FIA電動(dòng)方程式賽車第二賽季于2015年10月17日在中國北京啟動(dòng)，奧迪跑車團(tuán)隊(duì)的獨(dú)家技術(shù)伙伴ABT舍弗勒已準(zhǔn)備好展示其全新的全電動(dòng)傳動(dòng)系統(tǒng)。
“為了決定是使用1臺(tái)電機(jī)還是2臺(tái)電機(jī)，以及使用幾速的變速箱，我們進(jìn)行了大量計(jì)算。最后我們決定，使用1個(gè)電機(jī)、1個(gè)三速變速箱、以及符合法規(guī)要求的中央差速器，以實(shí)現(xiàn)最佳性能，”舍弗勒?qǐng)?zhí)行CEO兼首席技術(shù)官Peter Gutzmer教授表示。“”
Gutzmer以及其他參與開發(fā)世界首個(gè)全電動(dòng)車賽道的人員，在第二場(chǎng)季前賽的測(cè)試期間接受了《汽車工程雜志（Automotive Engineering）》的采訪。季前賽將在位于英格蘭多寧頓堡的著名景點(diǎn)——多寧頓公園賽道舉行。
在2014-15年的首次賽季中，無論在歐洲、亞洲還是美洲的賽道上，參賽的40輛碳纖維/鋁制單體殼底盤單座賽車全部搭載了麥克拉倫的傳動(dòng)系統(tǒng)。在2015-16賽季中，盡管所有電動(dòng)方程式賽車依然使用威廉姆斯先進(jìn)工程公司的28 kW·h儲(chǔ)能電池，但是每個(gè)團(tuán)隊(duì)都可以自行選擇傳動(dòng)系統(tǒng)。
FIA電動(dòng)方程式錦標(biāo)賽通訊專家Andrew Van De Burgt表示，10個(gè)車隊(duì)中有8個(gè)不愿繼續(xù)使用第一賽季的傳動(dòng)系統(tǒng)，該系統(tǒng)使用的是 Hewland Engineering的五速換檔撥片序列式齒輪箱。這8個(gè)團(tuán)隊(duì)選擇與技術(shù)專家合作，以開發(fā)一款全新的傳動(dòng)系統(tǒng)。
“目前參賽的變速箱從一速到五速都有。在去年比賽的啟動(dòng)環(huán)節(jié)中，個(gè)個(gè)參賽隊(duì)成績(jī)水平比較類似，因?yàn)榇蠹沂褂玫氖峭瑯拥淖兯傧?。而今年變速箱各不相同，因此我們可以看到截然不同的啟?dòng)風(fēng)格，” Van De Burgt表示。
從噪音角度看，由于變速箱和電機(jī)發(fā)生了變化，因此聲音也會(huì)不一樣。“你可以瞬間聽出哪一輛是ABT/舍弗勒的車，因?yàn)樗绕渌図懙枚?。你也可以聽出馬恒達(dá)隊(duì)、龍之隊(duì)和文圖里隊(duì)的車，因?yàn)樗鼈兎浅０察o。因此，今年的賽車聽起來會(huì)很不一樣，”Van De Burgt表示。
ABT舍弗勒的奧迪團(tuán)隊(duì)希望通過更換傳動(dòng)系統(tǒng)，繼續(xù)保持上一賽季的冠軍成績(jī)（共9個(gè)獎(jiǎng)位），該系統(tǒng)使用的是一臺(tái)純電動(dòng)電機(jī)，能夠提供比去年更高的效率和扭矩。
Gutzmer表示，舍弗勒電機(jī)比2014-15賽季中使用的麥克拉倫電機(jī)輕了57-lb (26-kg) ，后者加速至62 mph (100 km/h)需要3秒。“重量真的輕了很多。整個(gè)系統(tǒng)都是新的。但包括轉(zhuǎn)子在內(nèi)的部件都已經(jīng)其他商用車和賽車中使用過，”Gutzmer表示。
這臺(tái)三速手動(dòng)變速箱是由Hewland按照舍弗勒的要求生產(chǎn)的，比去年的更堅(jiān)硬、更緊湊。“我們將注意力全都放在效率提升和實(shí)現(xiàn)最大扭矩上，這臺(tái)三速變速箱在這兩方面上都比上一季的五速變速箱更出色，”Gutzmer表示。“我們認(rèn)為，這臺(tái)三速變速箱將是整個(gè)傳動(dòng)系統(tǒng)的制勝法寶。”
舍弗勒傳動(dòng)系統(tǒng)的另一大研究重心在于熱效率的提升。
“如果你將電池的一部分能量?jī)H僅用在克服導(dǎo)線、電機(jī)和其他地方的電阻上，那么這將造成巨大的浪費(fèi)，因?yàn)槟阍隈{駛的時(shí)候不能使用這些能量。我們將傳動(dòng)系統(tǒng)的熱效率提高了3%，而且在某些駕駛情況下還能達(dá)到8%。這是一個(gè)很大的進(jìn)步，因?yàn)檫@讓電池的使用變得更為合理，”Gutzmer強(qiáng)調(diào)。
ABT舍弗勒奧迪團(tuán)隊(duì)的賽手Lucas di Grassi表示，能源管理至關(guān)重要。上一賽季中，比賽認(rèn)證用的鋰電池功率限定在為200 kW以內(nèi)，比賽時(shí)最高可達(dá)150 kW，最大可用能量為28 kW·h。
“今年賽季的認(rèn)證功率沒有變化，但比賽時(shí)的功率限值改成了170 kW，比上一賽季高了20 kW，最大儲(chǔ)能則保持不變。因此，除了提高電機(jī)功率之外，還得提高它的效率，因?yàn)榧铀贂r(shí)消耗的能量將會(huì)更多，”di Grassi表示。
Gutzmer說，來自舍弗勒、ABT和奧迪車隊(duì)的技術(shù)專家都參與了軟件程序的重新編寫，“這樣做不僅可以徹底改變車輛的行為，而且還能對(duì)變速箱和電機(jī)進(jìn)行調(diào)諧。”
