Development of a noise optimization method for multi stage transmissions - consideration of dynamic interactions

• Applicant: Professor Dr.-Ing. Christian Brecher
• Subject Area: Engineering Design, Machine Elements, Product Development ; Acoustics
• Term: from 2015 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 273701591

Modern drivetrains have to fulfill many different requirements. They must be energy efficient, the must be failure safe, the must have a minimum weight and the must be silent. Transmissions with a high transmission ratio bigger than 5 have more than one gear stage. One example for multi stage transmissions is the electric drivetrain of cars. An electric drive is very noise sensitive and a challenge in the design phase. Today the transmission error and the force level of the tooth mesh are criteria for the gear acoustic. Usually each tooth mesh is optimized individually. Today it is not possible to predict the dynamic and acoustic behavior of a multi stage transmission in an early status of the design process. Due to this matter of fact it happens that the concept of a multi stage transmissions has weak points regarding its dynamic behavior. In case that the mesh frequencies of the different gear stages are close together it can happen that noise phenomenon occur what are annoying for human hearing It is the aim of this research project to develop a method to design multi stage transmissions with a low excitation and a good noise behavior. Therefore it is planned to adapt the results from Project to multi stage transmission. In the excitation behavior of single stage transmissions was evaluated in reference to psychoacoustic characteristics to predict the annoyance of the excitation. This methodology will be extended for multi stage transmissions. The approach of this project will be based on simulations and empirical trials to validate the simulation model.

• DFG Programme: Research Grants