Design and Analysis for Straight Bevel Gears with Ease-Off Flank Modification Based on Minimal Wear

An approach of ease-off flank modification for straight bevel gears is proposed to improve meshing performances and reliability. By means of technology of milling straight bevel gear with plate cutters on a cradle generator, the modified pinion is represented by a sum of two vector functions determining the conjugate gear tooth, and normal ease-off deviations expressed by both predesigned transmission error function and tooth profile modification curves. Then a numerical method of loaded wear tooth contact analysis considering wear is introduced according to tooth contact analysis, loaded tooth contact analysis and Archard formula of wear, which combines tooth surface geometry analysis with mechanical analysis and fully considers the coupling of alignment error, tooth surface modification and wear. So the wear depth of tooth profile reconstituted is obtained accurately and quickly. The best ease-off modification is determined by optimizing with minimal amplitude of loaded transmission error (ALTE) and maximal wear times as the objectives, and the influences of wear on ALTE are explored. The results show that the wear times with the same depths gradually decrease and tend to equal as increasing loads. The increasing wear times lead to increasing initial contact clearances from meshing zone of two pairs, which is mainly responsible for increasing meshing deformations. Under multi-load conditions, minimum ALTE and the corresponding load increase gradually with increasing wear times; mild wear facilitates reducing ALTE for conjugate tooth. © 2020, Editorial Office of Journal of Xi'an Jiaotong University. All right reserved.