Structure design and effects of conical gear roller on restraining rabbit ear defects during gear rolling

The gear rolling process using a conical gear roller was developed recently and has been proved to be feasible for forming cylindrical gears. However, the rabbit ear defect, which is normally present in the traditional rolling process, still exists. Therefore, an innovative structure for the conical gear roller is proposed to prevent rabbit ear defects. The size of the dedendum circle during the tooth forming stage is determined according to the height of the growing tooth on the blank at each moment, and the volume of the roller pressed into the blank is equivalent to that of the objective gear's tooth space. Both simulations and experiments are carried out to investigate the effects of the revised rollers on the rolling process. The results show that the formation of the tooth profiles can be effectively confined to the desired volume cavity, so that there is no extra space for the formation of rabbit ears. The tooth is fully filled, and the rabbit ear defects are obviously reduced. The experimental results agree well with the numerical simulation. The present study can help in improving the integrity and accuracy of the formed teeth for the gear rolling process.