Research On The Contact Characteristics Between Roller And Raceway Of Mining Excavator Slewing Bearing

Mining Excavator mainly used in extracting and stripping operations of strip mine. With strip mine centralized and large-scale, the demand for Mining Excavators gradually increases. The Slewing Bearing of Mining Excavator is an important part, their work frequently, and the stress of those is complex. The reliability of excavators has an important influence on the Mining Excavator. At present, the researches on the Slewing Bearing are considerable, and have become increasingly mature. But for large and medium-sized Mining Excavator, their Slewing Bearing are researched by their own manufacturer, therefore, the research of large and medium-sized Mining Excavator Slewing Bearing roller-raceway contact characteristics is necessary.This article is from the view of the practical applying of Mining Excavator Slewing Bearing, carrying a more in-depth research on structural features, stress case, and the contact between roller and raceway. Mainly include the followings:On the base of studying the structure and stress situation of Slewing Bearing of the 55m3 Mining Excavator, figure out maximum force value of the Slewing Bearing roller. Applying Hertz line contact theory, analyze the Misses Von Stress between roller and raceway, educe that with the increase of the roller radius Contact Stress decreases, and with the increasing number of roller Contact Stress increases.Research on roller-raceway contact characteristics by Finite element software. In the middle part of the tapered roller, from small end to large end, Contact Stress decreases, Misses Von Stress increases, and they appear stress concentration in both ends of the roller, the rotary axial displacement of tapered roller increases and increases obviously in both ends of the roller. The maximum Contact Stress is in the surface roller, and the maximum Misses Von Stress is in the sub-surface. Research on the contact characteristics between roller and raceway under the different. The results show that:the stress concentration of Contact Stress is not always exists, when hollowness ratio is in the 0.4-0.5, the stress concentration is almost non-existent; the stress concentration of Misses Von Stress is always exists, and the maximum Misses Von Stress is in the sub-surface; with the increase of hollowness ratio, the rotary axial displacement of tapered roller increases, and when hollowness ratio is greater than 0.5, the displacement increases rapidly.With the same geometric parameters of the upper and lower raceway (except roller tilt angle), research the relationship between the number of tapered roller and tapered roller radius, calculate the geometric parameters of roller tapered under different roller number, establish finite element model. Analyze the finite element model, the results show that:with the roller number increasing, The initial Contact Stress of Roller-raceway and rotary axial displacement of tapered roller changed little, the Misses Von Stress decreases.All above, with the reasonable distribution of roller-raceway Contact Stress and the minimum of Misses Von Stress as the optimization, optimize tapered roller Slewing Bearing, compared the Misses Von Stress and Contact Stress of before and after optimization.