the initial structure must be close-grained (ASTM 7 and above). N

156、on-homogenous pearlite-ferrite initial structures are not suitable. The importance of this initial structure and carbon content increases as module size decreases. If an increased quenching distortion is acceptable, inductive pre-quenching and tempering prior to contour hardening can greatly improve

157、 the gears ability to harden.Module size is another key factor in spin hardening. For the dual-frequency method with simultaneous frequencies, the range is 2.2 m 5mm. However, for cost reasons the gear diameter should be limited to approximately d 250mm. For modules where m 3.0mm, the separate dual-

158、frequency method is preferred. This is because a final hardening phase with HF achieves better hardening at an irregular distance to the face. The single frequency method is almost exclusively used for internal ring gears with a module where m 1.25mm, such as those frequently used in automatic trans

159、missions. Spin hardening is a versatile process that can harden spur-toothed, helical spur and internal gears at an irregular distance to the face. However, different gear forms influence the hardening results. With helical gearing, an asymmetrical hardening of the tooth flank at a depth of up to 2-

160、3mm from the gear face has to be accepted. This situation is however only pronounced with helix angles of 28. Patented coil solutions are available that limit this effect by enhancing power distribution. TTi38Casestudy: EFD InDuctIonTransmission Technology International | September 2010Figure1(right

161、):aschematictime-temperaturegraphforsimultaneousdual-frequencycontourhardening,whereMFequalslowerfrequencylevelsandHFequalshigherfrequencylevelsFigure2(below):theresultofsimultaneousdual-frequencycontourhardening,usingeFdinductionequipment.thelowerfrequencyhardenedtherootcircle,andthehigherfrequency

162、hardenedtheteethofthesystemhybrid amtDrivetrain Innovations develops cost-effective and fuel saving transmission solutions.Drivetrain InnovationsT +31 40 2931082info dtinnovations.nlwww.dtinnovations.nl 1.5 s0020406080100120246810123 sspeed km/htime sAcceleration 0-100km/hTorque filled AMTAMTdry DCT

163、Hybrid AMTCSCflywheel& clutchtorque fill modulee-KERS moduleFrom a Manual Transmission to a cost-effective low-voltage Hybrid AMTpowerpack1.6L diesel + MT3.7L/100km98 g/km+ torque filled AMT3.5L/100km93 g/km+ impulse start/stop3.3L/100km88 g/km+ e-KERS hybrid3.0L/100km80 g/kmco2Impulse start/stop mo

164、duleTorque fill module0231 DTI_adv_A4_DEF.indd 229-10-09 17:38www.engine-17, 18, 19 May 2011 Messe Stuttgart, Stuttgart, GermanyIncluding theFor more information contact Tim Sandford on +44 (0)1306 743744 or email | www.engine-Europes most important dedicated trade fair for powertrain design, produ

165、ction, components and technology!BOOK NOWFOR 2011!www.engine-n Meticulous attention to the design of production processes is a key factor that impacts component and subassembly costs. The current trend in design concepts toward increasingly complex formed parts is placing heavier demands on process

166、engineering. In the manufacture of transmission components, it has become common practice to combine the fineblanking and forming processes.When defining the process steps for components with multiple forming operations, certain criteria have to be considered. First, breaking down the sequence into

167、simple and readily controlled individual processes is very important, and as a result, the focus must be on configuring low-risk, individual elements within the tool station. Equally, engineers must ensure that design complexity still allows for individual tool elements that are practical in terms o

168、f maintenance. The second consideration in this area is to do with the limits of process splitting, which are reached when the useful diameter of the Fine production processesA detailed look at integrated production solutions for fineblanked and formed parts for new transmission systemsspecified pre

169、ss is fully exhausted and, more importantly still, when the culmination of tight positioning and forming tolerances of the various component features become critical. The necessary repositioning of the component as it arrives from the previous stage, together with changes in component dimensions res

