为提高修形齿轮加工效率,并降低齿轮副振动与噪音,提出切向滚齿加工双鼓形齿斜齿轮设计方法。根据空间啮合原理建立3自由度切向滚齿模型,设计滚刀齿形及修正工件附加转交角与安装中心距,并推导工件修形齿面;其次,结合LTCA技术以承载传动误差(LTE)幅值最小为优化目标,获得上述加工参数,并分析LTE幅值与齿轮副重合度关系。研究结果表明:设计加工参数可减小安装误差敏感性,避免边缘接触;齿轮副LTE幅值降低44%,因此,有利于降低振动与噪音;当滚刀有齿向修形时,再增加合理的切向运动,使得滚切过程中,产生沿齿向方向齿形的连续变化,可消除传统加工(改变中心距)产生的齿形扭曲。
A design and an analysis of topologically modified helical gears were proposed to improve the machining efficiency and reduce the noise and vibration. Firstly, the topologically modified pinion tooth surfaces finished by hobbing was established according to the meshing theory of three independent motion parameters of the tight rational meshing between work-gear and hobbing cutter and the traverse motion of work-gear along the axis of the work gear and tangential feed along the axis of the hobber. Besides, the modified teeth were determined by the profile gear-hob, the center distance between work-gear and hobbing cutter, the hob tangential feed and additional rotation angle of work gear. Secondly, the parameters were individually determined based on TCA and LTCA by optimizing the aim of minimum the amplitude of loaded transmission error of drive gears. Finally, a numerical simulation of example was performed. The characteristics of amplitude of LTE curves were investigated by analyzing the contact ratio with increasing loads on modified gears. The results show that the optimal modified tooth surfaces can reduce sensitivity caused by errors of axes alignment and prevent the gear’s meshing teeth from colliding with each other at the boundary, and make lower amplitude of LTEs reduce by 44%, which contributes to a lower vibration and noise. Besides, an accurate tangential feed of the hob with longitudinal correction can attain an anti-twist helical gear tooth flank with longitudinal tooth crowning, because continuous changes in profile along longitudinal of hobber contribute to reducing distortion of profile due to variable center distance hobbing without compensation of profile.