High speed temperature measurement in gear hobbing: Part I—design, concept and physical operation mode of the infrared-camera

Abstract

Gear hobbing is the major technology to manufacture external gears. The motions of the tool and workpiece are dynamically linked. Therefore it is difficult to apply external measurement devices in the process. Especially the temperature, which is a vital factor to determine the load on the cutting edge, cannot be measured as easy as in other processes (for example turning). Suitable infrared-cameras are not commercially available, because these do not meet the demands for temporal and geometrical resolutions. Furthermore, commercial equipment has to be calibrated for each individual temperature (above 350 °C). This forced the Institute of Manufacturing Technology and Quality Management to develop an own measuring device. This camera is able to measure the temperature of the cutting surface within the gear hobbing process. Despite focusing the usage of the camera on hobbing in this paper, it can also be used to monitor further highly dynamical machining processes with discontinuous cutting conditions. This paper is divided into two parts. The first part describes the set-up, the concept and the physical and optical basics of the IR-camera. In the second part, the experimental realisation and the results of trials during an analogy test of the hobbing process are presented.