Solutions for the demanding production of transmission components - this statement sums up the demanding task required of Kordel, headquartered in Dülmen near Münster. The company develops and produces complete transmission systems that are used in things like industrial trucks, as well as agricultural and construction machinery. To ensure that the technology they use can withstand tough, long-term continuous use, while at the same time ensuring efficient power transmissions, the specialists rely on high quality and precision requirements for their production. For over 20 years, Kordel has been relying on pick-up technology from EMAG, and continuously invests in new machines from the South German machine builder – most recently they purchased two VLC 200 GT turn-grind centers. With these systems, hard machining processes are performed on a variety of bevel gears, one right after the other, in just one set-up. The result: By combining turning and grinding, this technology ensures a long tool life and a qualitatively stable process.

Industrial trucks, agricultural machinery and construction equipment often need an enormous amount of torque to compensate for shock loads, while minimizing the amount of permanent environmental pollution – this means that extreme (force-) leads are normal for Kordel products. It is also imperative that gearboxes are able to perform their work for a very long time without any faults or failures. To meet this demand, the specialists at four locations in Germany and Poland are focused on quality and technology. The close work performed by the internal development department and production crews are essential for success here – they work “hand in hand” with flat hierarchies to ensure that newly developed components can be produced efficiently. The independence and expertise of the employees play a central role in the success.

This family-owned company has an enormous vertical range, with a production area that is approximately 60,000 square meters. All production process steps, from the blank to the finished gearbox, are performed under one roof, which allows for major simplification in quality assurance. Since the early 2000’s, Kordel has also invested heavily in the automation of production technology. Today, there are over 70 self-loading machines. With these systems, manual loading is typically also a possibility so that even small batch sizes can be produced economically. EMAG production solutions were on board right from the start! Currently there are a total of 17 EMAG machines in operation at Kordel – the oldest has been working for more than 20 years. The most recent additions were two VLC 200 GT turning and grinding centers. Why does Kordel keep relying on EMAG? “The price-performance ratio of complete solutions with integrated automation is the main consideration in these decisions," answered Managing Director Johannes Kordel. "That convinced us 20 years ago and it still applies today. We have also had great experiences with the stability of this technology. There is no reason to change when we already have such a convincing mechanical engineering partner."

Focus on Minimum Tolerances   

Many of these production solutions have helped Kordel to achieve long tool lives, while consistently maintaining high quality. This is very clearly illustrated by the two new VLC 200 GT turn-grind centers. One of the two machines is located at the Dernekamp site near its headquarters, the other is in Jawor, Poland. In Germany, the VLC 200 GT is used to manufacture a variety of different sized bevel gears, used in a one-wheel drive for industrial trucks. This is one of the central parts of the drive and requires an enormous amount of precision: the tolerances that are required in the finishing processes are minimal.

This basic principle is as simple as it is effective, and can be achieved by complete machining in one machine, with one clamping operation: after hard turning, only a residual allowance of a few hundredths of a millimeter remains on the bevel gear. The subsequent grinding of inner and outer contours – with the corresponding two grinding spindles inside the VLC 200 GT – creates a consistent surface quality that ensures a stable production process. In addition, the specifications of the grinding wheel can be designed specifically for the final quality, and tool costs are reduced because the grinding wheel wears more slowly with the low stock removal, it will also need to be dressed less frequently. An integrated measuring probe checks the diameter and length of the component after the process and corrects them automatically if necessary.

The entire design of the EMAG machines impresses by ensuring simplified processes at Kordel: the operator places the parts in one of the drag rings located in the circulating conveyor, and when the part is completed will also remove the part from here. Once loaded, the machine can operate autonomously for a long period of time, as loading (and later unloading) of the workarea is completely automated and performed very quickly by the pick-up spindle. Short chip-to-chip times are guaranteed by a linear motor in the X-axis, because it moves the parts into machining position very quickly. All of these features add up to drastically reducing overall downtimes within the process. Operators will also benefit from easy accessibility to the workarea and tool turret. This allows the turn-grinding machine to be retooled very quickly – a very important benefit when dealing with a large number of bevel gears.

“All in all, the use of the VLC 200 GT at Kordel is ideal because we developed this machine as a solution for the production of gear parts. Depending on the workpiece geometry and quality requirements, the two machining processes can be intelligently combined with a rapid changeover,” said Florian Rose of EMAG. The systems multi-functional technology opens up a wide range of production possibilities for users. Internal and external grinding spindles, turning tools, tool holders or the proven EMAG 12-station tool turret are used as required. All parts for the system come from the EMAG Group, guaranteeing the best quality and availability. “All in all, we offer gear manufacturers a customized, flexible and highly productive solution with an attractive price-performance ratio. In the end, this convinced our contacts at Kordel,” Rose said.