Two thirds of all electric drive trains are produced with manufacturing technology from the southern German family-owned company GROB. GROB ensures its rigorous quality requirements with quality solutions from ZEISS.

Pioneer for e-mobility

Martin Negele is Head of Quality Assurance at the long-established Mindelheim-based company and has the answer: “At GROB, we recognized several years ago that the future belonged to e-drives. At that time, this was still a controversial topic, but we took the plunge. Today, we have a 67 percent market share in stator technology alone. If you look at an e-drive train, it is very likely that our manufacturing technology is behind it.”

GROB earns this leadership role mainly by striving for uncompromising quality. To ensure this, the company relies on the comprehensive portfolio from ZEISS: “We combine microscopic, tactile and optical measurement technology to achieve optimal results,” says Martin Negele. This means that even the production of a demanding part such as a stator can be completely covered – with maximum certainty and productivity.

Stator: simple structure, complex manufacturing

The motor of an electric car is impressively simple: A rotating electromagnet (rotor) turns in the magnetic field of a stationary permanent magnet (stator). And the stator consists only of a sheet steel housing, the laminated core, and induction coils made of coated copper – although today hairpins are increasingly being used instead of wound wire coils.

“As advantageous as hairpins are as a finished product, their manufacture is demanding, especially when it comes to bending and welding,” explains Georg Knoll, supervisor of welding processes at GROB and head of the workshop testing laboratory. “That's why we have to constantly check from incoming goods to the finished assembled part.” Because undetected defects can lead to loss of performance or inoperability, and in the worst case even to fatal damage to the entire drive.

End-to-end testing requires combination of technologies

Initially, after the tensile test, a cross-section of the copper wire for the hairpins is analyzed under the microscope to check the condition of the insulation coatings. Once the hairpins are assembled in the laminated core, the welded ends of the hairpins are inspected using a computer tomograph. The assembled and welded stator is then inspected tactilely and visually to ensure matching dimensions and to rule out surface defects.

“With only few exceptions, we consistently rely on solutions from ZEISS,” explains Martin Negele. “And there are several reasons for this: First, hardly any other supplier offers its industrial customers such a high level of service and application understanding. And: No other supplier offers such a comprehensive portfolio with which we can cover everything an entire process such as the production of a stator from a single source."

Solutions from ZEISS make quality assurance 30% more productive

As coordinate measuring machines, GROB relies on ZEISS PRISMO – one of the most precise of its kind. ZEISS ScanBox functions as an automated optical 3D measuring machine – it simultaneously enables high process reliability and high throughput. And GROB also relies on proven ZEISS technology for microscopy with the ZEISS Axio Imager, an open microscope system for automated materials research.

Martin Negele emphasizes: “The uniform ecosystem saves us training effort and makes it easier for our employees to operate the different solutions. And it makes workload planning more flexible and efficient. As a result, our productivity has increased by 30 percent.” Georg Knoll adds, “And when our customers see our high-quality equipment from ZEISS, there are no discussions at all about quality claims or measurement values. They know that we employ state of the art solutions.”

Always one step ahead in terms of quality

GROB is also a pilot customer for new quality technologies from ZEISS. “This fits in with our claim that we want to stay one step ahead of our customers, who are already operating at an extraordinarily high level, when it comes to quality," says Martin Negele. "This is particularly important for new and emerging technologies such as e-motors or batteries. With ZEISS as our partner, we have the certainty of always being able to keep up with the leaders."

Do you want to learn more about ZEISS eMobility Solutions? Download brochure here.