RZ 60 for Planetary Pinions
The RZ 60 has been optimized for machining planetary pinions for the automotive industry. When grinding planetary gears, the cycle times are very short due to the small size of the workpieces and large batch volumes. The large batches are primarily a result of using three to five identical planetary pinions for every automatic transmission produced. In contrast, each component occurs only once in manual or double-clutch transmission. For the machine tool, this means that high priority has been given to the reduction of the cycle times, while compromises can be made for changeover times. Due to numerous, innovative measures, the primary machining times for grinding planetary pinions on the RZ 60 has been drastically reduced in comparison with previous applications. The robust machine structure, adopted from the much larger RZ 260, allows for the use of aggressive grinding parameters without negative effects on workpiece quality. At maximum speed the grinding and workpiece spindle positions are controlled with the new “Precision-Drive” electronic gearbox developed by Reishauer. This also enables the use of multiple start grinding wheels for planetary pinions which typically have a relatively small number of teeth resulting in high workpiece speeds and tooth meshing frequencies. In addition, it is possible to increase the cutting speed from the previous limit of 80 m/sec. to 100 m/sec due to the development and manufacture of new grinding wheels. Overall, these new advancements permit grinding times which can be as short as seven seconds for some gears.