170、ulting from shear forces and material displacement in subsequent operations, are the major reasons for this restriction of tolerance bandwidths.The example of a disk carrier blank clearly illustrates the situation described previously. The objective was to produce a deep drawn blank featuring a base

171、 with a raised lip and a center hole fineblanked to tight tolerances. The stock material was DC05 steel with a thickness of 2.1mm, as shown in Figure 1.The familiar, most obvious approach called for a four-stage solution process executed on a transfer press. The requisite transfer equipment was inst

172、alled on the press together with a zigzag in-feed arranged at 90 to the direction of the work piece flow, thus a so-called L configuration. For material of this thickness and quality, fineblanking the center hole was achieved using auxiliary forces in the tool frame in the fourth phase of the operat

173、ion. However, this set-up could not increase output to a level that would allow two finished parts per press stroke to discharge onto the outfeed conveyor belt.As an alternative to the solution proposal just described, production of the same component was tried on a fineblanking press. It was import

174、ant for the client that the conventional operations sequence be retained so therefore stamping out the blank, deep drawing one, deep drawing two, and then fineblanking the center hole.The geometric relationship of the four relevant diameters to each other, namely Case study: Feintool technologie41Se

175、ptember 2010 | Transmission Technology InternationalFigure 4: the Feintool production tool for internal gear carriers and componentsFigure 1: disk carrier blank (above)Figure 2: the Fientool production tool for disk carrier blanks (left)42Casestudy: Feintool technologieTransmission Technology Intern

176、ational | September 2010those of the center hole, the recessed cup, the raised lip, and the blank itself, allowed for the possibility of achieving the necessary forming operations using concentric tool elements in a single tool station. The trick here lies in actuating and controlling the individual

177、 tool elements so that the specific operations are cleanly executed in the defined sequence. This is critical, not only for the closing action, such as the actual fineblanking and forming operations, but also for tool opening and thus the staggered release of the work piece from the tool. All too of

178、ten, parts may be completely within specified tolerances during the production process, but after opening the tool when there is no longer contact with the active elements they no longer hold their former tolerances.Todays means of production hardware for these types of components have evolved to be

179、come single-station tools that easily extend to accommodate multicavity solutions. Disk carrier blanks are produced in a twin-cavity configuration (as shown in Figure 2), thus requiring a useful diameter of 380mm for the V-ring and counter forces that are typical features of fineblanking. This corre

180、sponds to a standard fineblanking press rated at 800 tons total capacity.The second example in this area focuses on a component found in automatic transmissions equipped with planetary gear sets. This component is an internal gear carrier with multiple deep-drawn geometries, circumferentially finebl

181、anked precision gear teeth, and a tightly toleranced center hole.The work piece material is 2mm thick HC300LA, with a maximum tensile strength of 530N/mm2. In contrast to the disk carrier blank, production of this specific part is very much influenced by the demanding, fineblanked outer gear teeth w

182、ith small corner radiuses (R0.3). Still, the question arises here whether the production should be planned around a transfer process on a long die table, or whether there are alternatives. The strip layout in Figure 3 shows the implemented solution. The process steps are as follows: pre-punching the

183、 centerhole to a smaller diameter, stamping out the blank, including deep drawing of the two steps, and calibration of the deep-drawn geometry, and fineblanking of the center hole and outer gear teeth.The selected process design integrates two sequential operations in both main stations and an upstr

184、eam hole punch in the normal feed direction of the strip. A transfer device attached to the tool grasps the component as it opens in the first main station, and then positions it in the calibration and fineblanking station. At an intermediate level of the transfer device, the finished and undamaged

185、part is then synchronously discharged to the rear of the machine. The two ring scraps are removed separately from the work pieces and out of the tool zone down a dedicated chute, as illustrated in Figure 4. The production machine is a latest-generation fineblanking press from Feintool, with a useful

186、 hydraulic diameter of 380mm.Process design begins with the process forces available from a specific machine series. Since hydraulic forces such as V-ring and counter force are no longer utilized solely for restraining coil stock, particular attention should be paid to their maximum values and assoc

