阿斯顿马丁别具特色的Vulcan车型输出功率可达600 kW（805 hp），定价150万英镑。该车驰骋于法国南部的保罗理查德高科技测试赛道时，视野和音效都令人叹为观止。同样令人惊叹的是，该款超级跑车搭载了一个塑料容器，外观质朴，却有望为发动机润滑油技术和服务带来飞跃性的进步。

Nexcel油箱由嘉实多研发，是一款更换式单体机油箱和过滤器，与动力总成实现集成。不仅如此，该油箱还有几大主要优势，如90秒完整更换机油；摩擦损失降低；二氧化碳排量“显著”降低；定制的、精密制造的机油，使用简易，适用于特定的发动机；以及卓越的可持续性。

该油箱的测试项目使用的车型是超高性能的奢华尊享（将仅仅生产24辆）Vulcan。测试展示了高难度技术进步，收获了巨大成功。嘉实多Nexcel首席工程师Oliver Taylor告诉《汽车工程杂志》：“我们预计，两到五年内，量产的公路用车将装配Nexcel油箱，之后会实现大规模应用。Vulcan测试之后，我们的技术研发将进入实施阶段。”

他预计，2020年到2025年，大多数的量产车都会使用该系统。除了Vulcan的V12车型，Nexcel油箱也在其他很多汽车发动机中进行了测试。

整车厂青睐概念车

Nexcel油箱也面临一大挑战。在量产车中，该油箱容量一般在3.0 L到5.0 L中间变化，这可能会带来发动机舱的包装难题。但嘉实多正在竭力设计、并打造合适的解决方案。并且，理想的情况是，将Nexcel集成到概念车和新发动机（或者车辆）的最初设计阶段，以适应管道、电子装置和整体空间；如果需要改变当前大规模量产的发动机那将带来制造和成本的挑战。

但整车厂反映良好，发动机制造商高度认可，因此，嘉实多对Nexcel的未来充满信心。

 “Nexcel是完全密封的，里面包括机油及机滤。它的出现，也标志着传统的机油更换方式就此终结，”Taylor解释道。该项目的设计灵感来自于一场四年前的头脑风暴，当时，集合了公司在全球的50个强大创新团队。他认为设计、研发和系统制造对于汽车产业来说是非常重要的，但当时，将这些问题当做核心议题的主要是公司的英国工厂。

在量产车里，Nexcel油箱将被置于一个“对接”区域，临近发动机组。油箱集成了电子装置，与汽车的CAN总线和发动机管理系统对接，不但可以监测可用机油量和质量（确保其等级和规格符合车辆要求），还可以评估机油的剩余可用时长。

 “这种技术有望确保‘精密润滑油’成为可能，”Taylor表示。“一旦汽车的预定服务启动，可以通过车载菜单选定‘服务模式’，一个小电泵可以将机油从油箱底壳输入油箱。整个过程持续约30秒。完成后，装有机滤的油箱可以与车辆断开连接。”

 “只要把装有新润滑油和机滤的新油箱置于对接位置，液压管会通过油箱底部的机械干断阀门连接，一条液压管会连到油箱底壳，还有两条液压管会连到回油孔。这就是完整过程，仅用时90秒。”

摩擦学仿真是关键

系统使用的精密润滑油是该技术中非常重要的一方面，Taylor强调道。因为精密润滑油很可能会减小磨损和二氧化碳排量：“整车厂对于该系统可以带来的全面的优势非常感兴趣。”

为了更好地了解降低磨损带来的好处，他花了七年时间学习相关知识，特别是详尽的摩擦学仿真设计，以及润滑油系统如何提升燃油经济性。

 “发动机的设计灵活多样，我们也知道有不同的表面处理方法、材料、以及轴承类型，所有这些都与发动机润滑油以不同的方式相互作用，”Taylor解释道。“为了达到特定发动机的最低摩擦，我们需要及其特殊的润滑油，专门为特殊应用和工作循环打造，以便进一步降低碳排放。”

热管理也支持更低排放。可以用电动油箱泵，确保冷启动时有精确数量的机油（发动机需要的最小安全数量），而其余机油储存在油箱里。这样可以保证机油和整体系统加热速度更快；Taylor表示，“完成预热后的发动机是非常高效的。”

系统在常规和干油底发动机中都可以工作，阿斯顿马丁的Vulcan配有一个干油底壳。

目前，对于二氧化碳减排方面的进步，Taylor非常审慎，并未给出具体的量化数据。但他表示，“从统计学的角度看，数据是非常可观的。”

