Technology: ZF is working on extending the range: More compact, lighter and further

2023-07-02 06:48:49

Technology: ZF is working on extending the range More compact, lighter and further

ZF electric drive EVSys800

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The supplier ZF is repositioning itself and has some interesting innovations up its sleeve. In addition to a compact, constantly powerful electric motor, a new thermal management system with an efficient heat pump that puts current models in the shade should ensure significantly more range for electric models – especially in winter.

In the automotive industry, transformation is currently one of the buzzwords par excellence. Sometimes one gets the impression that this attribute is applied as soon as a few new software developers tinker a new graphical interface of the infotainment. The supplier ZF is actually going through a fundamental change in corporate culture. Processes used to be clearly defined. The car manufacturer ordered so many components over the life cycle of a vehicle and the Friedrichshafen company delivered on time and with consistent quality. This business model no longer works like that. “Ten years ago, 60 percent of our sales were linked to the combustion engine, today it is 27 percent. Computer chips are ZF’s new gears,” explains CEO Dr. Holger Klein.

More compact, lighter and further

The automotive world is turning differently now and faster and faster. Accordingly, the industry is overheating and acting hectically on the way to electromobility. The German car manufacturers are apparently losing the reins of action, while the competition from the Far East is increasingly setting the pace. The Shanghai Motor Show a few weeks ago made this fact clear to every visitor. While the Chinese automobile manufacturers presented an impressive variety of different vehicle models, the China governor of a large German automobile manufacturer trudged through the spacious halls with a mournful expression on his face.

The suppliers have to join in this dance, whether they want to or not. However, one thing has remained the same. Your innovations must find buyers. A ZF achievement is the current electric motor with a peak output of 200 kW / 272 hp and a continuous output of 75 kW / 102 hp, which is in service in the Lotus Eletre. But the better is the enemy of the good. With the EVSys800, the next generation of the ZF-E machine, which is scheduled to appear in 2026, is just around the corner. The electric motor then creates a continuous output of 206 kW / 280 hp, with a maximum of 275 kW / 374 hp. The drive unit, which is significantly more compact than the current ZF drive generation, uses, as the name suggests, 800-volt technology, which enables fast charging, and consists of silicon carbide power electronics, the electric motor and a reduction gear. “Of course, the engine can also be scaled down or used in commercial vehicles,” explains Dr. Otmar Scharrer, Head of Development at ZF Electromobility.

The individual components of the drive module come up with improvements that show that the development of electric machines is far from over. It starts with the winding, which is a further development of the so-called wave winding and saves ten percent copper. The direct oil cooling of the copper rods enables the greater power output. The power is transmitted by a coaxial reduction gear with two planetary gear sets. The new technology made a good impression on the first rides in a prototype called EVbeat, which was equipped with the drive components. We especially liked the smooth, jerk-free acceleration.

“We don’t believe that the majority of electric motors need a manual transmission,” says Otmar Scharrer. What we couldn’t test was the repeatability of the performance, but the ZF engineers swear stone and leg that’s not a problem. The new electric motor is not smaller, but at just 74 kilograms it is around 40 kilograms lighter than the current ZF electric motors. It is interesting that the generation change does not take place abruptly, but little by little. The units are modular and individual components will be replaced with the new elements over time.

It is exciting how ZF manages to extend the range without increasing the battery’s installation space. The conventional way would be to pack the storage cells with higher energy density into the batteries. But many ideas shorten the way to Rome. ZF has its sights set on the heat pump to get more kilometers out of the batteries. Basically, a heat pump works in reverse like an air conditioner or refrigerator. It extracts the heat from the interior and releases it to the environment, and with the heat pump it is just the opposite. In Stromers, the compressor compresses the liquid refrigerant. This creates heat that heats the cold air flowing along. The principle works at low temperatures, but also in summer to cool the interior.

At temperatures of -20 degrees, this principle slowly reaches its limits as efficiency decreases. The reason lies in the properties of the R1234yf fuel used, which will probably soon be banned anyway. So the Friedrichshafen engineers pump propane into the lines of the new thermal management system (TherMaS), which uses three cooling circuits to cool the temperature-critical elements of the electric drive more efficiently than before, thus enabling more power and range. “TherMaS is the future,” Ottmar Scharrer is certain. The technician’s optimism is not unfounded, the fear of winter range should soon be a thing of the past. Since the propane has an efficiency of 2.5 at -20 degrees in the heat pump, the range is increased. The chemical advantages of propane also pay off in hot weather. On average, it is around 50 kilometers for 500 kilometers. It goes without saying that the component is more compact and lighter than previous systems.

The Friedrichshafen supplier follows a holistic approach with the motto “everything from a single source”. This starts with radar sensors that can be used both frontally and laterally and identify pedestrians up to a distance of 100 meters, through connectivity solutions to the automotive cerebrum ZF ProAI, which is available in five versions and is intended to pave the way for autonomous driving . The ZF products are designed in such a way that they can be integrated into most existing architectures, i.e. they can also interact with actuators from other manufacturers or software cloud solutions. So actually a real transformation.

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