187、iated displacement strokes.Feintool fineblanking presses, fitted with their basic equipment packages, and including controlled hydraulic cushions in the ram, as well as in the tie block, are an ideal platform for implementing integrated processes. These two power sources each deliver either 50% or 2

188、5% of the total press capacity, and are therefore capable of fulfilling significant forming operations. As a general rule, however, these functions require additional force-travel aggregates (auxiliary hydraulics) to keep the work piece material flat, usually inside and outside of the forming profil

189、e, as well as for the controlled release of the component. Hence, these presses are prepared for the connection to two or more additional hydraulic circuits that actuate and control tool-integrated cylinders and pistons as required. Automated fineblanking machines equipped in this manner are therefo

190、re transformed, and together with the tools described above, they form a triple-action fineblanking process into an integrated system performing anywhere from five to seven operations. With so much potential available, functions that are generally non-controllable such as mechanical spring packages

191、or nitrogen cylinder solutions are now a thing of the past.At first, it may seem that the integrated process solutions described may appear to be more of a hindrance than a help. The complexity of these series tools, some equipped with transfer systems, auxiliary hydraulic functions and monitoring s

192、ensors, demand greater technical know-how of operators and maintenance personnel. However, on the other hand, the enormous benefits they offer cannot be ignored. The feasibility envelope of components is significantly expanded thanks to the tighter tolerances guaranteed by the high process reliabili

193、ty. Likewise, decidedly smaller and useful diameters on press tables are an enormous benefit favoring such systems.The example of the disk carrier blank clearly demonstrates that space requirements can be reduced by a factor of almost three while at the same time doubling output (Figure 5).The corne

194、rstone of any cost-effective manufacturing process is a carefully thought-out tool design. Feintools experienced tool designers succeed in integrating ever more operations and functions into a single tool. Feintool is convinced that the alternative solutions presented here constitute an indispensabl

195、e approach to selecting optimized process layouts. The know-how gained from over 50 years of experience in tool making is one of the key factors defining the success of Feintool. TTiFigure3:striplayoutofaninternalgearcarrier(above)Figure5:thelayoutfortransferpressproductioncomparedwithalayoutfortheo

196、utputfromamultifunctionalfineblankingpress(leftandabove)?Disruptive technologies that could change the IC engine forever TOP HATZ ?HEAVY GOING ?Take one last look because?PICTURE PERFECT ?2010InternationalEngine of the Year Awardswinners interviewedn Transmission technologies are undergoing change.

197、Hybridization and more sophisticated control strategies are helping drivetrains to become more integrated and intelligent. The end result will be cars, trucks, buses and off-highway vehicles that have greater efficiency and the flexibility and know how to conserve energy and respond better to the de

198、mands of the driver and driving conditions. The question facing the industry is which combination of technologies will achieve this. A renaissance in transmission engineering is underway with much depending on manufacturers managing kinetic energy, tractive effort, torque and engine efficiency more

199、intelligently. This increased activity can be measured in the number and diversity of the projects underway at UK transmission-development company, Torotrak. The companys toroidal traction drive technology was originally created for Transmission transformationpassenger cars main drive transmissions

200、and has since proved to be of particular interest in the commercial vehicle and off-highway sectors. Allison Transmission, Carraro and a major European truck and bus manufacturer are among the clients developing the technology. Development work for the commercial vehicle sector is a key area for Tor

201、otrak, affirms the companys engineering director, Roger Stone, but its toroidal traction drives are also an enabling technology for flywheel hybrids and variable-speed supercharger drives. The potential applications for these range from buses to high-performance cars. “Improving transmission efficie

202、ncy is important to commercial vehicle engineers an improvement of just a few percent can contribute a lot of savings, especially in cruise conditions,” says Stone. “But some companies, having already spent decades refining their transmission technologies, are looking at the diminishing returns, and