为了促进可持续性的深入发展，嘉实多正在研发一个新体系，可以将油箱送至服务中心或者消费者商店，也可以从这些地方取回油箱。今后，嘉实多也将推广一种反物流模型，可以实现交付新油箱，并收集使用过的油箱，用于再处理，以便达到Taylor所说的“原装”质量，可以在类似发动机中再次使用。油箱会经过“多次”拆卸，清洗，装配新过滤器，再次充满，以及配送的过程。

他表示，Nexcel使用的机油根据特定的粘度等级进行分离和收集，“比现在的情况高效的多”。

严格的测试制度

Nexel是否会给终端用户（车主）增加成本？Taylor表示，大多数新技术的确会增加资本成本，但效率的提升可以抵消成本的增加。

嘉实多的Nexcel设计目标之一是，希望Nexcel的成本可以与普通机油更换服务成本持平，同时车辆也无需起重，这是附加效益。

Vulcan测试的是Nexcel油箱研发的最后几个阶段之一。在一个小规模投产（24辆）的车型中使用Nexcel，嘉实多和阿斯顿马丁可以进行更为密切的监测。

阿斯顿马丁特殊产品和赛车运动总监David King表示，Vulcan配有一个干油底壳润滑油系统，因此，只需用Nexcel油箱替代车辆原来配置的油箱，再对CAN总线做一些管道和连接处理就可以了。阿斯顿马丁也将为此制定非常严格的测试制度。

 “我们希望确保Nexcel系统在所有极端的测试环境中都能正常工作，” King表示。“包括在赛道的极端重力条件下的机油处理，极端加速和减速（最高可达1.8 g）的影响，以及振动和通气的影响，还有从特定的干油底壳系统经过Nexcel油箱的高机油流速。” 测试中流速最高达到600 L/min，是普通汽车发动机的10到20倍。

在进行真实的赛道测试之前，Nexcel经过了一系列成本高昂的实验室模拟，包括重力影响、耐久性试验、以及与普通系统的对比。King表示：“实验结果显示，我们的Nexcel油箱的性能不输普通油箱，在很多情况下，还要优于普通油箱。我们认为，将来Nexcel有潜力实现更大规模的车辆应用，所以我们才用Vulcan对其进行了测试。我认为，这是一种非凡的技术，我们是第一个将这项技术投入市场的企业！”

Vulcan最高时速可达320 km/h（200 mph）。现在，该车型的所有配置，包括机油更换设计，都彰显了速度与高效的特点。

作者：Stuart Birch
来源：SAE《汽车工程杂志》
翻译：SAE 上海办公室

Castrol’s removable oil cell heralds 90-s oil changes, reduced friction and CO2

The sight and sound of Aston Martin’s exotic 600-kW (805-hp) £1.5M Vulcan thundering around the Paul Ricard High-Tech Test Track in the South of France is spectacular. But on board the supercar, out of sight and making absolutely no sound, is a modest plastic container that promises to bring a major advance in engine lubrication technology and servicing.

Developed by Castrol, the Nexcel oil cell is in effect a removable one-piece engine oil tank and filter that integrates with the powertrain. But there is far more to it than that. It delivers several significant benefits: a complete engine oil change in 90 s, reduction of friction losses, a “significant” cut in CO₂ emissions, easy use of bespoke, precision-engineered oils to suit specific particular engines, and far better sustainability.

Its test program in the ultra-high performance and exclusive (only 24 will be built) Vulcan, is a demanding technology demonstration that is proving very successful, Castrol Nexcel Chief Engineer Oliver Taylor, told Automotive Engineering: “We expect to see production road vehicle installations in two to five years with high volume use following. Vulcan gets us onto the technology implementation curve.”

By 2020-25, he foresees a majority of cars entering production using the system. As well as the Vulcan's V12, Nexcel oil cells have been tested in a wide range of car engines.

OEMs like the concept

One challenge to be met is that the Nexcel oil cell’s capacity would typically vary between 3.0 L and 5.0 L on mass-production vehicles, causing potential engine-bay packaging challenges. But Castrol is working to design and engineer appropriate solutions. Also, ideally it needs to be integrated into the concept and initial design phase of a new engine (and probably vehicle) to accommodate plumbing and electronics as well as total space; attempting to adapt current high volume engines would bring manufacturing and cost hurdles.

But Castrol is highly confident of Nexcel’s future, reporting positive reactions from OEMs and engine manufacturers aware of the system.

