Erwin Junker Maschinenfabrik – a developer of high-speed grinding technologies – last year earned recognition from Germany’s Baden-Württemberg Ministry of the Environment for its JUMAT grinding machine, which can be used for high-productivity, energy-efficient mass production of worm shafts with a highly productive and energy-efficient method.
The new machine was introduced in 2021.
Worm gears figure prominently in power-transmission designs – gearboxes and drives – where they are used to achieve high-ratio changes in speed or torque. Finished worm gears figure in electrically driven systems for cars, like steering and brake systems and powered devices like seats, mirrors, and hatches; and in general mechanical engineering; and in multiple other industrial and consumer applications , some of which may require thousands or millions of worm shafts annually.
"Erwin Junker Maschinenfabrik GmbH has developed not only a new grinding process, but also a comprehensively new approach, which achieves improvements and savings in many ways. That is what motivated the jury to award the special prize to the JUMAT," explained Baden-Württemberg Environment Minister Thekla Walker.
The Erwin Junker JUMAT machine is a single operation for producing worm shafts, in contrast to established processes that may involve several discrete stages: milling, rolling, smoothing, and deburring. Obviously, each step involves time and handling.
In the new machine, a worm shaft is ground from a solid blank with the basic geometry of the finished part and two bearing seats. Next, the blank is fed into the fully automated process via a loading system and undergoes pre-grinding and finished-grinding. Then, the workpiece moves to an integrated deburring station, and a finished worm shaft comes out at the end.
Among the innovations of the Erwin Junker process are a newly developed tool geometry and an optimized pre-grinding process, which replaces the principal cutting capacity and works at very high feed rates.
According to the developer, around 40 percent of energy and material required to produce the worm gears can be saved via the JUMAT. Other advantages of the new production process include long tool life and reduced space requirements; at least 50-percent shorter cycle times; and about 25 percent lower energy consumption.
"We were rather conservative in our calculations. However, the values have proved to be realistic. The first customer applications that we were able to support in 2021 have in some cases significantly exceeded our forecasts,” reported Erwin Junker Maschinenfabrik managing director Joachim Himmelsbach.