Di Grassi的隊(duì)友Daniel Abt表示，賽車的后懸架也進(jìn)行了相應(yīng)修改。“因?yàn)槭紫雀淖兊氖请姍C(jī)和變速箱，所以懸架上的連接點(diǎn)也必須更改。我們更換了彈簧、緩沖器，所以后懸架也是全新的。”
賽手Daniel Abt 的比賽工程師Jacky Eeckelaert稱，這些修改共同造就了一輛性能更出色的賽車。Eeckelaert 在2014-15賽季中擔(dān)任di Grassi 的比賽工程師，他表示，“如果將今年和去年的數(shù)據(jù)進(jìn)行比較，可以清楚地看到，新車的傳動(dòng)系統(tǒng)不僅更出色，而且底盤及整體的動(dòng)力學(xué)性能也更好。”
Van De Burgt稱，盡管車隊(duì)不能在2015-16賽季開始前透露這臺(tái)全電動(dòng)傳動(dòng)系統(tǒng)的深入技術(shù)細(xì)節(jié)，但隨著比賽的進(jìn)展，將會(huì)披露更多信息。“讓人們相信，電動(dòng)方程式錦標(biāo)賽中使用的技術(shù)將會(huì)在未來的公路車輛上應(yīng)用，這種帶有推廣效應(yīng)的展示，對(duì)我們來說非常重要。”
在電動(dòng)方程式錦標(biāo)賽中登場(chǎng)的各種傳動(dòng)系統(tǒng)解決方案，展示了未來電動(dòng)汽車的無限可能，車隊(duì)主管Hans-Jurgen Abt表示。“最好的技術(shù)通常都來自于賽車。在第二賽季中，舍弗勒等賽車制造商將展示出他們的最大能耐。”
作者：Kami Buchholz
來源：SAE《汽車工程雜志》
翻譯：SAE 上海辦公室
Schaeffler's electric powertrain primed for FIA Formula E racing
The second season of FIA Formula E begins in Beijing, China on October 17, 2015, with the ABT Schaeffler Audi Sport team’s exclusive technology partner ready to demonstrate its novel all-electric powertrain.
“We did a lot of calculations because we needed to decide on one or two electric motors and the number of transmission gears. A single electric motor and a three-speed transmission in combination with the [rules-required] central differential is what we determined would be the best package for achieving optimal results,” said Prof. Dr.-Ing Peter Gutzmer, Deputy CEO and Chief Technology Officer forSchaeffler AG.
Gutzmer and others involved in the world’s first all-electric racing circuit spoke withAutomotive Engineering during preseason two testing at the renowned Donington Park Racing Circuit in Castle Donington, England.
In the 2014/2015 inaugural season, all 40 carbon-fiber/aluminum monocoque chassis single-seat cars ran a standardized McLaren Applied Technologies powertrain on street courses in Europe, Asia, and the Americas. Although each Formula E racecar still uses a Williams Advanced Engineering-supplied battery with 28 kW·h of stored energy, each team could elect to run a unique powertrain in the 2015/2016 season.
Andrew Van De Burgt, FIA Formula E communications specialist, said eight of the 10 race teams chose not to stay with the season-one powertrain package that featured a Hewland Engineering five-speed paddle shift sequential gearbox. The eight teams opting to develop and homologate a new powertrain did so via partnering with technology specialists.
