航空发动机球轴承剥落故障模式分析

为研究航空发动机球轴承的剥落故障模式，利用原子发射光谱技术、自动磨粒分析技术、铁谱技术及能谱分析技术对球 轴承加速等效试验滑油中磨粒的数量、大小、形貌及成分等信息进行分析。结果表明：金属颗粒污染物导致轴承出现初始疲劳剥 落；球轴承剥落的特征磨粒为滚动疲劳磨粒和球形磨粒，内衬套微动磨损的特征磨粒为铁的黑色氧化物和红色氧化铁磨粒；临近 轴承失效时，滑油中Fe元素质量分数由7.49×10 -6 增大至21.74×10 -6 ，特征磨粒数量也由48.9个/mL急剧增加至1433.8个/mL，且特 征磨粒直径主要分布在25～50 μm。金属颗粒污染物的存在使轴承承力内半圈滚道加速出现接触疲劳剥落，滚道剥落到一定程 度后，在轴向力、摩擦力及预紧力等综合作用下在内衬套与承力内半圈接触处发生微动磨损，进一步加剧了滚道的疲劳剥落，最终 导致球轴承失效。

Spalling Failure Mode Analysis of Aeroengine Ball Bearings

To study the spalling failure mode of aeroengine ball bearings, atomic emission spectroscopy, automatic wear particle analysis, ferrography, and energy-dispersive X-ray spectroscopy analysis were used to analyze the number, size, morphology, and composi? tion of the wear particles in the lubricating oil from the equivalent accelerated test of ball bearings. The results show that the metal particle contaminants lead to the initial fatigue spalling of the bearing. The characteristic particles of the ball bearing spalling were rolling fatigue particles and spherical particles. The characteristic particles of neck bushing fretting wear were black iron oxide and red iron oxide particles. Approaching bearings failure, the mass fraction of iron element in the lubricating oil increased from 7.49×10 -6 to 21.74×10 -6 , the number of characteristic particles also increased sharply from 48.9/mL to 1433.8/mL, with the size of particles distributed mainly in the range of 25 to 50 microns. The presence of metal particle contaminants accelerated the contact fatigue spalling of the raceway of the load- bearing inner half ring. After the raceway spalling to a certain extent, the fretting wear occurred at the interface between the bushing and the inner half ring under the combined effect of axial force, friction, and preload, which further aggravated the fatigue spalling of the raceway and ultimately led to the failure of the ball bearing.