Study on Mechanism of Impact Noise on Steering Gear While Turning Steering Wheel in Opposite Directions

This study is focusing on the cause of the clanking noise which is called "Tuk" in a vehicle. The noise was generated from a steering gear system under high load conditions while a steering wheel was turned in the opposite directions. In order to identify the mechanism of this noise, both experimental and simulation studies were performed on a steering gear system on lab-testing conditions. A simulation model was constructed based on modal testing and deflection data measured at several points on operating conditions. The detailed behavior of each component such as a rack bar, a yoke and a housing was investigated with the help of the transient analysis. As a results of the testing and the simulation, it was concluded that a vibration was induced by the collision of a rack bar and a pinion gear. The vibration which started from the gear interface was transferred to the neighboring parts and the noise was radiated mainly at the housing. Additionally, the impact phenomenon were confirmed with measuring transmission errors between the gears. Finally, the improved designs were suggested by the simulation analysis, and a significant reduction of noise level was detected from the test.