There are various methods for producing complete laminations for electric motors from electrical sheets: by stamping, gluing or with bonding varnish.
For the first time, Schuler has now seamlessly integrated the well-known Backlack technology into a complete turnkey, fully automated system with a high-speed press, stack formation and baking stations.
The production process always starts with punching the electrical sheets. High-speed presses with progressive dies are used for this in mass production. For electric vehicle drive motors, sheets with thicknesses of just 0.2 to 0.35 mm are increasingly being used to improve efficiency. The coating of the electrical sheets reduces iron losses in the motor package.
During punch stacking, small sections of the individual sheet metal are pressed onto the electrical steel below them in the tool. This type of interlocking (“clinching”) holds the stack together. However, such a connection between the sheets impairs the magnetic properties of the motor as it damages the insulation of the sheets. Alternatively, adhesive can be applied to the raw material before punching. The sheet stacks are then created by pressing the electrical sheets together. This leaves the insulation undamaged.
However, applying adhesive inside the punching tool can lead to a lower output rate and is only effective at certain points. In the Backlack process, the electrical sheets are joined together to form a stack under pressure and high temperature in a baking station from the Swiss company SWD AG. This creates a full-surface bond that reduces vibrations and noise later on in the engine. Thanks to the denser layering of the sheets, cooling liquids can neither escape nor penetrate.
The higher thermal conductivity of baking varnish compared to air also proves to be an advantage for cooling. Of course, the trays are also perfectly insulated from each other.
Schuler has embedded the separate work step in an overall solution: A fully automated system collects the electrical steel sheets underneath the progressive die, brings them in a controlled manner into the form of individual sheet stacks of the desired height and then transports them safely to the separate baking lacquer stations. Up to 80,000 rotor and stator stacks per year can be produced in this way.
© SWD
New control system extends press life
With a modernization, punching technology specialist Heinrichs ensures the supply of spare parts and enables remote access to the system. Schuler has already equipped numerous Müller Weingarten HUQ systems with a new control system. The advantages speak for themselves: a self-explanatory user interface in large format, the possibility of rapid assistance from Schuler Service via remote access and, last but not least, the guaranteed long-term supply of spare parts.
For these reasons, punching technology specialist Heinrichs, headquartered in Lennestadt, has now also decided to update its forming line in this way. The modernization was completed within just seven days, confirms Technical Manager Knut Schönewald: “I was quite surprised because I had never seen projects of this size before. But this update went very well thanks to the modular control system, and the Schuler employees were very committed.”
The experts backed up all the product and die data on site and uploaded it to the new system so that production could restart just a few days later after the feed had been optimized. The HUQ press from Heinrichs produces components for vehicle seats, among other things, on behalf of a major automotive supplier. The product portfolio includes a total of 1,580 different stamped parts. Many well-known car manufacturers are among the more than 160 customers of the fourth-generation family business, which employs around 360 people at three locations.
Last year, the Heinrichs Group achieved a turnover of 80 million euros.
The company was founded in 1913 by Wilhelm Heinrichs in Plettenberg; his son Karl Heinrichs moved the headquarters to Lennestadt-Meggen, just over half an hour’s drive away, in 1937. A second plant was added there in 2002, and another is located at the subsidiary Histeel in Kaunas, Lithuania, which was founded in 1994.
Background
Schuler offers customized technology in all areas of forming technology – from networked presses to press shop planning. In addition to presses, the product portfolio also includes automation, tools, process know-how and service for the entire metalworking industry. Within the Metris platform from Andritz, Schuler bundles digital solutions for networking forming technology and is constantly developing these to further improve the productivity and availability of the systems.
Schuler offers equipment and services in the cell assembly and forming process steps for battery production gigafactories. Customers include automotive manufacturers and suppliers as well as companies from the forging, household appliance and electrical industries. Presses from the Schuler Group mint coins for more than 180 countries. Schuler was founded in 1839 at its headquarters in Göppingen (Germany) and is represented by around 5,000 employees at production sites in Europe, China and America as well as service companies in more than 40 countries. The company is part of the international technology group Andritz.
Web: www.schulergroup.com
