e paper performance 2012, en

PerformanceCUSTOMER MAGAZINE COMPONENTS AND SYSTEMS FOR THE ENGINE AND ITS PERIPHERY 2012

eFFICIent AnD VARIABLe In DeSIGn:

NEW AIR FILTER MODULESFOR eURO VI

2 MAHLE Performance 2012

COntent

News briefs

What’s new at the MAHLe Group

iNterview

“engine components must be all-around performers”

eNgiNe systems aNd CompoNeNts

Less friction, greater strength—optimized crank mechanism for commercial vehicles


Low-cost and flexible: assembled camshafts for commercial vehicles


nIReVA® 3015—the new valve material from MAHLe


Polymer on Sputter coating: superior solution for HDD applications

filtratioN aNd eNgiNe peripherals

Modular and highly efficient: new valve covers with integrated oil mist separation


efficient and variable in design: new air filter modules for euro VI


For ultrahigh requirements: new fuel filters for euro VI


Lighter, cheaper, better: the new oil filter module for commercial vehicles

4

6

8

10

12

14

16

18

20

22

visit us:

from to trade fair name, location

Sept. 18 Sept. 22, 2012 Husum Wind (Husum/Germany)

Sept. 18 Sept. 21, 2012 Innotrans (Berlin/Germany)

Sept. 20 Sept. 27, 2012 IAA Commercial Vehicles (Hanover/Germany)

Oct. 8 Oct. 10, 2012 Aachen Kolloquium (Aachen/Germany)

Oct. 23 Oct. 25, 2012 parts2clean (Stuttgart/Germany)

Oct. 29 nov. 1, 2012 PtC Asia (Shanghai/China)

Oct. 30 nov. 1, 2012 AAPeX (Las Vegas, nV/USA)

nov. 14 nov. 17, 2012 Automechanika Argentina

Dec. 2 Dec. 5, 2012 PRI Show (Orlando, FL/USA)

impriNt

published by

MAHLe International GmbHPragstrasse 26 – 4670376 Stuttgart, Germanywww.mahle.com

responsible for the content

Dr. Jörg Stratmann

Contact

[email protected] +49 (0) 711 501-14612Fax +49 (0) 711 501-4414612

photography/picture credits

MAHLe Archiv

design & production

freelance project GmbH, Stuttgart

Reprint, even partially, only in accordance withand after authorization by the publisher.© MAHLe GmbH, 2012

mahle Performance—also available online: www.performance.mahle.com

MAHLE Performance 2012 3

eDItORIAL

dear readers,

Since we last came together at the IAA

Commercial Vehicles in 2010, the positive

trend continued in 2011. With an increase

of 7.6 percent, global production of com-

mercial vehicles developed favorably in

2011. Market developments in 2012 vary,

depending on the region and country. In

europe, growth has slowed significantly and

is expected to cool off further in the second

half of the year. South America had an ex-

pected weak start to the year due to the

“pre-buy” effect in 2011, and the year over-

all will come in 20 to 30 percent lower than

the previous year. Following consolidation in

2011, the Chinese market is far below 2010

levels, and commercial vehicle production

will only see slow growth. Only north America

was able to carry over its momentum to the

first half of 2012; market indications, how-

ever, also point to a slowdown. Altogether,

the future prospects must be considered

with a grain of salt due to their volatility.

MAHLe is well-positioned internationally,

which to some extent can help to compen-

sate for fluctuations in demand in individual

markets. With a view to the near future, we

are building on our solid market position and

innovative product portfolio.

the euro 6 emission standard will be intro-

duced shortly—a major topic at the IAA. While

previous reductions in emissions focused on

nOX and particulates, legislation has now

shifted the attention to CO2 reduction. this

is necessary both from an ecological and

economical perspective—less fuel means

greater economic eficiency as fuel prices are

Matthias Fix

Vice President Sales and Application Engineering

Commercial Vehicles

rising. With our components and systems,

we support our customers in the develop-

ment of new generations of commercial

vehicles. Reduced frictional loss, optimized

engine accessories, and the use of systems

components that can withstand greater me-

chanical and thermal loads contribute

greatly in this respect. One example I would

like to refer to is our polymer-coated main

and connecting rod bearings, which allow

stop-start functionality of the engine. With

the new Monolite design concept, we are

working on making our steel pistons for

ultrahigh loads even more compact.

In the future, it will be even more important

for MAHLe to be included in vehicle and en-

gine development at an early stage, so that

we can optimally adapt our components

and systems and subsequently offer highly

efficient, cost-optimized solutions. Our pro-

duction plants and research and develop-

ment centers—and thus the technical ex-

pertise of our employees working on global

projects—are located at customer sites

around the world.

Visit us at the IAA. You are cordially invited to

our stand, where we will be happy to show

you the novelties we have to offer.

Sincerely,

Matthias Fix


the mahle range extender—impres-

sive numbers, long cruising range

MAHLe has developed and built a special

engine for range-extended electric vehicles

(ReeVs). ReeVs offer signii cant advantages

over purely electrically powered vehicles

(eVs). In particular, they solve the problem

of the far too short cruising range of pure

electric vehicles. the MAHLe range extender

(Rex) is a very compact two-cylinder engine

with 600 cm3 displacement. It is lightweight

and can be produced at a low cost. In order

to gain experience relevant to the steps re-

quired to reach market readiness with a

ReeV and to refine the noise and vibration

properties, it has been installed in a demon-

strator vehicle. the compact class demon-

strator vehicle shows clearly how new MAHLe

technologies can allow signii cant reductions

in CO2 emissions without sacrificing driving

behavior or functionality.

MAHLE has installed a two-cylinder gasoline engine as a range extender in a roadworthy electric demonstrator vehicle.

MAHLE Powertrain implemented the entire engine concept and engine controls.