203、 wondering if the time to introduce alternatives is approaching.”Torotraks chief advantage lies in helping manufacturers realize higher powertrain efficiency across the entire system. In trucks, that means using the companys variable transmission technology to run the engine at the most efficient op

204、erating point available for the torque demand and speed. “Instead of the engine revving within fixed ratios, it operates close to its optimum point with the ratios varying instead,” adds Stone.Torotraks technology can provide a power-split arrangement that delivers high efficiency by passing engine

205、torque through a number of paths within the transmission. Most of the torque bypasses the variable-drive transmission, reaching the driveshaft via a gearset, and the remainder connects to Torotraks variator that can, between limits, infinitely vary the ratio. 44Casestudy:ToroTrakTransmission Technol

206、ogy International | September 2010The need for total drivetrain efficiency is making it important to manage kinetic energy, traction and torque more intelligently. One leading UK-based supplier is working hard to make headway in this areathetorotrak-developedCVtisakeypartofaflywheelhybridsystemthati

207、mprovescitybusfueleconomy.transmissionscompanyXtrachasalicensetomanufacturethetechnologyformotorsport-basedapplicationsThe same basic principle is useful for manufacturers looking to develop kinetic energy recovery systems (KERS) that use fl ywheels to store the recovered energy as an alternative to

208、 mild hybrids with batteries or supercapacitors. “Interest in mechanical KERS as a viable alternative to mild hybrid electric drivetrains is growing in different sectors,” says Stone. “Flywheel hybrids will be more cost-effective and easier to apply to existing vehicle architectures, but their effi

209、ciency depends a lot on the transmission.”In a mechanical hybrid, the round-trip effi ciency is around 70%, says Stone. Torotrak is involved in three projects part-funded by the UKs Technology Strategy Board that aim to demonstrate KERS. The company is leading Flybus, a project involving bus manufac

210、turer Optare, engineering consultancy Ricardo and Allison Transmission.The Ricardo-led Kinerstor project looks at low-cost kinetic energy storage for massmarket applications, and a Jaguar-led project, FHSPV, is developing a fl ywheel hybrid system for premium vehicles. The projects use a compact ver

211、sion of Torotraks CVT platform, scaled to deliver a rated power of 60kW.“Only Torotraks torque-controlled CVT can manage the complex speed-matching demands of such a system,” adds Stone. “The speed of the fl ywheel is independent of the vehicle or engine. The vehicle could stop at one red light with

212、 the fl ywheel spinning at 64,000rpm, at the next it could be 45,000rpm; the vehicle needs the same amount of torque to pull away, but to provide it, the CVT must take the fl ywheel through a completely different speed maneuver. Because a fl ywheels inertia is fi xed, its acceleration is a function

213、of torque and so to receive torque from it, you decelerate the inertia. That is relatively simple with our CVT. The system asks for a torque, within the CVT the corresponding hydraulic pressure is applied and the ratios sort themselves out.”Heavy vehicles that stop and start frequently have the most

214、 to gain from such a system. The Flybus project, using an Optare Solo city bus, aims to demonstrate fuel savings in the region of 20%, but at less expense than current bus hybrid systems; a typical hybrid system can increase the vehicles cost by 50% or more.CASE STUDY: TOROTRAK 45September 2010 | Tr

215、ansmission Technology InternationalTorotraks experience in optimizing its technologys application to different sized vehicles with different duty cycles will be useful. The research projects led by Jaguar and Ricardo will use Torotraks technology in fl ywheel hybrid systems for large and small passe

216、nger cars.Torotrak is also exploring areas where its technology could be further applied as an ancillary drive such as fan and supercharger drives. Its Rotrak joint venture with the supercharger company Rotrex is developing a variable-drive compressor using Torotraks CVT unit.Vehicles overall effi c

217、iency is becoming more important. The challenge for manufacturers is to determine the most cost-effective and effi cient for their customers. TTiOptare is partnering with Torotrak, Ricardo and Allison Transmission to integrate an advanced CVT-fl ywheel KERS system into its Solo city bus application.

