With its e-compressor, MAHLE is continuing
to develop into an overall systems provider
of air conditioning for electric vehicles too
—and thus an enabler of e-mobility
E-mobility requires many solutions — and MAHLE is driving them forward. The battery is one of the most important components in an electric vehicle — in terms of cost as well as performance. Its significance is thus comparable to that of the internal combustion engine — and it needs to be looked after just as carefully. Maintaining the correct battery temperature not only determines the service life of the battery, but also the speed at which it can be charged and even the cruising range of the vehicle. If the battery temperature is managed properly and its capacity handled carefully, you will get more out of it. The electric compressor from MAHLE is already at the center of the air conditioning and refrigerant circuit — ensuring the correct interior cabin temperature. Now it is also at the center of the battery cooling function — ensuring the correct battery temperature and it is becoming a key component in the e-mobility drive system. Because if the battery runs optimally, so will e-mobility — to the point that it can be perfectly integrated into everyday life.
»The power of the e-compressor lies in the detail. And this detail is the team striving for perfection.«
AKEEM FRANCIS, electrical engineer
York / USA
The electric compressor is made up of many precisely coordinated components. Just like the global team that is working intensively across borders on this product — from the United States through Slovenia, Spain, Hungary, and Germany— and uniting a wide variety of disciplines at the same time.
E-mobility — a global project
Amherst / USA. The success story of the e-compressor originates in the region of Western New York. Relatively far north on the border with Canada. Here, where winter temperatures sometimes reach minus 30 degrees Celsius, things are heating up inside the MAHLE building. Whirring, beeping, silence. Careful listening in sound-insulated rooms. Testing, adjusting, testing again. Engineering design and development with a precision that cannot be seen by the naked eye. This is where the engineers spend their time. Achieving absolute perfection. A walk through the product development and test laboratories, past test equipment, screws, and sensors, shows how a central component is brought to life from an idea at MAHLE.
In the first test room, an electric vehicle is connected to the laboratory through a complex array of cables and instrumentation. The e-compressor is sitting ready on the test bench. John O’Brien, systems engineer, begins: “The e-compressor is a crucial component for maintaining a comfortable cabin interior and providing adequate battery cooling — both during vehicle operation and during charging.” His team partner Jonathan Hammond, engineering manager, stands by his side and continues: “The cooling provided by the e-compressor is key to improving charging performance. You can speed it up.” He’s referring to one of the essential characteristics that will help to make e-mobility just as much a part of everyday life as combustion technology still is today. “The key to popularizing e-mobility is making the end product familiar to the consumer. Rapid charging is critical to that.” We continue through the engineering center. Workbenches, cabinets. Everyone is engrossed in their work.
It’s Friday. Delivery day. The next prototypes are going out to customers. There are components lined up on tables. These include parts from Slovenia and Spain because some colleagues are not on site. While MAHLE Electric Drives in Slovenia supplies the motor, or as the team colleagues explain, the “heart” with which the e-compressor can drive itself and hence be independent of the combustion engine, MAHLE Electronics in Spain provides the “brain” of the e-compressor: the power electronics. These components are now being assembled here in Amherst in the way that was planned at the very start. The distinguishing feature of MAHLE’s e-compressor is evident in this assembly: precision across all components. This is because MAHLE develops all of the components itself. And precision is exactly what has made MAHLE a pioneering automotive supplier since day one. With countless tests, meticulous attention to detail, and a huge amount of know-how.
Akeem Francis, electrical engineer, is age testing a motor winding specimen with electric power. He adjusts the test equipment providing current to the sample and the wires start to glow. This is an extreme way of testing the limits of materials under specific conditions. It is an extreme that will never be reached during normal use in the electric vehicle. But if you know the limits, you can guarantee safety. In terms of high voltage, this means that the electrical charge must not have any point of contact with the occupants of the vehicle.“I primarily work on the insulation system of the e-compressor,” says Akeem Francis, summing up his work in a nutshell. His colleague John O’Brien quickly brings the definition of precision to a charming, unprecedented level by proudly reformulating this for his colleague: “The customer is growing increasingly interested in insulation resistance, which Akeem focuses on. His work helps us tremendously.” Akeem Francis smiles and adds: “It’s vital to keep vehicle occupants and anyone else away from situations in which they could be exposed to the high voltage of the battery.”
»E-mobility is like a bicycle race: it’s not those who start fast and slow down at the end who win, but the ones who plan for the whole race. That’s MAHLE.«
Just a few meters away, another member of the team, James Campbell, prototype lab technician, sits in front of several modules. He explains his work in a comprehensive, almost poetic way: “The engineering team designs the concept and commissions the production of the parts. Then it comes to me.” When asked if he turns the engineers’ dreams into reality, he laughs and confirms: “In a way, yes.” His colleague Shelly Hamilton, senior mechanical engineer, supports him: “I prepare the components according to the desired configuration, and he assembles them. Then I’ll go and run tests to see if the individual parts perform as we need them to.” Anyone working day after day in this environment quickly takes all of the precision for granted.
