دانلود رایگان مقاله تحقیق در مکانیزم سایش بلبرینگ های استفاده شده در سطل بیل چرخ

ABSTRACT

This article presents the macro- and microstructural analysis of bearing raceways. Raceways of bearings, taken from two machines which had worked 100,000 and 30,000 h, were examined. This provided crucial information on the exploitation history of both bearings, which is especially important for the future design process. After these initial macroscopic observations, it was determined which areas of the bearing had been most severely worn. This was indicated by the areas in which the chassis stiffness was highest. Further microscopic analysis of the individual bearing sections was useful for the identification of the dominating, destructive mechanisms in these areas.

6. Conclusion

In conclusion, it has been shown that large size bearing do not wear evenly. The main form of wear is deformation wear, which causes changes to the depth of the raceway bottom and geometry (curvature). These geometric changes can reach up to 10% of the rolling ball's diameter. After the initial intensive phase of wear, the stabilization period follows. The final degradation stage is fatigue wear, which is characterized by severe pitting and micro-fracture of the material. Contrary to the conventional machine bearings, where durability is determined by the formation of initial damage, in low-speed bearings the rolling of pitting elements occurs and a secondary raceway is created. The study ofthe raceway's material showed that the most important step in increasing the durability of the bearing lies during the design stage. The key is to ensure a uniform stiffness distribution of the support components.