“We literally have everything from a single-speed to a five-speed transmission. Last year, the [race] starts were pretty uniform because everyone had the same transmission. Now with this vast difference in transmission technology, we could see a really big difference in the way they start,” Van De Burgt said.
From a noise perspective, there’s been a sonic sound shift from the first season because of the transmission and motor changes. “You can instantly tell the Abt/Schaeffler car because it’s much louder than the other cars. And you can tell the Mahindra, Dragon, and Venturi [team] cars because they’re really quiet. So there’s an audible difference this year,” said Van De Burgt.
The ABT Schaeffler Audi Sport team hopes to top last season’s nine podium finishes with the switch to a new powertrain that spotlights an electric motor that is more efficient and provides more torque than the predecessor.
Schaeffler’s electric motor drops double-digits in weight compared to the 57-lb (26-kg) McLaren Electronic Systems-supplied motor that propelled a 2014/2015 season racecar from 0 to 62 mph (100 km/h) in 3 seconds, according to Gutzmer. “It is a really significant weight savings. The whole system is new. But the components that we are using, including the rotor, have been approved already in other applications, [namely] commercial vehicles and motorsports,” said Gutzmer.
The three-speed transmission is being produced by Hewland to Schaeffler specifications. This new manual transmission is stiffer and more compact. “We were really focused on efficiency and maximum torque, and the three-speed transmission allows much more than last season’s five-speed transmission,” said Gutzmer. “We think the three-speed transmission is a success factor for this powertrain.”
Another focal point of the Schaeffler-developed powertrain was thermal efficiency.
“If you are taking energy out of the battery and using it just for resistance in the wirings, in the motor, and in other areas, that means a loss of power in terms of what you’re unable to use while driving the car. We improved the powertrain’s thermal efficiency in the 3% range, and it could be up to 8% better in certain driving situations. That’s a big step because it’s really important to be smart about battery usage,” Gutzmer emphasized.
Team ABT Schaeffler Audi Sport driver Lucas di Grassi said power management is vital. Last season each driver had 200 kW of power for qualifying and 150 kW of maximum power during a race from the Li-ion battery with maximum usable energy of 28 kW·h.
“The energy for qualifying remains the same, but we’re now allowed to use 170 kW in the race, so that’s a 20-kW increase over last season from the same amount of energy. So basically apart from making a motor that delivers more power, it has to be more efficient because when you accelerate, you’re using more energy,” said di Grassi.
Technical specialists from Schaeffler, ABT, and Audi Sport were involved in rewriting software code, according to Gutzmer. “It was done to alter the complete driving behavior of the car, and also was done to address the tuning of the transmission and the electric motor,” Gutzmer said.
Di Grassi’s teammate said a revised rear suspension rounds out the racecar alterations. “It starts with having a different motor and gearbox, so the connection points from the suspension change. We have different springs, different dampers, so the rear-end is all-new components,” said Daniel Abt.
All the modifications equal a better racecar, according to Jacky Eeckelaert, race engineer for driver Daniel Abt. “When we compare the data from this year to the data from last year, it’s clear the car is more competitive in terms of the powertrain and also in terms of the chassis/vehicle dynamics,” said Eeckelaert, who was the race engineer for di Grassi in the 2014/2015 season.
According to Van De Burgt, even though teams are hesitant to divulge in-depth technical details in advance of 2015/2016 racing, more information on the different all-electric powertrains is likely to be revealed as the second season progresses. “It’s very, very important for us to show a trickle-down effect from the technology that’s being used in Formula E to the technology that’s going to be used on the road cars of the future,” said Van De Burgt.
The various powertrain solutions featured in Formula E shine a bright light on what’s possible with future electrified vehicles, according to team owner Hans-Jurgen Abt. “All the good things come from motorsports normally. And now in season two it starts with Formula E and the participating manufacturers, like Schaeffler, who want to show the potential of what they can do.”
Author: Kami Buchholz
Source: SAE Automotive Engineering Magazine
與第一賽季一樣，第二賽季的40輛賽車都使用了同樣的Dallara底盤、威廉姆斯高級(jí)工程公司的電池組、18英寸車輪與米其林輪胎。但不同于第一賽季的是，今年各個(gè)車隊(duì)可以自由選擇使用哪種全電動(dòng)傳動(dòng)系統(tǒng)。圖為ABT舍弗勒奧迪車隊(duì)的賽車在英格蘭的季前賽測(cè)試中亮相。
舍弗勒的Peter Gutzmer教授（中）與ABT舍弗勒奧迪車隊(duì)的賽手Daniel Abt（左）和Lucas di Grassi（右）。
在ABT舍弗勒奧迪賽車的近照上，可以看到全新的舍弗勒電動(dòng)傳動(dòng)系統(tǒng)。這張照片上顯示的是電機(jī)與經(jīng)過優(yōu)化的懸架。