Robustness is also known as robustness. For gear modification, it is to ensure that the optimal modification scheme has stable objective function values within the tolerance zone, such as transmission error, on the premise of considering manufacturing tolerance. This is also to ensure that the optimization results are not too sensitive to the manufacturing tolerance. It is necessary to conduct sensitivity analysis on the specified modification method and modification amount. For the ideal state, the minimum transmission error is expected to be in the nominal value of the tolerance parameter, while the transmission error value of the whole tolerance zone is not beyond the limit.
Here, the second gear is used to illustrate the process and results of robustness analysis. The values before and after the parameter optimization of the second gear master-slave gear are given. For the undefined micro profile tolerance, the tolerance value is given according to grade 7 precision of din3962 standard, for example, the pressure angle tolerance is 7um, and the tooth deflection tolerance is 11um. Doe test design method is adopted in the analysis.
The sensitivity analysis results of the second gear to the optimization of the top trimming of the active / passive gear are given. The nominal micro dimension is represented by a black circle, while the modification tolerance range is represented by a black box. The change value of the color chart represents the first order transmission error, and the coordinate of the color chart is the design tolerance range. The sensitivity analysis results of the second gear profile modification to the pressure angle and the tooth deviation tolerance are given.
The sensitivity analysis results show that the designed addendum modification of the second gear will produce large transmission error within the manufacturing error range. By reducing the amount of trimming and the range of tolerance, the fluctuation of transfer error is smaller. In the driving gear surface, the second gear has a small transmission error in the allowable tolerance range, while for the large load reverse gear surface, the transmission error is relatively high at the edge of the tolerance zone.
The sensitivity of modification parameters to manufacturing tolerance before and after overall comparison and optimization. Within the manufacturing tolerance zone, the overall transmission error is reduced, and the robustness of error difference change is stronger, which plays an important role in the control of overall noise after batch production.