Numerical estimation of dynamic transmission error of gear by using quasi-flexible-body modeling method

When the power transmission systems are designed or improved, an understanding of gear dynamics is essential and very important. Gear systems are not easy to investigate because gear noise has to be carefully controlled. As a result, when designing and developing gear transmission systems, it is very important to grasp the noise and reduce it. Also, it is necessary to make a clear distinction between rattle noises and whine noises. The rattle noise occurs by mainly hitting the tooth, and whine noise occurs by mainly rubbing the tooth in meshing. Therefore, the whine noise is relatively related to high frequency characteristics. Our aim was to find a good way to evaluate whine noise with a numerical approach. When the gear dynamics are investigated to evaluate the whine noise, the dynamic transmission error (DTE) can be utilized. But, it is very difficult to obtain the DTE results by means of not only experimental ways but also numerical calculations. Although multi-body dynamics software has not been able to calculate the DTE practically yet, there is a possibility that the software can get the DTE results. Therefore, we propose a numerical modeling method to obtain the DTE results by using multi-body dynamics software (RecurDyn). To reduce the calculation time and represent flexibility, a rotational joint and force element with the bending stiffness are applied between gear teeth and trunk. Also the numerical results have been compared with the experimental data. The results show a good agreement with the experimental results.