如今，OEM開始更多的將注意力關(guān)注車輛的動(dòng)力傳動(dòng)系統(tǒng)上，并開始與一級(jí)供應(yīng)商合作，以追求更高的效率、更低的重量、更優(yōu)化的NVH特性以及更低的成本。目前 AAM（AmericanAxle & Manufacturing，中文譯名：美國輪軸制造公司 或 美國車橋制造有限公司）正在展示一種全新Quantum技術(shù)，這種技術(shù)背后的設(shè)計(jì)理念正是打造更高效、更輕質(zhì)、更“智能”的驅(qū)動(dòng)橋系統(tǒng)。Quantum是AAM的系列驅(qū)動(dòng)橋產(chǎn)品，據(jù)稱可以為車輛實(shí)現(xiàn)30%到40%的質(zhì)量減少，和20%的功率密度提升。近日，AAM副總裁兼CTO Phil Guys接受了《汽車工程》的采訪，向大家介紹了有關(guān)Quantum技術(shù)的相關(guān)研發(fā)情況，摘選如下：
SAE：Quantum的概念從何而來？
Phil：Quantum技術(shù)是我們先進(jìn)工程團(tuán)隊(duì)一次頭腦風(fēng)暴的成果。那時(shí)，我們剛剛完成了一項(xiàng)旨在實(shí)現(xiàn)更高能效的內(nèi)部項(xiàng)目 – 工程團(tuán)隊(duì)采用了新的軸承、更輕的潤滑系統(tǒng)以及超精加工的準(zhǔn)雙曲面齒輪。這是一次很常見的迭代，但我們認(rèn)為其他一級(jí)供應(yīng)商也能和我們做的一樣好，從產(chǎn)品功能的角度來說，這次迭代不能讓我們與其他廠商真正拉開差距。
我們知道客戶想要重量更輕、效率更高、運(yùn)行安靜、可靠耐用且成本更低的解決方案，在這種背景下，我們?cè)僖淮芜M(jìn)行了嚴(yán)肅對(duì)話，討論如何才能真正從驅(qū)動(dòng)橋市場中脫穎而出。我們的先進(jìn)工程團(tuán)隊(duì)開始將目光轉(zhuǎn)移至汽車行業(yè)之外，包括航空航天、醫(yī)療器械等領(lǐng)域中任何涉及扭矩能量轉(zhuǎn)移的設(shè)計(jì)。
6個(gè)月后，也就是2014年，他們拿出了一套方案，這也就是現(xiàn)在的Quantum技術(shù)。Quantum技術(shù)的橋設(shè)計(jì)采用了一套截然不同的齒輪支持結(jié)構(gòu)，結(jié)合了適用于后驅(qū)動(dòng)車型的梁式橋和獨(dú)立后懸掛（IRS）設(shè)計(jì)以及一款全輪驅(qū)動(dòng)（AWD）系統(tǒng)。當(dāng)時(shí)我們認(rèn)為這種概念過于激進(jìn)，可能不會(huì)有客戶感興趣。
SAE：Quantum技術(shù)“激進(jìn)”在哪兒？
Phil：嗯，這種解決方案與傳統(tǒng)的橋設(shè)計(jì)有很大不同，我們的一些客戶可能會(huì)有點(diǎn)懷疑，別人都沒見過這種設(shè)計(jì)，因此我們肯定要盡可能地提供更多的驗(yàn)證、開發(fā)、效率、NVH和耐用性數(shù)據(jù)，打消大家的疑慮。此外，我們還打造了多款演示原型，以展示Quantum產(chǎn)品的安靜運(yùn)行能力。
我們打造了一款梁式橋，這是目前公司產(chǎn)品目錄中最大的一款產(chǎn)品，也是Quantum技術(shù)的首個(gè)真正應(yīng)用。我們認(rèn)為，減重和提效應(yīng)該是卡車市場優(yōu)先考慮的重點(diǎn)，而我們的演示原型實(shí)現(xiàn)了30-35%的減重效果。目前，一款1500系列皮卡的標(biāo)準(zhǔn)梁式橋重量為82公斤（180磅），而Quantum解決方案的重量僅為57公斤（125磅），減重比例高達(dá)30%；2500系列皮卡的標(biāo)準(zhǔn)梁式橋重量為144公斤（317磅），Quantum解決方案的重量為98公斤（180磅），減重比例達(dá)30-40%。目前，我們還沒有嘗試量化Quantum可以在車輛減重方面發(fā)揮的作用，這可以留給客戶自己去做。
無論何時(shí)，Quantum技術(shù)總能給不同應(yīng)用帶來減重方面的能力提升。與現(xiàn)有技術(shù)先比，采用Quantum技術(shù)的AWD車型可實(shí)現(xiàn)40%左右的減重。“我們已經(jīng)減低了40%的寄生損失，并取得了大約1%的燃料經(jīng)濟(jì)性提升。”之前，我們已經(jīng)完成了一次迭代，并對(duì)Quantum進(jìn)行了更多優(yōu)化。14個(gè)月前，我們又完成了對(duì)Quantum技術(shù)的第二次迭代，并開始向客戶正式介紹這款產(chǎn)品。
SAE：Quantum技術(shù)的“秘密武器”是什么？
Phil：現(xiàn)在，我們還不會(huì)透露Quantum技術(shù)的內(nèi)部結(jié)構(gòu)，但可以說這款產(chǎn)品的核心在于采用了356號(hào)熱處理鋁材。我可以告訴你，雖然我們采用的金屬環(huán)-小齒輪滾珠軸承來自航空航天領(lǐng)域，但成本卻相當(dāng)親民！我們通過這種滾錐軸承實(shí)現(xiàn)了產(chǎn)品的差異化。Quantum系列產(chǎn)品的所有能效提升均來源于金屬環(huán)-小齒輪軸承結(jié)構(gòu)的支持，這些軸承并非雙排設(shè)計(jì)，也無需事先加載，因此我們并沒有使用墊片，而為了預(yù)先加載小齒輪軸承，通常墊片在車橋設(shè)計(jì)中的使用非常常見。這就是Quantum設(shè)計(jì)中最激進(jìn)的地方。
SAE：外殼和軸承座的設(shè)計(jì)也有不同嗎？
Phil：是的，這兩處的設(shè)計(jì)是完全不同的，但創(chuàng)新之處在于，我們將如何以最緊湊、最高效的方式將這些軸承應(yīng)用在我們車橋設(shè)計(jì)中。
OEMs are increasing their focus on the vehicle driveline, working with Tier 1s to wring out greater efficiencies, mass and NVH reduction and cost. Making drive axles as efficient, light and ‘intelligent’ as possible was the impetus behind the new Quantum technology now being demonstrated by American Axle & Manufacturing. Quantum is a family of drive axles that AAM claims deliver a 30 to 40% mass reduction and 20% greater power density as incumbent axles with the same torque capacity. Phil Guys, AAM’s Vice President and CTO, recently spoke with AE about Quantum developments.
Where did the Quantum concept come from?
From a brainstorming session with AAM’s advanced engineering team. We’d just been through an internal project aimed at seeking greater efficiencies—new bearings, lighter weight lubes, superfinished hypoid gears. A very iterative exercise, but we concluded that all of us in the Tier-1 axle space can do that. From a product-functional perspective there’s not a lot of differentiation.