218、 The research consortium expects to realize fuel savings of around 20%Request your FREE copy of Transmission Technology International magazine at: SUBSCRIBENOWONLINE READER ENQUIRY SERVICE ALSO AVAILABLE copy of Transmission Technology International AN ENGINE TECHNOLOGY INTERNATIONAL PUBLICATIONSept

219、ember 2010Whats new?Fords high-tech autoGetrags dry-clutch DCT design for Renault BorgWarners advancedeGearDrive system Sergio Cairola, transmission platforms vice president, Fiat Powertrain Technologies Jeffrey Baran, executive director of transmission program execution, General MotorsRolf Najork,

220、product development vice president, GetragGeared to the futureWhich designs will win and lose in a changing world of transmissions?INTERVIEWSn From planetary automatic transmissions, it is known that a fixed gear ratio with a planetary set can be selected by connecting either one of its three rotati

221、onal members (ring gear, sun gear or the carrier) to the transmission housing. This connection is usually established through a wet multiplated brake unit so that synchronization with the housing is possible with retained power transfer.DTIs powershift technologies use such a brake-controllable plan

222、etary gearset as a short term torque bypass while the main transmission shifts towards the next gear. One may compare the functionality to a limited slip differential (LSD), which controls the distribution of left- and right-drive shaft torque using a slip-controllable clutch. The functionality of t

223、he brake-controllable planetary gearset can be used to fill torque gaps that occur when shifting an AMT from one gear to the next.The installation of a planetary gearset and brake in the bellhouse leads to package neutrality for CSC equipped AMTs. The combination of an AMT and brake-controllable pla

224、netary gearset is termed Powershift AMT. Because the planetary gearset is only loaded during shift instances, the accumulated loading time of the gearset is about one order of magnitude lower than the lifetime requirements of the transmissions final drive. The material lifetime requirements of the d

225、ry brake-disc for the powershifting functionality are roughly the same as the material lifetime requirements of the main clutch.The cost-effective powershift module is particularly interesting in combination with a five-speed (A)MT installed in A/B-class Transmission evolutionA pioneering new struct

226、ure is helping to realize a number of important advantages over existing dry DCT systemsvehicles. In this vehicle segment, usually five-speed manual transmissions are installed, or alternatively, relatively inefficient four-speed automatic transmissions.The main benefit of the Powershift AMT is that

227、 the standard five-speed MT design can be dressed-up towards being a substitute for the four-speed AT or a five-speed AMT, and as such it constitutes a very lucrative step for producing the MT, AMT and Powershift AMT systems on the same production line.The brake-controllable planetary gearset can al

228、so be used as the main clutch in a six-speed DCT structure. As a first DCT-clutch, it must also perform functions such as vehicle launching, creep and hill-hold. Therefore, sufficient cooling capabilities of the (planetary) brake module are required. The six-speed DCT structure is such that when the

229、 engaged brake is in the planetary module, it establishes gears one, three and five, whereas the engaged clutch establishes gears two, four and six.The gear-pair used to establish the second transmission ratio is also used to establish the first gear by engaging the brake of the planetary gearset. T

230、he planetary gearset then realizes a pre-reduction for the second gear ratio and as such constitutes a first gear equivalent ratio. Furthermore, the fifth gear is composed by that same pre-reduction and a direct mesh between a selectable fifth gearwheel and the output gearwheel. In most other laysha

231、ft transmissions (including DCT), putting a gearwheel at that specific location makes no sense as the resulting gear ratio is then too high. In addition to this, the space above the output gear is usually occupied by an input shaft bearing and/or a clutch (dis)engagement system. The discussed new DC

232、T structure renders a number of important advantages over existing dry DCT structures. For example, the single layshaft re-uses at least one gear pair (first and second) and a double meshing output gear justifies the installment of the additional planetary gearset without the penalties on length com

233、pared to a standard single layshaft six-speed manual transmission. A second advantage is to do with its slender design, because the first gear pair can be left out and this enables a less asymmetric loading as well as a shorter center distance between input and output shaft and thus a more slender t

