| dc.description.abstract | Gear systems are widely used in various transmission applications, and to reduce noise and vibration during high-speed operation, increasing the contact ratio is one of the solutions. High-contact ratio spur gears, in addition to keep the advantages of spur gears in terms of ease of design and manufacturing, also its mesh stiffness has smaller effects to system vibration due to the increased contact ratio. As a result, they have received attention as one of the solutions. However, since spur gears often increase the contact ratio by lengthening the tooth height, high contact ratio spur gears are more susceptible to the effects of shaft deformation and misalignment. Moreover, with the increasing demand for high load and high speed, traditional static analysis is no longer sufficient.
In the past, discretization was used along with theoretical mesh stiffness for analysis. However, this approach often oversimplifies the model, and the dynamic models provide limited information. In contrast, static gear analysis is a well-established method. Therefore, this study aims to utilize a discrete multi-body model, combined with statically loaded tooth contact analysis (SLTCA), to understand the stress distribution of gears under dynamic conditions.
In the analysis, this study discretizes the system components, with the gear mesh stiffness determined from stiffness map calculated using the SLTCA method. Then, numerical methods are used to solve the system’s dynamic equations. After obtaining the shaft deformation and dynamic torque at the gears, these results are fed back into the SLTCA module to calculate the instantaneous stress distribution.
This study compares the dynamic characteristics of high-contact ratio gear systems under various conditions. By comparing the results of gears with and without gear modification, it was found that although modification increases dynamic loaded transmission error, it can improve the system’s mesh force and torque vibration behavior. In the case of shaft misalignment, modification helps reduce system vibration and returns the stress distribution to normal point contact. Finally, in the case of static acceleration, modification also helps reduce the excitation during startup and the subsequent vibration amplitude. | en_US |