Study On The Three-dimensional Stress Fields And Wear-life Estimation Method For Spherical Plain Bearings

Radial spherical plain bearing is one kind of plain bearing，which has the uniquefeature of simple structure, small size, and large carrying capacity. Comparing with therolling bearings, the structure and working mechanism of spherical plain bearing areentirely different. In order to increase the service life of spherical plain bearingpractically, many factors must be understand in-depth such as the fitting relations,carrying capacity, oscillating frequency and tillable angle range. The kind of sphericalplain bearing involved in the thesis is widely used in the aerospace industry, and itsservice behavior demanded usually is also high.In the paper, a finite element model of the spherical plain bearings under staticload stress field is developer based on APDL language of ANSYS software. In thefinite element model, the spindle and house components of the bearing are instead of arigid surface. The stress distributions of bearing under different load are carried out,then the ultimate loading capacity of the bearing is determined. The relationships ofthe maximum contact pressure with the bearing load are obtained using the linear leastsquares method. These formulas provide a theoretical reference for the structuralstrength selection of the spherical plain bearing. In addition, the parametric modelinginterface is secondary developed in APDL parametric design language, which is basedon the structural parameters of certain spherical plain bearing and a rod end. The finiteelement model can be set up quickly by the parametric modeling interface. Then, thestress field of the spherical plain bearing with a rod end set up by the interface isanalyzed on the same loaded conditions, and compared with the spherical plainbearing’s stress field on rigid hanger condition, the difference of the two supportstructure is pointed out and some useful suggestions and references for the selection ofsupport type in the finite element analysis method are presented. Next, the structure ofbearing is optimized design. The best nominal diameter by changing the nominaldiameter size is marked sure. And then, by the fitting relation of the bearing and shaft, shell hole is analyzed at different clearance or interference situation, the amount of gapor interference of the bearing in the installation design is confirmed in order toimprove the bearing service life. Meanwhile, by the analysis of stress field of sphericalplain bearing and a rod end on tillable conditions, it indicates that the maximumequivalent stress of bearing increases with the tilt angle increasing, and the maximumequivalent stress on the stress concentration area should be controlled in a reasonabletilt angle range, which provide a theoretical reference for choice of tilt angle of thespherical plain bearing.By comparing the life calculation methods in the domestic and foreign dominantenterprises of spherical plain bearing, the main factors related to service life of thespherical plain bearing are analyzed in detail, and the impact on life calculation resultscalculated by different methods is accessed. On these bases, the exploration andresearch about spherical plain bearing life calculation method based performancedegradation methods is implemented.