A structure in which a combination of an inner ring and a bead (a ball inner ring) can be freely tilted in an outer ring is formed by making a track of an outer ring to be spherical. Therefore, the bearing center and the center of the shaft can be automatically adjusted so that the bearings are not sprained if some degree of misalignment (axial misalignment) or shaft deflection occurs. Therefore, for the work of the assembly, the accuracy of the long axis of precision, simple structure of the transmission device, are suitable for such bearings. When used in combination with a bearing housing or a sleeve, it is easier to form a bearing device.