Load Carrying Capacities of the Coated Gear in Ultra-high Vacuum and Establishment of Inspection System to Tooth Surface Failure.

利用动力循环齿轮机研究了表面热扩散的不锈钢齿轮(SUS440C)在润滑脂润滑和干摩擦条件下的摩擦磨损特性和齿轮摩擦损失扭矩与传递扭矩的比值。对于润滑脂润滑，齿轮采用全氟聚醚基脂和以30%的质量分数掺入MoS_2添加剂的基脂进行润滑。试验在空气中和约10℃~4℃的真空中进行。此外，为了弄清扩散层对齿圆角应力的影响，还进行了轮齿的弯曲疲劳试验。得到了以下结果：(1)在真空条件下，含扩散层的齿轮在润滑脂(MoS_2质量分数为30%)的润滑下达到表面破坏的时间比不加添加剂的齿轮长约30%。(2)在空气中有扩散层的齿轮达到表面破坏的时间比在真空中的短约57%。(3)齿轮的摩擦损失扭矩与齿轮的传递扭矩之比随转数之和的增加而减小，当小齿轮的旋转次数达到10^5时，(4)齿轮经渗层处理后的弯曲疲劳强度约为450兆帕，比未渗层齿轮的弯曲疲劳强度提高约50兆帕。

The frictional and wear characteristics, and ratio of gear frictional loss torque to transmitted torque of the stainless steel gears (SUS440C) of which the surface layr was thermally diffused after being Snplated were investigated by a power-circulating gear machine under the conditions of grease lubrication and dry friction. For the case of grease lubrication, the gear was lubruicated with the base grease of perfluro-polyether and the grease in which MoS2 additives were mixed at the rate of 30 mass% in the base grease. The tests were run in air and in vacuum of about 10^<-4> Pa.Further, to clarify the effect of the diffused layr on the stress at the tooth fillet, the bending fatigue test of the gear teeth was carried out. The following results were obtained ;(1) In the case of the tests in vacuum, the time to reach destructive surface failure of the gears with diffused layr when lubricated with the grease (MoS2 additives : 30 mass%) was about 30% larger than that without the addtitives.(2) The time to reach destructive surface failure of the gears with the diffused layr in air was about 57% smaller than that in vacuum.(3) The ratio of gear frictional loss torque to transmitted torque of the gears decreased with increasing the sum of the number of revolution while the number of revolution of the pinion reached 10^5, and was between 0.01 and 0.015.(4) The bending fatigue strength of the gears with the difused layr was about 450 Mpa, and was about 50 Mpa larger than that without the diffused layr.