We had a significant dialogue about how do we truly differentiate ourselves in the market, knowing that customers want less weight, more efficiency, quiet operation, reliability and durability, at reduced cost. So our advanced team benchmarked products outside the automotive space, including aerospace, medical—anything with a torque element to it that had to transfer energy.
Six months later—this was in 2014—they came up with a proposal. And the idea that came out of it, now called Quantum, was so radical that we thought no one would want to buy it. Quantum technology is all about a totally different approach to the axle’s gear-support structure. The concept encompasses beam-axle and IRS [independent rear suspension] versions for rear-drive applications, and an AWD derivative.
What makes it ‘radical’?
Well, it doesn’t look like a traditional axle so there was a bit of skepticism from some of our customers. It is a different-looking animal so we were right to gather a tremendous amount of validation, development, efficiency, NVH and durability data in support of the technology. We also built models to prove that it’s a quiet axle when installed in a vehicle.
We built a beam axle, the biggest product in AAM’s portfolio. It’s the first application of this technology; we felt the truck market would be looking for weight and efficiency improvements as a priority. And in our prototype we saw a 30-35% weight reduction. A benchmark beam axle for a 1500-series pickup weighs 82 kg [180 lb]; the Quantum is 57 kg [125 lb]; that’s a 30% mass reduction. A benchmark 2500-series axle is 144 kg [317 lb]; Quantum is 98 kg [180 lb], so we took 30-40 pounds out of that. We haven’t even tried to quantify the savings on the vehicle side that can come from the “cascade” benefits we bring; we’ll let the customers do that.
Each time we applied the technology in a different application we saw weight-reduction improvements. On the AWD version the weight savings is about 40% relative to current-market technology. And we’re seeing on the order of 40% reduction in parasitic losses. We quantify that as about a 1% improvement in label-type fuel economy to the vehicle. We went through one iteration and found more opportunities to make it even better. We did a second iteration, tweaked it a bit more and started taking that technology to our customers about 14 months ago.
What’s AAM’s ‘secret sauce’ for Quantum?
I’m not ready to show the insides just yet. The center section is heat-treated 356. I can tell you that while the new ball bearings we’re using for ring-and-pinion support are from aerospace applications, their cost isn’t! We use tapered roller bearings for the differential. All of our efficiencies are coming out of the ring-and-pinion support. Those bearings are not double-row and are not preloaded, so we don’t use shims [typically used in axles to set pinion bearing preload]. The design is radical in this regard.
Is the IP in the case design and bearing saddles?
Yes, they’re totally different. But the innovation is in how we apply these bearings in an axle in the most compact, efficient manner.
Author: Lindsay Brooke
Source: SAE Automotive Engineering Magazine
AAM的首席技術(shù)官 Phil Guys表示，“我們已經(jīng)減低了40%的寄生損失，并取得了大約1%的燃料經(jīng)濟(jì)性提升?！?/span>