WHAt’S neW At tHe

MAHLE GROUP


neWS BRIeFS

tech Center in shanghai is being

expanded

the MAHLe tech Center in Shanghai is home

to the central functions such as sales, pur-

chasing, human resources, It, and finance,

but especially research and development for

all MAHLe product lines. the center is cur-

rently being expanded, with the addition of

three new buildings that will be officially

opened on november 13, 2012. Following

the expansion, the center will have six boxes

for complete engine test benches, instead

of previously only two. Overall, nearly 9,000

square meters of lab and ofice space will be

added to the already existing 7,000 square

meters. this will allow us to increase the

number of employees from today 230 to as

many as 450.

The newly planned campus in Farmington Hills/USA

The new plant in Kyushu/JapanIn Samutprakarn/Thailand, the existing plant (shown here in green) is being generously expanded.

the vehicles from thailand to the ASeAn

countries. MAHLe is adding extensively to

both of its locations in thailand.

MAHLe engine Components (thailand) is

expanding its plant at the Bangkok location,

which mainly produces pistons. Construc-

tion work on the new 45 by 90 meter build-

ing should be completed in September. the

new building will house an assembly line as

well as measurement and testing equipment.

It will also provide space for future machin-

ing and coating lines.

In Samutprakarn, MAHLe Siam Filter Systems

is adding considerably to the existing location.

the new buildings measuring 5,000 m2 will

primarily house storage areas and offices.

the previous areas that will be cleared will

then have space for two new production

lines for oil coolers and greater capacity for

the production of air intake systems and

valve covers.

two plant expansions in thailand

More and more Japanese vehicle manufac-

turers are producing in thailand—not only

for the thai market, but also for exporting

New mahle plant in Kyushu/Japan

In the northern part of the Japanese island

of Kyushu, a new production plant for air

intake systems, valve covers, and activated

carbon canisters is currently under construc-

tion. Well-known Japanese vehicle manu-

facturers, such as nissan, toyota, Daihatsu,

and Honda, currently produce about 1.5

million vehicles in this region annually. the

new plant is also in close proximity to Mazda

and Mitsubishi Motor. the production area

will comprise 7,500 m2, and completion is

planned for September 2012.

mahle bundles central functions in

North america at one location

With the purchase of an adjacent site,

MAHLe Industries, Inc. has gained an addi-

tional 50,000 square meters of office space

and storage area, and can thus consolidate

in Farmington Hills the central functions that

were previously distributed between two

locations. the operations that were located

in novi to date, such as MAHLe test Sys-

tems and engineering Services, will move to

Farmington Hills by 2013. Sales, finance,

legal, human resources, and It functions will

also be consolidated on a single campus.

The shaded buildings will be added to the Tech

Center in Shanghai.


InteRVIeW

In a conversation with MAHLE Perform-

ance, Prof. Stefan Breuer from Bochum

University of Applied Sciences explains

where he sees additional potential for

optimization in powertrains for long-

distance commercial vehicles, and why

it will be difficult to further increase the

efficiency of diesel engines to any sig-

nificant degree.

in a topography typical to central

europe, is an energy-efficient commer-

cial vehicle even conceivable?

Breuer: this question is near and dear to my

heart. the driving dynamics of a truck entail

two major factors that directly affect fuel

consumption, and therefore CO2 emissions

as well: grade resistance and acceleration

resistance. the act of braking in a truck

should theoretically be painful, because huge

amounts of energy are being destroyed again.

It may be helpful to make a comparison here

to passenger cars. If you drive a passenger

car at 120 km/h on the freeway, going up a

three-percent grade, more energy is required,

which you can get easily by pushing a little

harder on the gas pedal. When you drive

back down the same grade, you get the

energy back, because you don’t brake, you

just back off the gas. therefore, drivers of

cars don’t see much difference in fuel con-

sumption when driving on hilly roads. truck

drivers, on the other hand, have to fight

their way slowly up a grade, and then brake

continuously on the downhill side. All of

the energy invested in making the climb

disappears into braking energy. enormous

amounts of fuel are ultimately destroyed in

this way.

which inevitably leads us to the

question of hybrids.

Breuer: For a long time, I was of the opinion

that a hybrid powertrain would not make

sense for long-distance hauling. today’s

highly developed engines have very good

efficiencies of around 40 percent. But what

a truck with an exclusive combustion engine

powertrain cannot achieve is to recover en-

ergy from braking and downhill runs. If there

were a way to store that energy, it would be

possible to save a great deal of fuel.

the main priority in long-distance

trucking is transport efficiency—that

is, to carry as much freight as possible

at the lowest possible cost. looking at

both freight capacity and at costs, is

there any way at all to integrate the

required energy store and recuperation

systems?

Breuer: I don’t see any way to achieve this

with current technology. It would take up too

much space and weight. Rather, we need to

consider what possibilities there might be

for the future. We would certainly be looking

at short-term storage, thus not necessarily

electrical but more likely mechanical stor-

age that should be investigated. even if this

means that there may be some disadvan-

tage in the level of efficiency. the current

state is 100 percent loss when braking, after

all, and I am sure that we will not be able to

“enGIne COMPOnentS MUSt Be

ALL-AROUnD PeRFORMeRS”

Bio for Prof. Stefan Breuer

After secondary school, Breuer completed an apprentice-

ship as an auto mechanic, then studied general mechani-

cal engineering, with an emphasis on automotive engi-

neering, at the Technical University in Darmstadt/Germany.

He then worked briefly at Mercedes-Benz, but his great

interest in research led him back to the university, this

time in Essen, to obtain his doctorate.

From there he moved to Atlas Fahrzeugtechnik, an auto-

motive engineering firm, where he researched vibration

and riding comfort in commercial vehicles in the NVH

department. He then had a brief guest performance in

escalator development at Krone, before he moved to the

university for applied sciences in Cologne in 2004 as

professor for technical mechanics and commercial vehicle

engineering, and then later for driving dynamics as well.

