Speciale_EMO_Hannover

SPECIAL EMO 2023 11 are being optimized for electromobility and being completely redeveloped and launched on the market to meet custom- ers’ changing needs. A current machine series represents a good example here: It has been developed for the lightweight manufacture of components for the e-drive. Single- and two-spindle machines are also being adapted accordingly. For 2023, new machine sizes are also sched- uled which allow even larger components to be milled for the e-drive in a single oper- ation. This Grob series now comprises five machine types, meaning that every cus- tomer is certain to find the right solution. Battery frames The battery frame is a key component in every electrically powered vehicle. The electromobility experts at Mapal Fabrik für Präzisionswerkzeuge Dr. Kress KG in Aalen, Germany, have developed a ge- neric process based on various customer components. It contains the main battery frame machining operations for a generic component. Major machining challeng- es include stepped bores, bores with dif- ferent diameters through multiple layers, milled pockets with various dimensions, shoulders and, most importantly, vibra- tion susceptibility due to thin rib structures and chip breakage control. Mapal meets these challenges primarily using specially designed milling cutters. The cycle time is somewhat longer if bores are milled, how- ever the process offers distinct advantag- es in this specific case - short milling chips that can be easily removed, reduced burr formation, greater process reliability and no tool changes. The company recommends the use of a special solid carbide cutter for roughing the shoulders, pockets and grooves and for finishing the pockets. This creates the best possible surfaces and works stably even in corners with large wrapping and high loads. A special feature of this tool is that users can finish greater depths in a single action. This saves time and is therefore particularly economical. Surfaces of down to Rz = 1 µm (average roughness depth) are achieved during bat- tery frame finishing. A total of seven tools - including six milling cutters - are used in the entire generic process. New transmission architectures High-speed motors make it possible to produce low-volume yet high-powered electric motors. Transmission designs based on planetary sets meet these re- quirements. However, the cost-effective production of the required thin-walled internal gears and stepped planetary gears with close interference contour can be hampered by collisions between the workpiece and the tool. The gear skiv- ing process developed through to series production readiness at the wbk Institute of Production Science permits highly pro- ductive and flexible manufacturing of such gears. Significant fluctuations arise in gear quality in large-scale industrial production, however, due to tool wear and inconsist- encies between material batches. The lack of process data acquisition means that a wide range of options for correct- ing the gear geometry are currently largely unused. Machining forces and tool center point displacement are calculated from the machine’s own data. Real-time re- maining useful life prediction for gears can be used to forecast and correct the effect of machining forces on the manufactured gear quality. This can effectively compen- sate for the effects of tool wear and batch fluctuations in particular.