Bearing unit in CT bulb tube

The invention discloses a bearing unit in a CT bulb tube. The bearing unit comprises a bearing body and a bearing flange. The bearing body comprises an inner shaft, two rows of steel balls, two outerrings, a long sleeve and a C-shaped ring. The bearing flange is made of a nickel-based high-temperature alloy with a brand number of GH4169, the bearing flange is a hollow cylinder, an annular flangeplate is arranged at the front end of the bearing flange, a plurality of bosses are evenly distributed on the front end surface of the flange plate along the circumference, a threaded hole is axiallyformed in each of the center of each boss and the center of a groove between every two adjacent bosses, the rear end surface of the bearing flange integrally extends to form a section of shaft sleevematched with the shaft neck of the inner shaft, the shaft sleeve sleeves the shaft neck of the inner shaft in an interference fit mode, and fusion welding is respectively carried out on the axial joint surface and the radial joi