Since mid-2011, Breuer has been teaching design and

technical mechanics classes in the specific areas of

mechanical engineering and mechatronics at the Velbert/

Heiligenhaus campus of the college in Bochum, as part of

the mechatronics and information technology program.

A more in-depth area of automotive engineering is also

currently planned for the master’s program.

His drive: the fascination with the automobile, which

became particularly evident to him during his guest per-

formance in escalator development—it is simply more

fun to develop or analyze something for vehicles.

Breuer is the co-editor of the technical book for commer-

cial vehicles (Fachbuch Nutzfahrzeugtechnik, Springer

Vieweg), which is available in its 7th edition at the IAA

2012, and the technical correspondent for commercial

vehicle engineering for the technical journals ATZ and MTZ.


InteRVIeW

engine very much at this stage. the poten-

tial is limited to just a few percent, which in

view of the long service life of a truck, how-

ever, will have to be fully exhausted.

In transition, in the transient range, there will

certainly be future solutions that improve

responsiveness. One approach could be to

monitor cylinder pressure, so that engine

controls would no longer be based on an

operating map, but instead would use

pressure regulation. this would, however,

require measuring the highly dynamic pres-

sure in order to immediately adjust to the

target pressure.

Large steps forward, such as what the intro-

duction of charge air cooling made possible,

are in addition hardly feasible any longer with-

out extensive modiications to the power train

coniguration or the package itself. this really

does not come as a surprise, though; when

thousands of engineers work on developing

something, eventually it approaches the

optimum. Additional advancements in fuel

consumption and emissions therefore do

not sound very popular anymore. But every-

one who deals with the subject knows how

important they continue to be.

professor breuer, thank you very much

for your time.

The interview was conducted by Ruben Danisch.

accept that for much longer, as energy costs

will eventually be too high. especially in this

very cost-sensitive segment, this could be

definitive for development efforts.

One prerequisite, however, is that conditions

remain the same or become more uniform

across country borders. If, for example, a

neighboring country lowers fuel prices,

such efforts can quickly vanish once again.

Homogenization would be very desirable in

europe, for example.

are you hoping for globalization

effects?

Breuer: this would be a policy question, yes.

However, I also see technical opportunities

in globalization. In my opinion, for example,

a positive symbiosis has resulted from the

high mechanical requirements for engine

components in europe and the extensive

service life prevalent in the USA. the

approach of “one engine for the life of the

vehicle” should also be part of the energy

analysis. Melting down an old engine like-

wise requires energy. In terms of sustaina-

bility, therefore, globalization surely must

have positive effects, but it also means that

new engine components or systems—par-

ticularly the PCU, for example—must really

be all-around performers.

following your earlier energy analysis:

would it not be helpful, in terms of a

fairly simple measure, for lawmakers

to allow higher driving speeds for

trucks in certain areas, in order to be

able to gather momentum on downhill

runs that are immediately followed by

an incline?

Breuer: this is indeed done within certain

limits, but safety considerations make it

advisable to be somewhat restrictive. the

kinetic energy of a truck rises as the square

of its velocity, which means that the severity

of an accident also rises as the square. In

addition, traffic would be more dynamic if

this gate were opened. that would be very

detrimental, because more accelerations

would be necessary, which are very expen-

sive, particularly at high speeds. Accelerat-

ing a 40-ton truck from 60 to 80 km/h, at

an assumed specific consumption rate of

190 g/kWh—which would be best case—

consumes about 0.27 liters of diesel fuel,

according to the law of conservation of

energy. this represents an emission of about

780 g of CO2.

is there a technical approach that

could be helpful in the short term?

Breuer: the technology to be able to avoid

topographically inefficient routes or traffic

jams is available; its integration just needs

to be improved. In the future, however, it will

be even more difficult, as freight transport

continues to increase and traffic becomes

more irregular. It may be more valuable in

the short term to raise awareness among

car drivers as to what it means when they

force a truck to apply its brakes. It would be

nice to see more of a sense of community in

this respect. this has more potential on a

percentage basis than is likely to be achieved

by technical solutions.

Can the conventional powertrain profit

from interlinking topographical data

and engine management?

Breuer: this would certainly improve de-

mand-based actuation of engine accessories

in that they possibly would be operated on

downhill runs only. In addition, timely selec-

tion of the right transmission gear alone can

provide an advantage, as will soon be avail-

able in series production.

earlier you mentioned the very high

efficiency levels of combustion engine

powertrains in trucks. is there any

more potential for optimization at all?

Breuer: A great deal of energy is lost via the

exhaust gas heat; solutions to utilize it are

currently being worked on with great inten-

sity by the manufacturers. this might result

in another significant step forward in the

overall efficiency. It does not seem possible

to shift the optimal operating point of the

Fuel consumption of a commercial vehicle during

acceleration

From 0 to 80 km/ h :

E = mv 2= · 40 000 kg · ( 22,2 ) 2 = 9 856 800 Nm =

2,74 kWh

At 190 g/kWh, this represents 0.52 kg or 0.63 liters of

diesel fuel. From 60 to 80 km/h, using the approach above,

the result is 0.27 liters of diesel fuel, or about 0.27 × 2.85

= 778 g CO2

1 2

1 2

m s


Lower emissions, higher loads: the

requirements for commercial vehicle

diesel engines are not new, just more

stringent. There is room for improve-

ment in the crank mechanism, in par-

ticular, where large forces are at play.

MAHLE has now managed to extract

additional potential.

effects of the legal environment

the commercial vehicle is fundamentally

very sensitive to costs. A fleet operator for

long-distance hauling bases purchasing de-

cisions on transportation efficiency. Besides

the cost of the vehicle, ongoing operating

costs, which include fuel consumption, play

a decisive role. efforts to reduce fuel con-

sumption and therefore CO2 emissions,

however, will not be solely driven by cost

pressures in the future. now that the eU has

decided to limit CO2 emissions for light com-

mercial vehicles to an average of 147 g/km

starting in 2020, regulations for heavy freight

vehicles are also expected. Requirements

for engine power density will only continue

to increase rather than decline.