234、ransmission, leaving more room for top-mounted actuators. Other important advantages that the DCT structure allows is active cooling. The brake system can be actively liquid cooled to guarantee the lifespan of the launch-brake when used for heavy hill/trailer launches, hill-creep and long stop/start

235、 traffic circumstances. As a result, it enables capabilities that are seen only in wet-plate or torque-converter automatics while still maintaining the high efficiency manual transmission structure. Liquid cooling of the dry brake system can be established by integration of cooling channels (integra

236、ted with the engine cooling system) in the static brake pressure plates. Another benefit thats realized with the new structure is that the heat sinks of the brake and clutch are mechanically and thermally separated. As such, the functionality of the on-coming clutch or brake is not influenced by the

237、 temperature history of the off-going brake or clutch. This decreases the amount of calibration work of this DCT structure.Finally, the pressure-plates of the brake in the planetary gearset are non-rotating and therefore this new dry DCT structure does not noticeably increase the total inertia of th

238、e engine when compared to a manual. TTi46Casestudy:DTITransmission Technology International | September 2010thenewdCtstructurefocusesonanew,singlelayshaftthebrake-controllableplanetarygearsetasthemainclutchinadual-clutchtransmissionstructureSeptember 2010 | Transmission Technology International Requ

239、est your FREE copy of Transmission Technology International magazine at: SUBSCRIBENOWONLINE READER ENQUIRY SERVICE ALSO AVAILABLEA&D Technology Inc .IBCAfton Chemicals .23Brand KG .37Consilium Group Ltd .31CVT 2010 Conference .20Drivetrain Innovations BV .39EFD Induction AS .15Engine Expo North Amer

240、ica 2011 . 47Engine Expo 2011 .40Feintool Technologie AG .19GIF .13, 15IBS Filtran GmbH .7Innovative Automotive Transmission Symposium, Berlin . 11P.J. Wallbank Springs Inc .11SKF GmbH .20Smart Manufacturing Technology Ltd .9Solvay Advanced Polymers . IFCTransmission Technology Online Reader Enquiry

241、 Service .45Wolverine Advanced Materials .27www.EngineTechnologyI .43Zeroshift .OBC Index to Advertisers?25-27 October 2011The Rock Financial Showplace, Novi, MI, USAFor more information contact Tim Sandford on +44 1306 743744 or email | www.engine- Americas exciting, new, dedicated international t

242、rade fair for automotive powertrain design, production, components, and technology. 2011BOOK NOWFOR 2011!www.engine- theAN ENGINE TECHNOLOGY INTERNATIONAL PUBLICATIONSeptember 2010Whats new?Fords high-tech autoGetrags dry-clutch DCT design for Renault BorgWarners advancedeGearDrive system Sergio Cai

243、rola, transmission platforms vice president, Fiat Powertrain Technologies Jeffrey Baran, executive director of transmission program execution, General MotorsRolf Najork, product development vice president, GetragGeared to the futureWhich designs will win and lose in a changing world of transmissions

244、?INTERVIEWSWhat career did you want when you were growing up, and what was your fi rst job?I grew up close to an auto repair shop where they assembled and tested racing cars on local dirt tracks it was like a magnet in my youth. It was soon pretty obvious that I wanted to work with cars: either as a

245、 racing driver or car manufacturer. In the end, it turned out to be the latter, and I started my fi rst job at Porsche. I was employed there in different roles in working on acoustics, engine and vehicle development.How old were you when you started playing around with transmissions?I can remember t

246、he fi rst time I started playing around with powertrains and transmissions very clearly: it was when I got my fi rst car when I was fi ve years old: a Porsche 356 convertible from Distler. This model car had a transmission with two forward gears, neutral and a reverse gear as well as an all-electric

247、 powertrain a direct current motor that was started with a real ignition key.What are the best and worst elements of your job?I love designing something together with other people in a strong team. I hate excuses and apologies that come without solutions. What car do you currently drive?My company c

