Regulated quality

 Inside machining of bearing flanges in a closed process



The cutting edge of the KomTronic® U-axis system can be dynamically adjusted during machining, allowing complex geometries to be created in one contour operation and for wear to be compensated for. The mechatronic U-axis systems from the KOMET GROUP form the basis of the extremely high level of drilling quality that is achieved thanks to process-specific measuring in the machining centre using an exchangeable barrel gauge. 



Machining of gearbox housings is a complex matter, requiring a wide variety of milling, drilling and turning operations. With an automatically exchangeable KomTronic® U-axis system, it is even possible to perform turning work on the machining centre such as that required on a bearing flange. As a result, these components no longer need to be moved to a lathe. They can be completely finished with a single clamping arrangement in the machining centre. In addition, the freely programmable tooling systems mean that it is no longer necessary to use special forming tools. A typical task for KomTronic® U-axis systems would be the machining of bearing flanges on gearbox housings. They provide the opportunity to produce several diameters in a complex internal contour, including the lead radius, in a single operation.


The mechatronic U-axis systems essentially consist of one compact facing head with single slide that is driven by a servo motor and threaded spindle. The power supplied to the electronics and the drive is transmitted contact-free and inductively to the U-axis system. Similarly, the data is exchanged inductively with the U-axis system. A so-called stator is mounted on the spindle side. It is segment-shaped, which permits the tools to be replaced automatically. The ring-shaped inductive transmission unit (rotor) on the U-axis side ensures reliable data and energy exchange in every angular position, even when coolant is being used. The mechatronic U-axis systems are therefore automatically exchangeable NC axes. For flexible contour machining and grooving operations, the U-axis is interposed with the Z-axis. Programming is carried out in the usual NC programming language and is integrated into the machine control system. All the functions of normal ISO programming are available. A customised adaptor tool is used for bearing flange machining, which in this case is equipped with a PCD indexable insert from the KOMET® standard range.


The flexible cutting edge adjustment, which allows freely programmable contours to be created dynamically during machining, can also be used as static cutting edge adjustment for the purposes of wear compensation. This requires correction values to be generated using tool measurements or measurements on the workpiece. The latter was chosen for the bearing flange machining, and process-specific measuring technology was integrated into the machining centre in order to take the specified Cpk tolerance restrictions into consideration for certain fitting diameters. Because the surface quality of aluminium components can also be correlated with the cutting edge wear, the surface finish can be indirectly monitored at the same time.


Process-specific measuring is more or less the same as post-process measuring, but it takes place within the machine tool. A Blum BG 40 bore measuring head is used for this. The barrel gauge that can be automatically exchanged from the tool magazine provides the opportunity for the various machine components, such as axles and clamping devices, to be used during the measuring process. This measuring method does result in non-productive time, but saves the need to invest in separate systems. A significant advantage in this is that the clamping situation from the process remains unchanged and the time difference between processing and measuring is reduced to a minimum. Measurements are therefore taken with this method in thermal conditions that are close to the machining state. This is a considerable advantage when it comes to precision.


The measurements that are increased at regular intervals during bearing flange machining are supplied to a radius correction algorithm, which corrects the tool dimensions accordingly using the tool management system. In this respect, the 'turning tool definition' that is integrated into the machine control system is useful. It is offered as an optional extra for machining centres by control system manufacturers and saves programming in your own correction cycle. The combination of the KomTronic® U-axis system and the bore measuring head therefore offers a closed process chain within the machine tool, allowing simple and prompt correction of process parameters and stabilising the process with regulated quality.




With its brands KOMET®, DIHART® and JEL®, the KOMET GROUP is a leading global manufacturer of precision tools for bore machining, threading and reaming. The group has been at the forefront of innovation in the sector for over 90 years - a tradition that began with the early insert drills and that continues today with their mechatronic tool systems. The company currently employs more than 1,600 staff in its 20 subsidiaries and is represented in around 50 countries.