Previous efforts to meet eU directives up to

eURO VI have caused fuel consumption of

the basic engine to increase. In order to meet

market requirements despite this develop-

ment, numerous opportunities for fuel savings

have already been utilized in recent years.

potential from lower piston compres-

sion height

One significant untapped potential area in

the engine crank mechanism is the reduc-

tion of the compression height of the piston,

meaning a lower piston height. MAHLe is

aiming for 20 to 30 percent lower compres-

sion height than is typical today. On the one

hand, this measure could be implemented

with longer connecting rods. they guide the

piston more effectively in that they reduce the

lateral forces that the piston exerts on the

LeSS FRICtIOn, GReAteR StRenGtH

OPTIMIZED CRANK MECHANISMFOR COMMeRCIAL VeHICLeS


enGIne SYSteMS AnD COMPOnentS

cylinder wall, thus also reducing frictional

losses. MAHLe has investigated similar

actions for passenger car diesel engine

pistons and expects, based on this experi-

ence, up to 0.8 percent diesel fuel savings

in commercial vehicles. For a commercial

vehicle with fuel consumption of about 30

liters/100 km and a service life of 150,000

km/year, this equates to potential savings of

about 360 liters of diesel fuel per vehicle per

year. exact values for the savings potential

will be determined soon. As an alternative

to an extended connecting rod, the block

height of the engine could also be reduced

by the “shorter” piston, which would save

weight, installation space, and manufactur-

ing costs.

A piston with typical commercial vehicle

dimensions would also be about 2 kilograms

lighter. If the connecting rod is also optimized

for design and materials according to the

latest knowledge, up to 30 percent weight

savings can be achieved for the crank

mechanism of a typical commercial vehicle

engine. the lower mass reduces bearing

friction, thus contributing to increased effi-

ciency of the engine.

implementing the design with new

manufacturing methods

A more compact piston that offers optimal

cooling performance at the same time has

previously been limited by production. MAHLe

has now developed a new manufacturing

method that allows the necessary design

lexibility. Both the steel piston for passenger

cars and the commercial vehicle piston have

thus far been produced using frictional weld-

ing. For the irst time, MAHLe is going with a

beam-based welding method. this allows

signiicantly greater lexibility in piston design,

such as the shape of the cooling cavity or off-

set bowls. Less material is required in the

area of the weld seam in order to provide the

piston with suficient rigidity during welding.

the new method also enables the use of

highly temperature-resistant materials for

the combustion bowl.

Initial principle studies have been very suc-

cessful, and the beam-based joining method

is now being developed into a mature

process. this means that MAHLe will soon

be able to provide its customers with the

most innovative piston technology to meet

anticipated future requirements.

piston rings

Optimization of the crank mechanism in-

volves not only the piston and connecting

rod, but also piston rings and piston pins,

for example. One particular challenge is the

ongoing development of the first compres-

sion ring, which is subjected to the greatest

loading and is thus at high risk of wear. Until

now, it has withstood ultrahigh loads with a

coating made of MIP 230 chromium nitride

(Crn), which is applied in a PVD (arc evapo-

ration) process. Modern combustion en-

gines have less oil available for lubrication

in order to achieve lower emissions. this

leads to significantly greater thermal loads

on the ring, with the risk that the coating

might chip.

In order to be better prepared for such chal-

lenges, MAHLe has developed the new PVD

coating nanoBium MIP290. nanoBium is a

multilayered system comprising alternating

nanolayers made of niobium nitride and

chromium nitride.

this multilayer structure improves the fatigue

resistance and thermomechanical strength

of the ceramic layer. MAHLe has demonstrat-

ed the greater temperature fatigue resist-

ance of nanoBium MIP290 as compared to

the typical MIP230 chromium nitride coat-

ing in a 12.7 liter commercial vehicle engine.

the wear and seizure resistance of the two

coatings are at a similarly high level. Based

on the consistently positive results, MAHLe

has already applied for a patent for the

MIP290 nanoBium coating. After a long

search for better properties, this has been a

breakthrough, optimally equipping MAHLe

for the requirements of future generations of

engines.

In order to reduce friction losses at the rings,

MAHLe successfully tested the V-SHAPe

design on the two-piece oil control ring last

year. the tangential loads that press the

ring against the cylinder wall are up to 50

percent lower. the V-SHAPe has now been

further developed for increasing engine re-

quirements in that a PVD layer based on

chromium nitride is applied to the running

surface area. this increases the service life

and taps further potential for minimizing

friction.

piston pin

For piston pins in the steel piston, diamond-

like carbon (DLC) coatings showed very

promising results in initial studies for reduc-

ing frictional losses, regardless of the load.

Such coatings are being used more widely

in pins for aluminum pistons in diesel en-

gines and have now almost become the

standard. the advantage, in addition to

slightly lower friction, is reduced suscepti-

bility to seizing of the piston pin. Indications

of improved frictional loss balance in the

steel piston are being investigated by MAHLe

on a demonstrator engine.

Author: Dr. Stefan Spangenberg

Multilayer NanoBium coating, PVD with alternating

NbN and CrN layers

Interlayer <50 nm



LOW-COSt AnD FLeXIBLe:

ASSEMBLED CAMSHAFTSFOR COMMeRCIAL VeHICLeS

Assembled camshafts present a low-

cost, flexible solution for modern fuel-

efficient commercial vehicle engines.

