The utility model discloses a bearing ring turning fixing device which comprises a chuck and an inner supporting
assembly, the chuck comprises a chuck body, a plurality of clamping jaws are arranged on the chuck body, a fixing cover is arranged on one side of the chuck body, a gear disc is rotationally connected to the interior of the chuck body, a spiral groove is formed in one side of the gear disc, and the inner supporting
assembly is arranged in the spiral groove. The other side of the gear disc is meshed with a rotary gear; the inner supporting
assembly comprises a center rod, one end of the center rod is connected with the fixing cover, a plurality of supporting plates are evenly arranged on the outer portion of the center rod in the circumferential direction, the supporting plates are supported on the inner wall of the bearing ring, and the two ends of each supporting plate are connected with the center rod through connecting rods. The inner supporting assembly is arranged in the chuck, the bearing ring is jointly supported by the clamping jaws of the chuck and the supporting plates of the inner supporting assembly, the supporting area of the bearing ring is increased, the influence of
cutting force on the bearing ring is effectively dispersed and reduced, and the risk of deformation of the bearing ring in the turning process is reduced.