According to latest EU guidelines on the manufacture of electric motors, the energy-efficiency of many electric transmission systems is to be increased by 30 percent As manufacturers explore this market opportunity, this development also brings with it some challenges. As the manufacture of these components not only calls for solutions of greater effectiveness, the design of these modern motors also increases the demands made on its constituent components. “We know about these challenges in the manufacture of the central components for electric motors,” explains Dr. Guido Hegener, managing director of EMAG Salach Maschinenfabrik GmbH. “A particular focal point is the demanding shaft manufacture, where a lot depends on the machine tool used. In a batch production environment idle times must be kept short and component costs low. But this must be achieved without loss of flexibility in the production process.” Automation ensures short idle times The specialists at EMAG have developed their solution for the machining of shafts up to 400 mm length and 63 mm diameter in their VT 2-4 4-axis Vertical Pick-Up Turning Machine. Its automation provides for very fast chip-to-chip times and ensures component costs are kept low. Workpiece grabs are used to transport the raw-parts into the machine and retrieve them again upon completion of the machining process. Depending on the component, the changeover time can be as short as six seconds. “In a mass production environment such short idle times soon add up to provide enormous time savings,” adds Hegener. “They also guarantee an energy-efficient production process, as a large part of a machine tool’s energy is consumed during downtimes.” The actual turning process, with spindle speeds of up to 6,000 rpm, also helps to achieve extremely short cycle times. The shaft is clamped vertically between workspindle and tailstock and machined from two sides. This work is done by two turrets with twelve tool stations each. The stations can be equipped with turning tools and driven tools (with one station being occupied by the grab). For milling work, required for keyways for example, the machine can be equipped with a Y-axis. The vertical alignment of the workpiece ensures permanent process integrity, where the unhindered chip flow prevents the build-up of chip nests in the machining area. A true space-saver Another decisive factor for economic production is the external dimension of the machine tool. In the case of the VT 2-4, the machine base is already small as the vertical design minimizes its footprint. Production planners also don’t have to provide for additional raw-part and finished component storage, as this is integrated into the VT 2-4. These machines can also be linked-up in close formation, forming a complete manufacturing line. “We have developed an altogether very compact manufacturing system that is highly flexible and a future-safe investment,” explains Hegener. “There are a lot of possible applications out there for this system, especially in the manufacture of shafts for electric motors,” says Hegener. “We are offering a machine tool that allows the user to implement demanding machining processes and to save massively on costs. This kind of quality will no doubt assert itself.” The VT 2-4 4-axis Vertical Pick-Up Turning Machine was recently highlighted during EMAG's successful Technology Days event, celebrating 20 years of operation in the United States.