Cast iron camshafts have long been used

for light commercial vehicles, while medium

to heavy commercial vehicles have resorted

to forged steel camshafts. these technolo-

gies require relatively high tooling costs,

which are very disadvantageous relative to

passenger cars due to the low production

quantities. Assembled camshafts allow

higher contact pressure between the cam

lobes and cam follower in comparison to

cast camshafts, and offer significant weight

advantages over steel camshafts made from

solid material or raw forgings. the great

design flexibility of the individual assembled

components also provides cost advantages

with respect to materials and design. For

example, very durable cam lobes are made

of roller bearing steel and then inductively

hardened, while the drive input and output



shrink-fit method, parts such as cam lobes,

pulse-generator wheels, and driving and

output elements are joined to precision

steel tubes having a high degree of torsional

stiffness and flexural strength. the purely

elastic shrink-fit composite guarantees a

consistently high interference fit of the

joined components over the entire service

life of two million kilometers required for

commercial vehicle engines. Assembled

camshafts that are manufactured by plasti-

cally deforming the press fit, in contrast,

demonstrate an aging effect, and the press

i t joint becomes weaker over the service life.

MAHLe has produced assembled cam-

shafts for commercial vehicles under near-

series conditions in various concept studies

and successfully performed endurance

tests. With the series launch that is currently

underway at a well-known manufacturer in

europe, the first assembled camshafts for

commercial vehicles from MAHLe will see

large numbers built in series production.

In the course of rising requirements for

modern engines, additional potential gains

are being evaluated for assembled cam-

shafts, and the component is under ongoing

development. One possibility is to use a roll-

ing bearing in place of the hydrodynamic

plain bearing that is typical for camshafts.

the resulting reduction in frictional loss and

optimized oil balance further contributes to

optimizing CO2 and reducing fuel consump-

tion in the powertrain. MAHLe is currently

investigating the potential of this technology

for use in commercial vehicles.

Assembled camshafts for commercial vehi-

cles from MAHLe enable modern commercial

vehicle engines to fulfill increasing require-

ments related to service life at a low cost,

while simultaneously reducing weight and

optimizing fuel consumption. A clear trend

toward the use of assembled camshafts

can be seen in the development of future

commercial vehicle engines.

Author: Stefan Steichele

elements can be made of less expensive

materials, as needed.

the MAHLe production method for assem-

bled camshafts provides optimal conditions

for flexible manufacturing. Using a thermal

Assembled camshaft for commercial vehicles with rolling bearing and closed cast bearing supports


NIREVA® 3015

tHe neW VALVe MAteRIAL FROM MAHLe

Continuous improvements in exhaust

gas quality and fuel consumption in ad-

vanced engine design present a constant

challenge to the MAHLE valve develop-

ment team. Familiar trends in engine

design, such as downsizing, lead to rising

mechanical and thermal loads on engine

components, which in turn require new

solutions.



this also leads to new approaches in material

selection for the valve, valve seat insert, and

valve guide components. Well-established

low-cost materials are increasingly becoming

overloaded as specii c output levels are rising.

this is especially true for exhaust valves with

respect to their high-temperature properties,

and for commercial vehicle intake valves re-

garding corrosion performance. Some of the

requirements listed above can actually be

covered for valves with familiar high-per-

formance nickel-based materials, but these

are less acceptable from a cost standpoint.

While the cost factor has been accepted in

the past for niche applications such as sports

car engines, due to their requirements proi le,

it constitutes a problem today given the wide

range of applications and the associated in-

crease in cost pressure. For reliable operation

throughout the desired engine service life,

downsizing engines also require the use of

economical material solutions with adequate

high-temperature fatigue performance and

corrosion properties.

In the second half of the last decade, the

alloying element nickel saw huge price in-

creases, which inspired MAHLe to initiate a

global valve materials project in 2008.

the goal was to investigate available mate-

rials as well as new ones in order to identify

a valve material that would cover as wide a

range of applications as possible with re-

spect to cost and performance.

While the high-performance materials listed

above are made of around 75 percent nickel,

the alloying element that drives the cost,

various materials have been developed in

recent years that close the gap between

established heat-resistant materials and the

nickel-based high-performance alloys. Using

various alloying concepts, the nickel content

is typically reduced to about 30 percent, the

chromium content is adjusted for good cor-

rosion resistance, and additional suitable

elements are used to try to attain the best

possible high-temperature properties.

In order to find a solution that is particularly

well-suited for the specific requirements of

valves, various materials were extensively

tested as part of the project. Several candi-

dates entered the contest and were given a

catchy name: nIReVA, for nickel-reduced

valve alloys. One material, developed in Japan

and used there by two manufacturers for

passenger car engine exhaust valves, is

currently manufactured under license and

available for use. two materials have been

developed exclusively with a supplier of

steel for valves, and two more alloys were

developed regionally in China.

After examining costs and availability, exten-

sive lab testing for high-temperature fatigue

resistance, wear, and corrosion performance,

as well as internal and customer validation

runs in various commercial vehicle and pas-

senger car engines, it was soon evident that

the material developed in Japan presented

the best compromise.

Having technological properties similar to

those of the nickel-based materials, the ma-

terial known at MAHLe as nIReVA 3015®

has 30 percent nickel and 15 percent chro-

mium content, providing our customers with

interesting cost savings potential relative to

high-performance materials. Once the range

of applications in highly loaded commercial

vehicle and passenger car engines was de-

i ned, its good results convinced our custom-

ers during extensive technical discussions.

Following the first series production as a

hollow exhaust valve in a sports car applica-

tion this spring, several specifically highly

loaded passenger car engines will follow in

series production in the course of the current

year and the next. Customers have validated

and approved the material in various com-

mercial vehicle engines, and we have been

nominated for a series production applica-

tion starting in 2014.

Author: Alexander Puck


POLYMeR On SPUtteR COAtInG:

SUPERIOR SOLUTIONFOR HDD APPLICAtIOnS

Driving cycles and operating conditions

for heavy-duty diesel (HDD) applica-

tions require robust bearing solutions.

Load capacity, wear and seizure resist-

ance are the fundamental requirements

for ultrahigh performance and a long

service life.

