Fundamental Study on Surface Durability and Dynamic Performance of Gear with Multiplex Surface Modification

本研究为通过复合修形提高齿面耐久性，减小齿轮传动装置的尺寸奠定了基础。为了阐明齿轮齿面耐久性提高的机理、齿面失效机理、齿面耐久性设计方法和齿轮动态性能评价方法，对齿轮和滚子进行了表面硬化后喷丸强化的工作疲劳试验，使用1997年开发的动力循环齿轮试验机和传统的双缸试验机进行。在钢的情况下，由于喷丸处理增加了残余压应力，抑制了裂纹的萌生和扩展，提高了喷丸齿轮和滚子的表面耐久性。在烧结粉末金属的情况下，具有较高弧高值的喷丸处理由于材料中的孔隙被压碎并且缺口敏感性因子增加而降低了表面耐久性，同时，采用较低弧高值的喷丸处理，由于气孔不易被破碎，同时具有加工硬化和残余压应力的效果，提高了齿轮的表面耐久性，并利用小波变换对齿轮的动态性能进行了研究。经表面改性处理的烧结齿轮的振动和噪声均低于钢齿轮。

This research is a fundamental study for improving the tooth surface durability by multiplex surface modification to reduce the size of gear transmission unit. The aim of this study is to clarify the improving mechanism of tooth surface durability, the surface failure mechanism, the design method for surface durability and the evaluation method of dynamic performance of gear.The operating fatigue tests of gears and rollers, which were shot-peened after the case hardening, were performed using a power circulating gear test machine developed in 1997 and a conventional two cylinder test machine.In the case of steel, the surface durability of shot-peened gear and roller was improved since the compressive residual stress was increased by the shot-peening and the crack initiation and propagation were restrained.In the case of sintered powder metal, the surface durability was decreased by the shot-peening with the higher arc-height value since the pores in the material were crushed and the notch sensitivity factor was increased, while, the surface durability was increased by the shot-peening with the lower arc-height value since the pores were hardly crushed and the effects of work-hardening and compressive residual stress were achieved.The dynamic performance of the gear was also investigated using the wavelet transform. The vibration and noise of the surface modified sintered gear were lower than those of the steel one.