“Nexcel is fully sealed and contains all the engine oil, and the filter. It simply clicks into place— and could mark the end of the traditional oil change,” explained Taylor. He said the idea for the project came from brain storming sessions within the company’s 50-strong, global innovation Ventures Dept. about four years ago. Design, development and engineering of the system, which he believes to be unique in the car industry, then centered mainly on the company’s U.K. facilities.

In a series-produced car, the Nexcel oil cell would be positioned in a “docking” area close to the engine block. The cell incorporates electronics which “shake hands” with the car’s CANbus and engine management system, while monitoring both the amount of oil available and its quality (ensuring its grade and specification are correct every time the car is serviced). It also estimates the oil's remaining useful life.

“This allows a new potential to guarantee ‘precision lubrication’,” said Taylor. “When the car’s scheduled service is started, ‘service mode’ is selected via an onboard menu and a small electric pump transfers oil from the bottom of the sump into the oil cell. That process takes about 30 s. When complete, the cell, which incorporates the filter, can be unclipped from the vehicle.

“A new oil cell containing fresh lubricant and filter is simply inserted into the docking position, the hydraulic lines are connected through mechanical dry-break valves on the base of the cell, one to the bottom of the sump and two to the oil gallery. And that’s it: total time taken, 90 seconds.”

Tribology simulations were key

The precision lubrication that the system facilitates is a very important aspect of its technology, stressed Taylor, because of its friction reduction/CO2 lowering potential: “OEMs are interested in the overall benefits the system brings.”

To gain a greater understanding of just what can be achieved by friction reduction, he has spent seven years studying, particularly through tribology simulation, how lubrication systems can help deliver much improved fuel economy.

“Engines are of many designs and in them we find different surface finishes, materials, and types of bearing, all of which interact with engine lubricants in various ways," Taylor explained. "To generate the lowest friction possible for a particular engine we need hyperspecific lubricants tailored to specific applications and duty cycles in order to unlock further CO2 improvements.”

Thermal management also supports lower emissions. The electric sump pump can be used to ensure that when started from cold there is a precise amount of oil (the minimum safely needed) in the engine, while the remainder is in the cell. That ensures the engine oil and its systems heat up more quickly than usual; as Taylor noted, "a warmed-up engine is an efficient engine.”

The system works with both regular and dry-sump engines; the Aston Vulcan has a dry sump.

At present, Taylor is cautious about defining the CO₂ improvement but says it is “statistically significant.”

To provide a high level of sustainability, Castrol is developing a system that will get the cells to and from service or consumer outlets. A reverse logistics model will be put in place to deliver new oil cells and collect used for reprocessing to achieve what Taylor describes as ‘virgin’ quality for re-use in similar engines. The cell is taken apart, cleaned, fitted with a new filter and refilled and dispatched again “a number of times.”

Nexcel facilitates oil being segregated and collected into specific viscosity grades "far more efficiently than is generally the situation at present,” he said.

Rigorous test regime

Will Nexcel add cost for the end user (vehicle owner)? Taylor stated that most new technology does add capital cost but that it is offset by increased efficiency.

Castrol’s design target for Nexcel is also for it to involve no more expense than a normal oil change service cost, with the added benefit of freeing up vehicle hoist requirements.

Testing in the Vulcan is one of the last stages of Nexcel’s development. Using it for such a small production run (24 units) is allowing very close monitoring by Castrol and Aston Martin.

And David King, Aston’s Director of Special Products and Motor Sport, said that as the Vulcan has a dry sump lubrication system, it was just a matter of replacing the oil tank with the Nexcel oil cell and doing some plumbing and hooking up to the CANbus. And it would provide a very tough test regime.

"We wanted to make sure the Nexcel system would work in every extreme environment we could put the car through," King said. "These included oil handling under extreme g-forces on the track; the effects of very hard acceleration and deceleration (up to 1.8g), of vibration and aeration — and the high flow rates put through the Nexcel oil cell from a highly specified dry sump system.” Flow has been tested up to 600 L/min, 10 to 20 times that of a typical regular car engine.

The real world on-track testing came after extensive laboratory simulation of g-force effect, durability testing and comparison with a regular system. Said King: “We demonstrated at least equivalent — and in many cases superior — performance with the Nexcel oil cell. We would not be using it on Vulcan if we did not think it had serious potential to put it on higher volume cars in future. I think it’s a fantastic piece of technology and we are first to market with it!”

So now almost everything about the 320-km/h (200 mph) Vulcan is about speed and efficiency — including changing its oil.

Author: Stuart Birch
Source: SAE Automotive Engineering Magazine