Bearing halves are constructed in layers. A

typical composition for a HDD application is

a steel support layer, with a copper-based

substrate and an aluminum-tin sputtered



overlay. the addition of the overlay provides

an optimal combination of bearing material

properties, the right balance of hard and soft

properties are critical when selecting suitable

products for engine applications. Often, a

sputtered overlay is the only usable solution

due to durability requirements, even if the

greater load capacity may compromise sei-

zure resistance. the technological trend is to-

ward bearings with increasingly high specii c

loads, thinner oil films and higher operating

temperatures.

Under these operating conditions, the poten-

tial for direct contact between metal sur-

faces increases. the introduction of new

fuel-saving technologies for commercial

HDD applications can also be expected,

with more aggressive operating conditions

for the bearings, which will increase suscep-

tibility to wear and seizure.

In order to improve compatibility in some

applications, a sacrificial overlay is used to

improve the surface properties. these sacri-

i cial overlays, however, have the disadvan-

tage of wearing over time, which can result

in greater operating clearance, increased

running noise, and higher oil flow. the de-

velopment of a functioning overlay was there-

fore considered to be necessary in order to

maintain the properties of a polymer overlay

beyond the run-in period.

the proposed bearing solution consists of a

functional polymer overlay over a sputtered

layer. this proprietary polymer coating is made

up of a high-performance polyamide imide

(PAI), a solid lubricant, and metallic particles.

the combination provides excellent mechani-

cal strength and outstanding thermal and

chemical resistance. the homogeneously

distributed metallic particles, aligned in the

running direction on the surface, provides very

good wear resistance, mechanical strength,

and thermal conductivity.

In order to be able to compare the wear and

seizure resistance of coated and uncoated

sputter overlays, a customized inspection

procedure was developed for scuff seizure

(Fig. 1). the operating conditions were simu-

lated by interrupting the lubricant feed pres-

sure, which caused the oil i lm to be disrupted.

In addition, coated and uncoated sputter

bearings were tested in an HDD application

for 1,000 hours (Fig. 2). Compared to the

uncoated sputter, the polymer-coated sputter

showed outstanding wear and seizure re-

Figure 1: Comparison between a coated and an uncoated sputter bearing after the completion of the scuff

seizure test

Figure 2: Comparison between a coated and an uncoated sputter bearing after a 1,000-hour durability test

in an HDD application

sistance on the component bench and en-

gine test.

the combination of a polymer overlay on a

sputter layer provides the optimal balance

between hard and soft properties for high-

performance HDD applications, and is a

robust solution for difficult operating con-

ditions.

Author: James George

Uncoated sputter

Coated sputter

Uncoated sputter

Coated sputter


FILtRAtIOn AnD enGIne PeRIPHeRALS

MODULAR AnD HIGHLY eFFICIent:

WItH InteGRAteD OIL MISt SePARAtIOnNEW VALVE COVERS

separation at nearly any planned engine incli-

nation. these are challenging requirements,

as the engine platform is used in a large

number of vehicles, from mid-range trucks to

various offroad vehicles (Fig. 1). After pre-

cleaning, the blow-by makes its way to the

switched impactor/i ne separator developed

by MAHLe (Fig. 2). Since the differential

pressure of the MAHLe separation system

is the same for a wide range of blow-by vol-

ume flow rates, identical components were

able to be used for 4-cylinder and 6-cylinder

applications. the same separation unit, con-

sisting of impactors and pressure regulation,

can be used for both engines, despite their

different blow-by levels. Another highlight is

Fig. 1: Overview of valve cover types with identical component concept

Valve cover six-cylinder Valve cover four-cylinderValve cover six-cylinder (bus application “standing”)

New valve covers have been developed

for a new engine platform of a large

European commercial vehicle manu-

facturer. The focal points for the devel-

opment of this cover with integrated oil

separation were ultrahigh separation

levels, a modular concept for use in four-

cylinder and six-cylinder engines, and

not least an attractive appearance.

Walk-on areas, in particular, and a suitable

structure for the reduction of acoustic emis-

sions were designed for strength. the in-

take line of the compressor for the air brake

was also successfully integrated, which re-

duced the number of variants of this line to

a minimum.

the development started with investigations

into a suitable blow-by sampling point that

would provide low raw oil emissions for oil



cylinder engine (Fig. 4).the cleaned blow-by

then travels in a clean gas channel within

the cover, and is fed into the cylinder head.

Hose connections are thus eliminated.

extensive calculations have been performed,

particularly for the accessibility and acoustic

performance of the cover. Since the height

of the cover is very low, a support on the

camshaft frame is used to provide walk-on

stability. the cover bends in a defined man-

ner until it contacts the support points (Fig. 5).

the use of a specially developed pressure

regulator that reuses the energy from com-

pression to provide very i ne separation of the

oil mist. All passive energy sources are thus

put to use to achieve ultrahigh separation

levels. Despite a very fine droplet spectrum

for the engine, the impactor technology sep-

arates 1 µm particles at a rate of over 90

percent (Fig. 3).

Clean gas values of below 0.9 g/h have been

achieved in the full load range for the six-

Sound emission is also an important function

of the valve cover. Appropriate ribbing on

the inner side of the cover ensures that no

unpleasant noise is emitted during engine

operation.

Its appearance was likewise considered in

the design of the cover. When looking into

the engine compartment of a truck, the

valve cover is the first thing that meets the

eye. Attention was given to arranging the

components as symmetrically as possible in

order to achieve an attractive appearance.

Appropriate emblems can further improve

the appearance of the valve cover.

By working together very closely with the cus-

tomer, all of the requirements of this trend-

setting development were able to be met.

