调心滚子轴承（即“3”类轴承），属向心轴承类，滚动体为双列球面滚子，其内部结构有新老之分，老结构（图1a）的主要特点是：外圈滚道为球面，内圈带中小档边，球面滚子呈非对称型。新结构通常又可分CD型和OA型，CD型（图1b）的主要特点是：外圈滚道为球面，其外径中部带油槽 Spherical roller bearings (ie, “3” bearings), is a radial bearing class, rolling double row spherical roller, the internal structure of the old and new points, the main features of the old structure (Figure 1a) are: Ring raceway for the sphere, the inner ring with small stalls, spherical roller was asymmetric. The new structure can usually be divided into CD type and OA type, CD type (Figure 1b) the main features are: the outer ring raceway is spherical, the outer diameter of the middle tank