“The e-compressor is an incredibly precise machine. All the parts have to be flawless — that’s what keeps Shelly and James busy,” adds John O’Brien. “Making sure that all the parts fit together within our very narrow tolerance ranges.” Long before a single part can be put together, the work of Brett Bowman begins: “I conceptualize the electric architecture that drives the e-compressor. This ensures all three subsystems — electronics, motor, and compressor — operate together in the most effective way to meet the demanding customer requirements.” He doesn’t have much space for that either.
The room erupts into laughter as Jonathan Hammond clarifies the statement: “We are always reducing his space. The mechanical designers are pressured by the customer to make things smaller and lighter. And then the electrical engineers figure out how to make it happen.” The field of electrical applications is exciting and relatively new to everyone. Not just to MAHLE or the customer, but to the whole world. E-mobility is in its infancy. That leaves a lot of leeway for innovation. And completely new answers.
“You often have to work with the customer to understand what they really need at the end of the day. The way to tackle such a challenge is to collaborate closely and figure it out together,” explains Brett Bowman. The fact that so much is new can also be heard in the feedback from the most recent team member, Ilya Burdukov, mechanical design engineer. He has been working on mechanical compressors for years, but the electric compressor is a totally new product. “I had to go through a big learning curve, but I definitely enjoyed it.” In one of the last rooms, James Faller, electronics engineer, is tinkering with the electronics. He takes individual modules out of a cabinet and tests them. It is highly detailed work: “I inspect and confirm that each component performs as designed and then test it on the e-compressor. If there’s an issue, I try to debug, find solutions, and give feedback to the team in Spain.” The research and development center of MAHLE Electronics is located in Spain. MAHLE engineers from all over the world work here on developing innovative electronics solutions — and thus also for the e-compressor.
How an electric air conditioning compressor works
The air conditioning compressor produces cool air from heat energy — for the well-being of the vehicle occupants and the battery. It is based on the principle of an air conditioning circuit in which every single component counts.
The e-compressor compresses the gaseous refrigerant and thus ensures high pressures and high temperatures. The hot gas is then pumped to the condenser.
In the condenser, the gaseous refrigerant is cooled and liquefied by the ambient air.
The liquid refrigerant passes through an expansion valve, where its pressure and temperature are reduced.
The largely liquid refrigerant flows through the evaporator and through the chiller. This is where the evaporation process takes place.
Heat is removed from the air that passes through the evaporator and into the cabin, which is consequently cooled.
The refrigerant circuit and battery cooling circuit are connected via the chiller. This enables the transfer of heat from the battery coolant circuit to the refrigerant circuit.
The vaporized refrigerant returns to the e-compressor, and the cycle begins again.
»We once revolutionized mobility with the aluminum piston. The e-compressor has the same potential.«
»Electronics is the new power of mobility. With it, we created the most powerful e-compressor on the market.«
The e-compressor is now going into production in Hungary, on the world’s first production line for MAHLE e-compressors. The international team has worked across the various time zones and languages to successfully commence series production of the e-compressor. Despite the different cultures, one thing above all unites them: the MAHLE mentality. James Faller explains what it is: “At MAHLE, it’s never ‘No, you can’t do that,’ but rather ‘How can we do it?’ It’s very liberating and empowering for us to do what we do.”
The customers are convinced by this too. Aside from the technology, Dr. Armin Frommer, head of Product Development E-compressors, sees yet another crucial element as the basis for this success: “Trust in the team.” And adds: “We once revolutionized mobility with the aluminum piston. The e-compressor has the same potential. We want to shape and develop this change
too. Because one thing is certain: it doesn’t matter whether mobility is old or new, the challenges remain the same. We will carry on with our work as usual. With passion and systematic development activities.”
Akeem Francis sees it from a very sporty perspective: “For me as someone from an athletic background, it’s somewhat fundamental for the team to recognize that we’re here to play, and we’re able to win. And we did. Anything else would have been devastating.”
With the e-compressor, MAHLE is supplying the component that is central to the thermal management of the electric powertrain. And all the other components that are needed. It’s not just about offering systems expertise for e-mobility. It’s about clearing the path for anyone who wants to buy an electric vehicle. This path begins at MAHLE. And MAHLE has — once again — delivered.
And let’s not forget ...
... all the many other product solutions, projects, and initiatives that we delivered, initiated, and drove forward in 2018. Here are some highlights.
The patent-pending digital solution from MAHLE saves time and money, because TechPRO ADAS now allows vehicle workshops to adjust and calibrate driver assistance systems quickly and easily — using a single digital calibration panel. The new solution is continuously updated online and expanded to cover more vehicles. With this digital tool, MAHLE is setting new benchmarks in this product group.
Adsorption air conditioning
It’s possible to make standstill air conditioning powerful, engine-independent, and thus very quiet — with MAHLE. This new air conditioning concept from MAHLE works using the cycle of evaporation, adsorption, condensation, and desorption. The MAHLE Integrated Thermal System is extremely low-wear and absolutely noise-free. And thus more efficient than conventional systems.