Authors: Dimitri An, Christoph Lohre, Stefan Ruppel

Fig. 4: Gravimetric raw gas and clean gas values for

the six-cylinder engine

8

7

6

5

4

2

1

01,200 2,200 2,400

3

Oil

mass

flo

w [

g /

h]

Engine speed at Full load [1/min]

2.3

6.76.4

0.41

0.87 0.77

Raw gas

Clean gas

Fig. 3: Raw gas distribution and fractional separation

10

20

30

40

50

60

70

80

90

100

Fra

ktio

nsab

sche

ideg

rad

[%]

0100,1 1

0

0

0

0

0

0

0

0

Partikel größe [µm ]

PRV Rohgas am Motor

Fraktionsabscheidegrad

Gemessen mit LAP320 (TOPAS)

den

sity d

istr

ibu

tio

n q

3 [

-]

particlesize [µm]

engine raw gas

Separation efficiency

measured with LAP320 (tOPAS)

Sep

ara

tio

n e

ffic

ien

cy [

%]

Fig. 2: Functional integration

Clean side channel

Oil filler/cap

Pressure regulation valve

Pre-separator Switched impactor

Fig. 5: Walk-on stability

Shift [mm] at 90ºC


New requirements from commercial

vehicle customers have placed the focus

in air filter development not only on

compliance with maintenance intervals,

but additionally on achieving high sepa-

ration levels. The available installation

space has also become a more signifi-

cant factor. The new air filter module

from MAHLE not only meets these re-

quire ments, but also shines in the de vel-

op ment of overall concepts for specifi c

markets and customers.

there are two significant trends in commer-

cial vehicles that will greatly affect future

concepts of air management. SCR systems

increasingly supersede air intake from its

established installation location. this means

that new package solutions are required. If

a low-profile design can be produced, such

as the new MAHLe concept (Fig. 1), the air

filter module can be located behind the

driver’s cab; in spite of the fact that plat-

forms are getting longer and longer, so that

the space between the platform and cab is

getting ever tighter.

eFFICIent AnD VARIABLe In DeSIGn:

NEW AIR FILTER MODULESFOR eURO VI



When euro VI takes effect in 2013, air mass

flow measurement will be implemented in

modern commercial vehicle engines as well.

In order to ensure trouble-free functionality

of air mass flow sensors (which are at risk

from excessive particle loading) over the life

cycle of commercial vehicles, manufacturers

require air ilter modules with a signiicantly

higher separation level of > 99.95 percent.

In response to these trends, MAHLe has

developed air filter modules with two new

significant features.

flat plasticized filter inserts

the first feature consists in large plasticized

filter inserts (Fig. 2) that allow a flexible and

low-proile design (component height < 15 cm,

including housing). this concept provides

maximum freedom of design and can be

applied to inflow and outflow in any direc-

tion, even in tight installation spaces.

filter media with nanofiber layers

the second feature is a new filter media

concept. For the first time, MAHLe is using

nanoibers, speciically polyamide ibers with

a diameter of 90 to 110 nm (Figs. 3 and 4).

the nanofibers are applied to a thin, open-

celled cellulose medium in an electrical spin-

ning process.

the underlying concept is surface filtration.

this type of nanoiber fabric is very ine, ilters

with very high eficiency, and stores the dust

in a dust cake on the untreated side, outside of the medium. the very thin consistency of

the medium with a fine fiber layer enables

very tight pleating and therefore sufficient

filter surface in the plasticized inserts.

overall concept for specific markets

and customers

With the new air filter module, MAHLe has

developed a unique concept that utilizes

our strength in the area of plastification. Of

course, MAHLe also offers market-specific

concepts to address the challenges of dust-

laden countries, extreme conditions of use,

and increased water exposure. Precleaners

in the form of individual axial cyclones or

multicyclone systems are often designed to

meet individual customer requests and inte-

grated in the air filter module. the result is a

customized overall concept with a high level

of iltration performance for every application.

Authors: Andreas Enderich, Matthias TraubFig. 2: New type of commercial vehicle air filter insert with plasticized end plates

Fig. 1: Extremely low-profile air intake system

mounted between the driver’s cab and the platform,

with raw air intake and fin mesh for water separation

Fig. 3: Nanofibers on cellulose (thicker cellulose

fibers shine through the nanofiber layer)

Fig. 4: Nanofiber layer

Multi-disk grid for water separation optionally

with multi-cyclone for dusty countries

Air filter element

with plasticized

end caps and nano

fiber media

Dirty air side duct

Air filter module


FOR ULtRAHIGH ReQUIReMentS:

NEW FUEL FILTERSFOR eURO VI

Nearly all commercial vehicles today

use economical diesel engines with

common-rail high-pressure injection

systems, which require efficient water

separation in addition to a high particle

separation rate. MAHLE has developed

fuel filter modules for EURO VI heavy-

duty applications that meet ultrahigh

requirements for particle and water

separation, while simultaneously maxi-

mizing service life.

Modern fuel i lter modules also need to have

as little residual contamination as possible in

order to protect the injection system, even in

its new condition. A new clean room produc-

tion area at MAHLe makes this possible. At

the same time, components must be very

robust while taking up as little installation

space as possible.

the eURO VI modules, driven on the pres-

sure side, feature a high level of functional

integration. this is evident in the adapted

fuel cooler, the pressure sensor on the dirty

side for detecting the level of contamination

of the filter element, and several valves for

controlling pressure and flow within the

complex low-pressure fuel circuit. A manual

air bleed pump, a quick-fill valve for filling by

the customer, two nonreturn valves at the

tank connections, and a manual water dis-

posal system are also integrated.



Since the water to be disposed must gener-

ally have a residual hydrocarbon content of

less than 20 ppm, it lows through a cleaning

unit with activated carbon, patented by

MAHLe, which adsorbs hydrocarbons relia-

bly, even for strongly emulsified fuel content

(Fig. 3). Due to the excellent adsorption ca-

pacity of activated carbon, future standards

are also guaranteed to be fulfilled.

