Experimentally Validated Geometry Modification Simulation for Improving Noise Performance of CVT Gearbox for Vehicles

Noise pollution has become one the most important environmental issues in modern life. The automobile, a product of the second industrial revolution, has a very large sales volume of approximately 100 million per year. With the popularity of automobiles, the noise generated by them has become a major cause of noise pollution. This paper presents an experimentally validated geometry optimization method for reducing the noise by a CVT gearbox used in motor vehicles. We used the CAE software RomaxDESIGNER to simulate the transmission error and the load distribution on meshing gear tooth surfaces before and after gearbox optimization. After determining the best modification values, we carried out a series of noise bench comparison tests to verify the simulation results. The test results confirmed that the optimization reduced the fluctuation in noise that occurred during certain speed stages of the gearbox. Due to the optimization, the overall noise level decreased and the noise curve became smoother.