Extending a cutting force model for generating gear grinding while regarding micro-geometrical influences

• Applicant: Professor Dr.-Ing. Fritz Klocke
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: from 2015 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 269650351

State of the art for optimizing the load carrying capacity and quietness of gears is the fine finishing of case hardened gears after heat treatment. One option for fine finishing is the generating gear grinding process, which is a wide spread industrial application due to its high productivity. Despite the wide industrial application of the process, only few scientific investigations exist. One possible reason for this is that the contact conditions between tool and gear flank are complex During the grinding process, various tool flanks mesh with various gear flanks. This complicates the transfer of knowledge acquired form other grinding processes. The variation of the contact conditions can lead to a distinct dynamic excitation, which makes the development of the machine and the control engineering a challenge. Knowledge of the expecting cutting forces and their characteristics is necessary for describing the dynamics and optimizing the processes. The actual research project Development of a cutting force model for generating gear grinding of external gears gives a first approach for calculating the forces according Werner and Kassen. However this model simplifies the cutting by the grinding worm. Though necessary cutting force parameters were estimated by literature, the model gives a good qualitatively correlation to force measurements for generating gear grinding. Aim of the applied research project is the extension of the developed cutting force model for the calculation of the local cutting forces for all active tool and gear flanks for generating gear grinding. The extended model considers macro-geometrical parameters of the process as well as the micro-geometrical cutting of single grinding grids by determining appropriate cutting force parameters. With the help of single an multi grid scratch tests of corundum grids and case hardened steel the parameters are defined. Only few scratch tests were realized for these typical materials for the manufacturing process of gears so far. After the definition of the parameters and the model regarding to Werner and Kassen has been expanded for the mentioned materials, the knowledge will be transferred to generating gear grinding. The results of the model will be optimized by force measurements in grinding trials and finally verified by grinding a reference gear and measure the cutting forces.

• DFG Programme: Research Grants