The self-aligning roller bearing consists of an inner ring of a double raceway, two rows of spherical rollers, a cage and an outer ring of a large ball face. The self-aligning roller bearing can self-aligning, as shown in FIG. 1.3-1. Self-aligning roller bearings can withstand both axial and radial loads. There are two types of self-aligning roller bearing inner ring: straight hole and conical hole. Self-aligning roller bearings with conical holes in the inner ring can be mounted on a set sleeve or a discharge sleeve for installation at any position on the optical shaft or step shaft. The radial clearance of self-aligning roller bearings with tight sleeves can be adjusted by means of conical holes and tight sleeves.

Self-aligning roller bearings have the following structural types:

Type C, CC, EC bearing has two rows of symmetrical spherical roller, inner ring without barrier, with a middle retainer, and with two steel punching cage. The middle baffle ring is rotated by the inner raceway. EC type has reinforced symmetric spherical roller and has relatively high bearing capacity. The roller and raceway of CC type bearing are optimized to help guide the roller and reduce friction and heating.