An intelligent actuation and safety concept

determines the current operating condition

and guarantees safe systems function. Ad-

vantages of the BlueDrain® system, com-

pared with other functional principles, are

the low cost of the replaceable cleaning unit

and its suitability for both pressure- and

suction-side applications.

Authors: Matthias Gänswein, Hans-Peter Lang

highly efficient separation of water

from diesel fuel

In modern diesel fuel systems, water can lead

to wear in the form of corrosion, cavitation,

reduced lubricity, and microbiological growth,

which may cause the injection system to mal-

function. Fuels that contain biodiesel have

an even greater affinity to water, as well as

lower surface tension. this increases the

formation of fine, stable emulsions.

Conventional systems are not able to sepa-

rate out fine emulsions, and their water sep-

aration performance drops off quickly as the

filter medium becomes contaminated by

separated particles. MAHLe has developed

new filter concepts to meet these more

stringent requirements, enabling optimal

separation of even very small droplets and

the use of critical fuels throughout the life of

the filter.

the patented filter element for our current

modules is designed as a multistage assem-

bly. When ultrasonically welded to addition-

al components, a filter element is produced

that guarantees optimal particle and water

separation and very long service life, while

requiring very little installation space. Solid

particles are filtered out initially in the first

stage. In the subsequent stages, small wa-

ter droplets are coalesced into larger drops,

and then the water is separated out by a

hydrophobic end separator. the ilter element

also features continuous air bleeding during

operation. A screen acts as a preilter to pro-

tect the mechanical feeder pump from large

contaminants in the tank.

environmentally friendly, automatic

low-maintenance water disposal

system for diesel fuel filter modules

In addition to highly efficient particle and

water separation in the fuel filter, automatic

disposal of the separated water is increas-

ingly important. that is why MAHLe has de-

veloped an automatic water disposal system

for diesel fuel with a high water content,

which will be available in the future as both

a stand-alone system and an integrated sys-

tem unit in MAHLe fuel ilter modules (Fig. 1).

Filter modules with automatic water dispos-

al do not just reliably separate out the water.

they also discharge it to the environment in

a controlled manner. For conventional sys-

tems, it is necessary to check the water

level in the fuel ilter regularly, and to dispose

of the separated water manually, as needed;

the new MAHLe BlueDrain® system (Fig. 2)

takes care of everything automatically.

Fig. 2: Design of the MAHLE BlueDrain® system

Housing

Plug for electronic

control unit

BlueDrain® water

cleaning unit

Electronic control unit

Multi-level

water level sensor

Fig. 3: Functional principle of adsorption

Fig. 1: Heavy-duty fuel filter module for EURO VI

with manual water disposal

Manual priming pump

Pre-filter (100 µm)

Complex flow chart with

several integrated valves

to control pressure and

volume flow

Main filter (3 – 5 µm)

Fuel cooler

Water drain valve


The new MAHLE oil filter module for

commercial vehicles is highly versatile

in terms of integration on both the oil

side and the coolant side. This high level

of integration reduces the number of

interfaces and sealing points. High-

performance plastics are used to help

reduce weight and costs.

LIGHteR, CHeAPeR, BetteR:

THE NEW OIL FILTER MODULEFOR COMMeRCIAL VeHICLeS



the development and production of com-

plex oil filter modules has long been one of

MAHLe’s core competences. Besides filtra-

tion and cooling of lubricating oil, additional

functions can be integrated into the overall

system of “engine lubrication and cooling.”

high level of integration

In our newest oil filter module, the coolant

pump, coolant thermostat, and sensors for

temperature control are all integrated (Fig. 1).

A valve provides for venting of the cooling

circuit. the coolant drain screw is placed at

the lowest point of the module in order to be

able to empty the block quickly for service.

the integration of the oil thermostat and

various valves on the oil side helps to reduce

friction losses. the restricted installation

space for the heavy-duty platform requires

a high level of functionality. the module also

serves as a support for the bracket of the

charge air pipe. In order to ensure a lifetime

seal between the engine and the oil filter

housing, despite thermally induced shifting,

a molded elastomer gasket that is inlaid in

the gasket groove on the housing was se-

lected for this interface. the gasket groove

is cast as is, and the engine flange on the

housing is machined. this provides a sealed

joint that is optimized for function and cost.

It also meets the demanding requirements for

an ideally level flange on the bolted engine

connection.

the filter element, based on modern filter

media and production processes, fulfills the

requirements for as long a service interval as

possible (Fig. 2). the separation level meets

the requirements of a modern engine. the

high quality of the ilter media allowed the

reduction of the ilter surface. the element is

thus more compact for the same package

constraint. this improved the total pressure

loss of the module at low temperatures by

ten percent. the filter is easy to access, and

a reliably functioning drainage system is in-

tegrated, which improves the ease of main-

tenance. the element is patented and there-

fore provides additional protection when

used solely within the customer-specific re-

quirements.

weight and cost savings

High-performance plastics have been in use

in the passenger car market for years. the

application of high-performance plastics to

the high service life of commercial vehicles

is a challenge that MAHLe is glad to accept.

By changing the position of internal inter-

faces, the plastic content has been increased

considerably. this reduced component weight

relative to comparable oil filter modules by a

significant amount. the innovative pressure

die casting design helps to reduce even more

internal interfaces. the module is very com-

pact. Additional potential material substitu-

tions have been identiied in order to continue

to develop the module with respect to cost

and weight savings in the future.

Author: Sabrina Auer

Fig. 1: Heavy-duty oil filter module with controlled pump and oil thermostat

Fig. 2: Patented filter element with 120,000 km

service interval

Controlled coolant pump

with Visco® clutch

Coolant

temperature sensor

Interface

for coolant thermostat Oil thermostat

Coolant vent valve

Patented

filter element

Stainless steel cooler

(rear side)

Initial fill valve

Coolant drain screw

00007665EN3.09/12 www.mahle.com

e paper performance 2012, en

Automotive

engine peripheralsmodular

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new fuel filters

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