248、ar is an Audi A8 but I much prefer to drive my own, personal car, a Porsche 911 (996) convertible. I am emotionally attached to this model: after all, I had the privilege of playing a decisive role in designing and assisting in the development of this series during my time at Porsche.Ignore emission

249、s legislation for a moment, what would be your ideal engine and transmission design specifi cation? Id go for the last air-cooled powertrain from the Porsche 911 turbo with two turbochargers along with charge-air intercoolers, developing 450bhp. This engine was mated to a six-speed manual transmissi

250、on. I think it would be a dream come true if this engine was to be combined with a double-clutch transmission.Which engine and transmission specifi cation would you choose for todays eco-conscious world? There are two engineering solutions that Id choose. The fi rst would be a gasoline engine with t

251、he UniAir system and a turbocharger, as well as a seven-speed, double-clutch transmission. The second option Id choose is a diesel engine with piezo common-rail injection, turbocharging, particulate fi lter and SCR as well as a double-clutch transmission. Both of these two solutions would also featu

252、re a stop/start function. What is the best transmission that has ever been produced? It is very diffi cult to single out a specifi c transmission system. I think the new six- and seven-speed double-clutch transmissions have a slight advantage over modern, eight- and nine-speed automatic transmission

253、s with torque convertors.Which manufacturers do you have particular respect for in terms of their engine and transmissions development, and why?I admire the courage of engineers at Volkswagen who put the double-clutch transmission into volume production. This was a really brave step forward, and an

254、important development for the market. Aside from Volkswagen, there are other specialist transmission manufacturers that have also demonstrated great courage with regard to their technical solutions.What is the proudest achievement of your career so far?Looking back on my career so far, I am proud of

255、 the overall performance of the teams in which I have been involved. If I had to select one career moment, I would highlight the Porsche 911 (996) development project. It was a wonderful car in many ways, and a real high point in terms of successful team work. Aside from the Porsche 911 (996) develo

256、pment program, Id also like to mention products developed by the Schaeffl er Group, such as the dry double clutch.What personal career goals do you have for the future?I want to continue designing and developing innovative and pioneering automotive products with my colleagues.In your opinion, what w

257、ill be powering passenger cars in the year 2025?I believe that the types of drive systems available in 2025 will not be like those we know today there will be a much more varied range of vehicles on our roads. There will be an optimal solution for every application, from pure electric cars for mega

258、cities and different hybrid variants to high-effi ciency internal combustion engines for longer distance driving. Perhaps we will also see fuel cell technology in one or two vehicles. Furthermore, I also hope that there will be a special exemption that will allow the use of 30-year old vehicles as a

259、 reminder of our automotive history.What would you like to see the legislators and manufacturers do in the immediate future to improve drivetrain effi ciency?Legislators should only defi ne the framework conditions and objectives, and provide targeted support if necessary to the industry. This inclu

260、des, for example, legislation on emissions and aid for electric mobility, which will support the automotive industry during the parallel development of new types of drives, alongside the continuous optimization of the combustion engine. TTi48 LAST WORDTransmission Technology International | Septembe

261、r 2010“I admire the courage of engineers at Volkswagen who have put the double- clutch transmission into volume production. This was a really brave step and important development” Peter GutzmerExecutive vice president, Schaeffl er TechnologiesA&D Technology is a leading global supplier of advanced t

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267、 lubricated systems.AN ENGINE TECHNOLOGY INTERNATIONAL PUBLICATIONSeptember 2010Whats new?Fords high-tech autoGetrags dry-clutch DCT design for Renault BorgWarners advancedeGearDrive system Sergio Cairola, transmission platforms vice president, Fiat Powertrain Technologies Jeffrey Baran, executive director of transmission program execution, General MotorsRolf Najork, product development vice president, GetragGeared to the futureWhich designs will win and lose in a changing world of transmissions?INTERVIEWS