① Simulation results of vibration and noise of helical gear system before modification
The sound pressure nephogram of helical gear system at 230hz, 460hz, 690hz, 920hz and 1150hz when the friction coefficient before modification is 0.1 calculated by boundary element method is shown in Fig. 1 ~ 5. Figure 1 shows that the maximum sound pressure calculated at 230hz is 70.1db. Figure 2 shows that the maximum sound pressure calculated at 460hz is 74.1db. Figure 3 shows that the maximum sound pressure calculated at 690hz is 82.1db. Figure 4 shows that the maximum sound pressure calculated at 920hz is 85.5db. Figure 5 shows that the maximum sound pressure calculated at 1150hz is 93.8db.
② Simulation results of vibration and noise of modified helical gear system
The sound pressure nephogram of helical gear system at 230hz, 460hz, 690hz, 920hz and 1150hz with modified friction coefficient of 0.1 calculated by boundary element method is shown in Fig. 6 ~ 10. Figure 6 shows that the maximum sound pressure calculated at 230hz is 68.1db. Figure 7 shows that the maximum sound pressure calculated at 460hz is 72.8db. Figure 8 shows that the maximum sound pressure calculated at 690hz is 78.9db. Figure 9 shows that the maximum sound pressure calculated at 920hz is 82.1db. Figure 10 shows that the maximum sound pressure calculated at 1150hz is 92.1db.
③ Comparison of vibration sound pressure values of helical gears before and after modification
The change of noise sound pressure value of helical gear system before and after modification is shown in Figure 11. Figure 11 shows that the sound pressure value at each frequency decreases after helical gear modification. Comparison of vibration sound pressure values of helical gears before and after modification. After helical gear modification, the sound pressure value of helical gear vibration noise decreases by 2dB at 230hz, 1.3db at 460hz, 2.4db at 690hz, 2.4db at 920hz and 1.7hz at 1150hz.
