Experimentelle Untersuchung von Einflussgroessen auf das Rasselgeraeuschverhalten von Stirnraedern

摘要

The reduction of annoying sounds is crucial within the vehicle development process. Apart from gear whining, gear rattling is relevant within the driver's cabin. Gear rattling occurs due to a speed non-uniformity within the drive train, caused by the irregular combustion process of the combustion engine. The tooth flanks lose contact and move within the gear backlash when exceeding a certain angular acceleration amplitude, leading to vibro-impacts. This report examines the effects of the excitation frequency of the speed non-uniformity, the drag torque and the lubricant on the gear rattle noise of cylindrical gears. The rattle threshold is determined by analyzing the structure-borne noise and angular acceleration levels as well as vibro-impacts in time domain. Increasing the excitation frequency influences the impact occurrence per revolution and leads to a decreased rattle threshold. After exceeding the rattle threshold, the structure-borne noise levels at different excitation frequencies applied converge and at a certain speed oscillation amplitude, the structure-borne noise levels are comparable. The rattle threshold is influenced by the drag torque - nevertheless, the structure-borne noise and angular acceleration levels at different drag torques applied do not deviate significantly after exceeding the rattle threshold. The lubrication shows the highest impact on gear rattling at the given test parameters, comparing the lubricants SAE 0W-16 and SAE 85W-90. The structure-borne noise indicates higher damping of SAE 85W-90 when analyzing the decay curve at constant speed oscillation amplitude. The damping effect of the lubricant decreases when increasing the excitation frequency at constant speed oscillation amplitude.