Self-aligning ball bearing with two structures of bore cylindrical or tapered and retainers made of steel sheet or synthetic resins. The bearings are characteristic of their way into spherical shape, have so can compensate concentricity and deflection errors, but which shall not exceed 3 degrees between inner ring and outer.

Mainly bear radial load, and at the same time can carry small axial load. Shaft (shell) axial displacement limit within the clearance limit, with automatic self-aligning properties, allowed inside and outside under the condition of relatively little inclined to work properly, is suitable for bearing seat holes can't strictly ensure the alignment of parts.